Halifax Formation

Unit Name: Halifax Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Obsolete
Age Interval: Early Ordovician (485.4 - 470 ma)
Age Justification: Graptolites, found between 2,400 m and 850 m below the top of the formation, indicate an Early Ordovician age (Smitheringale, 1960; Crosby, 1962). The upper part of the underlying Goldenville Formation is probably also Early Ordovician, so that most of the Halifax Formation is probably Early Ordovician. The top of the Halifax may be younger since the overlying New Canaan Formation in the Kentville (NTS 21 H/1) area contains Silurian fossils. A brachiopod of Caradoc age was found in the Halifax Formation at Cape St. Mary (NTS 21 B/1).
Province/Territory: Nova Scotia

Originator: Ami, 1900d.

Type Locality:

Halifax, Halifax County, Nova Scotia (NTS 11 D/12). No type section was designated by Ami (1900d) or Woodman (1904a, 1904b). Bell (1929) regarded the thick section at Black River (NTS 21 H/1, 21 A/16) as the most complete section of the Formation in the province. Crosby (1962) reported that part of this section is now obscured, and suggested that the Halifax Formation should extend below the base designated by Faribault (1909). The complete section has never been thoroughly described.

Distribution:

Thickness varies from about 3,600 m in the type area to about 500 m in southwest Nova Scotia (Taylor, 1967a). Faribault (1909) measured a continuous section of 3565 m at Black River, Kings County (NTS 21 H/1, A/16). The formation is exposed widely in southern mainland Nova Scotia as numerous outliers in the cores of northeast or east-trending synclines. The underlying Ordovician or ?older Goldenville Formation is exposed in the intervening anticlines, except in a region of plunge depression centred in Lunenburg County, where a broad belt of the Halifax is present.

Locality Data:

Thickness(m): Minimum 500, Maximum 3600.

Lithology:

Greyish-green to black and, locally, red slate, siltstone, and minor sandstone, generally thinly bedded and strongly sheared. The slates locally contain abundant pyrite and arsenopyrite. The formation is regionally metamorphosed to greenschist and, in places, amphibolite facies, and is locally schistose. Hornfels is developed close to granitic plutons.

Relationship:

The Halifax Formation conformably overlies the Goldenville Formation, also of the Meguma Group, although Harris and Schenk (1975) suggested the two formations are in part contemporaneous. The contact with the overlying Ordovician to Silurian White Rock Formation is locally unconformable, but regionally conformable (Harris and Schenk, 1975). The Halifax Formation is intruded by Upper Paleozoic granitic plutons and unconformably overlain by the Lower Carboniferous Horton and Windsor groups and the Upper Triassic Wolfville Formation of the Fundy Group.

History:

Rocks of the Halifax Formation were included in the "Transition Clay-Slate Formation" of Jackson and Alger (1828, 1829a, 1829b) but were first identified as a distinct unit by Campbell (1863), who named them the "Lower Clay-Slate Group". This was revised to "Upper or Graphitic and Ferruginous Slate Group" by Faribault (1887). The name Halifax Formation was proposed by Ami (1900d). Halifax Series was used by Douglas et al. (1938). The following abandoned names apply to parts of the formation: Wolfville Formation and Greenfield Formation (Honeyman, 1879), Banded Argillite Division and Black Slate Division (Bailey, 1898a). Woodman (1904a) named the Meguma Series after the Micmac word, a root of the native term for their own tribe. Stevenson (1956, 1959) redefined it as the Meguma Group, including in the Goldenville and overlying Halifax formations.

Remark:

Obsolete, use Halifax Group.

Other Citations:

Ami, 1900a, Schenk, 1970; Waldron and Jensen, 1984.

References:

Ami, H.M., 1900a. Notes bearing on the Devono-Carboniferous problem in Nova Scotia and New Brunswick; Ottawa Naturalist, vol. 14, no. 7, pp. 121-127.

Ami, H.M., 1900d. pp. 179A-180A: in G.M. Dawson, Summary Report on the Operations of the Geological Survey for the Year 1900; Geological Survey of Canada, Annual Report for 1900, 203A p.

Bailey, L.W., 1898a. Report on the geology of south-west Nova Scotia, embracing the counties of Queen's, Shelburne, Yarmouth, Digby and part of Annapolis: Geological Survey of Canada, Annual Report for 1896, vol. 9, Part M, 154 p.

Bell, W.A., 1929. Horton-Windsor district, Nova Scotia; Geological Survey of Canada. Memoir 155, 268 p.

Campbell, J., 1863. Nova Scotia gold fields: Report, Halifax, 12 p.

Crosby, D.G., 1962. Wolfville map-area, Nova Scotia (21 H/1); Geological Survey of Canada, Memoir 325, 67 p.

Douglas, G.V., Milner, R.L., and MacLean, J., 1938. The deposition of the Halifax Series: Nova Scotia Department of Mines and Energy, Annual Report 1937, Part 2, pp. 34-45.

Faribault, E R., 1909. Southern part of Kings and eastern part of Lunenburg counties, Nova Scotia; Geological Survey of Canada, Summary Report for 1908, pp. 150-158.

Faribault, E.R., 1887. Report on geological surveys and explorations in the counties of Guysborough Antigonish, Pictou, Colchester and Halifax, Nova Scotia. Counties of Guysborough and Halifax: Geological Survey of Canada, Annual Report for 1886, vol. 2, Part P, pp. 129-163.

Harris, I.M. and Schenk, P.E., 1975. The Meguma Group: Maritime Sediments, vol. 11, pp. 25-46.

Honeyman, D., 1879. Nova Scotia geology - Kings County: Proceedings and Transactions of the Nova Scotian Institute of Science, vol. 5, pp. 21-31.

Jackson, C.T. and Alger, F., 1828. Mineralogy and geology of a part of Nova Scotia; Yale University, American Journal of Science, vol. 14, pp. 305-330.

Jackson, C.T. and Alger, F., 1829a. A description of the mineralogy and geology of a part of Nova Scotia (continued from vol. 14, pp. 330): American Journal of Science, vol. 15, pp. 132-160.

Jackson, C.T. and Alger, F., 1829b. A description of the mineralogy and geology of a part of Nova Scotia (continued from vol. 15, pp. 160): American Journal of Science, vol. 15, pp. 201-217.

Schenk, P.E., 1970. Regional variation of the flysch-like Meguma Group (Lower Paleozoic) of Nova Scotia, compared to Recent sedimentation off the Silurian Shelf; pp. 127-153: in J. Lajoie (ed.), Flysch Sedimentology in North America; Geological Association of Canada, Special Paper 7, 272 p.

Smitheringale, W.G., 1960. Geology of Nictaux-Torbrook map-area, Annapolis and Kings counties, Nova Scotia; Geological Survey of Canada, Paper 60-13, 32 p.

Stevenson, I.M., 1956. Shubenacadie, Nova Scotia; Geological Survey of Canada, Paper 55-27, map with marginal notes.

Stevenson, I.M., 1959. Shubenacadie and Kennetcook map-areas, Colchester, Hants and Halifax counties, Nova Scotia: Geological Survey of Canada, Memoir 302, 88 p.

Taylor, F.C., 1967a. Reconnaissance geology of Shelburne map-area, Queens, Shelburne, and Yarmouth counties, Nova Scotia; Geological Survey of Canada, Memoir 349, 83 p.

Waldron, J.W.F. and Jensen, L.R., 1984. Goldenville Formation, Eastern Shore, Nova Scotia; stratigraphic correlation and preliminary sedimentological results; pp. 147-155: in R.G. Blackadar et al. (eds.), Current Research, Part A; Geological Survey of Canada, Paper 84-1A, 666 p.

Woodman, J.E., 1904a. Nomenclature of the gold-bearing metamorphic series of Nova Scotia; American Geologist, vol. 33, pp. 364-370.

Woodman, J.E., 1904b. The sediments of the Meguma Series of Nova Scotia: American Geologist, vol. 34, pp. 13-34.

Source: CSPG Lexicon of Canadian Stratigraphy, Volume 6, Atlantic Canada; G.L. Williams, L.R. Fyffe, R.J. Wardle, S.P. Colman-Sadd, Boehner, R.C. (editor)
Contributor: J.W.F. Waldron
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 20 Jul 2018