Lowey, Grant W.1
(1) Yukon Geological Survey, Whitehorse, YT
ABSTRACT: Exploration of the Whitehorse Trough (Yukon, Canada): Petroleum Potential of a Frontier Basin
The Whitehorse Trough is a northward tapering belt (approximately 70 km wide and 600 km long) of Upper Triassic to Middle Jurassic volcanic and sedimentary rocks in the northern Cordillera of south-central Yukon, Canada. It formed during Early Mesozoic collisional convergence of the volcano-plutonic Stikine Terrane with the ancient North American margin, and consists of the Lewes River (Upper Triassic-Lower Jurassic) and Laberge (Lower-Middle Jurassic) groups. The Lewes River Group is subdivided into the Povoas and Askala formations, which represent subaerial and subaqueous volcanic and volcaniclasitic flows, and carbonate reefs and nearshore marine to beach deposits, respectively. The disconformably overlying Laberge Group is subdivided into the Richthofen, Conglomerate, Nordenskiold and Tanglefoot formations, which represent basinal marine clastics, proximal coarse clastics, epiclastics and tuff flows, and deltaic to shallow marine coal-bearing clastics, respectively.
Petroleum exploration of the Whitehorse Trough began in the 1950's with the permitting of 437,101 ha. In 1985 Petro-Canada carried out limited fieldwork to characterize source rock potential, and in 2001 the National Energy Board undertook a petroleum resource assessment of the Whitehorse Trough that identified 3 gas with minor oil plays and 5 soley gas plays and concluded that the Whitehorse Trough is an imature, maily gas-prone basin containing an estimated 25,000-116,000 million cubic meters (0.9-4.1 Tcf) of gas (although no petroleum wells have been drilled).
The Yukon Geological Survey is currently undertaking a detailed study of the stratigraphy, sedimentology and structural setting of the Whitehorse Trough, including a seismic survey and collecting samples for Rock-Eval analysis.
AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.