The PLATES 2020 Atlas of Plate Reconstructions (500 Ma to Present Day), PLATES Progress Report No. 396-1220

This atlas presents plate reconstructions from 500 Ma to the present-day derived by the PLATES Project, Institute for Geophysics, The University of Texas at Austin. The atlas was made possible through the scientific contributions of many researchers, from UTIG and from other institutions. Their efforts are highly appreciated by the members of the PLATES research team. The atlas was created using the PaleoGIS (paleogis.com) for ArcGIS plate reconstruction software by The Rothwell Group, L.P., and the GPlates (http://www.gplates.org/) plate reconstruction software. For more information, contact [email protected] Project, Institute for Geophysics, The University of Texas at AustinInstitute for Geophysic

Provenance analysis of Paleozoic strata in the Falkland/Malvinas Islands: implications for paleogeography and Gondwanan reconstructions

New U-Pb geochronological, Hf isotopic, heavy mineral, and sandstone petrographic results for Paleozoic clastic deposits of the Falkland/Malvinas Islands help address renewed debates on the plate tectonic history, regional paleogeography, and basin evolution of this geologic enigma prior to Mesozoic breakup of Gondwana. The Falkland/Malvinas Islands have been considered either an autochthonous part of the South American continent or part of an independent microplate displaced from the southeastern corner of Africa. We report detrital zircon U-Pb results (n = 1306 LA-ICPMS ages) for 11 sandstone samples from the Silurian-Devonian West Falkland Group (N = 7 samples, n = 837 grains) and Carboniferous-Permian Lafonia Group (N = 4 samples, n = 469 grains). Detrital zircon age distributions for the West Falkland Group point to consistent contributions from Neoproterozoic-Cambrian (650–520 Ma) and Mesoproterozoic (1100–1000 Ma) sources. Heavy mineral assemblages and sandstone petrographic data from these samples indicate significant input from recycled sediments. A potential shift in sediment sources during deposition of the Lafonia Group is indicated by the appearance of late Paleozoic (350–250 Ma) and Proterozoic (2000–1200 Ma) age populations, decreased proportions of stable heavy minerals, and a shift to juvenile Hf values for < 300 Ma zircons. The provenance change can be attributed to the onset of subduction-related arc magmatism and potential regional shortening and crustal thickening in southwestern Gondwana during the Permian transition of a passive margin into an active, retro-arc foreland basin. The detrital zircon age distributions identified here reflect potential source regions in southern Africa and/or the Transantarctic Mountains in Antarctica. These results are most readily accommodated within a Gondwana reconstruction that includes the Falkland/Malvinas Islands as a rotated microplate originating on the eastern side of southern Africa as part of the Gondwanide fold-thrust belt spanning from the Ventania region of Argentina through the Cape region of South Africa and into the Ellsworth and Pensacola mountains of Antarctica

Drake-Scotia Sea gateways: onset and evolution of the Drake Passage and Scotia Sea, implications for global ocean circulation and climate

Australasian IODP Regional Planing Workshop (2017. Sidney)Instituto Geológico y Minero de España, EspañaInstituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Científicas, EspañaIstituto Nazionale di Oceanografia e Geofisica Sperimentale, ItaliaSan Diego State University, Estados UnidosPeer reviewe

Onset and development of the Drake Passage and Scotia Sea gateways and its influence on global ocean circulation and climate (IODP proposal)

The DRAKE-SCOTIA SEA GATEWAYS is a new multidisciplinary International Ocean Discovery Program (IODP) drilling proposal aimed at determining the time of opening and pattern of development of gateways in the Drake Passage and the adjacent Scotia Sea, and their influence on global ocean circulation, biotic evolution and climate. The Drake Passage with the adjacent Scotia Sea represent one of Earth’s most important oceanic gateways, between the southern tip of South America and the Antarctic Peninsula, a crucial area for water mass exchange between the Pacific Ocean, the Atlantic Ocean and the Weddell Sea, the importance of which is evidence by in many multinational studies. Nevertheless, the region has not been yet drilled for scientific purposes. The objective of this work is to present the main scientific goals of this drilling proposal and its link with the IODP Science Plan for 2013-2023.Department of Earth Sciences, Royal Holloway University, Reino UnidoBritish Antarctic Survey, Reino UnidoDepartment og Geology and Geophysics, Yale University, Estados UnidosGeophysical Department, Geological Survey of Denmark and Greenland, DinamarcaAlfred Wegener Institute, Helmholtz for Polar and Marine Research, AlemaniaInstituto Geológico y Minero de España, EspañaOcean and Earth Science, University of Southampton, Reino UnidoUniversity Texas at Austin, Estados UnidosInstitute of Petroleum Engineering, Heriot-Watt University, Reino UnidoInstituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Científicas, EspañaInstituto Andaluz de Ciencias de la Tierra, Universidad de Granada, EspañaCollege of Earth, Ocean and the Environment, University of Delaware, Estados UnidosUniversity New South Wales, AustraliaUniversity Nebraska-Lincoln, Estados UnidosUniversidad de Buenos Aires, Argentin

Outline of the structural and tectonic history of the Ellsworth Mountains-Thiel Mountains Ridge, West Antarctica

The Ellsworth Mountains‐Thiel Mountains ridge and adjoining areas are divided into three tectonic provinces: (1) Haag Nunataks, (2) Thiel Mountains, and (3) Ellsworth‐Whitmore Mountains crustal block. Haag Nunataks are part of a Precambrian tectonic province the overall extent of which is not clearly known. The Thiel Mountains are part of a distinctive Transantarctic Mountains province that is separated by a major tectonic break from deformed sedimentary rocks of the Ellsworth‐Whitmore Mountains crustal block. The crustal block is divided, on the basis of a detailed structural analysis, into two domains: the Ellsworth and Marginal domains. The sedimentary rocks throughout the Ellsworth domain are correlated with parts of the Paleozoic succession forming the Ellsworth Mountains themselves. These rocks were all deformed by a single phase of northwest‐southeast trending structures, whereas in the Marginal domain the fold history is more complex and structures trend northeast‐southwest. The tectonic significance of the Marginal domain is discussed but is not clearly understood. Mount Woollard has a unique lithological association with the Ellsworth‐Whitmore Mountains crustal block; it consists of paragneiss and pegmatite of possible Middle Jurassic age and has a structural trend parallel to the Ellsworth domain structures