Depositional environment of the early Pleistocene Castlepoint Formation, New Zealand: a canyon fill in situ. Issue 4 (2nd October 2018)

• Record Type: Journal Article
• Authors: Buckeridge, John S.; Beu, Alan G.; Gordon, Dennis P.
• Is Part Of: New Zealand journal of geology and geophysics. Volume 61:Issue 4(2018)
• Page Start: 524
• Page End: 542
• Publication Date: 2018-10-02
• Subjects: Barnacle coquina -- barnamol -- bryomol -- Castlepoint -- canyon-head setting -- mixed shallow- and deep-water thanatocoenoses; Geology -- New Zealand -- Periodicals; Geology -- Periodicals; Geophysics -- Periodicals; Geofysica; Geologie; Geology; Geophysics; New Zealand; Periodicals; 559.3
• DOI: 10.1080/00288306.2018.1516227
• Languages: English
• ISSNs: 1175-8791

Abstract

ABSTRACT: The early Pleistocene (early Nukumaruan) Castlepoint Formation cropping out on the Wairarapa coast contains a diverse molluscan, bryozoan and barnacle assemblage, with a few brachiopods, corals, echinoids, crabs and polychaetes, comprising mixed warm- and cool-water taxa and outer shelf and shallow-water taxa. Sedimentary structures within the beds (fluid release structures, steep original dips, large load casts, displaced blocks) confirm a dynamic depositional setting by gravity sliding into what is interpreted as a canyon head. The barnacle- and bryozoan-rich molluscan coquina (barnamol and bryomol) that makes up much of the Castlepoint Formation comprises thanatocoenoses resulting from transportation of shallow-water elements, which accumulated deeper-water taxa in transit, to settle in a shelf-edge canyon environment. We interpret all stratigraphic contacts as sedimentary ones; the formation is essentially a canyon fill in situ .