Anomalous enrichment of molybdenum and associated metals in Lower Jurassic (Lias Group) black shales of central England, as revealed by systematic geochemical surveys

Abstract

Systematic multi-media geochemical surveying by the British Geological Survey's Geochemical Baseline Survey of the Environment (G-BASE) project has revealed significant anomalous patterns of enrichment for a suite of elements -copper (Cu) and

An Improved Approach to Characterize Potash-Bearing Evaporite Deposits, Evidenced in North Yorkshire, United Kingdom

“…The samples were then dried at 40°C, disaggregated in an agate pestle and mortar, and back-loaded into a standard stainless steel sample holder to provide a random orientation for analysis. At the British Geological Survey, XRD samples are routinely spray-dried (Hillier, 1999) in order to achieve a random orientation and the best possible quantification results (e.g., Breward et al, 2015). However, the temperature-sensitive nature of many of the minerals present in the potash samples precluded the elevated temperatures required to expedite the spray-drying process.…”

How quick was marine recovery after the end-Triassic mass extinction and what role did anoxia play?

“…The evidence for oxygen-restriction includes widespread black shale deposition in the epicontinental seaway of Europe during the earliest Hettangian and again during the Sinemurian (Richoz et al, 2012;van de Schootbrugge et al, 2013;Wignall and Hallam, 1991). The intensity of oxygen deficiency has been assessed using a range of proxies: redox sensitive trace metals such as Th/U (Hallam, 1995;Wignall, 2001) and molybdenum (Breward et al, 2015), pyrite sulphur isotopes (Jaraula et al, 2013;Luo et al, 2018), uranium isotopes (Jost et al, 2017) and the presence of isorenieratane (Blumenberg et al, 2016;Jaraula et al, 2013;Naeher and Grice, 2015;Richoz et al, 2012).…”