Crestmore quarries, Crestmore, Riverside Co., California, USA
|Latitude & Longitude (WGS84):||34° 1' 25'' North , 117° 23' 2'' West|
|Latitude & Longitude (decimal):||34.02361,-117.38389|
|Köppen climate type:||Csa : Hot-summer Mediterranean climate|
Two irregular, very roughly parallel, lenticular bodies of magnesium-rich limestone of Mississippian age were deposited, each approximately 400 feet thick, and whose principal portions have dips up to 45° E or ENE. The prevalent N or NNW strike conforms to the trend of the Peninsular Range to the south, and is almost perpendicular to that of certain other metamorphic rocks near Riverside (Woodford et al., 1941).
The lower is the Chino Limestone and the upper is the Sky Blue Limestone. They are separated by gneissic hornfelses, quartz-mica schists and diorite. The beds were metamorphosed and recrystallized into marble during the early Triassic. Several later magmatic intrusions produced a complex suite of contact metamorphic minerals.
The first intrusion was of quartz diorite that penetrated the Chino Limestone. The second intrusion was of a quartz monzonite porphyry that was responsible for the classic contact metamorphism and skarn mineralogy. This latter intrusion was comprised of two pipe-like structures, ranging from 200 to 300 feet diameter. The first pipe intruded the quartz diorite and the Sky Blue Limestone. The second pipe pushed up through the metasedimentary rocks and terminated in the Sky Blue Limestone (Forrester, 2004). Numerous large and small pegmatite dikes cut the quartz monzonite porphyry and extend into the adjacent rocks, especially into the great masses of garnet-rich contact rocks which have developed from the original limestone (Woodford et al., 1941). The end result was a high-temperature, low-pressure contact aureole with marbles, skarn and pegmatites.
For more information, see the Crestmore page (http://www.mindat.org/loc-15527.html).
Mindat ArticlesWightmanite by Richard Gunter
Mineral ListMineral list contains entries from the region specified including sub-localities
161 valid minerals. 8 (TL) - type locality of valid minerals. 1 (FRL) - first recorded locality of unapproved mineral/variety/etc. 1 erroneous literature entry.
Rock Types Recorded
Rock list contains entries from the region specified including sub-localities
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Entries shown in red are rocks recorded for this region.
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
0 - 0.0117 Ma
Age: Anthropocene (0 - 0.0117 Ma)
Description: Sand, gravel, and bedrock from pits, quarries, and excavations related to construction, mining, or quarrying activities; mapped primarily where materials are placed for construction of highways, canals, railway grades, dams, and water catchment basins. Only large features are mapped; not shown in some places where unit obscures detailed surficial or bedrock relations. Differs from disturbed ground (Qdg) in that generally large amounts of rock and (or) sediment have been imported to site
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. 
|Holocene - Pliocene|
0 - 5.333 Ma
|Quaternary alluvium and marine deposits|
Age: Cenozoic (0 - 5.333 Ma)
Stratigraphic Name: Temescal Formation; Modesto Formation; Victor Formation; Alameda Formation; Aromas Red Sands; Bautista Beds; Brawley Formation; Borrego Formation; Burnt Canyon Breccia; Cabezon Fanglomerate; Campus Formation; Casitas Formation; Chemehuevi Formation; Corcoran Clay; Cushenbury Springs Formation; Dos Picachos Gravels; Dripping Springs Formation; Frazier Mountain Formation; Friant Formation; Harold Formation; Heights Fanglomerate; Hookton Formation (part); Huichica Formation; La Habra Formation; Manix Lake Beds; Mohawk Lake Beds; Montezuma Formation; Nadeau Gravel; Ocotillo Conglomerate; Orcutt Formation; Pacoima Formation; Pauba Formation; Peckham Formation; Pinto Formation; Resting Springs Formation; Riverbank Formation; Rohnerville Formation; San Dimas Formation; Shoemaker Gravel; Temecula Arkose; Battery Formation; Bay Point Formation; Colma Formation; Lindavista Formation; Lomita Marl; Merritt Sand; Millerton Formation; Palos Verdes Sand; San Pedro Formation; Sweitzer Formation; Timms Point Silt
Description: Alluvium, lake, playa, and terrace deposits; unconsolidated and semi-consolidated. Mostly nonmarine, but includes marine deposits near the coast.
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.