Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title> <jats:p>Plio-Pleistocene records of ice-rafted detritus suggest northwest European ice sheets regularly reached coastlines. However, these records provide limited insight on the frequency, extent, and dynamics of ice sheets delivering the detritus. Three-dimensional reflection seismic data of the northwest European glaciated margin have previously documented buried landforms that inform us on these uncertainties. This paper reviews and combines these existing records with new seismic geomorphological observations to catalogue landform occurrence along the European glaciated margin and considers how they relate to ice sheet history. The compilation shows Early Pleistocene ice sheets regularly advanced across the continental shelves. Early Pleistocene sea level reconstructions demonstrate lower magnitude fluctuations compared to the Middle-Late Pleistocene, and more extensive/frequent Early Pleistocene glaciation provides a possible mismatch with sea level reconstructions. This evidence is discussed with global records of glaciation to consider possible impacts on our wider understanding of Plio-Pleistocene climate changes, in particular how well Early Pleistocene sea level records capture ice sheet volume changes. Resolving such issues relies on how well landforms are dated, whether they can be correlated with other proxy datasets, and how accurately these proxies reconstruct the magnitudes of past climatic changes. Many questions about Pleistocene glaciation in Europe and elsewhere remain.</jats:p>

<jats:title>Abstract</jats:title> <jats:p> In this paper, we trace the saga of the rocks and fossils discovered along Stevenson Road, northern Malawi. Fish and bivalves discovered along the road were proclaimed the first fossils of Central Africa. In the late nineteenth and early twentieth centuries, they became a large part of the ‘Tanganyika Problem’, the notion of whether a Jurassic incursion of the sea left fossils in what is now Malawi and relict marine invertebrates in Lake Tanganyika. Later studies clarified both the geology and zoology of the region, but no more informative fossils were found in Malawi until 2016 when a specimen of <jats:italic>Eunotosaurus</jats:italic> was discovered by a herdsman in the original nineteenth century fossil locality. He presented the fossil to the Cultural and Museum Centre Karonga, the public face of geoheritage in Malawi. That specimen constrains the upper age limit of the site to approximately 259 Ma (Late Permian). The Tanganyika Problem is now largely of historical interest, yet in a more current multidisciplinary context – the timing and mechanisms of the evolutionary transition of clades from the marine realm into freshwater biomes open new questions about historical biogeography in a geological context. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>Sites of geological relevance in East Portland are representative of the geological history of Jamaica and are important to elucidate Caribbean geotectonic evolution. Geological significance overlaps with natural and cultural heritage of international relevance, especially related to Maroon communities. In this region, the Jamaican highest peak rises steeply from sea level; the ocean is the focus of important conservation efforts. This study employs an interpretative phenomenological analysis to explore place attachment as experienced by East Portland residents. We engaged in conversations with 16 diverse community members through interviews and a focus group. Two dimensions of place attachment emerged: place identity and place dependence, showing that East Portland is home to people who depend on, identify with and are committed to protecting nature. We present an approach to mapping place attachment, which resulted in an important tool of analysis when overlapping with layers of information like geoheritage. The geological significance, natural and cultural richness and the connections the locals have with nature make East Portland an ideal prototype for geoconservation. This study also reveals that attachment to a place does not necessarily correspond to attachment to geoscientific significance; for common meanings to emerge, geoscientists and locals must collaborate.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Compared to other continents, the study of indigenous (non-western) knowledge of palaeontology in Africa is a relatively new field. The literature reviewed here nevertheless suggests a long-lasting string of traditions, geomyths and folklore related to fossilised items on the whole continent and encompassing many African cultures. It is often difficult to estimate the antiquity of these traditions, but the evidence gathered here suggests that they range from the 1800s to pre-colonial times, and up to many millennia. Palaeontological items were collected and used for a variety of reasons, but the African record seems unusual for its scarce use of fossils for traditional medicine. Also, despite substantial efforts, some famous localities with conspicuous fossils still remain without any documented indigenous knowledge. We stress that documenting fossil-related folklore and geomyths is not only a matter of preserving this knowledge or promoting diversity, but is also crucial for establishing strong bonds with local stakeholders to encourage preservation of geoheritage and discover new sites.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Fossil trackways in the Jura-Triassic rift basin of the Connecticut River Valley are important to geoheritage for their quality, preservation, and role in the history of geology, especially of ichnology. Discovered in the early 1800s, these trackways of small to large, bipedal, three-toed animals came to the attention of Edward Hitchcock, a prolific geologist and natural theologian. His first publication on the subject was in January 1836 and, in the same year, William Buckland included parts of the report, with illustrations, in his Bridgewater Treatise. Hitchcock and Buckland are credited with establishing the field of ichnology, the study of track and trails. Within the first decade, other traces documented include four-footed tracks, fish fossils, invertebrate burrows, plant impressions, ripple marks and raindrop impressions; few bones have ever been discovered in the valley. Early fossil-track collectors included Hitchcock, James Deane, Dexter Marsh and Roswell Field. Specimens quickly made their way to Europe, and publications brought the tracks to international attention, in both science and literature. In nineteenth-century discussions, the three-toed trackway makers – birds or dinosaurs? – were particular subjects of interest and debate. These fossil trackways remain well known and studied today, with several preserved field sites and museum collections.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Outcropping sedimentary deposits of the Potwar Plateau in northern Pakistan comprise the most complete record of Neogene Siwalik rocks and faunas to be found in the Indian subcontinent documenting an extraordinary record of terrestrial vertebrate fossils for the Miocene Epoch. The Potwar Plateau is a portion of the Siwalik Hills, the mountainous terrane of the outer Himalayas extending over 2000 km across the northern margin of the Indian subcontinent. Siwalik strata accumulated as a molassic sedimentary wedge shed southward with the erosion of the rising crust as it was uplifted via plate tectonics. The long Potwar record of numerous superposed assemblages of fossil vertebrates preserves a history spanning many millions of years, and constitutes a unique geoheritage resource for Asia and for the world. The record can be dated and interpreted with a high degree of precision rarely achieved in terrestrial settings. The Potwar Siwalik sediments document 18 million years of change in the subtropical ecosystem of South Asia, in which global to regional climate change directly impacted terrestrial palaeofloras and palaeofaunas, forcing coevolution of elements of the terrestrial food web, and with that the modernization of mammalian groups. The potential to trace coincidence of abiotic changes with evolution within lineages is unusual.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The Pliocene fossiliferous succession of the Volterra hill, a prominent place in Tuscany, Italy and, since the Renaissance, the site of important archaeological finds of the ancient Etruscan civilization, has formed the object of enquiry over six centuries of research on the inner nature of the Earth system. The works of Restoro d'Arezzo, Leonardo da Vinci, Nicolaus Steno, Giovanni Targioni, Nicolas Desmarest, Giambattista Brocchi, Alexandre Brongniart and Charles Lyell testify to the early recognition through fieldwork that those strata with seashells had formed at the bottom of the sea. This interpretation served different approaches to knowledge. Restoro, Leonardo and Steno, spanning nearly four centuries in the history of science (1282–1669), including the ‘Copernican Revolution’ and the start of the Modern Age, relied also on textual sources and trusted a speculative model of the Earth's interior, so that at Volterra they focused on vertical movements of the earth–water system. The authors of the eighteenth and nineteenth centuries abandoned pre-built young-Earth models and emphasized the geography of ancient Tuscany. Brocchi, Brongniart and Lyell promoted the taxonomic use of seashells to correlate rocks across Europe. This place deserves higher standards of valorization to promote understanding of the history and sociology of ideas.</jats:p>

<jats:title>Abstract</jats:title> <jats:p> The main Karoo Basin of South Africa and Lesotho preserves <jats:italic>c.</jats:italic> 120 myr of Earth's history. The sedimentary rocks of its Karoo Supergroup record massive environmental changes from the glacial Carboniferous to desert dunes and fiery flood basalts in the Early Jurassic. From the early Permian, the Karoo Basin was gradually filled with fluvial and lacustrine deposits, and the alluvial plains were successively colonized by a diverse suite of plants and animals. The fossils of these ancient inhabitants and their behavioural traces form an astounding Gondwanan geoheritage legacy in southern Africa, providing fossil evidence for the moving lithospheric plates and the effects of four mass extinctions and their subsequent biotic recovery. Here, we present six Karoo sites of global geoscientific importance that best display that heritage, with the caveat that these sites only touch upon the Karoo riches that are available for academic research and the emerging palaeotourism industry. It is our hope that these sites will become anchor points for a sustainable geoheritage future in southern Africa. </jats:p>

<jats:title>Abstract</jats:title> <jats:p> The Oligocene-Miocene Catahoula Formation occurs along the length of the Gulf of Mexico coastal plain from the Rio Grande to the state of Mississippi. In Starr County, in south Texas, the formation is typified by the 20-meter-thick Catahoula Volcanic Ash, interpreted to represent a single caldera eruption. The massive ash fall is the main source of the uranium that has been mined in South Texas since the late 1950's. It is also the origin of massive amounts of petrified wood, which was used in prehistory for making projectile points and continues to be used for landscaping. Diagenetic alteration of the volcanic ash produced the distinctive El Sauz Chert, which was used by native Americans for 10,000 years to make projectile points. More recently, the Catahoula Volcanic Ash was used as pozzolanic aggregate with Portland cement for the construction of Falcon Dam. The outcrop of the Catahoula Volcanic Ash in Starr County is the centerpiece of a geoheritage initiative, titled <jats:italic> <jats:bold>Ancient Landscapes of South Texas at the Nexus of Natural and Cultural History</jats:bold> </jats:italic> , whose goal is to connect the earth and social sciences to educate residents, students and visitors in how the region's geology has played a significant role in its social history. </jats:p>

<jats:title>Abstract</jats:title> <jats:p> Ancient human footprints have been known from Managua, Nicaragua, since the 1880s. The main footprint site, long preserved in the Acahualinca Tracks Museum ( <jats:italic>Huellas de Acahualinca</jats:italic> ), reveals hundreds of human footprints that represent a minimum of 12 clearly defined trackways and a trampled trail or path. Deer, opossum and bird tracks are also present at Acahualinca, and bison and tapir tracks have been documented from the nearby and stratigraphically equivalent El Recreo site. The age of the Acahualinca footprints is controversial, but the best current estimate is about 2–2.2 ka BP. The Acahualinca site is one of the most scientifically important human footprint sites known from the Holocene. It exhibits footprints that are very abundant, well-preserved, accessible for study and part of a large sample that demonstrates variation within a single population. The Acahualinca site has historical, cultural and archaeological importance in preserving at least two intervals of human occupation, that of the footprints and of the ceramics in much younger layers. Its significance to anthropology and palaeontology as a sub-fossil footprint locality is clear and the volcanological history of the area is intimately related to determining the age and the circumstances of footprint registration at Acahualinca. The Acahualinca footprints merit geoheritage status. </jats:p>