1978 



LiMESTONK IN I HE COAST RANGES 



37 



thousand tons of available limestone. The largest 

 masses lie in S\V'4 sec. 15 and on hill "1722" in SE'/ 

 sec. 15. Future development v^ould appear to be lim- 

 ited to supplying local markets with crushed rock. 



Clark Ranch deposit. An undeveloped deposit ot 

 "hvdraulic limestone" is reported 7 miles east of Ma- 

 drone (Watts, 1890, p. 619; Logan, 1947, p. .^2). Its 

 exact location is unknown. 



Guadalupe Creek (Guadalupe Lime Company) 

 deposits. Location: Near SWy, S\V'/^ sec. 29 (proj.), 

 T. 8 S., R. 1 F.., NL D., 5 miles east of Los Gatos; Los 

 Gatos 15-minute quadrangle. Ownership; Not deter- 

 mined (1962). 



Several small deposits of cherty limestone of the 

 Franciscan Formation lie 1,000 feet south of Ciuada- 

 lupe Creek. These were quarried by Guadalupe Lime 

 Company as a source of lime from about 1864 to 1890 

 or a little later (Irelan, 1888, p. 543; Watts, 1890, p. 619; 

 Crawford, 1894, p. 349). The limestone was developed 

 through several small quarries and hauled "by trucks 

 worked by a gravity pulley" to the kiln 400 feet below 

 (Irelan, 1888, p. 543). Considerable hand-sorting evi- 

 dently was necessary to remove the chert from the 

 limestone. Production during the summer of 1 890 was 

 150 barrels of lime per day (Watts, 1890, p. 619). 

 There is no record of further production, but there is 

 some evidence that more recent development work 

 was carried out in the quarry areas. The Guadalupe 

 Creek deposits may have been part of the holdings of 

 San Jose Cement Company (which see). 



The small, detached bodies of limestone that have 

 been quarried form a closely spaced, northwest-trend- 

 ing group lying just southeast of the fourth "hairpin" 

 curve of the paved access road. Other small limestone 

 masses are shown to the southeast and northwest of 

 that group by Bailey and Everhart (1964, plate 1 ) but 

 are undeveloped. Altogether, the limestone extends 

 discontinuously for 4,000 feet. Where developed, the 

 deposits are largely covered with talus and quarry 

 debris consisting mainly of light-gray, dense, fine- 

 grained, sometimes siliceous limestone and gray to 

 black, thin-bedded chert. Locally, dark-gray, white- 

 mottled, crystalline limestone is present. According to 

 Irelan (1888, p. 543), "dark-colored bituminous lime- 

 stone" also is found, but such material was not ob- 

 served during a brief visit in May 1962. The degree of 

 fracturing, as well as the presence of secondary calcite, 

 suggests the deposits mav be broken bv faults. 



'Fhe deposits are developed by several small quar- 

 ries over a length of 900 feet. Quarry development is 

 too irregular to estimate total production accurately, 

 but probably it is less than 50,000 tons. 



Limestone reserves cannot be accurately deter- 

 mined without better exposures and some drill data, 

 but available reserves do not appear to be large. Be- 

 cause of the presence of chert beds within the lime- 

 stone, the deposit is useful chiefly as a local source of 

 crushed rock. 



Guadalupe Reservoir deposits. Location: Near 

 SWy, sec. 33 (proj.), T. 8 S., R, 1 E., M. D., 6 miles 

 east-.southeast of Los CJatos; Los Ciatos 15-minute 

 quadrangle. Ounership: Not determined (1962). 



A C-shaped mass of limestone of the Franciscan 

 Formation was mapped by Bailey and Everhart (1964, 

 plate 1) just west of Hicks Road at the upper end of 

 Guadalupe Reservoir. '! he deposit is shown to be a 

 maximum of 150 feet wide and 1,600 feet long. Bed- 

 ding attitudes are not consistent with the mapped dis- 

 tribution of limestone, and it is likely that this 

 modest-sized deposit is broken by faults and is possi- 

 bly discontinuous. Small bodies of limestone also are 

 shown by Bailey to lie nearby. Fhe limestone is re- 

 ported by Bailey (1962, personal communication) to 

 be typical of the Franciscan Formation and it contains 

 thin chert interbeds. 'Fhere has been no commercial 

 development, although some prospecting was done at 

 the small limestone body near Hicks Road. 



Kennedy Road deposit. Location: S^^"/^ sec. 24, 'F. 

 8 S., R. 1 W., M. D., 3 miles east of Los Gatos; Los 

 Gatos 15-minute quadrangle. Ownership: Not deter- 

 mined (1962). 



A northwest-trending lens of Franciscan limestone 

 1,300 feet by a maximum of 1 50 feet is shown by Bailey 

 and Everhart ( 1964, plate 1 ) . The southeast end of the 

 lens, where crossed by Kennedy Road. v\as examined 

 briefly in July 1962. Here, the body consists of a some- 

 what faulted sequence of beds that dips moderately 

 south and is about 100 feet thick. The upper half con- 

 sists of typical light-gray, dense, foraminiferal lime- 

 stone with thin chert interbeds. Limestone in the 

 lower part is interbedded or otherwise mixed with 

 sandstone and volcanic rock of the Franciscan Forma- 

 tion. The deposit is partly brecciated and recemented 

 with calcite. 



The deposit is undeveloped; it appears to be suitable 

 mainly for crushed rock purposes. Maximum avail- 

 able reserves are probably less than 500,000 tons of 

 limestone and associated rocks. 



Los Gates Lime Company deposit (Ellis; Douglas 

 Ranch). Location: SW'/, NW'/, sec. 27 (proj.), T. 8 

 S., R. 1 W., M.D., 1 mile southeast of Los Gatos; Los 

 Gatos 15-minute quadrangle. Ownership: Lloyd Es- 

 tate, c/o Tal and John Llovd, 16140 C-vpress Wav, Los 

 Gatos (1962). 



Los Gatos Lime C^ompany quarried limestone 

 between 1886 and 1890, and most of it probably came 

 from property owned by J. E. Ellis (formerly Douglas 

 Ranch). 'Fhe limestone was hauled 2 miles to a kiln in 

 Los Gatos where lime was manufactured (Watts, 

 1890, p. 619). Some limestone also was sold for sugar 

 refining (Irelan, 1888, p. 545-546). Several thousand 

 tons of limestone shipped for sugar refining from the 

 Los Gatos area in 1938 by Basic Limestone Products 

 Company mav also have come from this deposit (Lo- 

 gan, 1947, p. 312). 



