Geological treasures of magma, wind, and water. Lanzarote and Chinijo Islands UNESCO Global Geopark

Geological treasures of magma, wind, and water Lanzarote and Chini jo Islands UNESCO Global Geopark Geological treasures of magma, wind, and water Lanzarote and Chini jo Islands UNESCO Global Geopark Juana Vegas, Carmen Romero, Inés Galindo, Esther Martín González, Nieves Sánchez & Gonzalo Lozano 2025 Authors of texts, photos and graphics: Juana Vegas. Geological and Mining Institute of Spain, IGME-CSIC Carmen Romero. La Laguna University, ULL Inés Galindo. Geological and Mining Institute of Spain, IGME-CSIC Esther Martín-González. Tenerife Museum of Nature and Archaeology. Government of Tenerife Nieves Sánchez. Geological and Mining Institute of Spain, IGME-CSIC Gonzalo Lozano. Geological and Mining Institute of Spain, IGME-CSIC Edited by: Lanzarote Island Council (Cabildo de Lanzarote) Layout and printing: Marta Sacristán. Rabalán Company S.L. Orthophotos and Digital Elevation Model: GRAFCAN, Government of the Canary Islands. https://visor.grafcan.es/# Geological mapping: GEODE (Geological Digital Map of Spain), Geological and Mining Institute of Spain, IGME-CSIC. ISBN: 978-84-1288-118-9 Legal Deposit: GC-581-2024 INDEX Presentation .................................................................................................................................7 Acknowledgements ..................................................................................................................11 Introduction .............................................................................................................................. 13 01 Lanzarote emerges from the ocean ........................................................................... 19 The silences of the great Los Ajaches Volcano .......................................................... 20 The volcanic veins of the Rubicón ................................................................................ 22 Femés: a unique sunken valley ....................................................................................... 24 The giant that is the Famara cliffs ............................................................................... 26 02 Quaternary Volcanoes......................................................................................................31 The great Caldera of Alegranza ...................................................................................... 32 Caldera Blanca: The White Giant ................................................................................... 33 Montaña Halcones: the coastline before Timanfaya ............................................... 34 The dykes of Montaña Clara: the arteries to the volcanoes .................................. 35 A Gulf volcano ..................................................................................................................... 36 Tinamala quarry: a hidden pyramid inside a volcano .............................................. 38 The ponds between the lava flows of Malpaís del Norte ....................................... 39 The lava tube of La Corona-Tunnel of Atlantis: a treasure inside the lava flows ..40 Peñas de Tao: the fallen giants of La Corona Volcano ............................................. 42 A Cactus Garden in the heart of a volcano................................................................. 43 03 Historical volcanoes of 1730-36 and 1824.......................................................... 47 The Farmer’s Monument: the soil covered by the great Timanfaya eruption ... 48 Pico Partido: a crater overflowing into a large channel ......................................... 50 Montaña Rajada: a crack into hell ................................................................................ 52 Macizo del Fuego: where the little devil of Timanfaya dwells .............................. 53 The Islet of Hilario: where the earth still burns ......................................................... 54 A sea of lava in Timanfaya ............................................................................................... 55 Mazo: when the earth splits during an eruption ...................................................... 56 Montaña Colorada: a grand finale for Timanfaya..................................................... 58 Tinguatón: the volcano that shot out jets of water ................................................. 59 5 6 7 La Geria: vineyards and wines rise from the pyroclast ............................................ 60 César Manrique Foundation: lava becomes art ......................................................... 62 04 Shifting sands .................................................................................................................... 67 El Jable: Lanzarote’s great sand corridor ..................................................................... 68 Lomos de San Andrés and Camacho: they are not volcanoes, they are dunes! ..70 Las Conchas-Montaña Bermeja: a white beach at the foothill of a volcano ....71 05 The actions of the sea .................................................................................................... 75 Hervideros: the sea thundering through the lavas ................................................... 76 Ajaches: self-exposed above sea level ......................................................................... 78 The Alegranza skylight: a window into a coastal cave ............................................ 79 Papagayo: a beach collection ......................................................................................... 80 Caletón Blanco: white sands among black lava ........................................................ 82 Playa Cochino: evidence of a tsunami ......................................................................... 83 El Salado: a coastal lagoon on La Graciosa Island .................................................... 84 El Río: the oldest salt mine in the Canary Islands .................................................... 85 The Janubio salt mines: cultivation of fleur de sel ................................................... 86 06 The shaping of the Geopark through rain and landslides .................................91 The hanging valleys of Famara: notches on the cliffs ............................................. 92 Valle de Temisa: a testimony of past climates ........................................................... 93 San José: a valley with no head nor feet..................................................................... 94 Las Laderas: a cliff far away from the sea .................................................................. 95 07 An underwater Geopark ................................................................................................. 99 The foundations of these islands on the ocean floor .............................................100 Las Bajas: an underwater volcano ...............................................................................101 Charco del Palo: diving among the crevices .............................................................102 Port of El Carmen: a coast flooded by the sea .........................................................103 Roque del Este: the Atlantic bell tower .....................................................................104 Arrecife Marina .................................................................................................................105 The River: sand bars linking islands ............................................................................ 106 08 Palaeobiodiversity hidden in the rocks ...................................................................111 Glossary ......................................................................................................................................115 “One step further on a long journey” Lanzarote and the Chinijo Islands are an archipelago located northeast of the Canary Islands in the Atlantic Ocean, off the coast of Africa. Since 2015, they have been part of the Global Geoparks Network, within the ‘International Geosciences and Geoparks Programme’ sponsored by UNESCO and with the collaboration of the IUGS (International Union of Geological Sciences). In this network, territories and people from all over the world come together to make geology of international relevance a common flag, through sustainable development. In the Lanzarote and Chinijo Islands UNESCO Global Geopark you can enjoy some of the most unique geological heritage in the world, with more than eighty geosites. On these North Atlantic islands it is possible to observe the interaction between the forces of the Earth’s interior and the external geological agents (weathering, erosion, transport, and deposition), achieving a symbiosis of volcanic, erosive and sedimentary forms and processes that is difficult to match. Not to mention the biodiversity that has inhabited this archipelago since its creation. Discovering and deepening our knowledge of this Geopark, a little beyond its mere landforms, is what motivates us to present this book. We hope that it will be one more step in a long journey that began in the interior of the planet some 15 million years ago and our desire is to understand more about its reality in the 21st century. Oswaldo Betancort Garcia President, Lanzarote Island Council 98 Geological treasures of magma, wind, and water “The most genuine history of our islands” The eruption of Timanfaya is a landmark in the history of the Lanzarote and Chinijo Islands UNESCO Global Geopark, recognised as a geological heritage site of international importance for Spain. This long eruption, which occurred between 1730 and 1736, radically changed the landscape of the island and the destiny of its inhabitants, becoming a sign of identity and an exponent of human adaptation. However, it is not the last volcanic event on the island, as the triple eruption of 1824 added to the volcanic landscape. Furthermore, other geological processes coexist in this Geopark that also make it unique. These include the shifting sands, the coastal and marine currents, the climate variability that has occurred over the last million years, and the biodiversity of its past in the palaeontological record, all of which have forged its great geodiversity. The spectacular natural and human landscape of these islands, together with their traditional uses and customs, as well as the excellence of their tourist infrastructures, make this territory an international tourist destination. It allows both its inhabitants and visitors the opportunity to get to know and enjoy geology in a unique environment, thus contributing to sustainable development. We invite everyone to join us on this journey back in time through the most genuine history of these islands. Samuel C. Martín Morera Councillor of the Geopark, Lanzarote Island Council 1110 Acknowledgements The study of the geosites of the Lanzarote and Chinijo Islands UNESCO Global Geopark has been carried out by a transfer contract signed between the Lanzarote Council and the Spanish National Research Council (CSIC), through the Geological and Mining Institute of Spain National Centre (IGME-CSIC). The authors of this book, from IGME-CSIC, La Laguna University, and the Museum of Nature and Archaeology (Tenerife Council), would like to thank the Marine Institute and the Canary Islands Marine Data Base (REDMIC) for providing the bathymetric maps produced by the Directorate General for Coast and Sea Sustainability for this project. We would also like to highlight the tremendous support provided by Elena Mateo, Scientific Director, and Clara Bonilla from the Lanzarote and Chinijo Islands UNESCO Global Geopark, and all staff at the Lanzarote Council, especially Jorge Toro and Reinero Brandon; Jaime Arranz and Orlando Hernández from the ‘Casa de los Volcanes’; Jeremías Cabrera and Melito from the Environment Dept.; and the patrol boat of the Security and Emergency Consortium of Lanzarote. We would also like to thank the crew of the patrol boat Rio Órbigo of the Civil Guard (Oscar Herrero Martín, Carlos Piñero Majano, Diego Antonio Gavilán Rodero, and Eduardo Santos Díaz) for their collaboration and the staff at Yaiza´s Civil Protection (Patrick Cazorla and Brahim Injehai). Special thanks to our colleague Dr. Javier Lario (UNED) for lending us the photographs of the Atlantis lava tube and to Leticia Pacheco for her collaboration in the fieldwork. We would also like to highlight the collaboration of the Timanfaya National Park, in particular, Director Pascual Gil, and thank the entire administrative and ranger staff for their efforts to highlight, research and preserve the 1730-1736 eruption, as well as Aurelio Centellas, Antonio López and Jorge Espinel on La Graciosa Island. We would also like to thank Enrique Jordán for his availability on the Islote de Alegranza, and Ginés Díaz Pallarés during the fieldwork. We thank our colleagues from IGME-CSIC, Miguel Llorente and Juan Carlos Rubio, geologists and divers, who together with Íñigo Labarga, Rafa Mesa and Hugo Pérez, professional divers, contributed with their knowledge of the underwater world. 1312 Geological treasures of magma, wind, and water Introduction In Spain, in 2024, there are 17 UNESCO Global Geoparks, making it the second country with the most Geoparks in the world, only behind China. The Canary Islands are home to two of them: El Hierro and Lanzarote and Chinijo Islands (included in the Global Network since 2015) which is the main reason for this book. This geopark is in the northeast of the Canary Islands, a volcanic archipelago located on a passive continental margin, where oceanic volcanic island processes can be observed and understood, and which in the case of Lanzarote has remained active for the last 15 million years of the Earth’s history. This Geopark is marked by the interaction of three geological elements that have been the main actors in the construction and modelling of these islands: fire from the Earth´s interior through magma, the trade winds, and water. All of these, together with the presence of past life in the fossil record, and finally the human being, have shaped a Geopark with outstanding natural and cultural values. Volcanic activity in Lanzarote throughout its geological history has interacted simultaneously with the processes of erosion and sedimentation. The magma has modelled a landscape of volcanoes, lava flows, and mantles of black and red pyroclasts on which the wind has deposited the white sands, which are common in Lanzarote and La Graciosa thanks to the abundance of Simplified geological map of the Lanzarote and Chinijo Islands UNESCO Global Geopark. Modified from the GEODE (Digital Geological Map of Spain), IGME-CSIC. In: https://info.igme.es/cartografiadigital/geologica/ Geode.aspx#info Alegranza La Graciosa Legend Sedimentary materials Historical eruptions Holocene Up. Pleistocene Mid. Pleistocene Low. Pleistocene Pliocene Miocene 0 2 4 6 8 10 1:400.000 N Km 29º N 29º N 28º N 28º N 18º W 16º W 14º W Lanzarote Montaña Clara Roque del Este 1514 Geological treasures of magma, wind, and water Introduction carbonate fragments and marine currents. The scarce but torrential rains have eroded the island’s surface, forming sedimentary deposits that fill in the valleys, deposited at the foot of the escarpments and along the ravines, and forming beaches of sand and pebbles on the coast. The sea, rain and wind have shaped the islands, engraving a unique volcanic landscape formed by ravines, valleys, beaches, cliffs, mountains and plains, offering astonishing geodiversity. Thus, this Geopark is a natural museum that bears witness to the evolution of the oceanic volcanic islands dominated by a subtropical-sub-desert climate. In this book we make a simple and accessible journey through the best geology of the geopark, via the most significant geological events in the history of Lanzarote and the Chinijo archipelago, which have been recorded in the selected Sites of Geological Interest (SGI or geosites). To facilitate this journey through time, we have included a very simplified geological map of the island and the location of these geosites, except for the palaeontological ones, which, due to the need to safeguard their conservation, are not published. Many of them are located in protected natural areas, so it is necessary to request permission in advance from the Island Council or the National Park and comply with the rules of these spaces. Each of the chapters begins with a ‘geological context or geological framework’ that describes the main geological and palaeo-environmental processes that prevailed at the time of the formation of the geosites. The climatic conditions, the sparse vegetation, the inhabitants and their rich culture, along with the well15.5 Ma 10 Ma 5.33 Ma Volcanic phases in Ajaches Miocene Pliocene Pleistocene Holocene NEOGENE 2.58 Ma 0.0117 Ma QUATERNARY Volcanic phase in Famara Monogenetic volcanoes Timanfaya & 1824 Miocene Climatic Optimum Closure of the Panama isthmus First hominins Glacial cycles Last Glacial Maximum Great American Fauna Exchange maintained tourist infrastructures, will allow us to enjoy this fascinating journey into the past and present of the Lanzarote and Chinijo Islands UNESCO Global Geopark. 1716 Lanzarote emerges from the oceanGeological treasures of magma, wind, and water 1 Lanzarote emerges from the ocean 3130 Lanzarote emerges from the oceanGeological treasures of magma, wind, and water Quaternary Volcanoes After a period of eruptive calm of about one million years, during which erosion dismantled the two ancient volcanic shields, a second stage of basaltic volcanism began, which continues to the present day. This new period is characterised by monogenetic volcanism, with the emission of low volumes of magma, leading to the formation of small volcanic cones from a single short-lived eruption (from hours to a few years). The construction of multiple edifices of this type along fractures and fissures has led to the formation of a volcanic field in the central area of Lanzarote, consisting of 360 volcanic cones. Some monogenetic eruptions have also occurred in the area of the ancient massifs, including those that have given rise to the Chinijo archipelago. The predominant volcanism during this period has been of Hawaiian and Strombolian type, with some phreatomagmatic eruptions, resulting from the explosive contact of magma with ocean water, which characterise the Lanzarote coastline both past and present. In this geological framework, a series of geosites are included that demonstrate the morphologies, volcanic products and structures formed during the Quaternary period, which spans from 2.58 million years ago to the present day, with the exception of historical eruptions which are discussed in the following section. Globally, the Quaternary is marked by the cyclicity of cold and warm periods, known as glacial and interglacial periods, and sea level oscillations that trigger high sea levels during interglacial periods due to the melting of global polar ice, and much lower sea levels than today during glacial periods as water is retained by the growth of polar ice caps and alpine glaciers. The genus Homo appears in the fossil record at the beginning of the Pleistocene, 2.4 million years ago, with the presence of Homo habilis, which is the oldest species discovered. LZ61 LZ17 LZ53 AL01 MC01 AL02 LZ35 LZ51 LZ05 LZ06 Un Jardín de Cactus en el corazón de un volcán (LZ53) Tubo volcánico de La Corona-Túnel de la Atlántida, un tesoro bajo las lavas (LZ06) Peñas de Tao, los colosos caídos del Volcán de La Corona (LZ05) Agua entre las lavas del Malpaís del Norte (AL01) Cantera de Tinamala, una pirámide escondida dentro de un volcán (LZ17) Un volcán muy Golfo (LZ35) Los diques de Montaña Clara, las arterias de los volcanes (MC01) Montaña Halcones, la línea de costa anterior a Timanfaya (LZ51) Caldera Blanca, el gigante blanco (LZ61) La gran Caldera de Alegranza (AL02) LUGARES DE INTERÉS GEOLÓGICO 3,5 1470 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo LZ61 LZ17 LZ53 AL01 MC01 AL02 LZ35 LZ51 LZ05 LZ06 Un Jardín de Cactus en el corazón de un volcán (LZ53) Tubo volcánico de La Corona-Túnel de la Atlántida, un tesoro bajo las lavas (LZ06) Peñas de Tao, los colosos caídos del Volcán de La Corona (LZ05) Agua entre las lavas del Malpaís del Norte (AL01) Cantera de Tinamala, una pirámide escondida dentro de un volcán (LZ17) Un volcán muy Golfo (LZ35) Los diques de Montaña Clara, las arterias de los volcanes (MC01) Montaña Halcones, la línea de costa anterior a Timanfaya (LZ51) Caldera Blanca, el gigante blanco (LZ61) La gran Caldera de Alegranza (AL02) LUGARES DE INTERÉS GEOLÓGICO 3,5 1470 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo GEOSITES LZ61 LZ17 LZ53 AL01 MC01 AL02 LZ35 LZ51 LZ05 LZ06 Un Jardín de Cactus en el corazón de un volcán (LZ53) Tubo volcánico de La Corona-Túnel de la Atlántida, un tesoro bajo las lavas (LZ06) Peñas de Tao, los colosos caídos del Volcán de La Corona (LZ05) Agua entre las lavas del Malpaís del Norte (AL01) Cantera de Tinamala, una pirámide escondida dentro de un volcán (LZ17) Un volcán muy Golfo (LZ35) Los diques de Montaña Clara, las arterias de los volcanes (MC01) Montaña Halcones, la línea de costa anterior a Timanfaya (LZ51) Caldera Blanca, el gigante blanco (LZ61) La gran Caldera de Alegranza (AL02) LUGARES DE INTERÉS GEOLÓGICO 3,5 1470 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo LZ61 LZ17 LZ53 AL01 MC01 AL02 LZ35 LZ51 LZ05 LZ06 Un Jardín de Cactus en el corazón de un volcán (LZ53) Tubo volcánico de La Corona-Túnel de la Atlántida, un tesoro bajo las lavas (LZ06) Peñas de Tao, los colosos caídos del Volcán de La Corona (LZ05) Agua entre las lavas del Malpaís del Norte (AL01) Cantera de Tinamala, una pirámide escondida dentro de un volcán (LZ17) Un volcán muy Golfo (LZ35) Los diques de Montaña Clara, las arterias de los volcanes (MC01) Montaña Halcones, la línea de costa anterior a Timanfaya (LZ51) Caldera Blanca, el gigante blanco (LZ61) La gran Caldera de Alegranza (AL02) LUGARES DE INTERÉS GEOLÓGICO 3,5 1470 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo LZ61 LZ17 LZ53 AL01 MC01 AL02 LZ35 LZ51 LZ05 LZ06 Un Jardín de Cactus en el corazón de un volcán (LZ53) Tubo volcánico de La Corona-Túnel de la Atlántida, un tesoro bajo las lavas (LZ06) Peñas de Tao, los colosos caídos del Volcán de La Corona (LZ05) Agua entre las lavas del Malpaís del Norte (AL01) Cantera de Tinamala, una pirámide escondida dentro de un volcán (LZ17) Un volcán muy Golfo (LZ35) Los diques de Montaña Clara, las arterias de los volcanes (MC01) Montaña Halcones, la línea de costa anterior a Timanfaya (LZ51) Caldera Blanca, el gigante blanco (LZ61) La gran Caldera de Alegranza (AL02) LUGARES DE INTERÉS GEOLÓGICO 3,5 1470 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo The great Caldera of Alegranza (AL02) Caldera Blanca: The White Giant (LZ61) Montaña Halcones: the coastline before Timanfaya (LZ51) The dykes of Montaña Clara: the arteries to the volcanoes (MC01) A volcano in the Gulf (LZ35) Tinamala quarry: a hidden pyramid inside a volcano (LZ17) Ponds between the lava flows of Malpaís del Norte (AL01) Peñas de Tao: the fallen giants of La Corona Volcano (LZ05) The lava tube of La Corona-Tunnel of Atlantis: a treasure inside the lava flows (LZ06) A Cactus Garden in the heart of a volcano (LZ53) LZ61 LZ17 LZ53 AL01 MC01 AL02 LZ35 LZ51 LZ05 LZ06 Un Jardín de Cactus en el corazón de un volcán (LZ53) Tubo volcánico de La Corona-Túnel de la Atlántida, un tesoro bajo las lavas (LZ06) Peñas de Tao, los colosos caídos del Volcán de La Corona (LZ05) Agua entre las lavas del Malpaís del Norte (AL01) Cantera de Tinamala, una pirámide escondida dentro de un volcán (LZ17) Un volcán muy Golfo (LZ35) Los diques de Montaña Clara, las arterias de los volcanes (MC01) Montaña Halcones, la línea de costa anterior a Timanfaya (LZ51) Caldera Blanca, el gigante blanco (LZ61) La gran Caldera de Alegranza (AL02) LUGARES DE INTERÉS GEOLÓGICO 3,5 1470 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo * Geosites with an area of less than 10 hectares are marked with a circle. Quaternary Volcanoes 3332 Geological treasures of magma, wind, and water The Great Caldera of Alegranza The Caldera of the Alegranza islet is a large phreatomagmatic volcano, which was formed between 15,000 and 10,000 years ago by the interaction of seawater and magma during its eruption. It is almost 300 m high and more than two kilometres in diameter at its base, with a circular crater of about 1,238 m in diameter and about 246 m deep. These dimensions make this cone the largest monogenetic edifice in all of the Canary Islands. In the area of La Capilla, located on its western flank, the action of the sea has carved a spectacular cliff with yellowish and ochre hues that allows us to observe its internal structure. It consists of intersecting and shearing layers and sheets of ash, known as pyroclastic surges, which are representative of this type of shallow offshore eruption. Erosive cliff on the eastern edge of the Caldera de Alegranza that exposes the pyroclastic surges originated by the phreatomagmatic eruption. Detail of the coastal cave caused by wave erosion that affects the base of the cliff and triggers landslides in the upper layers. Caldera Blanca: the white giant The volcanic edifice of Caldera Blanca together with the Risco Quebrado cone, which adjoins its western flank, is part of a group of phreatomagmatic volcanoes that marked the coastal boundary of Lanzarote during the Lower Pleistocene (2.58 million years to 780,000 years ago). Its impressive annular crater, with a diameter of almost 1,200 m and an interior depth of 315 m, makes it the deepest monogenetic volcano with the deepest crater floor in the Canary Islands. Both buildings are essentially formed by tuffs: ash and lapilli of ochre and yellowish tones, with alterations and textures related to their construction during Surtseyan episodes, which are very explosive due to water/magma contact. Since its formation, the edifice has been intensely eroded, so that the outer slopes show deep radial gullies. At the bottom of the crater, abundant debris has accumulated, forming an interior endorheic basin. In the past, during years of abundant rainfall, these materials retained moisture and allowed the cultivation of cereal. In the basal area of the outer slopes, ash from the Timanfaya eruption can also be identified, with an intense black colour that contrasts with the almost white colour of this giant, standing out in the landscape among the dark lava of the Volcanoes Natural Park. Caldera Blanca seen from the town of Mancha Blanca. Orthophoto and digital shadow model of Caldera Blanca, which has remained as a kipuka or islet among the black lava fields of Timanfaya. 3534 Geological treasures of magma, wind, and water Quaternary Volcanoes Montaña Halcones: the coastline before Timanfaya Montaña Halcones is a small arched ‘kipuka’, completely surrounded by the black lavas of Timanfaya, which marked the coastline prior to the great 18th-century eruption. It is a volcanic cone built in two distinct eruptive phases, an initial water/magma contact phase and a final phase with lava emission. Cutting through the deposits from the first eruptive stage, several dark, almost black dykes stand out, which are the volcanic conduits that fed the last phases of the eruption. The lava from Timanfaya reached the coast of Halcones during the first months and advanced the coastline to the south before mid-November 1731, according to the map of the eruption kept in the Simancas archive. This volcano is currently located inside the sea of lavas of the Timanfaya National Park, at a distance of approximately one kilometre from today’s coastline. Montaña Halcones, an islet or ‘kipupa’ of a phreatomagmatic volcano on the old north coast of Lanzarote, prior to the Timanfaya eruption (1730-1736) that has been surrounded by a field of black lava. The dykes of Montaña Clara: the arteries of the volcanoes In the southwestern sector of the Pleistocene edifice of the Montaña Clara islet, marine erosion has dismantled the tuff ring to the heart of the main volcano, developing an almost vertical cliff more than 200 m high. On this vertical escarpment, the yellowish pyroclasts can be seen, which are common in hydromagmatic cones, but the feed dyke of the overlying El Bermejo cone also stands out, cutting the deposits vertically and ascending to the summit, widening and connecting with the lavas and black pyroclasts at the top. These types of geological elements are difficult to observe since they tend to remain hidden inside the volcanoes. LIDAR image of the Montaña Clara islet. 36 Geological treasures of magma, wind, and water 37 A volcano in the Gulf The El Golfo volcano also erupted in a coastal environment, very close to the coast of Lanzarote, resulting in yellowish deposits with laminated structures typical of Surtseyan eruptions. The sea and the wind have eroded it and currently only one flank of the edifice is visible, surrounded by lava, except on the coastal sector. Here, among the remains of the volcanic edifice and a coastal ridge of pebbles that eventually closed off its crater, lies the Los Clicos lagoon, a coastal lagoon with a greenish hue caused by the microalgae community it plays host to. The eroded front of the crater’s interior is characterised by honeycomb texture, known as taffonis, formed by the chemical weathering of the rocks in marine areas, which give a unique ruinous appearance to this volcano, which is one of the most visited places in this Geopark. Taffonis on the walls of El Golfo. Lanzarote coast, before the eruption of El Golfo. Coastal eruption. Erosion of this volcano by coastal processes. El Golfo is covered by another strombolian volcano and a beach barrier is formed after the eruption of Timanfaya. Quaternary Volcanoes Quaternary Volcanoes 39 Geological treasures of magma, wind, and water 38 Geological treasures of magma, wind, and water Water among the lavas of the Malpaís del Norte The entire northern and northeastern slope of the islet of Alegranza is characterised by the presence of Pleistocene volcanic lava flows and blocky surfaces, originating from Montaña de Lobos. These ‘aa’ lava flows have a very rough, fragmented, and chaotic appearance, with a coarse and irregular surface. Between the large mounds of this surface, there are numerous circular depressions where, during the rainy season, water accumulates to form ephemeral puddles. Some of these ponds have traditionally fed the cisterns of the island’s lighthouse, the only site inhabited in the past. After evaporation, cream-coloured sandy-clay or silty deposits remain, dotting the black ‘Malpaís’ in the form of spots where sparse vegetation grows. Tinamala Quarry: a pyramid within a volcano The quarry faces excavated in the Tinamala volcano, in Guatiza, provide a different view of the interior of a strombolian volcanic cone of tephra, formed by the accumulation of spatter, pyroclasts of ballistic projection -lapillis and volcanic bombs-. These materials, of an dark red colour, are partially welded (as if glued together) because, as the fragments of hot, partially melted lava fell, they were joined together and upon cooling transformed into a porous yet very resistant rock, highly valued in Lanzarote as a building stone. The method of block extraction, developed by Jesús Soto, leaves Tinamala with a landscape of great aesthetic value, reminiscent of the villages of arid and desert areas built with red clays. In fact, in 1987, the site was used as the location for the filming of a Swedish film version of Verdi’s opera Aida. Spatters or scoria among the welded pyroclasts of the Tinamala volcanic cone. Quaternary Volcanoes 4140 Geological treasures of magma, wind, and water Entrance to the Cueva de los Verdes. Main access to the La Corona lava tube for tourist visits. Section of the lava tube of La Corona volcano submerged beneath the sea, known as Atlantis Tunnel. The lava tube of La Corona-Tunnel of Atlantis: a treasure beneath the lava La Corona has unique geological treasures, including a magnificent volcanic tube, which provides an insight into the subterranean volcanic world. 21,000 years ago, our planet was in the depths of the Last Great Ice Age, and the sea level was 120 m below the today’s coastline. The lavas from La Corona flowed over the ancient cliffs carved into the western shield of Famara and advanced up to a distance of 7.5 km, creating a network of underground tubes that make up the Cueva de Los Verdes-Jameos del Agua-Tunnel of Altantis. The rise in global sea level during the Holocene caused the flooding of the underground galleries in their final stretch, in the section known as the Tunnel of Atlantis. It is the world’s longest underwater volcanic tube, with a total length of 1,600 m, ending 81 m below sea level. Access to the interior of the Corona lava tube is made through collapsed sectors of the roof, known locally as ‘jameos’ or skylights, such as the Cueva de los Verdes and the Jameos del Agua, home to the Geopark’s most famous endemic fauna, the ‘jameito’ (Munidopsis polymorpha), a pretty small white-coloured blind crustacean. Interior of the lava tube in Los Verdes Cave. Quaternary Volcanoes 4342 Geological treasures of magma, wind, and water Remains of the black volcanic bombs among the pyroclasts and reddish spater welded from the volcanic cone of Calderetas de Guatiza that have been preserved in the Cactus Garden. A Cactus Garden in the heart of a volcano The extraction of pyroclastic rocks (lapilli and welded bombs that form volcanic cones) has been a common practice on the island and a necessary geological resource for natural stones and sandy soil cultivation. César Manrique launched an ambitious plan to recover one of these spaces that had been degraded once the extractive activity ended, in the old quarry of Las Calderetas de Guatiza. During the restoration, this mining site was converted into the Cactus Garden, one of the art and culture centres of the Lanzarote Island Council. In this exhibition space, among the hundreds of different species of cacti and in the form of monolithic sculptures, the original remains of the pyroclastic deposits that formed the volcanic cone and the dykes or conduits through which the magma ascended to the volcano’s summit are preserved. Nature and culture come together in a unique space, created to respect the spirit of the volcano. Peñas de Tao: the fallen giants of the La Corona Volcano The La Corona volcano had an intense magmatic activity that emerged in the highest part of the ancient massif of Famara 21,000 years ago. This eruption emitted a large amount of very fluid basaltic lava flows, which covered a large part of the northeastern tip of Lanzarote. During the phases of greatest magma input, the volcanic cone hosted a large lava lake in its crater, the pressure of which caused the collapse of the northern slope. The large fragmented blocks were dragged floating on the lava flows, until reaching the most distal areas where Órzola is located today. In some cases, the Peñas de Tao exceed 25 m in height and 40 m in length, and are located at distances of between one and four kilometres away, which is why they are known by the scientific term ‘erratic blocks’. Cactus Garden in the old quarry of Calderetas de Guatiza. 4544 Lanzarote emerges from the oceanGeological treasures of magma, wind, and water The historic volcanoes of 1730-36 and 1824 3 The historic volcanoes of 1730-36 and 1824 47 LZ21 LZ24 LZ26 LZ36 LZ30 LZ25 LZ31 LZ43 LZ27 LZ62 LZ70 Tinguatón, el volcán que expulsó chorros de agua (LZ24) Fundación César Manrique, la lava hecha arte (LZ30) La Geria, viñas y vinos que surgen de las cenizas (LZ36) Mazo, cuando la tierra se parte durante una erupción (LZ70) Montaña Colorada, un final grandioso para Timanfaya (LZ43) El mar de lavas de Timanfaya (LZ27) Islote de Hilario, donde la tierra arde (LZ25) Macizo del Fuego, en la morada del diablillo de Timanfaya (LZ62) Montaña Rajada, una grieta al infierno (LZ31) Pico Partido, un cráter desbordado en un gran canal (LZ26) Monumento al Campesino, el suelo cubierto por la gran erupción de Timanfaya (LZ21) LUGARES DE INTERÉS GEOLÓGICO 3,5 14 7 0 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo The historic volcanoes of 1730-36 and 1824 This geological framework coincides with the human occupation of the archipelago and the historical chronicles dating back to the 15th century, which have remained as direct witnesses of this land of volcanoes. Specifically, there is evidence of the first documented visit in 1312 by Lanceloto Malocello, precisely to Lanzarote, being the first island to be colonised in 1402. There is increasing archaeological evidence that proves Phoenician presence in Lanzarote and La Graciosa around the 10th century B.C., as well as evidence from the Roman period, which favoured the settlement of African groups, giving rise, specifically, to the Aboriginal culture. Thanks to the written chronicles from the 15th century onward, and especially to historical documents from the 18th and 19th centuries, there is a double record of volcanic eruptions: historical and geological evidence. Lanzarote was the site of the most extensive and significant eruptive process in the history of the Canary Islands: the 1730–1736 eruption, which gave rise to the Timanfaya volcanic field. This eruption, along with the triple eruption of 1824, which formed the Tao, Chinero, and Tinguatón volcanoes, makes Lanzarote the Canary Island where historical volcanism is most significant and has had the greatest impact on its topography, insular landscape and inhabitants. Being such recent eruptions, the rocks, morphologies and structures are very well preserved, which allows us to observe all the volcanic elements that are representative of fissural basaltic eruptions on oceanic volcanic islands. Due to its high scientific value, this is the geological framework of the Lanzarote and Chinijo Islands UNESCO Global Geopark in, which is of international relevance. LZ21 LZ24 LZ26 LZ36 LZ30 LZ25 LZ31 LZ43 LZ27 LZ62 LZ70 Tinguatón, el volcán que expulsó chorros de agua (LZ24) Fundación César Manrique, la lava hecha arte (LZ30) La Geria, viñas y vinos que surgen de las cenizas (LZ36) Mazo, cuando la tierra se parte durante una erupción (LZ70) Montaña Colorada, un final grandioso para Timanfaya (LZ43) El mar de lavas de Timanfaya (LZ27) Islote de Hilario, donde la tierra arde (LZ25) Macizo del Fuego, en la morada del diablillo de Timanfaya (LZ62) Montaña Rajada, una grieta al infierno (LZ31) Pico Partido, un cráter desbordado en un gran canal (LZ26) Monumento al Campesino, el suelo cubierto por la gran erupción de Timanfaya (LZ21) LUGARES DE INTERÉS GEOLÓGICO 3,5 14 7 0 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo GEOSITES LZ21 LZ24 LZ26 LZ36 LZ30 LZ25 LZ31 LZ43 LZ27 LZ62 LZ70 Tinguatón, el volcán que expulsó chorros de agua (LZ24) Fundación César Manrique, la lava hecha arte (LZ30) La Geria, viñas y vinos que surgen de las cenizas (LZ36) Mazo, cuando la tierra se parte durante una erupción (LZ70) Montaña Colorada, un final grandioso para Timanfaya (LZ43) El mar de lavas de Timanfaya (LZ27) Islote de Hilario, donde la tierra arde (LZ25) Macizo del Fuego, en la morada del diablillo de Timanfaya (LZ62) Montaña Rajada, una grieta al infierno (LZ31) Pico Partido, un cráter desbordado en un gran canal (LZ26) Monumento al Campesino, el suelo cubierto por la gran erupción de Timanfaya (LZ21) LUGARES DE INTERÉS GEOLÓGICO 3,5 14 7 0 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo LZ21 LZ24 LZ26 LZ36 LZ30 LZ25 LZ31 LZ43 LZ27 LZ62 LZ70 Tinguatón, el volcán que expulsó chorros de agua (LZ24) Fundación César Manrique, la lava hecha arte (LZ30) La Geria, viñas y vinos que surgen de las cenizas (LZ36) Mazo, cuando la tierra se parte durante una erupción (LZ70) Montaña Colorada, un final grandioso para Timanfaya (LZ43) El mar de lavas de Timanfaya (LZ27) Islote de Hilario, donde la tierra arde (LZ25) Macizo del Fuego, en la morada del diablillo de Timanfaya (LZ62) Montaña Rajada, una grieta al infierno (LZ31) Pico Partido, un cráter desbordado en un gran canal (LZ26) Monumento al Campesino, el suelo cubierto por la gran erupción de Timanfaya (LZ21) LUGARES DE INTERÉS GEOLÓGICO 3,5 14 7 0 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo LZ21 LZ24 LZ26 LZ36 LZ30 LZ25 LZ31 LZ43 LZ27 LZ62 LZ70 Tinguatón, el volcán que expulsó chorros de agua (LZ24) Fundación César Manrique, la lava hecha arte (LZ30) La Geria, viñas y vinos que surgen de las cenizas (LZ36) Mazo, cuando la tierra se parte durante una erupción (LZ70) Montaña Colorada, un final grandioso para Timanfaya (LZ43) El mar de lavas de Timanfaya (LZ27) Islote de Hilario, donde la tierra arde (LZ25) Macizo del Fuego, en la morada del diablillo de Timanfaya (LZ62) Montaña Rajada, una grieta al infierno (LZ31) Pico Partido, un cráter desbordado en un gran canal (LZ26) Monumento al Campesino, el suelo cubierto por la gran erupción de Timanfaya (LZ21) LUGARES DE INTERÉS GEOLÓGICO 3,5 14 7 0 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo LZ21 LZ24 LZ26 LZ36 LZ30 LZ25 LZ31 LZ43 LZ27 LZ62 LZ70 Tinguatón, el volcán que expulsó chorros de agua (LZ24) Fundación César Manrique, la lava hecha arte (LZ30) La Geria, viñas y vinos que surgen de las cenizas (LZ36) Mazo, cuando la tierra se parte durante una erupción (LZ70) Montaña Colorada, un final grandioso para Timanfaya (LZ43) El mar de lavas de Timanfaya (LZ27) Islote de Hilario, donde la tierra arde (LZ25) Macizo del Fuego, en la morada del diablillo de Timanfaya (LZ62) Montaña Rajada, una grieta al infierno (LZ31) Pico Partido, un cráter desbordado en un gran canal (LZ26) Monumento al Campesino, el suelo cubierto por la gran erupción de Timanfaya (LZ21) LUGARES DE INTERÉS GEOLÓGICO 3,5 14 7 0 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo The Farmer’s Monument: the soil covered by the great Timanfaya eruption (LZ21) Pico Partido: a crater overflowing into a large channel (LZ26) Montaña Rajada: a crack into hell (LZ31) Macizo del Fuego: where the little devil of Timanfaya dwells (LZ62) The Islet of Hilario: where the earth still burns (LZ25) A sea of lava in Timanfaya (LZ27) Montaña Colorada: a grand finale for Timanfaya (LZ43) Mazo: when the earth splits during an eruption (LZ70) La Geria: vineyards and wines rise from the pyroclast (LZ36) César Manrique Foundation: lava becomes art (LZ30) Tinguatón: the volcano that shot out jets of water (LZ24) LZ21 LZ24 LZ26 LZ36 LZ30 LZ25 LZ31 LZ43 LZ27 LZ62 LZ70 Tinguatón, el volcán que expulsó chorros de agua (LZ24) Fundación César Manrique, la lava hecha arte (LZ30) La Geria, viñas y vinos que surgen de las cenizas (LZ36) Mazo, cuando la tierra se parte durante una erupción (LZ70) Montaña Colorada, un final grandioso para Timanfaya (LZ43) El mar de lavas de Timanfaya (LZ27) Islote de Hilario, donde la tierra arde (LZ25) Macizo del Fuego, en la morada del diablillo de Timanfaya (LZ62) Montaña Rajada, una grieta al infierno (LZ31) Pico Partido, un cráter desbordado en un gran canal (LZ26) Monumento al Campesino, el suelo cubierto por la gran erupción de Timanfaya (LZ21) LUGARES DE INTERÉS GEOLÓGICO 3,5 14 7 0 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo * Geosites with an area of less than 10 hectares are marked with a circle. The historic volcanoes of 1730-36 and 1824 4948 Geological treasures of magma, wind, and water and offer a view of the sequence of events corresponding to the island’s most recent geological history. From the bottom to the top of the windows, it is possible to recognise the sand fields that were covered by pyroclasts from an ancient volcanic eruption. In turn, the soil was formed on top of the pyroclastic layer, which was later covered by the ash dispersion of Timanfaya and by the lava flows emitted from Montaña de Las Nueces volcano around 1733. The Farmer’s Monument: the soil covered by the great Timanfaya eruption The underground dining room of this Centre for Art, Culture and Tourism has been built using the pahoehoe lavas of Timanfaya as ornamental elements, making it possible to admire the heart of these lava flows. The interior corridor, which connects the dining room with one of the exits, runs under these pahoehoe lavas, allowing observation of their original base with the surface over which they flowed. On both sides of the corridor, two glass windows contain important information Basaltic lava flow from the last phases of Timanfaya (1733) displayed in its original position at the Museo del Campesino restaurant. The columnar jointing typical of these lava flows can be seen. Display case in the hallway of the Peasant’s Museum restaurant showing the section buried beneath a lava flow from the Timanfaya eruption. Detail of this display case with the layer of black pyroclasts (lapilli) from the Timanfaya eruption, which buried the palaeosol from 1730 that formed over a previous layer of altered pyroclasts from Pleistocene eruptions. The historic volcanoes of 1730-36 and 1824 6362 Geological treasures of magma, wind, and water The César Manrique Foundation is located on a lava flow, with only the tops of the palm trees visible above the surface through a skylight, as their trunks are rooted in the pre-Timanfaya soil beneath the lava. Cesar Manrique Foundation: lava becomes art This house has been built on two levels, taking advantage of the internal morphology of the lava flow. The local artist César Manrique created a remarkable blend of architecture and volcanic elements in all his works. Used for 20 years as the artist’s home, the house is masterfully adapted to the distal pahoehoe lava flows of the intermediate phases of the Timanfaya eruption. The design adapts and blends in with the interior of the inflation basaltic lava flows, which are characterised by their high porosity, and the presence of tumuli, tubes, jameos, columnar joints and inflation capsules. The inflation process of the basaltic lava flows is associated with extremely low-viscosity magma, the high gas content of an already cooled surface crust, which exerts pressure from within the lava flow. The five-domed rooms on the lower level of the house are interconnected by corridor-galleries that have been carved out of the lava. These domes have strong inflation levels that form in specific sectors of the lava flow. It is common for these rooms to have an open roof or skylight because of collapse where the lava flow is thinner. Skylights have traditionally been used indoors to cultivate fruit trees for the local community, called ‘chavocos’. César, in collaboration with Jesús Soto, has uniquely adapted to the volcanic features of this island. His genius, tenacity, and vision of the island are evident in his art, uniquely interpreting volcanic spaces. Images from inside the César Manrique Foundation show typical rooms formed by the inflation of lava flows. These rooms feature small skylights in the ceiling, which are used for cultivation and natural lighting. 65 Lanzarote emerges from the ocean 64 Geological treasures of magma, wind, and water Shifting sands 4 Shifting sands 6766 Geological treasures of magma, wind, and water Shifting sands This Geopark is home to one of the most fascinating geological process in the whole of the Canary Islands, which is the result of the wind being one of the most effective erosive agents; and the presence of abundant calcareous marine organisms that colonise the platform and the coastline. White sands, so abundant in these islands, are of organic origin and is composed of fragments of marine shells and calcareous algae, which give it its characteristic colour. This sand travels a long journey, beginning in the sea, where currents crush shells and algae into small sandy fragments that are carried by the coastal currents until they reach the shore. Once above sea level, the wind takes over, carrying them towards the beaches and inland, taking advantage of the low relief, forming fields, sand corridors and dunes, so abundant in Lanzarote and the Chinijo Islands. The wind has played a decisive role from the very first stages of the islands’ formation and still, today, continues to shape the landscape of the eastern Canary Islands. Near-white aeolian deposits are interspersed between the black volcanic rocks, evidencing the continuous interaction between internal constructive geological processes and external modelling agents. MAPA LIGS GONZALO GR07 LZ20 LZ09 Las Conchas-Montaña Bermeja, una playa blanca al pie de un volcán (GR07) Lomos de San Andrés y Camacho, ¡no son volcanes, que son dunas! (LZ20) El Jable, el gran pasillo de arenas de Lanzarote (LZ09) LUGARES DE INTERÉS GEOLÓGICO 3,5 1470 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS GR07 LZ20 LZ09 Las Conchas-Montaña Bermeja, una playa blanca al pie de un volcán (GR07) Lomos de San Andrés y Camacho, ¡no son volcanes, que son dunas! (LZ20) El Jable, el gran pasillo de arenas de Lanzarote (LZ09) LUGARES DE INTERÉS GEOLÓGICO 3,5 1470 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS GEOSITES GR07 LZ20 LZ09 Las Conchas-Montaña Bermeja, una playa blanca al pie de un volcán (GR07) Lomos de San Andrés y Camacho, ¡no son volcanes, que son dunas! (LZ20) El Jable, el gran pasillo de arenas de Lanzarote (LZ09) LUGARES DE INTERÉS GEOLÓGICO 3,5 1470 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS GR07 LZ20 LZ09 Las Conchas-Montaña Bermeja, una playa blanca al pie de un volcán (GR07) Lomos de San Andrés y Camacho, ¡no son volcanes, que son dunas! (LZ20) El Jable, el gran pasillo de arenas de Lanzarote (LZ09) LUGARES DE INTERÉS GEOLÓGICO 3,5 1470 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS El Jable: Lanzarote’s great sand corridor (LZ09) Lomos de San Andrés and Camacho: they are not volcanoes, they are dunes! (LZ20) Las Conchas-Montaña Bermeja: a white beach at the foothill of a volcano (GR07) Shifting sands 6968 Geological treasures of magma, wind, and water The Jable: Lanzarote’s great sand corridor Changes in global sea level during the Quaternary period have significantly impacted the extensive sandy deposits found throughout the Geopark. During glacial periods, much of the world’s water was frozen in glaciers, which caused a global lowering of the oceans and exposed parts of the island shelves. On the northern coast of Lanzarote, there is an abundance of bioclastic sands that move inland, forming wind deposits and light-colored dune fields. These sands, carried by the intense winds, cross the island like a large conveyor belt, from north to south, through the corridor known as ‘El Jable’. This area coincides with the central sector of lower relief on the island, acting as a large corridor between the eastern sector of Famara and the western sector of Timanfaya-Ajaches, which facilitates the passage of wind and sand, encountering very few obstacles. The deposits of this vast sand carpet have been exposed in many sectors of El Jable due to the small quarries, revealing in its interior the alternation of different layers that correspond to arid climates where white sands accumulated, and layers of darker paleosols associated with humid climates. It is a sedimentary system that remains active today, with intense sporadic storms that have caused problems for towns, roads and crops. The movement of sand has been altered by human activities such as deforestation, road construction, and buildings, which have impacted this fragile natural system and obstructed its flow from north to south. Erosion and aeolian sedimentation are the most active geological processes in arid environments. The movement of sands and dunes constantly changes El Jable´s landscape. ‘El Jable’ comes from the French word “sable” meaning sand. To the right is the Risco de Famara. Cereals have been cultivated in this region since historical times by Aboriginal inhabitants. With the arrival of the conquerors in the 15th century, new crop varieties were introduced (wheat, barley and rye). In the 19th century, attention was again focused on the ‘barrilla’, Mesembryanthemum crystallinum L., an herbaceous plant species of halophytic environments. Aboriginal populations used it to create dyes, soaps, and caustic soda. Its cultivation revived the island’s economy by exporting barilla stone to Europe for soap production. Shifting sands 7170 Geological treasures of magma, wind, and water Lomos de San Andrés and Camacho: they are not volcanoes, they are dunes! The Lomos de San Andrés and Camacho are two large, broad, hemispherical mounds, with a shield-shaped morphology, located at the foot of the Tamia volcano. Until very recently, due to their morphology, they had been interpreted as ancient, highly eroded strombolian volcanic cones. As they were covered with black lapilli, due to their circular plan and their insertion within the central volcanic field of Lanzarote, this certainly seemed to be the case. Inside, however, they harbored a significant secret revealed by the opening of quarries for lapilli extraction. Beneath layers of black pyroclastic material, bioclastic sands emerged, representing Pleistocene fossil dunes linked to the El Jable corridor sand system. They were densely covered by pyroclasts emitted during the eruption of Tamia volcano, remaining hidden and camouflaged among the other volcanoes in this area. Las Conchas-Montaña Bermeja: a white beach at the foot of a red volcano This active beach system on La Graciosa, accompanied by a string of dunes, is situated at the base of the Holocene volcano Montaña Bermeja, noted for its intense vermilion color. The white bioclastic sands are carried from submerged areas by marine currents, forming Las Conchas beach. The wind carries the sand inward across the island, aided by the beach’s shape. However, when it meets the volcano’s contours, it forms a line of small dunes, unable to progress further. In coastal areas, small isolated dunes can be seen, stabilized by vegetation. These give rise to larger dunes of varying heights, randomly distributed over a sand field. Finally, there is a well-stabilized aeolian layer that is also supported by vegetation. Quarry hollow in Lomo de Camacho. Beneath the black lapilli, at the bottom, cream-coloured aeolian sands emerge. Cream-coloured dunes and rocky pavement in lavas of an arid environment. La Graciosa Island. In the foreground is the cream-colored beach-dune system of Las Conchas, which is connected to the Montaña Bermeja volcano. 7372 Lanzarote emerges from the oceanGeological treasures of magma, wind, and water The action of the Sea 5 The action of the Sea 7574 Geological treasures of magma, wind, and water The action of the Sea Volcanic islands are continuously subjected to the action of the ocean along their coastline, resulting in deposits and morphologies that bear the unmistakable mark of current and past marine processes. The sedimentary deposits and morphologies indicate that the coastline position in this archipelago has varied over the Quaternary. On the coast, erosive and constructive processes continuously interact, with rocks, fossils, and sediments typical of marine and transitional environments predominating. Marine erosion sculpts the cliffs, and different landforms such as beaches, lagoons, and coastal caves, among other morphologies formed. The sedimentary process develops low-energy deposits, and high-energy deposits are also preserved. Storms and tsunamis, also known as tsunamites, occurred as well. Lagoons, salt pans, and unique springs that emerge on cliffs and at sea level are also common. LZ52 GR05 AL05 LZ37 LZ63 LZ41 LZ54 LZ04 LZ38 Salinas del Janubio, el cultivo de la flor de sal (LZ38) El Río, las salinas más antiguas de Canarias (LZ04) El Salado, una laguna litoral en La Graciosa (GR05) Playa del Cochino, las evidencias de un tsunami (LZ54) Caletón Blanco, arenas blancas entre lavas negras (LZ52) Papagayo, una colección de playas (LZ63) Jameo de Alegranza, una ventana en una cueva litoral (AL05) Los Hervideros, truenos del mar a través de las lavas (LZ37) Ajaches, una plataforma expuesta por encima del nivel del mar (LZ41) LUGARES DE INTERÉS GEOLÓGICO 3,5 1470 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo LZ52 GR05 AL05 LZ37 LZ63 LZ41 LZ54 LZ04 LZ38 Salinas del Janubio, el cultivo de la flor de sal (LZ38) El Río, las salinas más antiguas de Canarias (LZ04) El Salado, una laguna litoral en La Graciosa (GR05) Playa del Cochino, las evidencias de un tsunami (LZ54) Caletón Blanco, arenas blancas entre lavas negras (LZ52) Papagayo, una colección de playas (LZ63) Jameo de Alegranza, una ventana en una cueva litoral (AL05) Los Hervideros, truenos del mar a través de las lavas (LZ37) Ajaches, una plataforma expuesta por encima del nivel del mar (LZ41) LUGARES DE INTERÉS GEOLÓGICO 3,5 1470 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo LZ52 GR05 AL05 LZ37 LZ63 LZ41 LZ54 LZ04 LZ38 Salinas del Janubio, el cultivo de la flor de sal (LZ38) El Río, las salinas más antiguas de Canarias (LZ04) El Salado, una laguna litoral en La Graciosa (GR05) Playa del Cochino, las evidencias de un tsunami (LZ54) Caletón Blanco, arenas blancas entre lavas negras (LZ52) Papagayo, una colección de playas (LZ63) Jameo de Alegranza, una ventana en una cueva litoral (AL05) Los Hervideros, truenos del mar a través de las lavas (LZ37) Ajaches, una plataforma expuesta por encima del nivel del mar (LZ41) LUGARES DE INTERÉS GEOLÓGICO 3,5 1470 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo LZ52 GR05 AL05 LZ37 LZ63 LZ41 LZ54 LZ04 LZ38 Salinas del Janubio, el cultivo de la flor de sal (LZ38) El Río, las salinas más antiguas de Canarias (LZ04) El Salado, una laguna litoral en La Graciosa (GR05) Playa del Cochino, las evidencias de un tsunami (LZ54) Caletón Blanco, arenas blancas entre lavas negras (LZ52) Papagayo, una colección de playas (LZ63) Jameo de Alegranza, una ventana en una cueva litoral (AL05) Los Hervideros, truenos del mar a través de las lavas (LZ37) Ajaches, una plataforma expuesta por encima del nivel del mar (LZ41) LUGARES DE INTERÉS GEOLÓGICO 3,5 1470 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo Ajaches: self-exposed above sea level (LZ37) Hervideros: the sea thundering through the lavas (LZ41) The Alegranza skylight: a window into a coastal cave (AL05) Papagayo: a beach collection (LZ63) Caletón Blanco: white sands among black lava (LZ52) Playa Cochino: evidence of a tsunami (LZ54) El Salado: a coastal lagoon on La Graciosa Island (GR05) El Río: the oldest salt mine in the Canary Islands (LZ04) The Janubio salt mines: cultivation of fleur de sel (LZ38) LZ52 GR05 AL05 LZ37 LZ63 LZ41 LZ54 LZ04 LZ38 Salinas del Janubio, el cultivo de la flor de sal (LZ38) El Río, las salinas más antiguas de Canarias (LZ04) El Salado, una laguna litoral en La Graciosa (GR05) Playa del Cochino, las evidencias de un tsunami (LZ54) Caletón Blanco, arenas blancas entre lavas negras (LZ52) Papagayo, una colección de playas (LZ63) Jameo de Alegranza, una ventana en una cueva litoral (AL05) Los Hervideros, truenos del mar a través de las lavas (LZ37) Ajaches, una plataforma expuesta por encima del nivel del mar (LZ41) LUGARES DE INTERÉS GEOLÓGICO 3,5 1470 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo GEOSITES LZ52 GR05 AL05 LZ37 LZ63 LZ41 LZ54 LZ04 LZ38 Salinas del Janubio, el cultivo de la flor de sal (LZ38) El Río, las salinas más antiguas de Canarias (LZ04) El Salado, una laguna litoral en La Graciosa (GR05) Playa del Cochino, las evidencias de un tsunami (LZ54) Caletón Blanco, arenas blancas entre lavas negras (LZ52) Papagayo, una colección de playas (LZ63) Jameo de Alegranza, una ventana en una cueva litoral (AL05) Los Hervideros, truenos del mar a través de las lavas (LZ37) Ajaches, una plataforma expuesta por encima del nivel del mar (LZ41) LUGARES DE INTERÉS GEOLÓGICO 3,5 1470 Km Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo * Geosites with an area of less than 10 hectares are marked with a circle. Geological treasures of magma, wind, and water 76 77 The action of the Sea Los Hervideros: the sea thundering through the lavas Coastal erosion has affected the historical lava flows of Timanfaya, which are among the most recent on the island of Lanzarote. At the cliff face of Los Hervideros, fissures and hexagonal prisms of columnar jointing can be observed inside the lava flow, which form due to the retraction and loss of volume of the lavas during their cooling and consolidation. This network of fissures allows seawater to penetrate during swells, promoting erosion through these discontinuities and leading to the formation of sea caves, windows, arches, blowholes, and more. On days with strong swells, the compression of the waves within the open fissures forces jets of sea spray, locally known as ‘bufaderos’ or blowholes, to shoot up several meters above the surface of the lava flows, producing a loud roar. Los Hervideros blowholes in action during a day of heavy swell. Los Hervideros in the lava flows of the Timanfaya eruption: 1) The Timanfaya lava flows (17301736) reach the sea along the coast. 2) The lava flows cooled over the following decades from the outside in. 3) The lava flow is fragmented into hexagonal prisms by columnar jointing due to cooling. 4) Coastal erosion dismantles the cliff in favour of the hexagonal columns, creating arches, coastal caves and blowholes. 1 2 3 4 79 Geological treasures of magma, wind, and water The action of the Sea 78 The Alegranza skylight The so-called ‘Jameo de Las Palomas’, in Alegranza islet, is not actually a real skylight, understood as a partial collapse of the roof of a lava tube. This false ‘jameo’ was created by the partial collapse of a coastal cave that developed significantly in length. This cave was formed by wave action along a fracture in the hydromagmatic deposits on the La Caldera’s flank. Throughout the cave, there is a fracture in the center of the roof, likely a remnant of the discontinuity that caused its collapse. The hole in the ceiling, like a large window or skylight, provides a view from the ground into the partially flooded cave. The Jameo de Alegranza is a coastal cave that has a collapsed roof. A view of the interior of the Jameo de Alegranza, which was carved from pyroclastic surges. Ajaches: a shelf exposed above sea level In the Papagayo area, located at the southeastern tip of Lanzarote, highlights a large, flat surface with a gentle slope. This area averages about 40 meters above sea level and connects the Ajaches peaks to the coast. This flat plain is a direct witness to the marine past of this great volcanic edifice during the Pliocene. On the volcanic rocks, several layers of sandstone with marine fossils testify to this part of the island’s submerged past. Over time, the waves and marine currents eroded this shelf, shaping it as though it were crafted by a carpenter’s plane. Later, tectonic processes caused the island to rise from the sea, creating a network of valleys and small ravines that exposed marine levels from the Pliocene period. The Ajaches emerged as a prominent uplifted shelf in the southwest region of Lanzarote. Evolution of a marine shelf on the Ajaches coast. The action of the Sea 8180 Geological treasures of magma, wind, and water Papagayo: a collection of beaches At the Ajaches massif, the small hidden beaches and coves of Papagayo stand out at the mouths of its gullies, featuring clear sands. All of them adapt to the jagged and irregular coastline shaped by the numerous fractures and dykes in the volcanic rocks, which are mostly perpendicular to the coast. The sand is transported from the sea, accumulating on this beach or forming small rampant dunes that rise sloping areas driven by the wind. In coastal regions without gullies, waves erode cliffs, causing sand to accumulate and form small coves. Simplified geological map of Playa Mujeres. Playa Mujeres. These beaches are highly dynamic and frequently change their morphology during storms when gullies carry sediments from inland. Strong winds and high tides can cause beaches to lose sand. However, they typically recover quickly through natural processes. In just a few weeks, they return to their usual paradisiacal appearance, which remains one of the main attractions for visitors on the Geopark. Playa del Papagayo. The white box shows the location of the basaltic dyke, which is further enlarged in the photo on the right. The shaping of the Geopark through rain and landslides 9594 Geological treasures of magma, wind, and water Vega de San José: a valley with no head nor feet This is a large valley that has lost both its headwaters and its mouth. The headwater area became disconnected from the valley by its fluvial the capture by the Barranco de Maramajo, developed on the Famara escarpment. 1.2 million years ago, the eruption of the Guanapay Volcano closed the valley in its final stretch, leaving it as a closed lacustrine basin. Since then, sediments have accumulated at the bottom of the valley, filling up and displaying layers of intercalated soils. This sedimentary basin has traditionally been used on the island as ‘borrow lands’ for sandy crops. The summit of the Guanapay volcano is an excellent viewpoint overlooking the whole valley. The castle of Santa Bárbara was built on this volcano in the 15th century to defend and guard against pirate attacks. Las Laderas: a cliff far from the sea Las Laderas escarpment corresponds to the inland topographic extension of the Famara cliffs. This escarpment is in connection with the main cliff that has become ‘fossilised’ and is no longer connected to the sea. At the base of Las Laderas, huge detrital deposits from the erosion of the old cliff have accumulated, forming alluvial fans. These sediments and the emplacement of Pleistocene lava flows have disconnected this cliff from the coastline. There are two well-differentiated phases of alluvial fans, which evolve into extensive, flat surfaces called glacis, in the area furthest from the main escarpment. The more recent, darker detrital deposits with a gentler slope are formed from the small gullies that cut through the older, light-coloured fans, which rest directly on the escarpment. The San José Valley is a closed basin, transformed into an endorheic valley by the Guanapay Volcano (in the background in the photo). Geological evolution of Las Laderas, due to the progression of alluvial fans and the attached beach-dune system, which triggers the retreat of the cliff from the coastline. Sedimentary fill of the San José floodplain, which has been used as ‘borrow lands’ on the island by farmers. The different colours of the paleosols indicate the change of arid (lighter) and humid (dark reddish) paleoclimates. Las Laderas cliff, viewed from the island of La Graciosa. 97 Lanzarote emerges from the ocean 96 Geological treasures of magma, wind, and water A Geopark that is also underwater 7 A Geopark that is also underwater 9998 Geological treasures of magma, wind, and water LZ65 LZ45 RE01 LZ49 GR04 LZ48 LZ50 El Río y el Río de Montaña Clara, barras que unían islas (GR04) La Marina de Arrecife (LZ50) Roque del Este, el campanario del Atlántico (RE01) Puerto del Carmen, una costa inundada por el mar (LZ48) Charco del Palo, buceando entre grietas (LZ45) Las Bajas, el volcán sumergido (LZ49) Los cimientos de la isla en el fondo oceánico (LZ65) LUGARES DE INTERÉS GEOLÓGICO Km 5 20100 Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo A Geopark that is also underwater From the seabed to the present-day coastline, this Geopark also has geosites to discover. Below sea level, there are unique examples of the large structures that make up the island edifice, such as the island shelf and the island slope that connect with the deepest part of the abyssal plain, as well as other shallower structures related to volcanic, sedimentary, and erosive processes occurring in the marine environment. The most astonishing fact is that some geosites were formed on the surface when the sea level was 120 m below the current level, during the Last Glacial Maximum, only between 23,000 and 19,000 years ago. Due to the low global temperatures, seawater was trapped in glaciers that covered large regions and provoked the growth of the polar ice caps and alpine glaciers. This global Last Glacial Maximum caused sea levels to be much lower than today. The rise of the sea level during the Holocene interglacial period, up to its current position, has determined that many deposits, shapes, and even some volcanoes are now submerged under the sea. LZ65 LZ45 RE01 LZ49 GR04 LZ48 LZ50 El Río y el Río de Montaña Clara, barras que unían islas (GR04) La Marina de Arrecife (LZ50) Roque del Este, el campanario del Atlántico (RE01) Puerto del Carmen, una costa inundada por el mar (LZ48) Charco del Palo, buceando entre grietas (LZ45) Las Bajas, el volcán sumergido (LZ49) Los cimientos de la isla en el fondo oceánico (LZ65) LUGARES DE INTERÉS GEOLÓGICO Km 5 20100 Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo GEOSITES LZ65 LZ45 RE01 LZ49 GR04 LZ48 LZ50 El Río y el Río de Montaña Clara, barras que unían islas (GR04) La Marina de Arrecife (LZ50) Roque del Este, el campanario del Atlántico (RE01) Puerto del Carmen, una costa inundada por el mar (LZ48) Charco del Palo, buceando entre grietas (LZ45) Las Bajas, el volcán sumergido (LZ49) Los cimientos de la isla en el fondo oceánico (LZ65) LUGARES DE INTERÉS GEOLÓGICO Km 5 20100 Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo LZ65 LZ45 RE01 LZ49 GR04 LZ48 LZ50 El Río y el Río de Montaña Clara, barras que unían islas (GR04) La Marina de Arrecife (LZ50) Roque del Este, el campanario del Atlántico (RE01) Puerto del Carmen, una costa inundada por el mar (LZ48) Charco del Palo, buceando entre grietas (LZ45) Las Bajas, el volcán sumergido (LZ49) Los cimientos de la isla en el fondo oceánico (LZ65) LUGARES DE INTERÉS GEOLÓGICO Km 5 20100 Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo LZ65 LZ45 RE01 LZ49 GR04 LZ48 LZ50 El Río y el Río de Montaña Clara, barras que unían islas (GR04) La Marina de Arrecife (LZ50) Roque del Este, el campanario del Atlántico (RE01) Puerto del Carmen, una costa inundada por el mar (LZ48) Charco del Palo, buceando entre grietas (LZ45) Las Bajas, el volcán sumergido (LZ49) Los cimientos de la isla en el fondo oceánico (LZ65) LUGARES DE INTERÉS GEOLÓGICO Km 5 20100 Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo LZ65 LZ45 RE01 LZ49 GR04 LZ48 LZ50 El Río y el Río de Montaña Clara, barras que unían islas (GR04) La Marina de Arrecife (LZ50) Roque del Este, el campanario del Atlántico (RE01) Puerto del Carmen, una costa inundada por el mar (LZ48) Charco del Palo, buceando entre grietas (LZ45) Las Bajas, el volcán sumergido (LZ49) Los cimientos de la isla en el fondo oceánico (LZ65) LUGARES DE INTERÉS GEOLÓGICO Km 5 20100 Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo The foundations of these islands on the ocean floor (LZ65) Las Bajas: an underwater volcano (LZ49) Charco del Palo: diving among the crevices (LZ45) Port of El Carmen: a coast flooded by the sea (LZ48) Roque del Este: the Atlantic bell tower (RE01) Arrecife Marina (LZ50) The River: sand bars linking islands (GR04) LZ65 LZ45 RE01 LZ49 GR04 LZ48 LZ50 El Río y el Río de Montaña Clara, barras que unían islas (GR04) La Marina de Arrecife (LZ50) Roque del Este, el campanario del Atlántico (RE01) Puerto del Carmen, una costa inundada por el mar (LZ48) Charco del Palo, buceando entre grietas (LZ45) Las Bajas, el volcán sumergido (LZ49) Los cimientos de la isla en el fondo oceánico (LZ65) LUGARES DE INTERÉS GEOLÓGICO Km 5 20100 Esri, TomTom, Garmin, Foursquare, METI/NASA, USGS; Esri, NASA, NGA, USGS * Los LIG con una superficie menor de 10 Ha se han representado con un círculo * Geosites with an area of less than 10 hectares are marked with a circle. A Geopark that is also underwater 101100 Geological treasures of magma, wind, and water The foundations of the island on the ocean floor The Lanzarote and the Chinijo Island UNESCO Global Geopark are connected to Fuerteventura under the sea through a shallow shelf about 100 m deep, creating a single island structure in the past. The continuous action of the Atlantic Ocean has shaped the island coasts and formed an insular shelf. On the western coast of the Geopark, from the edge of this shelf, an island slope with a gradual dip extends down to the abyssal plain over a width of 19-29 km, which is cut by canyons and dotted with submerged volcanoes, some of which are related to eruptions during the Last Glacial Maximum. However, on the southeast coast of Lanzarote, at the edge of the shelf, the island slope is located, which on this side is almost vertical, connecting to the abyssal plain at a depth of 1,000 m, just a couple of kilometers from the coast. This vertical slope is related to the great faults that cross between the Canary Islands and Africa. Las Bajas: the submerged volcano About 800 m from Famara Beach there is a breakwater area, called Las Bajas, where some black basaltic rock edges and ridges emerge. They are the remains of a volcano that was formed on the island´s surface during the Last Glacial Maximum, and which has been almost submerged due to the global sea rise during the Holocene. The summit of the volcano is intensely eroded, although the feed dykes can still be distinguished, opening towards the northwest. Bathymetry map of this seabed, can be interpreted that at least two lava flows were emitted from this volcano, which covered a surface area of more than 12 km2, similar to that of the current Alegranza islet. In pink: the island shelf of the Geopark. In blue: the steeper eastern island slope. In green: the western island slope, dotted with volcanoes and canyons. In the foreground, rising from the seabed, are the eroded remains of the Las Bajas volcano. It was submerged during the Holocene. A Geopark that is also underwater 103102 Geological treasures of magma, wind, and water Charco del Palo: diving among the crevices During the Holocene eruption of the Guatiza Caldera, its lava flows reached the coast, forming a lava delta that advanced into the sea. These lava deltas tend to be very unstable due to their rapid growth and interaction with the marine currents, which often leads to broke lavas, and even the collapse of their most distal parts to the abyssal floor. In the submerged area near Charco del Palo, the lava delta can be observed, along with some fine deposits of hyaloclastites (accumulations of fragmented magma deposited in a marine environment) and morphologies that suggest the presence of pillow lavas. Of particular note are the numerous fractures that cut through the delta, known as ‘streets’ to divers, which allow them to swim through the delta lavas. Puerto del Carmen: a coast flooded by the sea Diving off the coast of Puerto del Carmen is like walking through a museum of coastal erosive shapes. The underwater caves, such as La Catedral, the erosive tubes or the prismatic joint columns of lava flows from the Middle Pleistocene, are spectacular. The most unique morphologies of this underwater environment are the mushroom-shaped volcanic monoliths. In reality, it is a succession of erosive landforms, in which one in particular has reached its maximum development, and being completely detached from the wall, it is recognisable from a distance and is striking for its shape, so different from its surroundings. Mushroom-like erosional morphologies. A Geopark that is also underwater 105104 Geological treasures of magma, wind, and water Roque del Este: the bell tower of the Atlantic Roque del Este is a crescent-shaped islet, barely reaching 85 m in height, whose southern back forms a wide arc open to the original crater. The islet is the remains of a highly eroded hydromagmatic edifice, in which the internal structure of the volcano can be seen, with the typical features, colours, textures, and structures of hydromagmatic deposits, including the feeder dykes. One of these dykes emerges at the northeastern end of the arc, creating a topographic prominence known as ‘El Campanario’ (The Bell Tower), precisely because of its tower-like shape. Under the sea, this dyke forms the wall of a spectacular underwater tunnel about 80 m in length that completely crosses the islet from one side to the other. This islet is a hotspot for biodiversity and has the highest legal protection, so visiting it is restricted to research expeditions only. Arrecife Marina Arrecife, the capital of Lanzarote, is located on an ancient lava flow, whose surface was intensely eroded by the sea, creating a shallow marine shelf dotted with pools and rocky islets that currently protect the coast from waves and ocean currents. This natural protection was one of the reasons for building the port and moving the island’s capital from Teguise to Arrecife. The low slope of the platform means that the tidal range is wider than in other coastal areas of this island, leaving a large surface exposed during low tide. At the lowest points, cream-coloured sandstones with fossils are uncovered on the marine platform, which are evidence of ancient beaches that coexist with a striking network of fractures. Roque del Este islet. Dotted line and white arrow indicating the location of the Bell Tower dyke. Sandstones and beach-rocks on the platform that are exposed during low tide.Black dyke that forms The Bell Tower in the Roque del Este islet. A Geopark that is also underwater 107106 Geological treasures of magma, wind, and water El Río and Montaña Clara: bars that connected islands The global sea rise during the Holocene has left other submerged geosite in the Geopark. This is the case of the sand bars or ridges that linked Lanzarote to La Graciosa, which in turn linked it to Montaña Clara. These sandstone bars are currently about 20 m deep and show structures that suggest the existence of sand fields evolving into aeolian dunes. The bars show intense erosion typical of coastal environments, so they must have been exposed to the onslaught of waves for a considerable time during the Last Glacial Maximum. El Río, located between the islands of Lanzarote and La Graciosa (in the background). 109108 Lanzarote emerges from the oceanGeological treasures of magma, wind, and water The biodiversity hidden in the rocks 8 Lanzarote emerge del océano 111110 Geological treasures of magma, wind, and water The biodiversity hidden in the rocks Palaeontological sites and the fossils they contain are of high scientific value and fragility. These factors determine that in this book, the geosites of palaeontological interest are not disclosed, promoting their preservation. However, contrary to what many believe, in this oceanic volcanic Geopark, there are also fossiliferous outcrops that allow to infer its palaeobiodiversity and paleoclimate throughout its geological history, long before the arrival of humans to the archipelago. The main types of geosites in Lanzarote and Chinijo Islands are fossil beaches, paleodunes, and paleosols. They contain fossils of corals, marine and terrestrial molluscs, remains of several species of vertebrates, some of which are endemic. Please, never collect fossils, as by doing so, we irreversibly lose a link to the past. 113 Lanzarote emerges from the ocean 112 Geological treasures of magma, wind, and water Glossary 9