From source-to-sink: The Late Permian SW Gondwana paleogeography and sedimentary dispersion unraveled by a multi-proxy analysis

Abstract

The Late Permian sedimentary succession of the Paran a Basin, southern Brazil, provide a valuable source of information about sediment provenance, tectonic processes and, consequently, the paleogeography of the southwestern Gondwana supercontinent. In order to understand the patterns of sedimentary dispersal and reconstruct the Late Permian source-to-sink dynamic, we report a complete series of U-Pb ages and Hf isotopic compositions of detrital zircons from the Rio do Rasto Formation sandstones allied with detailed paleocurrent and sedimentologic data. Our integrated provenance study reveals a consistent sediment transport from the south to the north and northwest. According to the evaluation of zircon ages and Hf isotopes, it was possible to determine four distinct source areas: (i) a distant Late Paleozoic active magmatic arc located in the southwestern Gondwana margin (i.e. Gondwanides Orogen), corresponding to the North Patagonian Massif; (ii) recycling of orthoquartzites from the uplifted Paleozoic Ventania Fold Belt and immature sandstones from the Claromec o Foreland Basin in centraleastern Argentina and the Silurian-Devonian successions of the southern Paran a Basin (central-northern Uruguay) and North Patagonian Massif; (iii) exhumed areas of the Archean-Paleoproterozoic basement and Neoproterozoic to Early Paleozoic mobile belts of the Damara in southwestern Africa and Ribeira Fold Belt in Uruguay and southern Brazil; and (iv) southeastward provenance of Grenvillian (1.2 e1.0 Ga) zircons coming from the mafic to intermediate Mesoproterozoic igneous units of the Namaqua-Natal Belt in South Africa and Namibia. These data allow us to argue that sediments deposited in the Paran a Basin during the Late Permian come from both short-and long-distance source areas. In this context, an important population of Permian detrital zircons comes from the Gondwanides Orogen in the south, probably carried by transcontinental alluvial systems. Close to the source area, antecedent river channels would have eroded older sedimentary rocks of the Ventania Fold Belt, Claromec o and Chaco-Paran a basins and North Patagonian Massif, crosscutting a peripheral bulge and flowing towards the alluvial plain of the intraplate setting to areas further north. Concomitantly, these sediments are reworked by strong winds that even helped carrying the grains to the Paran a Basin depositional site.

Reply to the comments on: “From source-to-sink: The Late Permian SW gondwana paleogeography and sedimentary dispersion unraveled by a multi-proxy analysis” [journal of South American earth sciences 70 (2016) 368–382] by Vesely & Schemiko

“…In the offshore of the Pennsylvanian to Lower Triassic Hesp erides Basin of Argentina, P angaro et al 2015described a large (hundreds of kilometers) submarine lobe complex that progradated to the NE direction. In this way, our recent published paper (Alessandretti et al, 2016) is in complete consonance with the paleogeographic reconstructions proposed by recent works as P angaro et al (2015) for the Hesp erides Basin, Andersen et al (2016) for the Karoo Basin, and Zerfass et al (2003Zerfass et al ( , 2004 and Canile et al (2016) for the Paran a Basin.…”

“…The formation of the Gondwanides Orogen (Keidel, 1916) in southern Gondwana reordered the whole arrangement of the Late Paleozoic drainage system, catchment areas and, consequently, altered the sediment dispersion pattern. These remarkable paleogeographic modifications resulted in changes in the stratigraphic architecture of the southwestern Gondwana basins during the Late Permian to Early Triassic (Andreis and Cladera, 1992;L opez-Gamundí et al, 1995, Zerfass et al, 2004Limarino et al, 2013;Ramos et al, 2013;Alessandretti et al, 2016). As mentioned by Vesely & Schemiko (this issue), the sedimentary succession of the Rio do Rasto Formation is chronocorrelated and contiguous to the Gai-As Formation in northern Namibia (Stollhofen et al, 2000).…”

“…Vesely and Schemiko (2016, this issue) criticize the sedimentologic data and provenance interpretation presented by us (Alessandretti et al, 2016), putting in question our interpretations of the sedimentary sources and sedimentary dispersal pattern during the Permian of the Paran a Basin. In this reply we show how the comments are not well grounded on robust sedimentological information and a careful examination of key previous studies.…”

“…The paleogeography of the SW Gondwana has been intensely debated for over a century, since the precursor works of Keidel (1913Keidel ( , 1916 and Du Toit (1927,1937). More recently, significant contributions provided a range of new data on the tectonic evolution of the southwestern sector of Gondwana, shedding light on some key questions on this issue (Newton et al, 2006;Tankard et al, 2009;Ramos et al, 2013;Linol et al, 2015;P angaro et al, 2015;Andersen et al, 2016;Alessandretti et al, 2016;Canile et al, 2016;Uriz et al, 2016). Ramos et al (2013) reported a detailed provenance study of the Paleozoic Ventania System of central-eastern Argentina, reinforcing the proposition of the Late Paleozoic collision of Patagonia terrane against the southern Gondwana continental margin.…”

A Possible Cause of the Siberian LIPs: "Collisions Aggrgation Effect" of an Aerolite Impact

“…According to the global paleogeographic maps and data about the Late Permian, the SLIP (point A in Figure 5) is located at 60°N, 80°E in the Siberian Plateau at the Late Permian ( Figure 5) [28][29]; the Falkland Plateau crater (Point D in Figure 5) is located at 70°S, 30°E of the southwestern corner of the Gondwanaland in the southernmost point of the South America [18], [28], [30], and the Wilkes Land crater (point E in Figure 5) It may be at 60°S, 110°E [9,28]. Figure 5 shows the Falkland Plateau crater is in the junction of the Antarctic and South American plates, near the southern orogen of South America [28], and the state may be pressure-type; The Wilkes Land crater is in the eastern Antarctica, close to the Australian plate, not in the orogenic belt, the stress state should not be the pressure type, but is a wide range of ice cover [28].…”