78 



California Division of Mines and Geology 



Bull 197 



Table 16. Chemical analyses of carbonate rock samples 

 from Junipero Serro deposits, Monterey County. 



Ign. 



N D. not done. 



SP samples collected in SEVi 6-2IS--5E by Oliver E. Bowen and Earl W Hart. 

 July 18, 1957,andanaly7,edby Abbot A. Hanks, Inc., March 25, 1958, SP-I 

 is Sur Series crystalline limestone; SP-2 and -3 are pale brown, siliceous 

 dolomite of the Monterey Formation 



Jun samples collected in SW'/^ 36-20S-5E by Frank Watkins in 19.57 and 

 analyzed by Abbot A. Hanks, Inc., March 26, 1958. Samples are from Sur 

 Series 



The Indians samples were collected by Oliver E. Bowen, April 30, 1959, and 

 analyzed by Lydia Lofgren of the Division of .Mines and Geology, Octo- 

 ber 26, 1^62. The samples are from small lenses of Sur Series exposed 

 along Indian Road in SW/, sec, 13, NW'/ sec, 24, and SW'/i sec, 36, T, 

 20 S,. R, 5 E, 



Lambert Ranch (Jamesburg) deposit. Location: 



SW'X sec. 17, SE% sec. 18, and NW'/, sec. 20, T. 18 S., 

 R. 4 E., 24 miles southeast of Monterey and V/i miles 

 southeast of Jamesburg; Jamesburg 15-minute quad- 

 rangle. Ownership: Not determined. 



The deposit consists of several small limestone 

 lenses which were mapped by Fiedler (1944, p. 18.?, 

 plate 9) as a single lens half a mile long, trending N 

 20° W and centering just east of the SW cor. sec. 17. 

 The limestone is described by Oliver E. Bowen (Hart, 

 1966b, p. 66-67) as medium to coarse crystalline, 

 white to light blue gray, and cut by numerous fingers 

 of granitic rock. It is developed by two small quarries, 

 long abandoned. Because the deposit locally contains 

 silicate minerals and is small, it probably is not of 

 commercial interest. Bowen collected three samples of 

 limestone in 1954 and had them analyzed by Abbot A. 

 Hanks, Inc. The first two are from the north quarry 

 and the third from the south quarry. 



Sample S1O2 FeiOj AI2O3 CaO MgO P^is ~ 



LSL-2 0.24% 0.09% 0.13% 54.38% 0.99% Tr 



LSL-3 0.18 0.08 0.12 .54.29 1.12 Tr 



LSL-4 0.16 0.11 0.13 54.39 1.06 Tr 



The limestone probably was quarried as a source of 

 lime, but there is no record of production. 



Limekiln Creek deposit (near Chualar). Loca- 

 tion: E'/j sec. 28, T. 16 S., R. 4 E., M.D., 4 miles south 

 of Chualar; Salinas 15-minute quadrangle. Owner- 

 ship: Not determined. 



'Fwo small lenses of Sur Series limestone, located 

 just north of the canyon mouth of Limekiln Creek, 

 were developed by tiny quarries many years ago. The 

 rock was calcined for lime at a nearby kiln. The lime- 

 stone is white, medium to coarse crystalline, and local- 



ly graphitic. The main or northeast lens is a little over 

 100 feet long and is a northwest-trending pendant in 

 granitic rock (Oliver E. Bowen, 1960, personal com- 

 iTiunication). Two limestone samples, one from each 

 lens, were collected by Bowen and analyzed by Abbot 

 A. Hanks, Inc., in 1955 (Hart, 1966b, p. 67). 



Sample S1O2 Fe^Oi AIM CM MgO PsPs 



LSL-8 32% 0.09% 0.21% 53.53% 1.66% 0.03% 



LSL-9 0,54 0,06 0,30 52,81 2.07 0.02 



Production is believed to total 1,000 tons or less. The 

 limestone lenses apparently are too small to be of eco- 

 nomic interest. Several other carbonate masses are in- 

 dicated to the northwest in sees. 8, 13, and 14, T. 16 S., 

 R. 3 E., and sees. 18, 19, and 21, T. 16 S., R. 2 E. by C. 

 L. Herold (1935, unpublished thesis); but these are 

 probably small and inaccessible. They have not been 

 examined. Two additional deposits of crystalline lime- 

 stone are reported by Oliver E. Bowen (1968, oral 

 communication) to underlie several acres of SW'/ sec. 

 9, T. 16 S., R. 3 E. at the head of San Benancio Canyon. 



Limekiln Creek deposits (near Lucia). Location: 

 Sec. 10, SW'X sec. 11, NW'/, sec. 14, and sec. 15, T. 22 

 S., R 4 E., M.D., 1 to 2 miles east of Lucia; Lucia, 

 Junipero Serra, and Cape San Martin 1 5-minute quad- 

 rangles. Ownership: S. H. Cowell Foundation, 25 Cal- 

 ifornia Street, San Francisco, and U.S. Government 

 (1964). 



Numerous small to moderate-sized deposits of car- 

 bonate rock are reported between the main and west 

 forks of Limekiln Creek. These are interbedded with 

 schist of the Sur Series and are commonly cut by dikes 

 of light and dark granitic rocks. Because carbonate 

 rock talus is so prevalent in sees. 10 and 15, the impres- 

 sion is given that an immense carbonate body exists 

 (see Reiche, 1937, p. 163 and map). However, Oliver 

 E. Bowen (1964, personal communication) reports 

 that the largest body present in this area is a northeast- 

 dipping rib of carbonate rock averaging perhaps 100 

 to 150 feet thick. The rib is situated near the SJ4 cor. 

 sec. 10 and is best exposed on the west side of the main 

 spur south of "hill 2449". The deposit is a complex 

 mixture of massive, white, coarse-crystalline to platy, 

 gray, banded, fine-crystalline limestone. Some of the 

 limestone is dolomitic (cream-colored dolomite), and 

 much is siliceous. The carbonate rocks have been con- 

 tact-metamorphosed, forming various magnesium, 

 calcium, and aluminum silicates; and commonly they 

 have been brecciated and recemented. According to 

 Bowen, other impure carbonate mas.ses are found in 

 the vicinity, but most are small and none is of suffi- 

 cient quality to be of significant economic interest. 

 (Chemical analyses of samples from the prominent car- 

 bonate lens exposed near "hill 2449" in S'/, sec. 10 are 

 presented below. Analyses were made in 1964 by Mat- 

 ti 'Favela and Lydia Lofgren of the Division of Mines 

 and CJeology. The samples are typical of the limestone 

 and dolomite and probably represent the great bulk of 

 the deposit. 



