48 



California Division of Mines and Geology 



Bull. 197 



worked intermittently, and small amounts of lime- 

 stone have been produced for use as road material and 

 as roofing granules. Most or all of the later production 

 was by Western Limestone Company (operated and 

 owned in 1963 by Harry Crowley, Felton) apparently 

 under a sublease arrangement with Limestone 

 Products, Incorporated (a subsidiary of Granite Rock 

 Company, Watsonville). The latest production was in 

 late 1962 or early 196.3, but the operator was preparing 

 to produce additional limestone from existing tailings 

 piles in August 1963 when the property was visited. 



The Holmes deposits consist of massive beds of 

 crystalline limestone and common schist interbeds ex- 

 posed in several ill-defined areas in NE^ sec. 20. The 

 largest deposit, lying astride Bennett Creek, covers an 

 area perhaps 1,500 feet long east- west by 700 feet wide. 

 Although much of the deposit is covered by quarry 

 debris and vegetation, the limestone apparently oc- 

 curs in crudely bedded sequences which are as much 

 as 50 or 100 feet thick and which are interspersed at 

 irregular intervals with thinner sequences of mica 

 schist. Based on obscure stratification, the predomi- 

 nant dip appears to be about 50° N. The limestone is 

 nearly white to gray, fine to coarse crystalline, and 

 high in calcium. An analysis (SACR-4) of typical 

 coarse-crystalline rock from the quarry is given in 

 table 9. A few hundred feet south of the main area, 

 near the crest of the ridge, a small deposit of similar 

 limestone appears to dip about 60° S. To the east of this 

 deposit are large tailings dumps consisting largely of 

 off-white to gray, medium- to coarse-crystalline lime- 

 stone. Other small limestone deposits are reported to 

 the south and west(?) in NEVi sec. 20 but were not 

 examined. 



Development of the main Holmes deposits has been 

 by surface and underground methods. The main quar- 

 ry, consisting of several benches over a relief of about 

 400 feet, covers an area of 8 or 9 acres. At an elevation 

 of about 1,250 feet just north of Bennett Creek, an adit 

 leads to a series of underground rooms, supported by 

 pillars and extending more than 400 feet to the west. 

 Although the adit is partly caved at its portal, the 

 workings are reported to be accessible and in good 

 condition. At the southwest part of the deposit, a quar- 

 ry with a floor elevation of 1,400 feet opens into the 

 main quarry area. This quarry is about 150 feet wide, 

 400 feet deep, and has a maximum face of nearly 200 

 feet. Three hundred feet to the southeast, a smaller 

 limestone deposit is developed by a quarry having a 

 diameter of about 100 feet and a face of more than 100 

 feet. An old tramway site and a large tailings dump of 

 medium- to coarse-crystalline limestone lie to the east 

 of the quarry. Another old quarry is reported to the 

 southeast near a southwest branch of Bull Creek. 

 Remnants of two kiln sites can still be observed in sec. 

 21 immediately east of the deposits. 



The present operator, Harry Crowley, has not done 

 any quarrying but has utilized the extensive dumps at 

 the main quarry as a source of limestone. A mill, locat- 



ed below the lowest two benches, consists of jaw and 

 gyratory crushers, screens, and two large metal stor- 

 age bins. A portable crusher and grizzly also were 

 previously used to produce crushed limestone. In Au- 

 gust 1963, the operation was inactive except for repair 

 work on the mill. 



Based on the size of workings, total limestone pro- 

 duced at the various Holmes deposits may have aggre- 

 gated more than a million tons. Recent production of 

 limestone from tailings probably amounted to a few 

 thousand tons per year. Limestone reserves are virtu- 

 ally impossible to estimate, as quarry debris, soil, and 

 vegetation conceal much of the limestone and related 

 schist. However, reserves at the main deposit could 

 amount to several million tons or more. The deposits 

 to the south appear much smaller, although reserves 

 are undetermined. Extensive surface and subsurface 

 exploration, including drilling, are needed to evaluate 

 the deposits. 



Other references: Irelan, 1888, p. 554; Crawford, 1894, p. 395; Aubury, 

 1906, p. 85; Huguenin ond Costello, 1920, p. 238; Laizure, 1926, p. 85; 

 Hubbord, 1943, p. 44; Leo, 1967, p. 31. 



Ice Cream Grade deposits. Location: SE'X sec. 1 3, 

 T. 10 S., R. 3 W. and W'/, sec. 18, T. 10 S., R. 2 W., 

 M.D., 3/2 miles west of Felton; Ben Lomond 15- 

 minute quadrangle. Ownership: Not determined 

 (1963). 



Several small limestone deposits are exposed along 

 Ice Cream Grade road in the vicinity of Laguna Creek. 

 The limestone is crystalline and forms well-defined 

 massive beds interlayered with schist and quartzite. 

 These small deposits are somewhat impure and appear 

 to be of little or no economic interest. 



Two old stone lime kilns, situated on the east bank 

 of Laguna Creek just south of the Ice Cream Grade 

 road, testify to early efforts to develop limestone in the 

 vicinity. The kilns are identical; each measures 15 feet 

 by 21 feet on the inside, and both are completely open 

 at the top (no stack). No limestone quarry was identi- 

 fied in the area, and there is evidence that only a little 

 lime was burned. A quarry location and the general 

 distribution of limestone outcrops is indicated by 

 Branner et al. (1909, map) and Leo (1967, p. 30). 



IXL deposit. Location: SE'/, sec. 17, T. 10 S., R. 2 

 W., M.D., 1/2 miles west-northwest of Felton; Ben 

 Lomond 15-minute quadrangle. Ownership: H. S. Co- 

 well Foundation, 25 California Street, San Francisco 

 (1963).* 



A substantial amount of limestone for lime was pro- 

 duced from this deposit between the 1880s and 1919. 

 The IXL Lime Company opened the deposit about 

 1885 or earlier and produced 50,000 barrels of lime per 

 year (Irelan, 1888, p. 555; Crawford, 1894, p. 395). 

 Around 1895, the deposit was being operated by 

 Blackman and Cerf who manufactured small quanti- 



• i he dept>sn rcp<jrtcdly was purchased by Granite Rock Company in 1970 

 as a source of riprap. 



