Extinction and dawn of the modern world in the Carnian (Late Triassic)

The Carnian Pluvial Episode (Late Triassic) was a time of global environmental changes and possibly substantial coeval volcanism. The extent of the biological turnover in marine and terrestrial ecosystems is not well understood. Here, we present a meta-analysis of fossil data that suggests a substantial reduction in generic and species richness and the disappearance of 33% of marine genera. This crisis triggered major radiations. In the sea, the rise of the first scleractinian reefs and rock-forming calcareous nannofossils points to substantial changes in ocean chemistry. On land, there were major diversifications and originations of conifers, insects, dinosaurs, crocodiles, lizards, turtles, and mammals. Although there is uncertainty on the precise age of some of the recorded biological changes, these observations indicate that the Carnian Pluvial Episode was linked to a major extinction event and might have been the trigger of the spectacular radiation of many key groups that dominate modern ecosystems

An Exceptionally Preserved Terrestrial Record of LIP Effects on Plants in the Carnian (Upper Triassic) Amber-Bearing Section of the Dolomites, Italy

The Carnian Pluvial Episode (CPE) has been recognized as a time of plant radiations and originations, likely related to observed swift changes from xerophytic to more hygrophytic floras. This suggests that the increasing humidity causally resulting from LIP volcanismwas the trigger for these changes in the terrestrial realm. Understanding the cause and effects of the CPE on the plant realm, requires study of well-preserved floras that are precisely aligned with the CPE. We therefore focus on the best age-constrained section within the CPE for the terrestrial to marginal marine environment to understand the floristic composition at the early CPE. This is found in the Dolomites, Italy, and is remarkable for the preservation of the oldest fossiliferous amber found in the rock record. An integrated study of palynomorphs and macro-remains related to the conifer families of the fossil resin bearing level brings together the floral components from this section. This observed mixture of different taxa of extinct and modern conifer families underlines firmly the effects of the LIP-induced CPE on the evolution and radiation of conifers

Evolution and organization of the Sciliar/Schlern carbonate buildup (Triassic Dolomites - Italy).

The Sciliar/Schlern area is the type area of the Dolomia dello Sciliar. Here it’s where the biological origin of ancient carbonate platforms has been recognized for the first time in the Dolomites. This area has been widely studied since the 19th century because of the outstanding outcropping of carbonate platforms: here lateral facies transition and depositional geometries are very well preserved. This allowed us to study composition, architecture and depositional environments of a fossilized reef. In this report we present an integrated stratigraphical and sedimentological study combined with a facies analysis of the area. Our data lead us to better understand the evolution and the growing mode of several different generations of superimposed carbonate buildups from Anisian to Carnian p.p. (Triassic), and the relationships between the inner organization of the carbonate platforms, the margin rim and slope and the correlated basinal facies. The stratigraphic correlations resulted from the lithological data and the facies analysis have been integrated with known and new biostratigraphic data (mostly ammonoids and palynomorphs) in order to build a high resolution bio-chronostratigraphic framework. The result is the remodeling of the evolution of the Sciliar/ Schlern buildup which is the consequence of the growing of different generations of carbonate platforms. The three-dimensional development of each growing phase of the platform seems to be controlled mainly by the rate of accommodation , by the inherited morphology of the previous body and by the variation in basinal sedimentation rate that forces the decrease of the clinoforms’ angle. Another peculiarity of the last phases of the evolution of this platform is the huge number of megabreccias bodies and carbonatic olistoliths (“Cipit boulders”) found in the Alpe di Siusi/Seiser Alp volcanoclastic basinal sediments. These bodies are probably related to frequent displacements which involved both the slope and the reef, testified by several scallops features recognized along the paleo-slope

Note Illustrative della Carta Geologica d'Italia alla scala 1:50.000, Foglio 029 Cortina d'Ampezzo

descrizione della geologia del foglio Cortina d'Ampezzo, con carta geologica alla scala 1:50.000 allegat