The Sylvania Sandstone 1n Southwestern Ontario

CIM Bulletin, 1961

G. H. REAVELY ; C. G. WINDER

The lower Middle Devonian Sylvania Sandstone occurs in the subsurface in the western part of Malden township, Essex county, Ontario. The formation is composed of well rounded, frosted quartz grains with a silica content varying from 42 to 93 per cent and the grains are cemented by carbonate, constituting up to 57 per cent of the rock. This sandstone is not a homogeneous bed but the bedrock from Fort Erie westward to Woodstock and London and northward to the Lake Huron shoreline from the vicinity of Grand Bend to Port Elgin, and the greater part of Essex county (Sanford, 1958). The total thickness varies between 500 and 700 feet. STRATIGRAPHY OF THE LOWER MIDDLE DEVONIAN SOUTHWESTERN ONTARIO CARBONATES SANDSTONES MAX THICKNESS OELAW~RE 240 COLUMBUS 35 . is divided by strata rich in carbonate cement. The thickness of the Sylvania in Malden township varies up to a known maximum thickness of 88 feet. The lower contact with the chert-bearing Bois Blanc formation is sharp but the upper contact with the Amherstburg formation (Detroit River group) exists as a transition by a gradual downward increase in quartz grains. The Sylvania would seem to outcrop in the lake bottom near the mouth of the Detroit River dipping to the north along a broad anticline the axis of which follows the Detroit River. Just south of Amherstburg, a local east-west trending flexure brings the Sylvania to the bedrock surface. Outcropping in the bottom of the Amherstburg channel has been confirmed by dredging at the south end of Bois Blanc Island.

Keywords: Amherstburg, Detroit River, Ontario, Sylvania Formation, Sylvania Sandstone Innerkip quarry., Carbonate, carbonates, Cement, formation, limestone, North, Ontario, quartz, Sandstone, Silica