Morgans, H.E.G. 2016 The Weber Formation at its type location in Southern Hawke's Bay, and its distribution through the East Coast, North Island, New Zealand. Lower Hutt, N.Z.: GNS Science. GNS Science report 2015/38 iv, 95 p.
Abstract: The Weber Formation is described from its type locality in the Akitio River at Weber, Southern Hawke’s Bay, and a new type section is designated (Fig. 1). , Also described are other sections from the Weber area. The distribution of Weber Formation strata throughout the East Coast of the North Island is also discussed. In the type area the formation ranges in thickness from 200–340 m although, if all sections were complete, and adding the mudstone lithofacies, the total could well exceed 400 metres. In other areas of the East Coast the thickness varies from 80–700 m. It is comprised of fine-grained, hard, light-grey, calcareous sediments with some sandstones about the middle of the formation and predominantly calcareous sandstone and siltstone at the top of the formation. The formation is informally subdivided into four lithofacies: (1) Glauconitic lithofacies, (2) Limestone lithofacies, (3) Flysch lithofacies, and (4) Mudstone lithofacies. At the type locality the lower Weber Formation appears to conformably overlie slightly glauconitic mudstones of the Wanstead Formation and the upper Weber Formation is unconformably overlain by dark blue-grey siltstones of the Ihungia Formation. The age of the formation is Late Eocene (Kaiatan–Runangan) to Late Oligocene (early Waitakian). The formation was deposited mainly at deep bathyal depths. (auth)