Alberhill Clay pits (Alberhill Coal & Clay Company deposit), Alberhill, Temescal Valley, Riverside Co., California, USA
|Latitude & Longitude (WGS84):||33° 43' 19'' North , 117° 23' 4'' West|
|Latitude & Longitude (decimal):||33.7219444444, -117.384444444|
A former clay pit operation located in secs. 21, 22, 23 & 26, T5S, R5W, SBM, 4½ miles N of Lake Elsinore with a number of pits S of Alberhill, SE end of the Temescal Valley. Also in secs. 15, 24 & 25.
3 valid minerals.
Major Regional Geological Units
This 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 geology at this locality but it gives a background for the region in which it is found.
56 - 66 Ma
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
56 - 66 Ma
|Paleocene marine rocks, unit 1 (Central and Southern California)|
66 - 145 Ma
|Cretaceous plutonic rocks|
66 - 145 Ma
|Cretaceous volcanic: intermediate rocks|
References for regional geology:
Data provided by Macrostrat.org
Garrity, C.P., and Soller, D.R.,. Database of the Geologic Map of North America: adapted from the map by J.C. Reed, Jr. and others (2005). U.S. Geological Survey Data Series 424 .
Geological Survey of Canada. Generalized geological map of the world and linked databases. doi:10.4095/195142. Open File 2915d.
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.
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.
Allen, Victor T. (1946), Some United States boehmite localities: (abstract) Geological Society of America Bulletin: 57: 1173.
Engel, R., T.E. Gay, and B.L. Rogers (1959) Mineral deposits of Lake Elsinore quadrangle, California California Division Mines and Geology Bulletin 146: 77-95.
Minobras (1973), Southern California Industrial Minerals: 51.
Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 108, 235.
Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 144, 438.
Anthony, J. W. et al. (1997): Handbook of Mineralogy, Vol. 3: 70.