Clay mineral formation and transformation in non-marine environments and implications for Early Cretaceous palaeoclimatic evolution: The Weald Basin, Southeast England

Analyses of clay minerals within the Early Cretaceous Weald Basin, Southeast England reveal kaolinite, illite and chlorite as main detrital while glauconite smectite are subordinates. A kaolinite-rich assemblage which characterized sand-dominated Ashdown Tunbridge Wells Sand formations an illite-dominated associated mostly with Wadhurst Clay recognized. Kaolinite was enriched in during warm humid climate high precipitation that encouraged chemical weathering leaching, cold dry conditions favoured concentration formations. Rainfall patterns were drastically reduced drier climatic conditions. Most origin, being more prominent than previously Contrary to previous studies assumptions, this study revealed authigenic present Hastings Beds, vermiform mica-replacive kaolinite most common, consistent depositional environments. Isolated is also present, along a chloritized grain, providing evidence for mesodiagenesis. The absence dickite occurrence suggest formed relatively shallow burial conditions, indicating maximum depth 2500 m–3000 m, about 1000 m deeper estimates 1500 m–2000 m. Authigenic absent Formation possibly because hindered flow meteoric water limited growth space minerals. This significant in: 1) reinforcing multiple methods facilitate robust balanced knowledge formation transformation minerals; 2) investigating mineral assemblages when assessing palaeoenvironments sedimentary basins.