Tupuangi Formation facts for kids

Quick facts for kids Tupuangi Formation Stratigraphic range: Cenomanian-Turonian ~99–89Ma PreЄ Є O S D C P T J K Pg N
Tupuangi Formation at Waihere bay, Pitt Island
Type	Geological formation
Unit of	Waihere Bay Group
Sub-units	Kokowai Allomember, Waihere Allomember, Morgan's Hollow Allomember
Underlies	Kahuitara Tuff
Overlies	Unseen
Thickness	Not bounded, 430 m (1,410 ft) exposed onshore, possibly 700 m (2,300 ft) offshore
Lithology
Primary	Sandstone, siltstone
Other	Conglomerate
Location
Region	Oceania
Country	New Zealand
Extent	Pitt Island, Chatham Islands
Type section
Named for	Tupuangi, Pitt Island
Location	Northern end of Waihere Bay
Coordinates	44°15′32.8″S 176°14′57.1″W / 44.259111°S 176.249194°W / -44.259111; -176.249194
Approximate paleocoordinates	78°54′S 135°54′W / 78.9°S 135.9°W / -78.9; -135.9
Thickness at type section	~400 m (1,300 ft)

The Tupuangi Formation is a geological formation in New Zealand, only exposed on Pitt Island in the Chatham Islands. It is the oldest exposed sedimentary unit within the archipelago. It was deposited in terrestrial deltaic to paralic conditions during the Cenomanian to Turonian stages of the Late Cretaceous. During this time period the Chatham Islands were attached to Antarctica within the Antarctic Circle, at approximately 70° to 80° south.

Description

The lithology consists of a basal conglomerate, which grades into sandstone and carbonaceous siltstone in the upper part of the formation. The formation is notable for its fossil content, including many varieties of plant, including abundant conifers, including members of Araucariaceae, Podocarpaceae, Cupressaceae, Cheirolepidiaceae, as well as Ginkgo and Ginkgoites. Other flora includes mosses, ferns, liverworts and lycopodians. Compression fossils of insects have been found including members of Carabidae and Buprestidae, and acritarch Introvertocystis. Amber is also known from the deposit associated with the conifer Protodammara reimatamoriori, a member of Cupressaceae.