1978 



Limestone in the Coast Ranges 



61 



'4 ' . kf^f??=r4.-r^_^^\-: 



^%^'fi 



photo 10. Homilton limestone deposit, upper prospect quarry, showing massive white crystolline limestone (left) and decomposed granite. Exploration tunnel 

 (center) runs westerly (toward left) through limestone cut by granitic dikes. 



limestone is similar to the rest of the deposit, being 

 white and coarse crystalline. Recent surface develop- 

 ment has obliterated much of the old quarry, but the 

 limestone is exposed over a width of 60 feet and height 

 of 45 feet on the remaining face. The limestone appar- 

 ently supplied the two vertical stone lime kilns located 

 close by on Harlan Creek. Reserves of the two south- 

 ern lenses have not been determined but may aggre- 

 gate 500,000 tons or more. 



Based on the chemical composition and the obvious 

 whiteness of the limestone, the Hamilton deposit may 

 prove useful as white filler, in glass manufacture, or 

 for other special purposes. In all probability, the 

 deposit would have to be mined selectively or benefi- 

 ciated or both in order to obtain a substantial produc- 

 tion of a uniform, high-quality product. Accessibility 

 is good via an improved dirt road, but rail facilities are 

 about 18 miles away at HoUister. 



Other references: t>.iA>\irf, 1906, p. 76; loizure, 1926, p. 237; logon, 1947, 

 p. 274-277; Bowen ond Gray, 1959, p. 38. 



Harmony Hills deposit. Location. SW'/i sec. 17 

 (proj.), T. 1.? S., R. 5 F.., M.D., 5 miles southwest of 

 Hollister; Hollister 15-minute quadrangle. Owner- 

 ship: Howard Harris, 7800 Cienega Road, Hollister 

 (1966). 



Lhe Harmony Hills deposit is a small body of lime- 

 stone that may be of economic interest in the near 

 future because of its white color and easy accessibility. 

 The body is lenticular in plan, striking northwest 

 along the crest of a small hill through a relief of 60 to 

 80 feet. It is at least 500 feet long and has a ma.vimum 

 uidth of about 100 feet. Typically, the limestone is 

 white, medium to very coarse crystalline, and high in 

 calcium. There is local blue-gray mottling, and some 

 of the limestone is stained vellowish brown along frac- 

 tures and joints. Ciranitic rocks cut the deposit in sev- 

 eral places and probably comprise the country rock. 



A typical clean limestone sample shows 52.37% 

 CaO, 2.60% MgO, 0.32% SiOj. 0.08% Fe^O,, 0.14% 

 AljO,, and 0.01% P^O, (Bowen and Gray 1959, p. 25). 



