1978 



Limestone in iiii Coasi Ranges 



49 



ties of lime (Crawford, \W6, p. 6.^1). The Henry Co- 

 well Lime and Cement Company acquired the 

 property about 1905 and produced a large amount of 

 lime rock until 1919, when they ceased operations. 

 There has been no development since that time. 



The deposit is situated at the east end of a high, 

 east-plunging spur flanked by South Fall Oeek and a 

 northwest tributary. The limestone has been mapped 

 as an irregular lensoid mass (in plan), having a length 

 of nearlv 2,000 feet and a ma.ximum width of 900 feet, 

 and is exposed over 700 feet of relief (Leo, 1967, and 

 unpublished Stanford thesis). It consists of thick beds 

 of high-calcium limestone interbedded in some places 

 with biotite schist. Where bedding can be observed, 

 the strike is usually west or northwest; but the dips are 

 variable to the north and south, indicating structural 

 complications. At one place on the north side of the 

 deposit some granitic rock is exposed, but its relation- 

 ship to the limestone is not known. Most of the lime- 

 stone near the east end of the deposit is white to light 

 gray, coarse to extremely coarse crystalline, generally 

 graphitic, and high in calcium. However, some is fine 

 to medium crvstalline, white to dark gray, and mot- 

 tled or banded. Chemical analyses of three samples 

 (SACR-5 to 7) given in table 9 show the type coarse- 

 crystalline limestone to be of good quality. 



The deposit was worked at the east and north sides 

 through several quarries. One quarry, situated about 

 250 feet higher than the kilns on the north side of the 

 deposit, has a high face and is 40 feet by 40 feet in floor 

 plan. A double-track tramway served the quarry and 

 kilns. Lower in elevation and to the southeast is an- 

 other quarry with a face of perhaps 200 feet. Remnants 

 of a bank of three stone kilns and several enormous 

 piles of broken limestone exist below the quarries. 



Proved limestone reserves cannot be determined 

 without drilling, particularly as the ratio and relation- 

 ship of noncarbonate rocks to limestone is not known 

 in detail. However, available limestone reserves may 

 amount to several million tons or more. If the chemi- 

 cal analyses are representative of a substantial volume 

 of rock, the deposit might be a useful source of lime- 

 stone for the manufacture of glass and lime, and for 

 other industrial uses. 



Ofher references: Aubury, 1906, p. 86; Huguenin and Costelto, 1920, p. 

 238; Loizure, 1926, p. 85; Hubbard, 1943, p 44; Logan, 1947, p. 319; Leo, 

 1967, p. 31. 



Pacific Limestone Products Company (Kalkar; De 

 Dero; Thurber; Caplat/.i; Miller) deposits. Loca- 

 tion: SEViSWy; sec. 1 1 and adjacent part of sec. 14, T. 

 II S., R. 2 W., M.D., just west of Spring Street in 

 northwest Santa Cruz (city); Santa Cruz. 7'/2-minute 

 quadrangle. Ownership: Pacific Limestone Products 

 Company (estate of Fred W. Johnson), 535 Spring 

 Street, Santa Cruz (1967). 



The deposits consist of crystalline limestone uncov- 

 ered in two adjacent quarries. The north quarry was 

 worked by Louis De Dero (pre- 1894 to 1907) and 



VV.A. (-aplatzi (1907 to 1922), who produced crushed 

 rock, poultry feed, and agricultural limestone. Fhe 

 south quarry was developed as a source of crushed 

 rock at least as early as 1894 by T.J. (or S.L.) Thurber 

 and later (pre-1920), on a smaller scale, by W.E. Mil- 

 ler (Crawford, 1894, p. 395; 1896, p. 631, 632; Aubury, 

 1906, p. 88, 324; Huguenin and Costcllo, 1920, p. 237, 

 239; Laizure, 1926, p. 86-88). Pacific Limestone 

 Products Company began operations in 1922 when 

 they took over the north (Caplatzi) quarry, and ex- 

 panded in 1927 when they acquired the south (Miller) 

 quarry (Hubbard, 1943, p. 44-46). Livestock feed and 

 poultry grits, marketed as the "Kalkar" brand, have 

 been the principal products of the present operation. 

 The two quarries are situated 450 feet apart on a 

 gentle soil-covered slope. The area of limestone uncov- 

 ered is about 8 acres at the north quarry and 3 to 4 

 acres at the south quarry (figure 4). Extent of the 

 deposits beyond the quarries is masked by soil at least 

 6 to 8 feet thick. The deposits mainly consist of mas- 

 sive beds of coarse- to exceedingly coarse-crystalline, 

 off-white to blue-gray, relatively pure limestone in- 

 terbedded with thin beds, bands and lenses of impure 

 limestone and calc-silicate rocks. The south deposit is 

 also cut by a granitic dike. The impure interbeds, 

 which are white to dark gray and generally fine 

 grained, are more prevalent at the north deposit. Con- 

 tact metamorphism and introduction of mineralizing 

 fluids have given rise to the formation of a wide vari- 

 ety of silicates, sulfides, and arsenides, including some 

 rare minerals (Gross er al., 1967; Leo, 1967, p. 41). As 

 a result, the locality has become noted as an important 

 site for mineral-collecting. Both deposits are some- 

 what crushed and broken by minor faults. Bedding 

 attitudes are obscure but appear to be gentle and to the 

 north in the north quarry. Limestone reserves are un- 

 known because the vertical and lateral extent of the 

 deposits have not been determined. Chemical analyses 

 of five samples (Kal-1 to 5) reflect the variable quality 

 of limestone at the deposits (see table 10). 



I he two quarries have been worked on a modest 

 scale for 70 years (prior to examination in 1963). The 

 north quarry is the largest, having an irregular plan 

 and maximum dimensions of 1,000 feet by 600 feet by 

 80 feet. Maximum dimensions of the south quarry are 

 estimated to be 500 feet by 250 feet by 80 feet. Roughly 

 1 million tons of limestone and associated rocks have 

 been quarried from the deposits. Both quarries are 

 worked bv primary and secondary blasting and hand- 

 sorting. The impure limestone and calc-silicate rocks 

 are stored in unused parts of the quarries for eventual 

 sale as rubble and riprap. The purer coarse-crystalline 

 limestone is hand-loaded into small skips, which are 

 periodically picked up by special vehicles and deliv- 

 ered to the adjacent mill for processing. ,\x the mill, 

 which has a capacity of 100 tons per 8-hour day, the 

 limestone is reduced in size through jaw and gyratory 

 crushers, a hammer mill, and an impactor. Fhe 

 material is screened to several grit sizes and some is 

 ground to flour. Poultry feed and grit are the most 



