Lord Mine, Corona, Santa Ana Mts, Riverside Co., California, USA
|Latitude & Longitude (WGS84):||33° 49' 40'' North , 117° 35' 12'' West|
|Latitude & Longitude (decimal):||33.82778,-117.58667|
A former Fe (ochre) occurrence/mine located in the NW¼ sec. 14, T4S, R7W, SBM, about 6.0 km SSW of Corona (center), on the divide between Hagador Canyon on the N and Main Street Canyon on the S, along the eastern margin of the Santa Ana Mountains, on apparent National Forest land. Material used as a paint pigment. MRDS database stated accuracy for this location is 100 meters.
Local rocks include Mesozoic volcanic rocks, unit 4 (Peninsular Ranges).
Workings include unspecified surface openings.
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
56 - 66 Ma
Age: Paleocene (56 - 66 Ma)
Description: Nonmarine and marine sandstone, siltstone, and conglomerate. Dickerson (1914) first recognized Paleocene rocks in Santa Ana Mountains, and based on faunal similarities, correlated strata with Martinez Formation of central California. Woodring and Popenoe (1945) described unit in detail and named it Silverado Formation. Formation was deposited on deeply weathered erosional surface. Rocks underlying Silverado are characteristically saprolitic. Silverado Formation consists of basal conglomerate overlain by relatively thin sequence of sandstone and siltstone. Distinctive Claymont clay bed overlies sandstone and siltstone sequence, and is overlain by thick sequence of sandstone, siltstone, and conglomerate that includes second clay bed, known as Serrano clay bed. Basal conglomerate is thoroughly weathered, 2- to 25-m-thick, massive, pale gray to reddish-brown, pebble conglomerate. Very locally is boulder conglomerate. Overlying conglomerate is sandstone and siltstone which is also thoroughly weathered, consisting largely of quartz and clay. Claymont clay bed is 1- to 3-m thick, brown, green, and gray clay that weathers to distinctive brownish-red. Bed is mostly clay, partly pisolitic, and has scattered quartz grains in it. Locally, supports large-scale clay operation. Upper part of unit above Claymont clay bed is diverse section of marine and nonmarine sandstone, siltstone, and conglomerate, and includes Serrano clay bed. Latter is about 1 m thick, pale gray to white, and composed of nearly equal amounts plastic clay and quartz. In addition to clay, upper part of section contains carbonaceous shale and lignite beds. Thicker lignite beds were locally mined for fuel. Upper part of unit also contains abundant marine mollusks. Some eastern exposures of formation contain distinctive and diagnostic Paleocene Turritella pachecoensis. Basal conglomerate (Tsicg) and Serrano Clay (Tsis) are subdivided locally
Reference: Morton, D.M., F.K. Miller . Geologic Map of the San Bernardino and Santa Ana 30' x 60' quadrangles, California. U.S. Geological Survey Open-File Report 2006-1217. 
56 - 66 Ma
|Paleocene marine rocks, unit 1 (Central and Southern California)|
Age: Paleocene (56 - 66 Ma)
Stratigraphic Name: Laguna Seca Formation; Las Virgenes Sandstone; Lodo Formation; Martinez Formation; Pattiway Formation; San Francisquito Formation; Silverado Formation; Simi Conglomerate; Vine Hill Sandstone; Locatelli Formation; Point Reyes Formation
Comments: Miscellaneous units
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. 
USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10164012.
U.S. Bureau of Mines Minerals Availability System/Mineral Industry Location System (MAS/MILS): file #0060650925.