Please use this identifier to cite or link to this item: http://bura.brunel.ac.uk/handle/2438/24839
Title: Clay mineral formation and transformation in non-marine environments and implications for Early Cretaceous palaeoclimatic evolution: The Weald Basin, Southeast England
Authors: Akinlotan, OO
Moghalu, OA
Hatter, SJ
Okunuwadje, S
Anquilano, L
Onwukwe, U
Haghani, S
Anyiam, OA
Jolly, BA
Keywords: Clay minerals;Clay mineral transformation;Palaeoclimate;Early Cretaceous;Weald Basin;Wealden;Southeast England
Issue Date: 20-Apr-2022
Publisher: Elsevier
Citation: Akinlotan, O.O., Moghalu, O.A., Hatter, S.J., Okunuwadje, S., Anquilano, L., Onwukwe, U., Haghani, S., Anyiam, O.A., Jolly, B.A. (2022) ' Clay mineral formation and transformation in non-marine environments and implications for Early Cretaceous palaeoclimatic evolution: The Weald Basin, Southeast England', Journal of Palaeogeography, 0, pp. 1 - 23. doi:10.1016/j.jop.2022.04.002.
Abstract: Analyses of clay minerals within the Early Cretaceous Weald Basin, Southeast England reveal kaolinite, illite and chlorite as the main detrital clay minerals while glauconite and smectite are subordinates. A kaolinite-rich assemblage which characterized the sand-dominated Ashdown and Tunbridge Wells Sand formations and an illite-dominated assemblage associated mostly with the Wadhurst Clay and Weald Clay formations are recognized. Kaolinite was enriched in the Ashdown and Tunbridge Wells Sand formations during warm and humid climate with high precipitation that encouraged chemical weathering and leaching, while cold and dry conditions favoured the concentration of illite in the Wadhurst Clay and Weald Clay formations. Rainfall patterns associated with warm climate were drastically reduced during the drier climatic conditions. Most clay minerals are detrital in origin, with chlorite being more prominent than previously recognized. Contrary to previous studies and assumptions, this study revealed that authigenic clay minerals are present in the Hastings Beds, with vermiform and mica-replacive kaolinite being the most common, consistent with humid depositional environments. Isolated authigenic illite is also present, along with a chloritized grain, providing evidence for mesodiagenesis. The absence of dickite and occurrence of kaolinite, suggest that authigenic illite formed in relatively shallow burial conditions, indicating a maximum burial depth of 2500 m–3000 m, about 1000 m deeper than previous estimates of 1500 m–2000 m. Authigenic clay minerals are absent in the Weald Clay Formation possibly because of hindered flow of meteoric water and limited growth space for authigenic minerals. This study is significant in: 1) reinforcing multiple methods to facilitate a robust and balanced knowledge of formation and transformation of clay minerals; 2) investigating detrital and authigenic clay mineral assemblages when assessing the palaeoenvironments of sedimentary basins.
Description: Availability of data and materials: Supplementary data are available as Appendix 1. The corresponding author can be contacted for queries or clarifications.
URI: http://bura.brunel.ac.uk/handle/2438/24839
DOI: http://dx.doi.org/10.1016/j.jop.2022.04.002
ISSN: 2095-3836
Appears in Collections:The Experimental Techniques Centre

Files in This Item:
File Description SizeFormat 
FullText.pdf7.22 MBAdobe PDFView/Open


This item is licensed under a Creative Commons License Creative Commons