1978 



Limestone in the Coast Ranges 



73 



is medium- to coorsc-crystolline and blue-gray to nearly white. The 

 chemical voriotions, based upon nearly 100 surfoce somples, ore 

 indicated in the following table: 



Fe SiOs AIsPj 00 MgO S 



Mn 



RsOj HsO 



.i.vio li-v. ,o:-6! v.i-m lo-u: oi-iio? ooi-ii ,o:-06 !4-<)i 4;-h 



"8ec(;use of the heterogeneous nature of the deposit uniform rock 

 con only be obtained in masses containing less than 1 ,000,000 tons 

 each; many are much smaller than this." 



Other carbonate deposits exist to the west in sec- 

 tions 9 and 10, but nothing is known of them. These 

 and the VVestphal Ranch deposit are undeveloped. 



Westvaco (nollister;0'Hara Ranch) deposit. Lo- 

 cation; Sec. 2 (proj.), V. \S S., R. ."> E., M.D., 7 miles 

 south of Hollister; Gonzales 15-minute quandrangle. 

 Ownership: Inorganic Chemicals Division, FMC Cor- 

 poration, P.O. Box .^44, Newark (196.?). 



Crystalline dolomite, exposed on a low hill half a 

 mile south of the winery in Cienega Road, has been 

 quarried extensively since 1915. In that year, two com- 

 panies opened quarries within half a mile of one an- 

 other. San Benito Quarries Company (Baldi and 

 Rothschild) developed a quarry and adit near the top 

 of the hill on the O'Hara Ranch and produced modest 

 amounts of dolomite until 1926. About half a mile to 

 the west, on the property of San Benito \'ineyards 

 Company, and near the center of sec. 20, A. A. Haskins 

 opened a hillside quarry which he apparently worked 

 in a limited way for a few years. From 1937 to 1946, 

 A. E. Hamilton produced an average of 7,000 or 8,000 

 tons of dolomite annually from the same area as Has- 

 kins. This part of the deposit may still be owned by 

 Mrs. A. E. Hamilton. Hamilton also had an option on 

 the O'Hara Ranch property, which he explored to 

 some extent. 



In April 1944, Westvaco Chlorine Products Corpo- 

 ration (predecessor of present owner) acquired that 

 option and has produced substantial amounts of dolo- 

 mite every vear since 1947. Practically all of the dolo- 

 mite produced prior to 1947 was shipped to San 

 Francisco and Los .Angeles for use as a refractory lin- 

 ing in open hearth steel furnaces. All of the dolomite 

 produced from 1947 to 1968 was shipped to the 

 owner's chemical plant in Newark where the 

 dolomite was calcined and reacted with salt water 

 bitterns to produce magnesium compounds. The 

 Newark plant ceased operation in August 1968. Quar- 

 ry operations were either stopped or greatly reduced 

 by the end of 1968, although some dolomite fines were 

 being sold for agricultural use and glass manufactur- 

 ing. Total production of dolomite from 1915 to 1968 is 

 estimated to be about 2'/, million tons. 



According to previous descriptions and unpub- 

 lished mapping, the Westvaco deposit apparently is 

 half a mile long but may consist of several disconnect- 

 ed masses of dolomite mostly in SE'/< sec. 2. The main 

 part of the deposit has been examined and described 



by Bowen and Gray (1959, p. 37): 



"White, medium crystalline dolomite occurs in a northwest-elon- 

 goted moss roughly oval in plan. The mass is at least 1,800 feet 

 long and 600 feet wide and has been explored to a depth of neorly 

 200 feet. It is enveloped in deeply weathered schist and granitic 

 rock and granitic instrusions penetrate the dolomite in several 

 places. The deposit is in or close to the Son Andreas fault zone and 

 the dolomite has been thoroughly crushed throughout the deposit. 

 This lowers the cost of quarrying but raises the proportion of waste 

 material. Several million tons of usable rock were proved. Further 

 exploration was being done during the summer of 1958. According 

 to the company the rock runs close to the theoretical composition 

 for dolomite — slightly over 21 percent MgO. Iron oxide stains 

 along the fracture surfaces ore the only visible impurity. Logan 

 (1947, p. 278) lists an onolysis made by Smith-Emery Company 

 from a sample collected toward the north end of the moss from a 

 quarry then operated by A. E. Hamilton, which is probably repre- 

 sentative of the deposit." 



SiOi AI2O3 FeiOj 



CaO 



MgO 



Mn 



CO! 



0.17% 



0.36% 0.11% 31.00% 21.23% 0.006% 47.30% 



Other references: Bradley and Logan, 1919, p. 633-635; Averill, 1947, p. 

 49-50. 



PANOCHE HILLS DISTRICT (C-2) 



Marly magnesian limestone is found as lake beds in 

 the Tulare Formation of Plio-Pleistocene age in sev- 

 eral places in the Panoche Hills, Fresno County (plate 

 iC) . The carbonate rock, known as the Marlife depos- 

 it, was produced in the vicinity of sec. 18, T. 14 S., R. 

 1 1 E., between 1947 and 1953 for use in soil condition- 

 ing. The material is considered too impure to be of 

 value for most limestone or dolomite uses. 



Marlife (Burkhart and Teaford) deposit. Loca- 

 tion: Sees. 17, 18, 19,20,29, 30, T. 14S., R. 11 E., M.D., 

 V/i miles east of Mercy Hot Springs and 24 miles west 

 of Mendota; Panoche \'alley 15-minute quadrangle. 

 Ownership: A. R. Burkhart and Otis Feaford (1951); 

 operated by Marlife Company, Fresno, J. H. McCloy, 

 Jr., President (1953). 



The Marlife marl deposit was first developed in 

 1946 by A. R. Burkhart and Otis Teaford, who located 

 15 placer claims at the crest of the Panoche Hills, 

 (ximmercial development followed in 1947 when the 

 Marlife Company, apparently under a lease from the 

 owners, commenced production that continued at 

 least until 1953. There was a little production in 1955, 

 apparently all experimental. 



The marl (impure limestone), exposed along the 

 crest of the Panoche Hills in sees. 17, 18, 19, 20, 29 and 

 30, occurs as a capping and as thin strata interbedded 

 with clay, silt, and sand of the flat-lying, nonmarine 

 Tulare Formation (Plio-Pleistocene). Some of the 

 limestone resembles caliche, but most of it was proba- 

 blv formed as lake beds. Where quarried at the hill 

 crest in sec. 18, the limy bed is estimated to be 3 to 5 

 feet thick and is covered by 1 to 4 feet of soil. The 

 limestone is nearly white to light buff, porous, soft to 

 moderately hard, and breaks or crumbles easily into 

 small fragments. As indicated by the analyses in table 

 1 5, the material is quite impure, being siliceous, alumi- 



