14 



California Division of Mines and Geology 



Bull 1976 



stimulated tungsten exploration in the early 1950s 

 (Ver Planck, 1955, p. 260, 265-266). According to the 

 owner, none of the limestone bodies shows a thickness 

 of more than 25 feet. Because of small reserves and its 

 intimate association with schist and granitic rock, the 

 limestone is not believed to be of economic interest. 



Benicia Cement Works deposit. Location: Proba- 

 bly SE/, sec. 34, T. 3 N., R. 3 W., M.D., in Benicia; 

 Benicia T'/j-minute quadrangle. Ownership: Not de- 

 termined. 



California's first cement plant was established at 

 Benicia about 1860 to manufacture "hydraulic" ce- 

 ment. The cement works, which had a productive 

 capacity of about 100 barrels of cement per day, was 

 operated intermittently and produced only modest 

 amounts of cement. After appro.vimately 30 years of 

 intermittent production, the works was abandoned. 

 Total production of cement is not recorded in the 

 literature although Williams (1885, p. 675) reports the 

 largest production was in 1872, when 25,500 barrels of 

 cement were made. The cement was used in various 

 construction projects, including a seawall in San Fran- 

 cisco Harbor and the San Francisco City Hall, and in 

 the manufacture of drainage and water pipe. Rem- 

 nants of an old kiln along the Benicia waterfront south 

 of EyeStreet between 8th and 9th Streets still exist and 

 very likelv are the remains of the Benicia Cement 

 Works. 



The source of "hydraulic" limestone seems uncer- 

 tain, and there may have been more than one quarry 

 area or deposit. The limestone source has been vari- 

 ously reported to be in the hills behind Benicia (Whit- 

 ney, 1865, p. 101; Browne, 1868, p. 245), 1 mile south 

 of X'allejo (Williams, 1883, p. 463), and in sec. 33 with- 

 in the Benicia town limits (Aubury, 1906, p. 185). The 

 nature of the raw material also is unclear. Whitney 

 (1865, p. 101) states that the "hydraulic limestone" is 

 associated with "beds of passage" between "sand- 

 stones and shales" (veins filling a fault or fracture?). 

 A description of the material is given by Browne 

 (1868, p. 245) who reports two grades of hydraulic 

 limestone which he describes as being "of a dark yel- 

 lowish color, speckled with black, tolerably soft; 

 breaks with a dull, earthy fracture, without any ap- 

 pearance of crystallization." Exactly what rock type 

 or units are represented has not been determined. Fhe 

 principal carbonate materials found near the old kiln 

 are part of an upper Pleistocene marine unit (Weaver, 

 1949, p. 52 ) . Along the waterfront, in a cove northwest 

 of the kiln, this unit consists mainly of bedded mud, 

 shells, and sand of estuarine origin. Five to ten feet of 

 the unit are composed principally of oyster shells 

 similar to Ostrea lurida (Carpenter. This is overlain by 

 about 20 feet of mudstone with occasional shelly 

 streaks. About 5 feet of impure carbonate beds of vari- 

 able character (shells, sand, mud, and possibly second- 

 ary calcitc) and uncertain origin overlie the mudstone 

 (Oliver E. Bowen, 1964, oral communication). Al- 



though these carbonate rocks would seem to be the 

 logical source for the Benicia cement, Whitney refers 

 to the oyster beds (1865, p. 102) but does not relate 

 them to cement manufacture. Another possible source 

 is indicated by calcareous shale and argillaceous lime- 

 stone fragments found in and about the kiln (Oliver 

 E. Bowen, 1964, oral communication). Similar materi- 

 al commonly occurs in the Paleocene and Cretaceous 

 units exposed in the vicinity of Benicia. 



Other references: Irelan, 1888, p. 632; Crawford, 1894, p. 381; Logan, 

 1947, p. 333. 



Cement Hill deposits. Location: Sees. 5, 7, and 8; 

 T. 5 N., R. 1 W., M.D., 3 to 4 miles northeast of Fair- 

 field; Mount \'aca and \'acaville 15-minute quadran- 

 gles. Ownership: Mineral rights — Ideal Cement Com- 

 pany, 420 Ideal Cement Building, Denver, Colorado 

 80202; surface rights— E.N. Tooby, Fairfield (1962). 



Travertine and related surficial carbonate deposits 

 on Cement Hill were first developed prior to 1865 for 

 use as lime rock and ornamental stone (Whitney, 1865, 

 p. 104) . The rock was extensively used as an ornamen- 

 tal material known as "Suisun marble". As a lime 

 rock, the travertine was burned in a vertical kiln locat- 

 ed just south of E'X cor. sec. 7. Remains of the kiln still 

 stand. For some years prior to 1900, the travertine was 

 also obtained from Dicky's quarry for use as flux at 

 ASARCO's Selby smelter (Crawford, 1894, p. 395). 

 Some macadam also was produced. Probably the bulk 

 of the carbonate rock produced was used to manufac- 

 ture Portland cement. 



The first cement mill was constructed by Pacific 

 Portland Cement Company (predecessor to Ideal Ce- 

 ment Company) in 1902 at the foot of Cement Hill, 

 700 feet north of SW cor. sec. 8. The plant was expand- 

 ed in 1903 and 1905, reaching a capacity of 2,500 bar- 

 rels of cement per day (Bradley, 1916, p. 303). 

 According to Huguenin and Costello (1920, p. 243), 

 this plant was "completely wrecked" shortly before 

 1920. In 1907, another cement mill was constructed 

 2,000 feet to the southeast in sec. 17. Capacity of the 

 second mill was 3,500 barrels per day. Prior to 1910, 

 the carbonate raw material came from the Cement 

 Hill deposits. After 1910, however, most of the lime- 

 stone was imported by rail from Cool, El Dorado 

 County. The cement plant was closed and dismantled 

 in 1927. 



Following the cement operation, travertine from 

 Cement Hill was quarried intermittently for orna- 

 mental and terrazzo uses. P. Grassi and Company 

 (1927, 193.5-36) and United Quarries, Inc., (1939-42) 

 were the operators. It is reported that Kasser (?) and 

 Ball and the Morrison-Knudsen Company quarried 

 large amounts of travertine and underlying sandstone 

 in the early 1940s to construct airstrips at Travis Air 

 Force Base. 



The Cement Hill deposits consist of travertine, cal- 

 careous tufa, and related calcareous materials. The 

 carbonate rocks form numerous surficial deposits on 



