Logo Picture Left SideLogo Picture Right SideLogo Text at Center
Home > Search > Site Map > California > CA - Quarry Links & Photographs > Contra Costa County - List of Stone Quarries, Etc.

Contra Costa County - List of Stone Quarries, Etc. *

(* Please note this list does not include all of the sand or gravel quarries in Contra Costa County.)

  • Contra Costa County, California – Canal Boulevard Quarry (Stone) (active ca 1996) (From Mines and Mineral Producers Active in California (1994-1995), Special Publication 103 (Revised 1996), California Department of Conservation, Division of Mines and Geology, in cooperation with California Department of Conservation, Office of Mine Reclamation. Used with permission, California Department of Conservation, California Geological Survey.)

    Mine name: Canal Boulevard Quarry; Operator: Bauman Landscape; Address & County: 115 Brookside Dr., Richmond, CA 94801, Contra Costa County; Phone: (510) 231-1212; Latitude: 37.91, Longitude: -122.37, and Mine location number: Map No. 43; Mineral commodity: Stone

  • Antioch (south of), Contra Costa County, California – Antioch Quarry (Gravel) (From The Structural and Industrial Materials of California, Bulletin No. 38, California, State Mining Bureau, San Francisco, California, 1906.)

    “Antioch Quarry. A small quarry is located about one mile south of the Southern Pacific Railroad depot at Antioch, in a bank of loosely cemented gravel, which is easily quarried and furnishes a very good macadam. It is worked intermittently as macadam is needed for the roads.”

  • Antioch (southwest of), Contra Costa County, California – Harkinson Lime Deposit (Lime) (From The Structural and Industrial Materials of California, Bulletin No. 38, California, State Mining Bureau, San Francisco, California, 1906.)

    “Harkinson Lime Deposit, in Sec. 16, T. 1 N., R. 1 E., M. D. M.; R. Harkinson, Antioch, owner. The deposit, which is about 7 miles southwest of Antioch, in Oil Cañon, has been developed by a tunnel. The rock is an amorphous, compact, bluish-gray fossiliferous limestone. Very little of the rock has been shipped.”

    • Antioch (southwest of), Contra Costa County, California - Harkinson Limestone Quarry (Limestone) (From "Mines and Mineral Resources of Contra Costa County, California," California Journal of Mines and Geology, Vol. 54, No. 4, State of California, Department of Natural Resources, Division of Mines, San Francisco, California, October, 1958, pp. 501-583.) (Used with permission, California Department of Conservation, California Geological Survey.)

      "Claim, mine, or group": Harkinson. This quarry was located at 1 N, 1 E, M. D. "In Oil Canyon, 7 miles southwest of Antioch. Compact, amorphous, bluish-gray, fossiliferous limestone. Small shipment (?). Idle (B 38:67.)."

  • Antioch (southwest of), Contra Costa County, California - Limestone Quarry (From "Mines and Mineral Resources of Contra Costa County, California," California Journal of Mines and Geology, Vol. 54, No. 4, State of California, Department of Natural Resources, Division of Mines, San Francisco, California, October, 1958, pp. 501-583.) (Used with permission, California Department of Conservation, California Geological Survey.)

    "Claim, mine, or group": Coates. This quarry was located at 1N, 1E, M. D. "In Oil Canyon, 7 miles southwest of Antioch. Adjoins Harkinson deposit. Small production (?). R 12:380; B 38.66.)."

  • Brooks Island, Contra Costa County, California - Brooks Island Sandstone Quarry (Graywacke)
    • Brooks Island, today a part of the East Bay Regional Park District.

      Brooks Island is a small island located just off the Richmond Inner Harbor. It is now a part of the East Bay Regional Park system. According to the description on the East Bay Regional Park district web site, “With the advent of European settlers, the island was used for grazing and quarrying.”

      According to the “Brooks Island Shoreline Regional Shoreline” Brochure (pdf), “Access available by permission permit only.”  Call 510-636-1684 for reservations and information.”

    • Brooks Island Regional Preserve – About the Park  (photographs, history, information, & trail map)

      “...Over the years, Brooks Island has had many owners – and has been known by a variety of names, including Isla de Carmen, Rocky Island, Bird Island, and Sheep Island. The East Bay Regional Park District acquired the island in 1968.”

    • Brooks Island Shoreline Regional Shoreline” Brochure (pdf), presented by the East Bay Regional Park District.

      (The following excerpts are from the brochure regarding the sandstone quarry.)

      “Access available by permission permit only.  Call 510-636-1684 for reservations and information.

      “...Rusting quarry equipment, old rock and concrete foundations, exotic-looking wind-sculptured trees, offshore rotting hulls of sunken ships, deteriorating pier pilings surrounded by water – all transport us from our busy daily lives to an authentic historic storybook setting of mystery.”

      “Brooks Island was used as a quarry intermittently from 1892-1938.  The rock is said to have been used by San Quentin prisoners in constructing Treasure Island as well as the south cell block of San Quentin penitentiary.  They Army Corps of Engineers built harbors and a breakwater to protect the Richmond Marina.  The quarrying left extremely steep slopes along the top of the island.  For your safety, please stay on established trails.”

    • Brooks Island, Contra Costa County, California – Sandstone Quarrying on Brooks Island.  The following excerpt is from Lepidoptera (Butterflies And Moths) of Brooks Island, California (pdf), by Jerry A. Powell, Essig Museum of Entomology, University of California, Berkeley, CA 94720, June 2005, pp. 1.

      “Brooks Island is situated in San Francisco Bay, less than a mile from the Richmond Marina and about a quarter mile from Point Potrero on the northeast shore of the bay.  Nonetheless the island has remained relatively secluded from casual visitors through a history of private ownership and guarded by surrounding mud flats that prevent boat access except during higher tide hours. The main island consists of a rocky ridge of Franciscan chert and is about 47 acres (22 ha) in area, rising to 160 feet (49 m) at the south end of the ridge, where it abruptly drops into a bowl representing the remnants of intermittent quarry operations prior to 1938. The island was purchased by a construction company about 1920 and was used as a quarry. Rock was removed for landfill at Treasure Island, San Quentin, and other bay projects and to construct a breakwater that protects the channel leading into the Richmond inner harbor. The breakwater, which was constructed in the 1920s, extends nearly two miles westerly from the island’s northwest corner and has accumulated sufficient sand to form a broad sand spit with coastal strand habitats, including several native plants and the insects dependent upon them. Quarrying ceasing in 1938 when the island was sold to a hunting club, who in effect protected the habitat until 1968 when the East Bay Regional Park District acquired the land. The Brooks Island Regional Shoreline Preserve occupies 75 acres, including the main island, sand spit, and an offshore rock that serves as a shore bird rookery.”

    • Brooks Island, Contra Costa County, California – Brooks Island Sandstone Quarry (Graywacke) The following information is from “An Island in Time:  A mile off the Richmond shoreline, tiny patch of land is host to history and nature – and not many people,” by Katherine Tam, in Contra Costa Times Sunday Edition, May 15, 2011, pp. A1 and A9.  (Several photographs are included with this article including the following photo caption:  “Dave Zuckermann, a supervising naturalist with the park district, stands near an old conveyor system that years ago was used to quarry rock from Brooks Island.”)

      “Thousands of Ohlone Indians lived on the island up to 3,000 years ago...European settlers arrived in the late 1700s...Remnants of the past remain:  rusting quarry equipment, ponds created by quarrying operations, old pilings...From the 1890s to the 1940s, the island was used as a rock quarry where workers harvested graywacke sandstone, some of which was used to build the Bay Bridge Toll Plaza and the Berkeley Aquatic Park.”

  • Concord (south of), Contra Costa County, California - Henry Cowell Lime Company's Lime Quarries (Limestone & Lime) (From The Structural and Industrial Materials of California, Bulletin No. 38, California, State Mining Bureau, San Francisco, California, 1906.)

    "Henry Cowell Lime Company's lime quarries lie 3 miles south of Concord, in the foothills on the northwest end of Mount Diablo. The rock is a travertine, which outcrops over a considerable area in the vicinity of the quarries. It varies in character, a large part of it being a very compact drab-colored stone, very faintly banded. In places it is bluish colored, and brecciated. Part of the stone is a snow white, porous, light tufa, which is irregularly mixed through the other rock. The compact rock, because of its high specific gravity, is thought to be aragonite.

    "There are two quarry openings. The one now in operation is an irregular, funnel-shaped opening, about 50 feet deep and covering probably about half an acre at the top. The other quarry is on the point of the hill, about one eighth of a mile south of west from the first mentioned and 50 feet or more above it, and has a face of 50 feet of limestone. The only covering over this stone at either opening is a thin layer of dark-brown adobe. The stone is cut by numerous seams and cracks, which cause it to come from the quarry in such small dimensions that there is very little of it that needs further breaking for the limekiln.

    "The stone is hauled by wagon from the quarry to the kiln on the railroad at Concord, where it is burned ready for shipment. At present (August, 1904) some unburned stone is being shipped."

    Ill. No. 25. Limestone Quarry of Henry Cowell Lime and Cement Company, Concord, Contra Costa County. Limestone Quarry of Henry Cowell Lime and Cement Company
    • Cowell, Contra Costa County, California – Cowell Portland Cement Co.  The following photograph are from “Growth of Cement Industry on Pacific Coast” (pdf), in Concrete-Cement Age, April 1913, Vol. 2, pp. 196-198.  (This magazine is available on Google Books at the following web address.)

      Works of the Cowell Portland Cement Co.” (Fig. 2, pp. 196) Works of the Cowell Portland Cement Co., Cowell, Contra Costa County, CA ca. 1913
      Cowell, Cal. ‘Mt. Diablo’ Cement”  (pp. 197) Works of the Cowell Portland Cement Co., Cowell, Contra Costa County, CA ca. 1913
    • Cowell, Contra Costa County, California - Henry Cowell Lime & Cement Company (Limestone) (Excerpt from "Limestone in California," by Clarence A. Logan, California Journal of Mines and Geology, Vol. 43, No. 3, July 1947, California Division of Mines, San Francisco, California, pp. 175-357. Used with permission, California Department of Conservation, California Geological Survey.)

      "Henry Cowell Lime & Cement Company. The cement plant is at Cowell, about 5 miles south of east from Concord and the travertine and clay used are quarried along the Mount Diablo fault nearby. Although the deposits of travertine on the part of Lime Ridge covered in the adjacent Concord quadrangle were not mentioned favorably in the San Francisco folio (Lawson, A. C. 14) the beds of this mineral worked by the Cowell interests have supported the cement plant for a long time.

      (*Andrew Cowper Lawson, Description of the San Francisco District: Tamalpais, San Francisco, Concord, San Mateo and Hayward Quadrangles, U. S. Geological Survey Geological Atlas, San Francisco folio (no. 193), 24 pp., maps, 1914.)

      "An analysis of a sample of the Cowell travertine taken by E. C. Eckel indicated 95.7 percent CaCO3, 1.4 percent silica, 0.92 percent alumina, and 0.76 percent magnesia. Several of the superficial deposits, 20 feet or more in thickness have been worked by electric shovel. The cement plant has a capacity of 4800 barrels a day. Operation of this plant was ended in 1946.

      "This travertine has been derived by springs from the calcareous sandstone of the Tejon (Eocene)."

      (Also see: Cowell, Contra Costa County, California - the Henry Cowell Lime and Cement Company Cement Mill (Lime and Limestone) below.)

    • Cowell (near), Contra Costa County, California - Limestone Quarries (Henry Cowell Lime and Cement Co.) (From "Mines and Mineral Resources of Contra Costa County, California," California Journal of Mines and Geology, Vol. 54, No. 4, State of California, Department of Natural Resources, Division of Mines, San Francisco, California, October, 1958, pp. 501-583. Used with permission, California Department of Conservation, California Geological Survey.)

      "Claim, mine, or group": "Cowell (Henry Cowell Lime and Cement Co.); Henry Cowell Lime Co.; Spreckels Sugar Company. "Owner name, address": Henry Cowell Lime and Cement Co., 2 Market St., San Francisco" These quarries were located at 8, 9, 17, 20, 1N, 1W, M. D. (projected) "Discontinuous masses of travertine crop out over a considerable area on Lime Ridge. Stone is white, buff or pale blue in color. Used in pre-1900 era for manufacture of lime. Quarried 1908-46 for manufacture of cement. Idle. (B 38:66; R 17:55; 23:15; 43:220; 47:567; 574.)."

    • Cowell, Contra Costa County, California - the Henry Cowell Lime and Cement Company Cement Mill/Plant (Lime and Limestone) (From "Mines and Mineral Resources of Contra Costa County, California," California Journal of Mines and Geology, Vol. 54, No. 4, State of California, Department of Natural Resources, Division of Mines, San Francisco, California, October, 1958, pp. 501-583.) (Used with permission, California Department of Conservation, California Geological Survey.)

      "The Mount Diablo quarries near Pacheco were the site of the first lime-making in California after the American occupation. This began in the spring of 1851 (Logan 1947) although no records of production previous to 1903 are available. The Henry Cowell Lime Company reported lime production from 1903 until 1915, excepting 1906 and 1908. The limestone was originally hauled from the quarries on Lime Ridge 3 miles southeast of Concord to Concord where the kiln was located. Later, four standard continuous kilns were installed immediately below the quarry.

      "The Henry Cowell Lime and Cement Company erected a cement mill at Cowell about 3 miles southeast of Concord in 1907. This dry-process plant went into production in 1908 using as raw material the travertine and clay deposits from the west slope of Lime Ridge immediately south of the plant. Cement was produced continuously from 1908 to 1946 except for a temporary shutdown in 1942, owing to strike conditions. Loss of railroad facilities to the U. S. Navy and the approaching depletion of the limestone deposits caused permanent closing of the plant in 1946. Rated production capacity was 4800 barrels of cement per day and between 200 and 250 people were employed at the plant. In 1952 all the mill equipment was sold at auction. The principal building is currently used as a warehouse (1958)."

      Photo 1. Cowell limestone quarry.                Cowell limestone quarry
  • Contra Costa County, California - the Stege Quarry (Sandstone) (From The Structural and Industrial Materials of California, Bulletin No. 38, California, State Mining Bureau, San Francisco, California, 1906.)

    "Stege Quarry; Hutchinson & Co., corner of Fourteenth and Franklin streets, Oakland, owner. It is 8 miles north of Oakland. A gravity tram, 5290 feet long, brings the rock from the quarry face to the crusher. The rock is a metamorphosed sandstone, and is used for macadam and concrete purposes."

    Ill. No. 138. Stege Quarry, Contra Costa County. Hutchinson & Co., of Oakland, owner. Stege Quarry, Contra Costa County. Hutchinson & Co
  • Cowell (near), Contra Costa County, California - Limestone Quarries/Pits (From "Mines and Mineral Resources of Contra Costa County, California," California Journal of Mines and Geology, Vol. 54, No. 4, State of California, Department of Natural Resources, Division of Mines, San Francisco, California, October, 1958, pp. 501-583. Used with permission, California Department of Conservation, California Geological Survey.)

    "Claim, mine, or group": Unnamed. "Owner name, address": L. R. & M. Ginochio (?), 123 Beede Way, Antioch. This quarry was located at 7, 1N, 1W, M. D. "Three pits on west side of Lime Ridge. Extend from Treat Lane northwestward for mile.)."

  • Cowell (south of), Contra Costa County, California - the Spreckels Sugar Company Quarries (Limestone) (From "Mines and Mineral Resources of Contra Costa County, California," California Journal of Mines and Geology, Vol. 54, No. 4, State of California, Department of Natural Resources, Division of Mines, San Francisco, California, October, 1958, pp. 501-583. Used with permission, California Department of Conservation, California Geological Survey.)

    "The Spreckels Sugar Company quarried travertine from pits located south of the Cowell quarries for many years previous to 1915. This stone was shipped to the sugar refinery at Crockett and to the Selby smelter. At the latter plant it was used as a flux for smelting gold, silver and lead ores. This property was purchased by the Henry Cowell Lime and Cement Company in 1916."

    • Cowell (near), Contra Costa County, California - Limestone Quarries (From "Mines and Mineral Resources of Contra Costa County, California," California Journal of Mines and Geology, Vol. 54, No. 4, State of California, Department of Natural Resources, Division of Mines, San Francisco, California, October, 1958, pp. 501-583. Used with permission, California Department of Conservation, California Geological Survey.)

      "Claim, mine, or group": "Cowell (Henry Cowell Lime and Cement Co.; Henry Cowell Lime Co.; Spreckels Sugar Company." "Owner name, address": Henry Cowell Lime and Cement Co., 2 Market St., San Francisco." These quarries were located at 8, 9, 17, 20, 1N, 1W, M. D. (proj) "Discontinuous masses of travertine crop out over a considerable area on Lime Ridge. Stone is white, buff or pale blue in color. Used in pre-1900 era for manufacture of lime. Quarried 1908-46 for manufacture of cement. Idle. (B 38:66; R 17:55; 23:15; 43:220; 47:567; 574.)."

  • Martinez, Contra Costa County, California - the Fitzgerald Quarry (Sandstone and Shale) (From The Structural and Industrial Materials of California, Bulletin No. 38, California, State Mining Bureau, San Francisco, California, 1906.)

    "Fitzgerald Quarry, on Haven street, Martinez. The rock is a soft, friable sandstone and sandy shale, and is sold by the load for macadam purposes."

  • Martinez (southwest of), Contra Costa County, California - the Franklyn Sandstone Quarry (Sandstone) (From The Structural and Industrial Materials of California, Bulletin No. 38, California, State Mining Bureau, San Francisco, California, 1906.)

    "Franklyn Sandstone Quarry, in Sec. 24, T. 2 N., R. 3 W.; Wilson-Lyon Construction Company, 220 Market street, San Francisco, owner; William Haley, superintendent. It is 3 miles southwest of Martinez, in Franklyn Cañon, just east of Franklyn station, on the Santa Fe Railway. The stone is fine-grained, light blue in color, and is very soft when green, but upon exposure it seasons well and makes a very firm building stone. It occurs in beds about 26 feet thick and dipping in a general northerly direction at an angle of 45 degrees. At the present the quarry face is nearly 100 feet from crest to bottom. The Santa Fe Railroad Company has run a switch to the quarry and the cars are loaded by means of an electric hoist and derrick. The waste rock is used for ballast and rubble. Any size dimension stone is obtainable but considerable waste is entailed in taking out large pieces. This stone was used in two new buildings in Martinez, and in the new schoolhouse in Redwood City. Twelve men are employed in the quarry."

    Ill. No. 55. Franklyn Sandstone Quarry, Contra Costa County. Wilson-Lyon Construction Company. Franklyn Sandstone Quarry, Contra Costa Count
    • Franklin Canyon, Contra Costa County, California - Sandstone Quarry (From "Mines and Mineral Resources of Contra Costa County, California," California Journal of Mines and Geology, Vol. 54, No. 4, State of California, Department of Natural Resources, Division of Mines, San Francisco, California, October, 1958, pp. 501-583. Used with permission, California Department of Conservation, California Geological Survey.)

      This quarry was located at 24 (?) 2N, 3W, M. D. "Inactive. Sandstone quarried in 1890's from Martinez formation for use as building stone (Aubury 06:126)."

  • Martinez (south of and west of), Contra Costa County, California - the Martinez Quarry (Sandstone) (From The Structural and Industrial Materials of California, Bulletin No. 38, California, State Mining Bureau, San Francisco, California, 1906.)

    "Martinez Quarry; Mrs. S. E. Rankin, Martinez, owner. About three fourths of a mile south of west of Martinez, in a small ravine in the rear of the residence. The quarry was last worked about fifteen years ago, when some stone was taken out for use in the buildings of the Napa Asylum. The stone is rather fine-grained and buff-colored. It is soft when green, but hardens upon seasoning, and occurs in beds which dip at a high angle in a general southwest direction. These beds range from 1 to 8 feet in thickness, and are somewhat broken up, probably from careless blasting. Only a small quarry face was opened and not enough development work has been done to prove the quantity of stone available, but the outcrop which extends across the cañon would indicate a considerable body."

    • Martinez (southwest of), Contra Costa County, California - Sandstone Quarry (From "Mines and Mineral Resources of Contra Costa County, California," California Journal of Mines and Geology, Vol. 54, No. 4, State of California, Department of Natural Resources, Division of Mines, San Francisco, California, October, 1958, pp. 501-583. Used with permission, California Department of Conservation, California Geological Survey.)

      This quarry was located at 2N, 2W, M. D. "Inactive. Located three-fourths of a mile southwest of Martinez. Martinez sandstone used in Napa State Hospital in 1890's (Aubury 06:126)."

  • Martinez, Contra Costa County, California – Tucker’s Quarry ca. 1874 (Sandstone)  (The following excerpt is from The Contra Costa Gazette, Martinez, Contra Costa County, California, Saturday, 1 August 1874, transcribed by Dee Sardoch and presented on the Norcal email list January 31, 2012.)

    Shipping The Rock –

  • “A schooner load of the rock now being got out from Tucker’s quarry, for the Branch Insane Asylum building at Napa, is now lying at Bray’s landing for shipment. The rock is a fine, firm, soft-blue colored sandstone, and is designed for the stone work of an octagon tower that forms a prominent feature of the architectural design of the building. It is got out in large blocks, some of which must be of more than a ton weight.”

    • Martinez, Contra Costa County, California – Captain John Tucker’s Quarry ca. 1879  (Sandstone)  (The following excerpt is from the Report of the President of the University on behalf of the Regents, University of California, 1879, pp.  97.  (Available on Google Books.)

      “Tucker, Captain John:  Sent from his quarry, at Martinez, several pieces of Sandstone containing fossil shells.”

  • Martinez (between Martinez and Port Costa, Contra Costa County, California - Sandstone Quarry (From "Mines and Mineral Resources of Contra Costa County, California," California Journal of Mines and Geology, Vol. 54, No. 4, State of California, Department of Natural Resources, Division of Mines, San Francisco, California, October, 1958, pp. 501-583. Used with permission, California Department of Conservation, California Geological Survey.)

    This quarry was located at 2N, 3W, M. D. "Inactive. Located on line of Southern Pacific RR between Martinez and Port Costa; sandstone used at Port Costa in 1890's (Crawford 94:398.)."

  • Oil Cañon (in), Contra Costa County, California - Col. Coates (Limestone Outcrop) (From The Structural and Industrial Materials of California, Bulletin No. 38, California, State Mining Bureau, San Francisco, California, 1906.)

    "Col. Coates, in Sec. 15, T. 1 N., R. 1 E., M. D. M. Limestone occurs on the property of Col. Coates, in Oil Cañon. The outcrop is similar and adjoins the deposit belonging to Mr. Harkinson."

  • Pacheco (west of), Contra Costa County, California - the Christen Quarry (formerly the Avery Ranch) (Sandstone) (From The Structural and Industrial Materials of California, Bulletin No. 38, California, State Mining Bureau, San Francisco, California, 1906.)

    "Christen Quarry (formerly the Avery Ranch); Joseph M. Christen, owner. This small quarry lies one quarter of a mile west of Pacheco. The rock is a soft, friable sandstone, formerly used for macadamizing the roads about Pacheco. The quarry has been practically idle of late years, because the rock is too soft to make a good road material."

  • Pacheco (near), Contra Costa County, California - the Mount Diablo Limestone Quarries (Limestone) (From "Mines and Mineral Resources of Contra Costa County, California," California Journal of Mines and Geology, Vol. 54, No. 4, State of California, Department of Natural Resources, Division of Mines, San Francisco, California, October, 1958, pp. 501-583. Used with permission, California Department of Conservation, California Geological Survey.)

    "The Mount Diablo quarries near Pacheco were the site of the first lime-making in California after the American occupation. This began in the spring of 1851 (Logan 1947) although no records of production previous to 1903 are available. The Henry Cowell Lime Company reported lime production from 1903 until 1915, excepting 1906 and 1908. The limestone was originally hauled from the quarries on Lime Ridge 3 miles southeast of Concord to Concord where the kiln was located. Later, four standard continuous kilns were installed immediately below the quarry.

    "The Henry Cowell Lime and Cement Company erected a cement mill at Cowell about 3 miles southeast of Concord in 1907. This dry-process plant went into production in 1908 using as raw material the travertine and clay deposits from the west slope of Lime Ridge immediately south of the plant. Cement was produced continuously from 1908 to 1946 except for a temporary shutdown in 1942, owing to strike conditions. Loss of railroad facilities to the U. S. Navy and the approaching depletion of the limestone deposits caused permanent closing of the plant in 1946. Rated production capacity was 4800 barrels of cement per day and between 200 and 250 people were employed at the plant. In 1952 all the mill equipment was sold at auction. The principal building is currently used as a warehouse (1958).

    "The Spreckels Sugar Company quarried travertine from pits located south of the Cowell quarries for many years previous to 1915. This stone was shipped to the sugar refinery at Crockett and to the Selby smelter. At the latter plant it was used as a flux for smelting gold, silver and lead ores. This property was purchased by the Henry Cowell Lime and Cement Company in 1916.

    "The Mount Diablo Lime Marl Company produced travertine from 1924 to 1927 which was crushed for agricultural use. These operations were probably centered on Lime Ridge in section 7 where there are three discontinuous small shallow pits.

    "The principal limestone deposits are located on the west slope of Lime Ridge, a northwesterly spur of Mount Diablo. They extend over a linear distance of nearly 3 miles, from section 7, to section 20, T. 1 N., R. 1 E., M. D., projected. Most of the production came from deposits southeast of the highway in section 17.

    "The limestone deposits are surficial masses of travertine of Quaternary age which originated from calcareous springs issuing along a fracture in the underlying sedimentary rocks of the Tejon formation (Eocene). Vertical dips in the Tejon rocks along the highway were noted in this vicinity. Although the travertine crops out on the surface at many points along Lime Ridge, the deposits are more frequently obscured by a thin mantle of dark brown soil, calcareous tufa, marl or chalky clay, 5 to 15 feet thick.

    "The central core of the travertine is pale blue in color, grading outward to a buff-colored stone. The weathered surface is whitish gray and the outer surface of the buff stone is frequently lined with a selvage of white chalk. Textural gradiations can also be seen from a central core of hard, fine-grained travertine outward into calcareous tufa and marl. The solid travertine exhibits faint banding and swirling. Differential weathering along the bands has given rise in many places to a porous texture. The travertine has been slightly fractured subsequent to deposition; the fractures have been filled with secondary calcite.

    "The travertine has been mined from an innumerable series of shallow cuts, pits and benches which frequently merge from one into another. Many bench-cuts range from 5 to 50 feet high and are a quarter of a mile long. The largest pit is located about a mile south of the cement mill. It has a face about 200 feet high above the water level in the pit and extends for about half a mile laterally. Small tonnages of good minus 12-inch stone are distributed irregularly in piles along the hummocky floor.

    "A smaller pit immediately to the south explores a face of travertine about 25 by 25 feet in size which grades outward into calcareous tufa. Apparently the miners attempted to follow and mine the central high grade cores of travertine and when these passed into tufa the pit was abandoned. Although these travertine deposits were not originally regarded with great favor in some quarters, they produced cement rock in sufficient quantity to run the cement plant continuously for almost 40 years...."

  • Pacheco (south of), Contra Costa County, California - the Slater Quarry (Sandstone) (From The Structural and Industrial Materials of California, Bulletin No. 38, California, State Mining Bureau, San Francisco, California, 1906.)

    "Slater Quarry; A. E. Slater, owner. This quarry lies about one quarter of a mile south of Pacheco. The rock is a very soft, friable sandstone, used for macadam."

  • Port Costa, Contra Costa County, California - the Port Costa Cut (Sandstone and Shale) (From The Structural and Industrial Materials of California, Bulletin No. 38, California, State Mining Bureau, San Francisco, California, 1906.)

    "Port Costa Cut. The Southern Pacific Railroad Company is operating a steam shovel at the foot of the steep hillside at the side of its tracks at Port Costa. The material is used for ballast. It is a friable clay shale and shaly sandstone."

  • San Pablo, Contra Costa County, California - the San Pablo Quarry Company - Anson Stiles Blake Business Records, 1897-1938, by Anson Stiles Blake, San Pablo Quarry Company, Blake and Bilger Company, Blake Brothers Company, San Francisco Quarries Company. (Available at the California Historical Society in San Francisco, California.)
  • Walnut Creek (northeast of), Contra Costa County, California - Limestone Quarry (From "Mines and Mineral Resources of Contra Costa County, California," California Journal of Mines and Geology, Vol. 54, No. 4, State of California, Department of Natural Resources, Division of Mines, San Francisco, California, October, 1958, pp. 501-583. Used with permission, California Department of Conservation, California Geological Survey.)

    "Claim, mine, or group": Mt. Diablo Lime Marl Co. This quarry was located at 7 (?), 1N, 1E, M. D. "Produced crushed limestone for agricultural use from deposit 5 miles northeast of Walnut Creek, 1924-27. (R 27:15.)."

  • Walnut Creek (northeast of), Contra Costa County, California - Mount Diablo Lime Marl Deposit (Limestone) (Excerpt from "Limestone in California," by Clarence A. Logan, California Journal of Mines and Geology, Vol. 43, No. 3, July 1947, California Division of Mines, San Francisco, California, pp. 175-357. Used with permission, California Department of Conservation, California Geological Survey.)

    "Mount Diablo lime marl deposit is on Lime Ridge about 5 miles northeast of Walnut Creek. From 1924-27 inclusive the Mount Diablo Lime Marl Company operated a plant there for grinding and screening the material which was sold for agricultural use. There has been no record of activity since."

    • Cowell (near), Contra Costa County, California - the Mount Diablo Lime Marl Company Quarry Operations (From "Mines and Mineral Resources of Contra Costa County, California," California Journal of Mines and Geology, Vol. 54, No. 4, State of California, Department of Natural Resources, Division of Mines, San Francisco, California, October, 1958, pp. 501-583.) (Used with permission, California Department of Conservation, California Geological Survey.)

      "The Mount Diablo Lime Marl Company produced travertine from 1924 to 1927 which was crushed for agricultural use. These operations were probably centered on Lime Ridge in section 7 where there are three discontinuous small shallow pits."

      "Claim, mine, or group": L. C. Hopper. "Leased Mt. Diablo Lime Marl Co. deposit and plant in September 1926. (R 27:16.)."

[Top of Page]