Multi‐proxy approach to palaeoenvironmental modelling: the English Lower Cretaceous Weald Basin

Abstract

Palaeoenvironmental reconstructions of the Wealden (Lower Cretaceous) in southeast England have been previously based mainly on field and fossil data. This study presents new interpretations of multi-proxy data sets such as sandstone petrography, elemental geochemistry and sideritic ironstones, supplemented by outcrop and clay mineralogical data. The dominance of quartz arenites, kaolinite and thorium and the presence of Zr in the sediments suggest that they were sourced mainly from granitic and/or gneissic rocks. Materials from metamorphic sources are secondary in abundance. The mineral and textural maturity of the sediments coupled with inferred short transport distances suggests reworking from older sources. Palaeoclimatic conditions in the source areas were generally warm and humid in nature, which supported an intensive weathering regime. The nature of the sediments suggests they may have been sourced directly or indirectly from a stable craton. The lithology, facies, sedimentary structures, architecture and gamma ray data confirm the freshwater origin of the sediments. Redox-sensitive trace elements such as Mo, U, V and Co suggest anoxic conditions in the basin. The results presented in this paper reinforce the importance of integrating multi-proxy data sets for interpreting the palaeoenvironmental conditions of sedimentary basins: when traditional data sets such as field and fossil data are not readily available or insufficient to enable adequate interpretations, the integration of petrographic, mineralogical and geochemical data sets may prove to be useful in similar palaeoenvironmental studies. Copyright © 2017 John Wiley & Sons, Ltd.

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