Figure F38. Dolerite clast at the boundary between a dolerite sill and overlying conglomerate unit. Rounded clast has red weathering products rimmed by green (5GY 7/2) weathering products (at right side of clast). This suggests an environmental change from a subaerial (oxidation) to a lagoonal (reduction) setting, in accordance with other observations (interval 180-1109D-45R-3, 27-30.5 cm).