1Q78 



LlMFSTOM IN HIE COAST RANGES 



17 



V 



There is some indication that high-grade limestone 

 from Santa Cruz was used to "sweeten" the raw- 

 material mix. The cement mill utilized the drv 

 method, employing two large rotary kilns and 10 small 

 rcHary kilns with a total capacity of 2,500 barrels of 

 cement per day. 



Other references: Bradley, 1916, p. 262-268; Huguenin and Cosfello, 

 1920, p. 158; Eckel, 1933, p. 359-360. 



Noren deposit. Location: Near S'/, sec. 5.S, T. 3 N., 

 R. 9 W. (proj.), M.D., 1 mile southwest of Point Reyes 

 Station; Point Reyes 15-minute quadrangle. Owner- 

 ship: C. R. Noren, Inverness Park (1962). 



A small pendant of metamorphic rock in quartz 

 diorite is situated 1,000 feet south of the intersection 

 of Sir Francis Drake Highway and Bear \'alley Road. 

 The pendant consists of coarse-crystalline, white to 

 brown (stained?) limestone and fine-crystalline, gray 

 limestone interbedded with biotite schist similar to 

 that of the Sur Scries. The gray limestone is silicified 

 and locally replaced by scheelite, which was prospect- 

 ed to .some extent in \952 (\'er Planck, 1955, p. 260, 

 266). Another small pendant of limestone is reported 

 half a mile to the southwest in the same creek. From 

 what was seen (April 1962) and reported, the Noren 

 deposit appears to be too small and impure to be of 

 commercial value as a source of limestone. 



Olema ("Russian Kilns") deposit. Location: Ap- 

 prox. sec. 28, T. 2 N., R. 8 W. (proj), M.D., 4 miles 

 southeast of Olema and 6 miles southeast of Point 

 Reyes Station; Mount Tamaipais 15-minute quadran- 

 gle. Ownership: Sam Smoot, Petaluma (1955). 



The Olema limestone deposit was first developed 

 about 1850 as a source of lime rock. Lime was calcined 

 in three adjacent kilns. According to Treganza (1951, 

 p. 69), the lime kilns probably were operated last in 

 1852, although it is possible lime could have been 

 burned as late as 1869. Production is believed to have 

 been minor, as no large quarry exists at the deposit. 

 The kilns, v\ hich are located on the east bank of Olema 

 Creek immediately below the limestone exposure, 

 were previously believed to have been built and used 

 by the Russians at an early date. However, this theory 

 is fairly well disproved by I'reganza ( 1951), who stud- 

 ied the kilns in detail. 



The limestone is confined to a single outcrop about 

 50 feet wide, 100 to 125 feet long, and 40 to 50 feet high. 

 Approximately 50 feet of strata are present, and these 

 strike N 60° VV and dip 55° SW. The deposit consists 

 of thin-bedded Franciscan limestone and minor in- 

 terbedded chert, which is associated with other Fran- 

 ciscan rocks along the San Andreas fault zone. The 

 limestone typically is light tannish gray, dense, fine 

 grained, and foraminiferal. Chemistry of the lime- 

 stone is indicated bv analyses of samples 8 to 11 in 

 'Fable 2. 



Because no limestone is visible beyond the exposed 

 deposit, it is presumed the limestone deposit is a fault 



sliver that does not extend much beyond the outcrop 

 area. Some fragments of similar limestone are report- 

 ed from two areas 1,000 feet and 2 miles to the south- 

 east in the fault zone (Galloway, unpublished report). 

 At the latter locality there are remnants of another old 

 kiln. Reserves of limestone at the Olema deposit are 

 estimated to be in the order of 10,000 to 15,000 tons. 



Other references: logon, 1947, p. 251; Ver Plonck, 1955, p. 261; Gollo- 

 woy, 1962, p. 395, 398. 



Tolenas Springs (California Onyx Marble) depos- 

 its. Location: W'/, sec. 2 (proj.), T. 5 N., R. 2 W., 

 M.D., 4 miles north of Fairfield; Mount Vaca 15- 

 minute quadrangle. Ownership: Woods Fstate Ranch 

 (1962); operated by Folenas (.^arry Company, 537 

 Cottonwood Drive, Fairfield (1969). 



Travertine and calcareous onyx have been known at 

 Tolenas Springs at least since 1878, when specimens 

 were displayed at the Paris Exhibition. Exactly when 

 the deposits were first worked commercially is not 

 known, but it may have been about the same time 

 (Hanks, 1884, p. 72; Goodyear, 1890, p. 670). The 

 deposits have been worked intermittently on a small 

 scale as a source of ornamental stone and terrazzo 

 materials. I'he early operators are not known; but the 

 later developers include S. Miletin ( 1926 and earlier?), 

 P. Grassi and Company and L. Cardini (1928-1936), 

 and Ray McRoberts and Paul Lahmon of Tolenas 

 Quarry Company (since about 1960). Total produc- 

 tion is believed to be several thousand tons. 



Several small deposits of travertine and onyx lie in 

 the vicinity of 'Folenas Springs in NW'/ sec. 2 (proj.). 

 Fhese rest on sandstone — apparently of the Chico 

 Formation. The main deposit is situated at the east 

 end of the group on the south bank of Soda Springs 

 Creek. It covers an area about 400-by-200 feet and may 

 have been 2 5 feet thick or thicker at one time (Good- 

 year, 1890, p. 671). The travertine is typically fine 

 grained, tan or brownish, thinly banded, and some- 

 what porous. Fhe calcareous onvx is microcrvstalline 

 to finely fibrous, milky white to pale amber, translu- 

 cent, semiresinous to waxy, delicately banded, and 

 dense but commonly cavernous (vuggy). The onyx 

 occurs as lenses and irregular fracture fillings in the 

 travertine. Both materials are somewhat fractured and 

 arc obtained in small pieces. Similar, but smaller, 

 spring deposits can be traced to the southwest for a 

 quarter of a mile. Another deposit 200 yards to the 

 northwest of the main deposit is shown bv Weaver 

 (1949, plate 5). but nothing is known of this. 



Development has been sporadic and limited princi- 

 pally to the main deposit. Recent (1962) workings 

 consist of a quarry face 1 5 feet high and 100 to 1 50 feet 

 long. By April 1967, small amounts of onyx or traver- 

 tine had also been produced from pits a quarter of a 

 mile southwest of the main quarry (Oliver E. Bowen, 

 personal communication, 1967). I'o the west and 

 southwest arc two small old quarries, one of which is 

 about 30-by-30 feet with a 10-foot face. In 1962, the 



