Gays River Formation

Unit Name: Gays River Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Early Carboniferous (359.2 - 318.1 ma)
Age Justification: The Gays River Formation contains complex carbonate mounds located on paleotopographic highs. They contain a varied fauna of Cnidaria, Ectoprocta, brachiopods, pelecypods, gastropods, tabulate corals, and algae (Ryan, 1978a, 1978b). Blue-green Codiacean and Dasycladacean algae are common mound constituents and often dominate the biota (Giles et al., 1979; Giles, 1981). Based on lithology, the Gays River Formation was placed at the base of the Windsor Group, within the A faunal subzone of Bell (1929), which indicates an Early to Middle Viséan age. Rocks containing fossils of subzone A are typically very sparsely fossiliferous, with the exception of the Gays River. Miospores, immediately beneath the Gays River in New Brunswick, were assigned by Utting (1980) to his Assemblage Zone I indicating a Middle Viséan age.
Province/Territory: New Brunswick; Nova Scotia

Originator: Giles, Ryan and Boehner, 1979.

Type Locality:

Imperial oil Ltd. diamond-drill hole GR 256 (45 deg 01'54" N, 63 deg 20'31" W; NTS 11 E/3W), between 15.5 and 48.2 m, near the Gays River Mine, Shubenacadie subbasin, Nova Scotia (Ryan, 1978a, 1978b). A reference area is at the Mosher Brothers Limestone quarries (NTS 11 E/2W) at Upper Musquodoboit, Musquodoboit subbasin, central Nova Scoba (Boehner, 1977). Auxilliary reference sections are in New Brunswick: 120 m downstream to the tributary of Trout Creek, from intersection of roads to Walker and Chambers settlements (NTS 21 H/11W); Borehole P-10 (45 deg 39'20" N, 66 deg 43'24" W; NTS 21 H/12E), between 126.9 and 204.9 m, Peekaboo Corner, Kings County, New Brunswick. The core is stored at the Geological Surveys Branch, New Brunswick Department of Natural Resources, Sussex.

Distribution:

At the type section, the formation is 32.7 m thick where it is a bank facies, but may be as thin as 3 m in the flanking interbank facies. The bank facies is developed locally and, together with the interbank facies, they are widespread regionally in the Musquodoboit subbasin, the adjacent Shubenacadie subbasin, and in many areas of Nova Scoba (Giles et al., 1979) and New Brunswick (McCutcheon, 1981b). In New Brunswick the apparent maximum thickness is about 80 m. It outcrops intermittently from Chambers Settlement (NTS 21 H/11W) southwestward along the Caledonia Highlands to Upham (NTS 21 H/5E). It also outcrops in the Peekaboo Corner (NTS 21 H/12E) and Havelock (NTS 21 H/14W) areas, Kings County; near Berryton (NTS 21 H/15W) and in the Wilson Brook (NTS 21 H/15E) area, Albert County.

Lithology:

A complicated suite of dolomitued carbonates, including algal boundstone and bafflestone with associated skeletal packstone and wackestone and locally developed basal breccia-conglomerate. In New Brunswick, it is represented generally by nondolomitized carbonates, including fossiliferous algal boundstone with interbedded bioclastic wackestone and packstone.

Relationship:

The Gays River Formation conformably overlies the Lower Carboniferous Horton Group and it overlies pre-Carboniferous terrain (Cambrian to Ordovician Meguma Group) with angular unconformity where the Horton is absent. It is conformably overlain by the Carrolls Corner Formation in the Shubenacadie subbasin and locally by the Meaghers Grant Formation. Bnehner (1977) and Giles and Boehner (1982a) correlated the Gays River Formation with the Macumber Formation (Weeks, 1948). The Windsor Group includes, in the Shubenacadie subbasin, the Macumber and laterally equivalent Gays River, Carrolls Corner, Stewiacke, MacDonald Road, and Green Oaks formations. In the adjacent Musquodoboit subbasin, it includes the Gays River, Meaghers Grant, Carrolls Corner, Elderbank, and Green Oaks formations. In New Brunswick the Gays River Formation unconformably overlies pre- Carboniferous terrain and disconformably overlies the Lower Carboniferous Hillsborough Formation of the Moncton Group (McCutcheon, 1981b). It is disconformably overlain by the Carboniferous Hopewell Group. The formation is laterally equivalent to the Macumber and Upperton formations, also of the Windsor Group.

History:

The Gays River Formation was introduced by Boehner (1977) in the Musquodoboit subbasin, Nova Scotia, in a M.Sc. thesis. It was described further by Giles and Boehner (1979, 1982b), Giles et al. (1979) and Ryan (1978a, 1978b). The name was first applied to rocks in New Brunswick by McCutcheon (1981b). Prior to this they were not mapped as a separate unit. Gesner (1841, p. 37) referred to the Windsor Limestone as "Lias". Bailey (1865) included these rocks in his Sub-Carboniferous Series. Bailey and Ells (1878, pp. 380-383) described Gays River rocks under Division V of their "Lower Carboniferous Formation". Young (1912) included them in his "Intermediate group". Rocks of the Gays River Formation were included in Zone No. 2 of the Hillsborough Series of Wright (1922), the Hammond River Formation (abandoned) of Hayes and Howell (1937), the Upham Formation (abandoned) of Alcock (1938), the Devine Corner Member (abandoned) of Anderle et al. (1979), and in the undivided Windsor Group in various places (Alcock and MacKenzie, 1946; Norman, 1941a; Stewart, 1941b). Gussow (1953) believed that these rocks belonged to Subzone B of Bell (1929).

Other Citations:

Alcock, 1938; Alcock and MacKenzie, 1946; Anderle et al., 1979; Bailey, 1865; Bailey and Ells, 1878; Bell, 1929; Boehner, 1977; Gesner, 1841; Giles, 1981; Giles and Boehner, 1979, 1982a, 1982b; Giles et al., 1979; Gussow, 1953; Hayes and Howell, 1937; McCutcheon, 1981b; Norman, 1941a; Ryan, 1978a, 1978b; Stewart, 1941b; Utting, 1980; Wright, 1922; Young, 1912.

Source: LEXICON_NB
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 26 Feb 2005