Recovery – 2011 CSPG CSEG CWLS Convention
1
Seismic-stratigraphic Analysis and Sequence-stratigraphic Controls on the Second-
order Transgressive – Regressive Cycle of the Uppermost Devonian to Carboniferous
Deposits and the Exploration Significance of the Erosion Unconformity in the Upper
Paleozoic Strata of the Eagle Plain Basin, Northern Yukon of Canada
Gillian Q. Chi*
University of Calgary, Calgary (Open Students),
2500 University Drive N.W. Calgary, Alberta, Canada T2N 1N4
qchi@ucalgary.ca
Larry Lane
Geological Survey of Canada, Calgary
Summary
Investigation of the Uppermost Devonian to Carboniferous sedimentary strata in the Eagle Plain basin of
Northern Yukon shows that this highly cyclic rock succession is composed of a second-order transgressive
– regressive cycle characterized by the Uppermost Devonian sandy incised channel-fills in the base and
resting on a large scale of unconformity separating with the underlying Upper Devonian turbidite deposits;
thick shaly Lower Carboniferous Ford Lake Formation transgressing these channel deposits and followed
by eight southward prograding depositional wedges from the Hart River to Ettrain Formations during the
Middle and Late Carboniferous. High rates of sediments supply, subsidence on the continental shelf and
regional and local tectonic activities are believed to produce and control to some extent these prograding
wedges that recorded the high frequency regressive episodes and were corresponding to the globe sea level
drop. Large scale of slump occurred during this time and covered a large area in the southern Eagle Plain
basin. Parts of the top surfaces of these wedges have been eroded out by the fast tectonic uplifting in the
north. Oil and gas have been discovered half century ago in one of these wedges, such as the Chance oil
field with a type of structural - stratigraphic trap. Local faults cut these wedges, extended to the underlying
source rock of the Middle to Late Devonian Cano and Imperial Formations and controlled on local
hydrocarbon migration. So to delineate the complex stratigraphic framework of these depositional wedges
with the relationship of the local faults is vital to hydrocarbon resource assessment in this play.
