Baillie-Hamilton Island, Section 12, Unit 20, GSC loc. C26982 (Devonian of Canada)

Also known as Gypidula-Atrypa-Schizophoria Community

Where: Nunavut, Canada (76.8° N, 94.3° W: paleocoordinates 2.2° S, 25.0° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Lochkovian (419.2 - 410.8 Ma)

• Unnamed formation about Cape Phillips Formation. "The age of this carbonate unit is early Lochkovian, corresponding to Klapper's faunas 1 and 2."

• bed-level stratigraphic resolution

Environment/lithology: deep subtidal shelf; gray, argillaceous, silty, sandy lime mudstone

• Deposits in this region are of two general kinds: shallow-water stable carbonate platform (generally in the NW part of Arctic Archipelago) and deeper basinal facies (generally to the SE). This collection is in the former. Smith's Gypidula-Atrypa-Schizophoria Community, which sits in zone 3 in his 6-zone onshore to offshore gradient, shallow to deep subtidal, below wave base.

•SEP environmental call based on given info and regional context

• This part of section as a whole: "Unnamed carbonate unit (at least 500 m thick) which can be broken into three members. The lower member is coposed of thin-bedded argillaceous lime-mudstone containing common argillaceous seams and contains a varied brachiopod fauna as well as corals, gastropods and, in the upper parts, oncoloites....second member consisting of thin to med. bedded silty lime-mudstone containing common to abundant colonial corals as well as bryozoans. The third member is thin to very thin bedded, silty argillaceous lime mudstone containing in places lime mud intraclasts exhibiting sedimentary drape, channeling, as well as what appear to be small-scale ripple marks and common to abundant leperditiid ostracodes." This unit: "Argillaceous lime mudstone: thin bedded, undulatory; med. dk. grey to grey-brown,...well indurated, common yellow-grey argillaceous seams, other seams grey-green; few brachiopods, common colonial corals; slightly silty to sandy; some beds have fair amount of tiny comminuted debris..."

Reposited in the GSC

• Smith gives specimen counts.

Primary reference: R. E. Smith. 1980. Lower Devonian (Lochkovian) biostratigraphy and brachiopod faunas, Canadian arctic islands. Geological Survey of Canada Bulletin 308:1-155 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 26538: authorized by Michael Foote, entered by Michael Foote on 16.10.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

• Focus of the entire monograph is on brachiopods. Other taxa mentioned but not necessarily listed in detail.
Strophomenata
 Orthotetida - Chilidiopsidae
Rhynchonellata
 Athyridida - Meristellidae
? Meristina sp. Hall 1867
 Spiriferinida - Cyrtinidae
? Cyrtina sp. Davidson 1858
 Spiriferida - Delthyrididae
 Rhynchonellida - Hebetoechiidae
 Orthida - Schizophoriidae
Conodonta
 Ozarkodinida -
"Ozarkodina cf. remscheidensis" = Nicollidina remscheidensis
"Ozarkodina cf. remscheidensis" = Nicollidina remscheidensis Ziegler 1960 conodont