The geochemical indices consisting of B, Ga, Sr, Ba and V, and
the ratios of B/Ga and Sr/Ba, serve as the lithosome indicators.
Variations revealed lithosome changes from terrigenous to marine
environments, suggesting high and low sea-level stands
(transgression and regression). Sr/Ba indicated one transgressive
and regressive event (well LL1); and three transgressive and two
regressive events (wells LL2 and LL3). Sr and Ba values recorded
two transgressive and one regressive events (wells LL1 and LL3)
and two transgressive and regressive events (well L2) (Fig. 16).
The depositional environments as controlled by the eustatic
changes suggest marine transgression in the Quaternary. Trace
element indices suggest fluvial, shallow and marginal marine
lithosomes.