|
|
|
Lower and Middle Devonian (L. Gal, L. Pyle) |
Lower and Middle Devonian strata in the Peel Plateau and Plain include a series of shelf carbonates that pass westward to basinal shales. The carbonates are also overlain stratigraphically by shale, including important hydrocarbon source rocks.
During the 2006 and 2007 field seasons, several stratigraphic sections through these strata were examined and measured. Dolostone and limestone comprising the Peel, Tatsieta, Arnica, and Landry formations are mainly shallow water, relatively tight carbonates. Some medium and coarse-grained dolomite, and breccias were observed, principally within Arnica Formation. Western exposures of Arnica Formation include fossiliferous limestone biostromes. The overlying Hume Formation is very fossiliferous, but it is argillaceous, and reefal bodies are lacking. Hare Indian Formation shale at the top of the Middle Devonian includes the basal Bluefish Member, a black organic shale. Canol Formation is a second organic shale, overlying Hare Indian Formation. Locally developed Ramparts Formation limestone lies between Hare Indian and Canol formations. In the eastern part of Peel Plain it includes reefal Kee scarp member
About 65 outcrop samples of shale were collected for Rock-Eval and for total organic carbon analysis. Petrographic studies of selected carbonate rocks will focus on porosity development, diagenesis, and dolomitization. Newly measured sections will be tied to subsurface boreholes.
|
Photo gallery
|
|
|
The Powell Creek section: On the left, Hume Formation weathering orange-grey, Hare Indian Formation poorly exposed where the trees come down to creek level, Upper Hare Indian and Ramparts Formation in the center, yellow-orange-red and black weathering Canol Formation at center right, and rusty-weathering Imperial Formation on the right. |
|
|
|
A large solitary coral in Hume Formation. |
|
|
|
|
Looking north of a ridge at the front of the Mackenzie Mountains toward Peel Plain. Kindle Formation in foreground, overlain by recessive orange and grey-weathering Peel Formation, followed by Tatsieta Formation light grey resistant limestone. Light and dark grey striped Arnica Formation is visible at the end of the ridge. |
|
|
|
Arnica Formation medium-grained sucrosic dolostone. A sample similar to this had 6% porosity. |
|
|
|
Stromatolite in Tatsieta Formation limestone. |
|
|
|
Outputs |
Gal presented An assortment of observations and analyses regarding petroleum potential of Paleozoic rocks, Peel Plateau and Plain, Northwest Territories and Yukon, a talk at Yellowknife Geoscience Forum November 18-20, 2008.
Rock-Eval 6 / TOC analyses from outcrop samples in northern Mackenzie Mountains, eastern Richardson Mountains, and southern Peel Plateau and Plain Northwest Territories and Yukon Canada. Download Now
Petroleum Reservoir and Source Rock Potential in Lower and Middle Paleozoic strata of Peel Plateau and Plain, Northwest Territories and Yukon. Poster presented by Gal et al. at the CSPG-AINA Gussow Geoscience Conference (October 15-17, 2007) in Banff, AB.. Download Now
|
|
