A mantle plume is a proposed mechanism of convection within the Earth's mantle, hypothesized to explain anomalous volcanism. Because the plume head partially melts on reaching shallow depths, a plume is often invoked as the cause of volcanic hotspots, such as Hawaii or Iceland, and large igneous provinces such as the Deccan and Siberian Traps. Some such volcanic regions lie far from tectonic plate boundaries, while others represent unusually large-volume volcanism near plate boundaries.
In geology and physical geography, a plateau, also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side. Often one or more sides have deep hills or escarpments. Plateaus can be formed by a number of processes, including upwelling of volcanic magma, extrusion of lava, and erosion by water and glaciers. Plateaus are classified according to their surrounding environment as intermontane, piedmont, or continental. A few plateaus may have a small flat top while others have wider ones.
The Altiplano, Collao or Andean Plateau, in west-central South America, is the most extensive high plateau on Earth outside Tibet. The plateau is located at the latitude of the widest part of the north–south-trending Andes. The bulk of the Altiplano lies in Bolivia, but its northern parts lie in Peru, and its southwestern fringes lie in Chile.
Tectonic uplift is the geologic uplift of Earth's surface that is attributed to plate tectonics. While isostatic response is important, an increase in the mean elevation of a region can only occur in response to tectonic processes of crustal thickening, changes in the density distribution of the crust and underlying mantle, and flexural support due to the bending of rigid lithosphere.
The geology of Chile is a characterized by processes linked to subduction, such as volcanism, earthquakes, and orogeny. The building blocks of Chile's geology were assembled during the Paleozoic Era when Chile was the southwestern margin of the supercontinent Gondwana. In the Jurassic, Gondwana began to split, and the ongoing period of crustal deformation and mountain building known as the Andean orogeny began. In the Late Cenozoic, Chile definitely separated from Antarctica, and the Andes experienced a significant rise accompanied by a cooling climate and the onset of glaciations.
The Andean orogeny is an ongoing process of orogeny that began in the Early Jurassic and is responsible for the rise of the Andes mountains. The orogeny is driven by a reactivation of a long-lived subduction system along the western margin of South America. On a continental scale the Cretaceous and Oligocene were periods of re-arrangements in the orogeny. The details of the orogeny vary depending on the segment and the geological period considered.
The geology of Bolivia comprises a variety of different lithologies as well as tectonic and sedimentary environments. On a synoptic scale, geological units coincide with topographical units. The country is divided into a mountainous western area affected by the subduction processes in the Pacific and an eastern lowlands of stable platforms and shields. The Bolivian Andes is divided into three main ranges; these are from west to east: the Cordillera Occidental that makes up the border to Chile and host several active volcanoes and geothermal areas, Cordillera Central once extensively mined for silver and tin and the relatively low Cordillera Oriental that rather than being a range by its own is the eastern continuation of the Central Cordillera as a fold and thrust belt. Between the Occidental and Central Cordillera the approximately 3,750-meter-high Altiplano high plateau extends. This basin hosts several freshwater lakes, including Lake Titicaca as well as salt-covered dry lakes that bring testimony of past climate changes and lake cycles. The eastern lowlands and sub-Andean zone in Santa Cruz, Chuquisaca, and Tarija Departments was once an old Paleozoic sedimentary basin that hosts valuable hydrocarbon reserves. Further east close to the border with Brazil lies the Guaporé Shield, made up of stable Precambrian crystalline rock.
The Karakoram fault is an oblique-slip fault system in the Himalayan region across India and Asia. The slip along the fault accommodates radial expansion of the Himalayan arc, northward indentation of the Pamir Mountains, and eastward lateral extrusion of the Tibetan plateau. Current plate motions suggest that the convergence between the Indian Plate and the Eurasian Plate is around 44±5 mm per year in the western Himalaya-Pamir region and approximately 50±2 mm per year in the eastern Himalayan region.
The Altiplano–Puna volcanic complex, also known as APVC, is a complex of volcanic systems in the Puna of the Andes. It is located in the Altiplano area, a highland bounded by the Bolivian Cordillera Real in the east and by the main chain of the Andes, the Western Cordillera, in the west. It results from the subduction of the Nazca Plate beneath the South American Plate. Melts caused by subduction have generated the volcanoes of the Andean Volcanic Belt including the APVC. The volcanic province is located between 21° S–24° S latitude. The APVC spans the countries of Argentina, Bolivia and Chile.
Cerro Guacha is a Miocene caldera in southwestern Bolivia's Sur Lípez Province. Part of the volcanic system of the Andes, it is considered to be part of the Central Volcanic Zone (CVZ), one of the three volcanic arcs of the Andes, and its associated Altiplano-Puna volcanic complex (APVC). A number of volcanic calderas occur within the latter.
Clumped isotopes are heavy isotopes that are bonded to other heavy isotopes. The relative abundance of clumped isotopes (and multiply-substituted isotopologues) in molecules such as methane, nitrous oxide, and carbonate is an area of active investigation. The carbonate clumped-isotope thermometer, or "13C–18O order/disorder carbonate thermometer", is a new approach for paleoclimate reconstruction, based on the temperature dependence of the clumping of 13C and 18O into bonds within the carbonate mineral lattice. This approach has the advantage that the 18O ratio in water is not necessary (different from the δ18O approach), but for precise paleotemperature estimation, it also needs very large and uncontaminated samples, long analytical runs, and extensive replication. Commonly used sample sources for paleoclimatological work include corals, otoliths, gastropods, tufa, bivalves, and foraminifera. Results are usually expressed as Δ47 (said as "cap 47"), which is the deviation of the ratio of isotopologues of CO2 with a molecular weight of 47 to those with a weight of 44 from the ratio expected if they were randomly distributed.
Lauca is a 5,140 metres (16,860 ft) high andesitic stratovolcano in the Central Volcanic Zone of the Andes on the Altiplano in northern Chile. Administratively it is located in Putre, Arica y Parinacota Region. The volcano was active during the Late Miocene from 10.5 million years ago onwards. A major ignimbrite collapsed the volcano in the Late Pliocene.
In geology, orogenic collapse is the thinning and lateral spread of thickened crust. It is a broad term referring to processes which distribute material from regions of high gravitational potential energy to regions of low gravitational potential energy. Orogenic collapse can begin at any point during an orogeny due to overthickening of the crust. Post-orogenic collapse and post-orogenic extension refer to processes which take place once tectonic forces have been released, and represent a key phase of the Wilson Cycle, between continental collision and rifting.
Brian K. Horton is an American geologist, currently the Alexander Deussen Professor of Energy Resources at the Jackson School of Geosciences, University of Texas at Austin. He studies sedimentary geology and tectonics, with emphasis on foreland basins and fold and thrust belts. His research addresses nonmarine depositional systems, sediment provenance, river catchment evolution, and mountain building along convergent plate margins, with a focus on the evolution of the Andes Mountains and Amazon Basin. Horton received the Geological Society of America Donath Medal in 2004, an Alexander von Humboldt Foundation fellowship in 2005-2006, and the Society for Sedimentary Geology (SEPM) William R. Dickinson Medal in 2018. He is a fellow of the Geological Society of America and the Alexander von Humboldt Foundation.
Suzanne Mahlburg Kay is the William & Katherine Snee Professor of Geological Sciences at Cornell University. She studies the origin and evolution of the continental crust. She is a Fellow of the Geological Society of America, the American Geophysical Union and the Mineralogical Society of America.
The paleogeography of the India–Asia collision system is the reconstructed geological and geomorphological evolution within the collision zone of the Himalayan orogenic belt. The continental collision between the Indian and Eurasian plate is one of the world's most renowned and most studied convergent systems. However, many mechanisms remain controversial. Some of the highly debated issues include the onset timing of continental collision, the time at which the Tibetan plateau reached its present elevation and how tectonic processes interacted with other geological mechanisms. These mechanisms are crucial for the understanding of Mesozoic and Cenozoic tectonic evolution, paleoclimate and paleontology, such as the interaction between the Himalayas orogenic growth and the Asian monsoon system, as well as the dispersal and speciation of fauna. Various hypotheses have been put forward to explain how the paleogeography of the collision system could have developed. Important ideas include the synchronous collision hypothesis, the Lhasa-plano hypothesis and the southward draining of major river systems.
Julie Carol Libarkin is a professor of Earth Sciences and Director of the Geocognition Laboratory at Michigan State University. Her research considers how people understand and make decision about the planet. She is a Fellow of the Geological Society of America. She also researches and addresses inequality in academia, and tracks academic sexual misconduct cases.
Earth system interactions across mountain belts are interactions between processes occurring in the different systems or "spheres" of the Earth, as these influence and respond to each other through time. Earth system interactions involve processes occurring at the atomic to planetary scale which create linear and non-linear feedback(s) involving multiple Earth systems. This complexity makes modelling Earth system interactions difficult because it can be unclear how processes of different scales within the Earth interact to produce larger scale processes which collectively represent the dynamics of the Earth as an intricate interactive adaptive system.
Delores Marie Robinson is an American geologist and tectonicist who is a professor and department chair at the University of Alabama. Her research considers how orogenic systems evolve from porto-magmatic arcs, with a particular focus on Western Nepal, India, Bhutan and Southern Tibet.
Teresa (Terry) Jordan is a sedimentary geologist known for her research on the geology and hydrology of the Atacama Desert and the use of water and geothermal heat from sedimentary rocks.
