Anachronistic facies from a drowned Lower Triassic carbonate platform: Lower member of the Alwa Formation (Ba'id Exotic), Oman Mountains

Biological Influences on Seafloor Carbonate Precipitation

“…In contrast, an example of a putative aragonite crystal fan occurrence documented from the Lower Triassic Union Wash Formation, Inyo Mountains, Californiaone of the youngest observed in the sedimentary record-does not reveal the expected random grain orientations in the mosaic where the map area covers multiple blades, suggesting a primary calcite mineralogy (Figs. 6C-D) (Woods et al, 1999(Woods et al, , 2007Pruss et al, 2006;Woods and Baud, 2008).…”

“…Alwa Formation, Oman (Woods and Baud, 2008) Iron-manganese coatings described within sequence that contains crystal fans fluxes across the sediment-water interface. Despite strongly supersaturated seawater with respect to both aragonite and calcite over modern carbonate platforms, this style of seafloor precipitation does not occur today.…”

Frutexites encrustations on rugose corals (Middle Devonian, southern Morocco): complex growth of microbial microstromatolites

“…In contrast to many other deep-water Frutexites occurrences, however, the shrubs under study neither projected freely on the seafloor (cf. Woods and Baud 2008), nor encrusted the roofs of sub-seafloor cavities (cf. Reolid and Molina 2010;Lazȃr et al 2012).…”

“…Generally, Frutexites seem to have preferred low-energy environments, characterized by low sedimentation rates and often limited availability of oxygen; they are consequently commonly found on the bottoms of deep, dysaerobic basins (Playford et al 1976;Tsien 1979;Böhm and Brachert 1993;Reitner et al 1995;Mamet and Préat 2006;Woods and Baud 2008;Lazȃr et al 2012), not uncommonly in association with hardground surfaces (Mišík and Aubrecht 2004;Reolid and Nieto 2010). Where present in shallow-water settings, in turn, Frutexites are typically limited to cryptic environments, such as such as small cavities and sheet cracks (Hofmann 1969;Horodyski 1975;Walter and Awramik 1979;Myrow and Coniglio 1991).…”

Lower Triassic anachronistic facies capping the Qinghai-Tibet Plateau seamount: Implications for the extension of extraordinary oceanic conditions deep into the interior Tethys Ocean

“…Documented Lower Triassic anachronistic facies are mainly distributed in carbonate platforms from South China, the Middle East and western North America (Ezaki et al, 2003;Wang et al, 2005;Pruss et al, 2006;Baud et al, 2007;Woods and Baud, 2008;Woods, 2009). During the Early Triassic, the Middle East was located in the southern Palaeo-Tethys, the South China block lay between the Panthalassa Ocean and the Palaeo-Tethys Ocean, and western North America was situated along the eastern border of Panthalassa (Fig.…”