Greenhouse to icehouse: a biostratigraphic review of latest Devonian–Mississippian glaciations and their global effects

Abstract

AbstractThe latest Devonian–Mississippian interval records the long-term transition from Devonian greenhouse conditions into the Late Palaeozoic Ice Age (LPIA). This transition was punctuated by three short glaciation events in the latest Famennian, mid-Tournaisian and Visean stages, respectively. Primary evidence for glaciation is based on diamictite deposits and striated pavements in South America, Appalachia and Africa. The aim of this review is to assess the primary biostratigraphic and sedimentological data constraining diamictite deposits through this transition. These data are then compared to the wider record of eustasy, mass extinction and isotope stratigraphy in the lower palaeolatitudes. Precise age determinations are vital to integrate high- and low-palaeolatitude datasets, and to understand the glacial control on wider global changes. Palynological techniques currently provide the best biostratigraphic tool to date these glacial deposits and to correlate the effects of glaciation globally. This review highlights a high degree of uncertainty in the known history of early LPIA glaciation as much of the primary stratigraphic data are limited and/or unpublished. Future high-resolution stratigraphic studies are needed to constrain the history of glaciation both spatially and temporally through the latest Devonian and Mississippian.