The implications of clay mineralogy to palaeoclimate and provenance during the Jurassic in NE Scotland

Publisher Website
Google Scholar
Abstract
Synopsis: Clay mineral logs for the Jurassic succession at Brora are presented as vertical profiles in lithostratigraphic units. The shale clay mineralogy is dominated by ordered illite/smectite and kaolinite. A sub-tropical, possibly seasonal, climate is inferred. High kaolinite content is attributed to reworking of probable Carboniferous kaolinitic regoliths, uplifted and eroded due to initiation of the formation of the Viking Graben. Kaolinite abundance is not due to tropical weathering in the Jurassic. A Jurassic weathering environment more humid than in the Triassic is proposed, eroding a variety of sedimentary rocks and a high-grade quartzose metamorphic terrain.