CLARENCE SERIES

major division of Cretaceous rocks and time in New Zealand (the Cretaceous Period lasted from 144 to 66.4 million years ago). Rocks of the Clarence Series overlie those of the Taitai Series and underlie rocks of the Raukumara Series. Clarence rocks (sandstones, conglomerates, graywackes, mudstones, and basaltic lava flows) have been divided into four stages representing shorter spans of time. The oldest of these is the Coverian Stage, which consists of about 300 metres (1,000 feet) of mudstones. The Coverian is followed by the Urutawan Stage, about 900 metres (3,000 feet) of mudstones and sandstones. The Motuan follows the Urutawan Stage and is followed by the Ngaterian Stage, about 600 metres (2,000 feet) of alternating mudstones and sandstones. During the Upper Motuan and throughout the Ngaterian, basaltic volcanic lavas were deposited in the Seymour River region of eastern New Zealand. Rocks of the Clarence Series are characterized by distinctive forms of fossil mollusks.