New lithostratigraphic units in the Notch Peak and House Formations (Cambrian-Ordovician), Ibex area, Western Millard County, Utah


Type areas of the uppermost Cambrian Millardan Series and lowermost Ordovician Ibexian Series are in the Ibex area of Millard County, Utah. The Notch Peak Formation and the House Limestone include this series boundary, which is near the middle of the Lava Dam Member of the Notch Peak Formation, the youngest of its three members. Slightly above the series boundary is the Tank Canyon Bed (new), an ooid grainstone that in most places is less than one meter thick and is 1-2 m above the series boundary. Slightly higher is the Lawson Cove Bed (new), a stromatolite or thrombolite bed 1-1.5 m thick. These beds can be traced from the northern Wah Wah Mountains to the Sneakover Pass area in the central House Range. The Tank Canyon Bed can be traced westward into Nevada. Type sections of both beds are in the Lawson Cove area in the northern Wah Wah Mountains. The House Limestone is herein divided, in ascending order, into three members, the Barn Canyon, Burnout Canyon, and Red Canyon members. The Barn Canyon and Burnout Canyon members have type sections in the Lawson Cove area, and the type section of the Red Canyon Member is in the Lava Dam area in the southern House Range. These members can be traced throughout the southern and central House Range and into the northern Drum Mountains. The lower two members can be traced westward into Nevada.


Geography, Geology, and Planning

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Brigham Young University Geology Studies