Unit Name: Theresa Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Early Ordovician (N.A.) (491 - 473 ma)
Province/Territory: Ontario; Quebec

Originator: Cushing, 1908, Bull. GSA vol. 19, p. 159.

Lithology:
"beds consist of sandstone, alternating with buff and grey-buff dolomite, and sandy dolomite." (Sanford & Quillian, 1959)

Remark:
This unit was first described in NY and was extended into SW Ontario by Sanford & Quillian (1959). This unit is a formation of the Beekmantown Group.

Other Citations:
Cushing, H.P., 1908, Bull. GSA vol. 19, p. 159; Sanford, B.V. and Quillian, R.G., 1959, GSC Paper 58-12, p. 5, 8 [formation]; Globensky, Y., et.al., 1993, QMER DV 91-23, p. 273 [formally described].

References:
Cushing, H.P., 1908. Lower portion of the Paleozoic section in northwestern New York; Geological Society of America Bulletin, vol. 19, pp. 155-176.
Sanford, B.V., and Quillian, R.G., 1959. Subsurface stratigraphy of Upper Cambrian rocks in southwestern Ontario (report and map 30-1958). Geological Survey of Canada, Paper 58-12, 33 p.

Source: GSC file of geological names; T.E. Bolton and J. Dougherty (compiler)
Contributor: A.A. Coyne
Entry Reviewed: No
Name Set: Lithostratigraphic Lexicon
LastChange: 28 Apr 2014