Robust sequential Factor Analysis of geochemical data from the Permian-Triassic Gartnerkofel-1 core (Southern Alps): the geochemical response to changing paleo-oceanographic conditions in shallow-marine carbonate platforms

Abstract

The Gartnerkofel-1 core provides a high-quality multi-element dataset that characterizes an Upper Permian to Lower Triassic shallow-marine carbonate sequence (Bellerophon and Werfen Formations) of the Carnic Alps (Southern Alps). Based on the well-known sedimentological evolution, robust sequential Factor Analysis is explored as a multivariate statistical technique to understand geochemical processes in carbonate platforms. The results demonstrate that 93% of the whole-rock compositional variability of the Gartnerkofel-1 core can be explained by the detrital input that is diluted by the carbonate production and the early diagenetic redox state. Two stages of anoxia, one at the Permian/Triassic boundary and one in the Mazzin Member of the Werfen Formation, are related to indicative factor scores. The factor scores within this interval suggest an enhanced dolomitization of shales and marls, a mobilization of manganese, and an accumulation of syndiagenetically precipitated pyrite.