Mockingbird Mine (Talc & Lacy claim), Colorado area, Whitlock District, Bagby-Mariposa-Mount Bullion-Whitlock District, Mother Lode Belt, Mariposa Co., California, USA
|Latitude & Longitude (WGS84):||37° 33' 33'' North , 119° 58' 48'' West|
|Latitude & Longitude (decimal):||37.55917,-119.98000|
|Köppen climate type:||Csb : Warm-summer Mediterranean climate|
A former lode Au mine located in sec. 27, T4S, R18E, MDM, 1.0 km (3,100 feet) W of the Colorado School, along a small tributary of Saxon Creek, on private land. Named the Talc & Lacy claim (pre-1900). Discovered < 1890. Produced 1890's to 1920. Patented claim(s) amounted to 20 acres. Operator David W. And Maxie S. Dukes. MRDS database stated accuracy for this location is 1,000 meters.
Mineralization is a vein deposit hosted in slate and greenstone. The ore body strikes N40-45W and dips 90. Gold occurs at the border of a nearly vertical, chloritic, altered greenstone dike where gently-dipping quartz stringers cutting the dike cut the slate wall rocks. Altered dike averages 3 feet thick. The quartz stringers are a fraction of an inch to several inches thick. The deposit produced specimens of wiry & arborescent gold. Local rocks include Mesozoic volcanic rocks, unit 2 (Western Sierra Foothills and Western Klamath Mountains) and/or Jurassic marine rocks, unit 1 (Western Sierra Nevada and Western Klamath Mountains).
Workings include surface and underground openings with an overall depth of 30.48 meters comprised of 1 shaft with drifts and a tunnel several hundred feet long.
Production data are found in: Bowen, O.E., Jr. & C.H. Gray, Jr. (1957).
No other production record found.
7 valid minerals.
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
|Late Jurassic - Triassic|
145 - 252.17 Ma
|Jurassic marine rocks, unit 1 (Western Sierra Nevada and Western Klamath Mountains)|
Age: Mesozoic (145 - 252.17 Ma)
Stratigraphic Name: Agua Fria Formation; Colfax Formation; Cosumnes Formation; Galice Formation; Hunter Valley Cherts; Mariposa Formation; Merced Falls Slate; Salt Spring Slate; Jasper Point Formation
Comments: Western Klamath Mountains, western Sierra Nevada. Primarily slate and metamorphosed graywacke; minor siltstone, conglomerate, chert, and volcanic rocks. Mainly Late Jurassic in age, but also includes some Early Jurassic or older rocks
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. 
Laizure, Clyde McK (1928), Mariposa, Madera Counties: California Journal of Mines and Geology, California Mining Bureau (Report 24): 24: 101.
Bowen, O.E., Jr. & C.H. Gray, Jr. (1957), Mines and mineral deposits of Mariposa County, California: California Journal of Mines and Geology: 53(1&2): 133, 286.
Bowen, W.E. and Evans (1966).
Clark, Wm. B. (1970a) Gold districts of California: California Division Mines & Geology Bulletin 193.
Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 24 (map 2-13).
USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10114883 & 10031128.
Mineralogical Record (2007): 38: 212.
Cook, R. & T. Gressman (2008) The Mockingbird Gold Mine, Mariposa County, California. Rocks & Minerals 83(5): 392-401.
U.S. Bureau of Mines, Minerals Availability System (MAS) file ID #0060430462.