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Latest Triassic marine Sr isotopic variations, possible causes and implications
Author(s) -
Callegaro Sara,
Rigo Manuel,
Chiaradia Massimo,
Marzoli Andrea
Publication year - 2012
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/j.1365-3121.2011.01046.x
Subject(s) - conodont , geology , paleontology , biostratigraphy , igneous rock , weathering , large igneous province , sill , mesozoic , tectonics , geochemistry , magmatism , structural basin
Terra Nova, 24, 130–135, 2012 Abstract Large igneous provinces have been suggested to trigger global environmental perturbations and, in turn, major biotic crises. The high resolution of marine biostratigraphy is here applied to constrain the detailed timing of the Central Atlantic Magmatic Province onset. Analyses of biogenic apatite from stratigraphically well‐constrained Tethyan realm conodont samples indicate two significant shifts of the oceanic 87 Sr/ 86 Sr composition during the latest Triassic: a rapid drop of 87 Sr/ 86 Sr during the lower Rhaetian, followed by an increase during the upper Rhaetian. These shifts are positively correlated with synchronous variations of oceanic 187 Os/ 188 Os and they may be attributed to a rapid emplacement and erosion of the Central Atlantic Magmatic Province, followed by a rapid increase in continental weathering. These interpretations require a short duration for the Rhaetian stage (<2 Ma) and are consistent with volcanogenic triggering of end‐Triassic climatic perturbations and biotic crisis starting from the Norian–Rhaetian and culminating at the Triassic–Jurassic boundary.