Integrated chitinozoan, conodont, and graptolite biostratigraphy from the upper part of the Cape Cormorant Formation (Middle Ordovician), western Newfoundland
R. Albani et al., Integrated chitinozoan, conodont, and graptolite biostratigraphy from the upper part of the Cape Cormorant Formation (Middle Ordovician), western Newfoundland, CAN J EARTH, 38(3), 2001, pp. 387-409
The Cape Cormorant Formation of the Table Head Group exposed on the Port au
Port Peninsula, western Newfoundland, is composed of dark-brown to black s
hales with interbeds of thin calcareous silty and sandy distal turbidites.
Distinctive carbonate conglomerates and breccias derived from the founderin
g shelf are occasionally found in the formation. The sediments accumulated
in the foreland basin formed during the early stage of the Taconic orogeny.
The faunas from the upper part of the Cape Cormorant Formation include gra
ptolites, conodonts, and chitinozoans. The graptolites are well preserved,
but are of low diversity and are referred to the Darriwil Pterograptus eleg
ans Zone. Conodonts recorded from the distal turbidites are rare and fragme
nted. The faunas include taxa that are known from the St. George and Table
Head groups. The conodont fauna is tentatively assigned to the Histiodella
kristinae Phylozone and to the younger, unzoned interval. The chitinozoans
are well preserved and the yield is high. The fauna is assigned to the Cyat
hochitina jenkinsi Zone and to an undefined interval. The abundance and div
ersity of the chitinozoan assemblages display a cyclic pattern, which is re
lated to changes of the oceanic watermass in the foreland basin. The new ch
itinozoan species Belonechitina nevillensis n. sp., Belonechitina uniformip
unctata n. sp., and Cyathochitina cormorani n. sp. are described.