GSC #75212 - Good Hope Lake section, Cassiar Mountains (Cambrian of Canada)

Also known as 75212

Where: British Columbia, Canada (59.3° N, 129.2° W: paleocoordinates 1.7° N, 78.8° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Limestone Member (Sekwi Formation), Atdabanian (521.0 - 516.0 Ma)

• Longest continuous section containing Archaeocyathids in northwestern North America where archaeocyathidfs occur over a sttratigraphic distance of 750 feet within the lower 900 ft of the limestone unit of the Atan Group. Section measured in the limestone ("upper") unit of the Atan Group. Collection form 600 ft above base of limestone unit.

• bed-level stratigraphic resolution

Environment/lithology: shallow subtidal; dolomitic, ooidal limestone

• The Atan Group probably represented relatively stable conditions on the Pelly-Cassiar Platform. The limestone unit possibly represents a large carbonate unit with water depths ranging from subtidal (oolite accumulations) to in excess of 50 m.
• Collection from oolitic limestone facies. Evidence of dolomitization is prevelant at this section.

Size class: macrofossils

Preservation: replaced with dolomite

Reposited in the GSC

• Collections made by Handfield during 1965 and 1966. Collections are reposited at Geological Survey of Canada

Primary reference: R. C. Handfield. 1971. Archaeocyatha from the MacKenzie and Cassiar Mountains, Northwest Territories, Yukon Territory and British Columbia. Geological Survey of Canada Bulletin 201:1-119 [A. Miller/A. Hendy/A. Hendy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 49010: authorized by Austin Hendy, entered by Austin Hendy on 05.04.2005

Creative Commons license: CC BY (attribution)

Taxonomic list

• Exhaustive fro archaeocyathids
 Capsulocyathida - Coscinocyathidae
Coscinocyathus cf. multiporus Kawase and Okulitch 1957 archaeocyath sponge
 Ajacicyathida - Ethmophyllidae
Ethmophyllum cf. whitneyi Meek 1868 archaeocyath sponge
 Archaeocyathida - Archaeocyathidae
"? Cambrocyathus sp." = Pycnoidocyathus (Cambrocyathus)
"? Cambrocyathus sp." = Pycnoidocyathus (Cambrocyathus) Okulitch 1937 archaeocyath sponge