Paleoclimatic Controls on Clay Mineral Distribution in the Early Cretaceous(Barremian):The Wessex Basin,Southeast England  

作　　者：Oladapo O.Akinlotan Ogechukwu A.Moghalu Stuart J.Hatter Byami A.Jolly Okwudiri A.Anyiam 

机构地区：[1]Faculty of Health,Medicine&Social Care,Anglia Ruskin University,Chelmsford,CM11SQ,UK [2]Department of Geology,University of Nigeria,Nsukka,410001,Nigeria [3]Badley Ashton&Associates Ltd.,Winceby,Horncastle,LN96PB,Lincolnshire,UK [4]Department of Geology,Ahmadu Bello University,Zaria,Nigeria

出　　处：《Journal of Earth Science》2024年第6期2050-2066,共17页地球科学学刊（英文版）

摘　　要：This study describes the clay mineralogy of the Lower Cretaceous(Barremian)rocks of the Wessex Basin for paleoenvironmental interpretations.Seventy-four samples were subjected to optical microscopy,scanning electron microscopy/energy-dispersive X-ray spectroscopy(SEM/EDS),and quantitative evaluation of minerals by scanning electron microscopy(QEMSCAN^(R))techniques.The results revealed an illite-dominated sedimentation in most sections of the basin,with kaolinite,chlorite,smectite and glauconite occurring in subordinate quantities.Inferred paleoclimatic conditions from the clay mineral trends indicates a warm and dry climate,with seasonal precipitation.Kaolinite to illite ratios indicate that more arid climate conditions were prevalent but brief periods of warm and humid conditions were also present.A strong positive correlation between chlorite and tourmaline indicates that excess chlorite may have been contributed from tourmaline-chlorite-schists in a tourmalinedominated provenance.SEM confirms that most of the clay minerals are detrital in origin but authigenic kaolinite is also present as vermiform and mica-replacive kaolinite which formed during early diagenetic modification from flushing meteoric waters in warm humid climates.This study is significant because it demonstrates the importance of multi-proxy methods for understanding clay minerals within sedimentary basins for interpreting the paleoclimatic conditions of depositional systems.

关 键 词：clay minerals KAOLINITE Lower Cretaceous English Wealden QEMSCAN^(R) 

分 类 号：P534.53[天文地球—古生物学与地层学] P532[天文地球—地质学]