sequences on all major continents there is a prominent and well-constrained Mid-Carboniferous unconformity (Blake and Beuthin 2008; Dyer et al. 2015; Hallam 1992). It has been inferred that this unconformity was established simultaneously in North America, North Africa, Europe, the Urals, Turkey, Uzbekistan, China and Australia (Lucien 2014, Saunders and Ramsbottom 1986). The Mid-Carboniferous unconformity is also found in South America (Spalletti et al. 2010). Stratigraphic evidence from Mid-Carboniferous shelf and basin successions in numerous parts of the world indicates a major marine regression (Lucien 2014, Ross and Ross 1988). Regressions are inferred from karstification, erosional sedimentary hiatuses and other signs of dessication. A spectacular karst paleorelief of up to 100 m is recognizable in North Africa (Hallam 1992). b. Laurasia The Mid-Carboniferous unconformity coincides with the close of the Kaskasia cratonic sequence of Sloss (Saunders and Ramsbottom 1986; Sloss 1964). In North America it marks the Mississippian-Pennsylvanian boundary (Hallam 1992). In the United States, the mid-Carboniferous is marked by a set of paleokarst features (Silvestru 2000). The Mississippian Redwall Limestone in the Grand Canyon is notable for its karst features, including caves. A Mid-Carboniferous paleovalley system has been inferred to have been incised in the central Appalachians, draining large areas of the emergent North American craton (Blake and Beuthin 2008). In North America, Mississippian carbonate strata represent a transition from the marine conditions of the Middle Paleozoic to the more nonmarine conditions of Pennsylvanian and Permian time. At the end of the Mississippian, a major regression drained the craton. By the end of the Permian, practically the entire North American continent has been inferred to have stood above sea level, and great volumes of Pennsylvanian and Permian clastic sediments had been deposited (Prothero and Dott 2010). c. Gondwana Mid-Carboniferous uplift and exhumation of upland East Antarctica has been inferred to have led to “glaciation” and following this the region is said to have become the focus of Permian “post-glacial” flow of sediment in East Gondwana (Veevers 2009). An alternative interpretation is that East Gondwana was already an upland area and that receding waters of a marine regression caused exhumation on East Antarctica along with mass flow features, to be then followed by less energetic sedimentation. Sea-level fall associated with the Mid-Carboniferous unconformity has been interpreted as relating to the inception of a major phase of “glaciation” across Gondwana (Veevers and Powell 1987). The Late Paleozoic “glacial” episodes in Gondwana are reflected in transgressive-regressive depositional sequences, including cyclothems, in Euramerica (Veevers and Powell 1987). Euramerica, also known as Laurasia, is commonly said to have been a continent that incorporated North America, Greenland and Europe. The evidence for major Gondwanan Late Paleozoic “ice sheets” has been inferred to be confined to the Late Carboniferous to Early Permian time range (Frakes 1979). Final “melting of the ice” in the Mid-Permian should have caused a comparably important sea level rise, which has not been apparent from the stratigraphic record. The Late Permian has been inferred to be a time of relatively low sea level stand, especially at the end (Hallam 1992). Thus, it is reasonable to conclude that glacial melting was not involved. The end Permian has been inferred to have had the lowest sea level of the Paleozoic and even of the entire Phanerozoic (Golonka and Kiessling 2002; Hallam 1992; Haq and Schutter 2008). 3. Late Paleozoic facies Lacustrine deposits have been inferred within Carboniferous strata of the Panganzo Basin of Argentina, the Weber Sandstone of Colorado, Mazon Creek of the Illinois Basin, along with the Dunkard, Monongahela, and Conemaugh Groups of the Appalachian Basin, the Pennant Series of South Wales, and numerous other locations in other parts of the world. Lacustrine deposits have been inferred in Permian strata of the Rotliegende basins of Europe, the Karoo Basin of South Africa, the Mackellar formation of Antarctica, northwestern China, the Speiser Shale of Kansas, and other locations (Park and Gierlowski-Kordesch 2005). Late Paleozoic fluvial deposits have been inferred in strata such as North America’s Carboniferous Enrage Formation and Shepody Formation of New Brunswick (Cant 1982), Carboniferous Port Hood Formation of Nova Scotia (Gersib and McCabe 1981) and Permian Cook sandstone of the Midland Basin, Texas (Cant 1982); southwestern Australia’s Permian (Freeman 2001); Europe’s Carboniferous basins such as the Saar-Lorraine, Upper Silesian and Penarroya Basins (Oplustil et al. 2022). An accelerating Late Permian sea level fall has been inferred based on the distribution on marine and nonmarine facies in successive time intervals throughout the world (Hallam 1992; Holser and Magaritz 1987). Subaerial exposure establishes the reality of sea level fall. Redbeds are the trademark of Permian and Triassic strata on five continents (Prothero and Dott 2010). C. The Late Paleozoic “Ice Age” (LPIA) From the Mid-Carboniferous onwards, “ice” is said to have expanded across South America, southern Africa, and Australia, and, at the start of the Middle Pennsylvanian, into southern Africa, Oman, and Arabia. A massive expansion of “ice” is claimed to have occurred at the Pennsylvanian-Permian boundary, with “glaciation” becoming bipolar at that time. “Ice sheets” have been inferred to have been at their maximum extent during the earlier Permian, after which they decayed rapidly over much of Gondwana (Fielding et al. 2008). However, it has been questioned why Gondwana did not have extensive “glacial” events throughout the Paleozoic, since Gondwana has been inferred to have been over the South Pole from the Neoproterozoic until Early Triassic. The secular search for the “smoking gun” of continental glaciation, particularly the so-called Late Paleozic “Ice Age”, remains elusive (Blakey 2008). A feature of Permo-Pennsylvanian coal-bearing strata, especially in North America and Europe, is the occurrence of numerous repetitious sequences known as cyclothems. Cyclothems are cyclical successions of carbonate, coal and clastic facies. Their origin has been proposed as being the result of repeated transgression and regression of water, submergence and emergence of land, and even due to waxing and waning of Gondwanan so-called “ice sheets” causing eustatic sea level fluctuations (Merriam 2005). The latter being a far-field record of the southern hemisphere affecting the northern hemisphere. The estimated time of the best known cyclothemic deposits in EurDICKENS Flood Waters Lead to Seafloor Spreading 2023 ICC 450
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