—In post-Cambrian time, five events—the end-Ordovician, end-Frasnian in the Late Devonian, end-Permian, end-Triassic, and end-Cretaceous—are commonly grouped as the ‘‘big five’’ global intervals of mass extinction. Plotted by magnitude, extinction intensities for all Phanerozoic substages show a continuous distribution, with the five traditionally recognized mass extinctions located in the uppe...

Klonowska, I. 2017. Deep subduction of the Seve Nappe Complex in the Scandinavian Caledonides. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1595. 63 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-513-0139-6. This thesis seeks to improve our understanding of the processes involved in continental collision zones, with a particular f...

Magnetostratigraphic studies of the Ordovician provide evidence for nature core-mantle boundary interactions, and means dating correlation across differing environmental regimes. We new magnetostratigraphic data from Middle Upper Ordovician, compiling this into a polarity chronostratigraphic scale Dapingian to Hirnantian interval. The are derived Backside Beck Cheney Longville sections in Brita...

The upper part of Shirgesht (UPS) and lower part of Niur (LPN) formations (Ordovician-Silurian) consist of sandstone, shale and limestone, respectively. The petrography and geochemical analysis conducted to evaluate provenance of siliciclastic deposits in order to understand the paleogeography of Central Iran during the Early Paleozoic time. This study shows that quartz and K-feldspar are the m...

Abstract It remains unclear whether waning of the volcanic degassing CO2 source or enhancement mafic (Ca, Mg-silicate) weathering sink, both, caused global cooling leading to Ordovician greenhouse–icehouse transition. We present a uniquely age-constrained and integrated Middle–Late (470–450 Ma) continental isotopic proxy data set (87Sr/86Sr ?Nd(t)) from carbonate rocks Antelope Range central Ne...

The five largest mass die-offs in which 50–95% of species were eliminated occurred during the Ordovician [490–443 million years ago (mya)], Devonian (417–354 mya), Permian (299–250 mya), Triassic (251–200 mya), and Cretaceous (146–64 mya) periods. Most recently, human actions espe­ cially over the past two centuries have precipitated a global extinction crisis or the ‘‘sixth great extinction wa...