Chalk Mountain District, Churchill Co., Nevada, USA
|Latitude & Longitude (WGS84):||39° 19' 45'' North , 118° 7' 25'' West|
|Latitude & Longitude (decimal):||39.32917,-118.12361|
|Köppen climate type:||BWk : Cold desert climate|
No description has been added for this locality. Can you add one?
Mineral ListMineral list contains entries from the region specified including sub-localities
37 valid minerals.
Rock Types Recorded
Rock list contains entries from the region specified including sub-localities
Select Rock List TypeAlphabetical List Tree Diagram
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
|Middle Jurassic - Middle Triassic|
163.5 - 247.2 Ma
|Walker Lake Terrane - Pamlico-Lodi assemblage - Carbonate and volcanogenic rocks|
Age: Mesozoic (163.5 - 247.2 Ma)
Stratigraphic Name: Dunlap Formation; Excelsior Formation; Gabbs Formation; Sunrise Formation; Luning Formation
Description: The Pamlico-Lodi assemblage differs stratigraphically from the Luning-Berlin assemblage in that the Triassic carbonate sequences are interstratified with volcanic and volcanogenic rocks, not continentally derived epiclastic chert, conglomerate, sandstone, and argillite (Oldow, Satterfield, and Silberling, 1993; Silberling and John, 1989). The uppermost part of the sequence is a regionally extensive carbonate shelf like the Luning-Berlin assemblage. This is conformably overlain by quartz arenite and poorly sorted coarse clastic rocks faunally dated as Early Jurassic that grade upward into volcanogenic sedimentary and volcanic rocks (Oldow, 1984a; Oldow and Bartel, 1987). The Pamlico-Lodi assemblage has a polyphase folding history similar to the Luning-Berlin assemblage that was caused by northwest-southeast directed thrusting that displaced the rocks tens of kilometers toward the southeast (Oldow, 1984a). Compared with the Luning-Berlin assemblage to the east, however, rocks of the Pamlico-Lodi assemblage manifest much more shortening from this first deformation of southeast-directed tectonic transport (Speed, Silberling, and others, 1989). This assemblage is exposed in Churchill, Mineral, and northern Nye Counties. It includes rocks mapped as Dunlap, Excelsior, Gabbs, Sunrise, and Luning Formations.
Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052.