Diversity and factors controlling widespread occurrence of syn-rift Ladinian microbialites in the western Tethys (Triassic Catalan Basin, NE Spain)

摘要: Abstract The fault-block carbonate ramps of the Ladinian (Middle Triassic) Catalan Basin hosted a wide variety microbial deposits which formed during syn-rift stage. Stratigraphical and sedimentological analyses these microbialites allow us to reconstruct two depositional models for such deposits. Moreover new insights into interplay between intrinsic extrinsic factors that controlled widespread development are provided. Stromatolites, ooidal-muddy laminites thrombolites were analyzed on basis their geometry, lamination textural attributes. These distributed over Transgressive–Regressive sequences coexisted Fassanian (Early Ladinian) regressive Later, stromatolites developed Longobardian (Late transgressive Three types lamina couplets reflect distinct accretion processes linked water chemistry, sediment supply hydrodynamic conditions. Thrombolite textures produced by accretionary, binding encrusting (microbially mediated) pervasive cementation. occurrence is explained as consequence biogeochemical cascade events (e.g., anoxic/dysoxic seawater conditions, volcanic activity, upwelling alkaline waters, nutrient concentrations, blooms), promoted favorable conditions growth in Tethys Ladinian. Furthermore, Basin, fault induced subsidence local energy gradients exerted an essential role distribution three through space time. Thrombolites prone grow hanging wall block half-graben (subtidal conditions), whereas flourished preferably foot setting (intertidal–shallow subtidal conditions). However, fact exhibit abundant botryoidal isopachous fibrous marine cements, corrosion significant evidence hypothesize about relationship thrombolite hydrothermal fault-controlled fluid circulation Triassic rifting. here proposed constitute step forward understanding platform-to-basin microbialite heterogeneity Furthermore this work sheds light mechanisms likely period major ecological restructuration complex oceanographic