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California Stone Industry (historical account up to circa 1950)

Excerpts from

Geologic Guidebook of the San Francisco Bay Counties:
History, Landscape, Geology, Fossils, Minerals, Industry,
and Routes to Travel, Bulletin 154

Olaf P. Jenkins, Chief, California Division of Mines,
San Francisco, California, December, 1951.

(Continued)


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California Crushed Stone Production

"Most of the crushed stone produced in northern California, as elsewhere, is used as aggregate material; but certain types are also poultry grit, roofing granules, and numerous other chemical and industrial materials. Sources of crushed stone are widespread in the San Francisco Bay region. The locations of quarries are determined as much by the cost of removal and transportation as by the quality of material."

California Cement Industry

"The cement industry of northern California owes its existence mostly to the availability of large bodies of usable limestone. Such bodies have been economically developed in the Coast Ranges between San Francisco and Santa Cruz and in the foothills of the Sierra Nevada. Additional and unusual raw materials for cement manufacture are the large tonnages of sea shells and silt dredged from the San Francisco Bay itself. The limestone bodies of the Coast Ranges and Sierra Nevada form parts of metamorphosed sedimentary rock sequences of pre-Tertiary age, and are commonly highly deformed and difficult to exploit. Nevertheless, the cement industry of this region supplies not only northern California, but exports its products to such distant points as Seattle, Washington, and Hawaii. Limestone from northern California sources is also consumed in the manufacture of lime used by the construction, chemical, and agricultural industries."

Limestone and The Cement Industry of the San Francisco Bay Counties, by Oliver E. Bowen, Jr., Associate Mining Geologist, California State Division of Mines.

(Also see the section below entitled, "Old Lime Kilns Near Olema," by Adan E. Treganza below.)

"Few mineral resources are more important to metropolitan development in the San Francisco Bay area than the limestone and shell-lime deposits in and adjacent to the bay. If one considers the essential materials utilized in erection of any building, he will realize that mortar, lime-plaster, and portland cement are three items without which construction would be both difficult and prohibitively expensive. In all three of these building materials lime is an essential constituent. Not only is the construction industry almost wholly dependent upon lime as a raw material but so also are dozens of other ventures. Lime itself is one of the most important industrial chemicals, and it is used in the manufacture of myriads (sic) of other compounds.

"Industries in the vicinity of San Francisco make use of two types of natural lime-bearing raw materials. The first, seashells, have been calcined to lime for as long as the process has been known to the human race. It is exceedingly uncommon, however, to find seashells in sufficient concentration to form source material upon which to justify erection of a modern industrial plant. Nevertheless, the Pacific Portland Cement Company's mill at Redwood City, which produces cement far in excess of a million barrels annually, utilizes seashell accumulations from San Francisco Bay as its sole source of lime. There are shell deposits on certain parts of the bay floor large enough to support such a plant for many decades.

"A second natural source of industrial lime lies in the limestone deposits scattered through the Coast Ranges. The most extensive quarries now in use are developed along Permanente Creek near Los Altos by Permanente Cement Company. Sufficient limestone is mined there annually to produce more than 5,000,000 barrels of cement. Two other localities have limestone deposits of major proportions which are now being exploited; and, though these are outside the group of 12 San Francisco Bay counties, they are located closely adjacent thereto and the bulk of rock taken from them goes into cement marketed in cities bordering the bay. One is located in the Santa Cruz mountains near Davenport; the other is at the edge of the Gabilan Range southwest of San Juan Bautista. Both support cement plants.

"A third type of raw material formerly important to cement manufacturers in the bay region is shell marl, a rock made up of fragments of seashells in a matrix of calcite and clay. A deposit of this material near Benicia, Solano County, was utilized for hydraulic cement intermittently between 1860 and 1880. Another deposit of shell marl located near Napa, Napa County, was quarried between 1902 and 1922 for portland cement by the Standard Portland Cement Company. Other small occurrences of shell marl and shell limestone have been mined and burned to lime for local use at various times.

"Although precise records dealing with the burning of lime and with the nature and source of the raw materials from which it was made are few, various lime mortars and cements were used in the construction of many of the missions, assistencias, and other public buildings during the Spanish period. Captain George Vancouver stopped at Monterey and Yerba Buena (as San Francisco was then called) in 1792 and his mention of the burning of seashells to lime is one of the earliest records of lime manufacture in California. Shell limestone was quarried near El Toro, Orange County, and burned in the lime kilns of Mission San Juan Capistrano during its construction. Many of the missions were whitewashed both inside and out, and large quantities of lime were used for this purpose as well as for making mortars and cements. It is generally agreed that most of the lime used during the early Spanish Period was made from seashells, most commonly from the well-known abalone.

"One of the first records of utilization of limestone during the American period may be seen in the lime kilns located a few miles south of the town of Olema in Marin County. These date from the gold rush period, more precisely from 1850. Largely because of fire hazard, brick construction, requiring large quantities of lime mortar, became increasingly popular from the 1850's to well toward the turn of the century. Both lime and hydraulic cement were used in early-day brick mortars and for the first decade of the American era these materials were largely imported. By 1868, more than one third of all lime marketed in San Francisco came from the quarries and kilns of Santa Cruz County, and a substantial part of the remaining consumption was produced in other parts of northern California. In spite of the rise of California lime production, lime was still imported in large amounts until the use of portland cement became widespread.

"The rise of portland cement concrete as a structural material revolutionized limestone quarrying in California as well as in other parts of the United States. In 1894, when cement production amounted to only 8000 barrels, the total limestone quarried in California amounted to only 92,760 tons. At the end of 1904, by which time three cement mills had come into production, the annual output of California limestone quarries had risen to more than 474,000 tons. Present consumption (circa 1950) is in excess of 8,250,000 tons, of which more than 90 percent goes into portland cement. Although manufacture of quicklime and hydrated lime for use in the construction industry has decreased with expanded use of portland cement, the use of lime as an industrial chemical and as a soil conditioner in agriculture has risen tremendously. Consequently, lime production as well as cement production has substantially increased.

Quantity production of portland cement in California began with the opening of the California Portland cement plant at Colton, San Bernardino County, in 1894. Prior to that date a small annual production of cement had been recorded from the Jamul Ranch in San Diego County beginning in 1891. There has been some discussion as to whether or not the Jamul product was a true portland cement or merely a hydraulic cement. Portland cement differs from most other early hydraulic cements in that the ingredients are heated to incipient fusion to form a clinker whereas calcining of most early hydraulic cements are accomplished in an ordinary lime kiln at temperatures somewhat less than that maintained for clinkering as now practiced. In any event, the Jamul cement was near a portland cement and probably should be so classified.

"Portland cement manufacturing in the San Francisco Bay region dates from the period 1902-03. During this interval Standard Portland Cement Company opened plants at Napa Junction, Napa County, and Davenport, Santa Cruz, County. A third plant was opened at this time by Pacific Portland Cement Company at Cement, Solano County. Depletion of limestone reserves and other economic considerations caused cessation of the Napa enterprise in 1918, and the Solano County operation in 1928. The Davenport plant was taken over by the Santa Cruz Portland Cement Company in 1907.

"In 1908, a plant was put into production near Mount Diablo at Cowell, Contra Costa County, by the Henry Cowell Lime Cement Company. This operated until 1946 at which time depletion of local limestone reserves and loss of rail facilities forced a permanent shutdown.

"Old Mission Portland Cement Company began marketing cement in the San Francisco Bay area in 1918 from a plant located at San Juan Bautista, San Benito County. In 1927 the plant was taken over by Pacific Portland Cement Company, which has operated it intermittently every (sic) since. The brand name 'Old Mission' has been retained. Pacific Portland Cement Company also operates the well-known Redwood City plant which utilizes oyster shells from San Francisco bay.

Fig. 1. Pacific Portland Cement Company's Redwood City plant, the only one in California using oyster shells and bay mud as the basic raw materials for cement manufacture. Pacific Portland Cement Company's Redwood City plant

"In 1927, Yosemite Portland Cement Company commenced production at Merced, Merced County; much of the company's output was marketed in the San Francisco Bay area. Limestone was shipped to the plant from Jenkins Hill, Mariposa County, via the Yosemite Valley railroad. The plant operated until 1944 at which time the Yosemite Valley Railroad was abandoned. The increased cost of truck haulage over rail freight from the quarry to the plant was deemed sufficiently serious to warrant liquidation of the plant. It was sold to the Kaiser interests which dismantled and shipped the equipment to South America.

"Largest and most recently completed of the cement plants now operating in the bay region is that of Permanente Cement Company near Los Altos, Santa Clara County. Opened in 1940 to supply the gigantic Shasta dam construction project, Permanente has since developed an organization which helps supply not only the bay area and environs but the Pacific islands as well. In addition to its truck fleet which delivers bulk and bagged stocks to bay industries, Permanente operates its own seagoing vessel, the Silver Bow, into which cement for foreign markets is loaded and unloaded by compressed air blowers. The Permanente plant has many unique features which make it the show place of the California cement industry.

"The only cement plant in northern California is located near San Andreas in Calaveras County and is operated by Calaveras Cement Company. This enterprise came into active production in 1926. It supplies the central valley counties and the east-central part of the state, Nevada, and, to a lesser extent, projects in the San Francisco Bay area. With the decline of gold mining, this cement plant has become of major importance to the economy of the foothill region in which it is located.."

Old Lime Kilns Near Olema, by Adan E. Treganza, Assistant Professor of Anthropology, San Francisco State College.*

(* According to the CERES (California Environmental Resources Evaluation System) web site, the old lime kilns are located at "300 ft W of State Hwy. 1 (P.M. 22.1), 4.2 mi. S of Olema.")

"Aside from the debated location of Francis Drake's landing and Mission San Rafael Archangel building, few places of historical interest in Marin County have attracted as much attention as have the old lime kilns near Olema. Much of this interest can be attributed to two facts - that for many years the original builders of the kilns have remained unknown, and that the setting of the Kilns has an air of antiquity. Most impressive is the presence of two large Douglas fir trees growing directly out of the architectural structure of the kilns. Both trees, obviously, started their growth after the kilns were abandoned. The lack of true knowledge concerning the age of these trees has led to speculations that the builders of the kilns were the Russians established at Fort Ross in 1812, or the Spanish padres who erected the mission of San Rafael in 1817. With the passing years, the cool, moist climate of the Marin coast has caused the stone structure to become so covered with moss and lichens that it assumes a natural position in the landscape.

"The lime kilns are located on the east bank of Olema Creek about 100 yards west of State Highway 1. Because of the topography and the vegetational covering, neither the kilns nor the limestone outcrop can be seen from the highway. The present owner of the property is Mr. Sam Smoot of Petaluma (circa 1950).

"Mr. Bliss Brown deserves credit for discovering the historical document establishing the time of construction and the identity of the original builders of the Olema Creek lime kilns. Though his description of architectural features may be subject to several additional notes and some revision, the date of July 13, 1850, presented by him as the original time of building, goes unchallenged.

"Speculations that the Russians, established at Fort Ross in 1812, and at Bodega Bay somewhat earlier, could have built and operated the kilns, find no basis in historical fact. From all indications it would appear that the construction of the kilns was a costly and fairly long-term project such as would have been undertaken either by a group of people intending to establish a large settlement or by some group of individuals intending to exploit the limestone deposit for a ready and profitable market. Neither of these situations provides a suitable frame for the picture of Russian penetration into upper California. First of all, the Russians, with the aid of Aleut Indians, were moving southward to obtain sea-mammal skins, and to establish bases in warmer latitudes where they could grow vegetable produce to ship back to their settlements in southern Alaska. Secondly, Russian architecture employed a highly involved notched-wood construction technique, of which an excellent example still remains in the ruins of the old block house at the northeast corner of the compound at Fort Ross. Lime was not used. A ready market for the sale of lime seems improbable, as the nearest purchasers would have been the Spanish settlers on San Francisco Bay, and at that time relationship between the two parties was anything but favorable. Also, the buildings of the mission period consisted in large part of adobe brick set in a mud mortar. Had the Spanish required lime in any great quantity, one would expect to find kilns in a chain from Baja California to San Francisco. Actually, only a few exist. When lime was required by the Fathers at Mission Carmel, for example, they burned in a kiln abalone shells obtained from the Indian shell mounds.

"The land upon which the Olema kilns are situated was originally granted to James R. berry by the Mexican Government on March 17, 1836; at that time there was no mention of any limestone or kilns. The property must later have changed hands, for the first historical document that bears reference to the lime kilns is dated July 13, 1850. This document established the true identity of the builders of the kilns, thus eliminating much of the mystery surrounding them - especially any implication of an early Russian or Spanish origin. The document consists of a lease between Rafael Garcia, owner, and James A. Shorb, county judge in 1850, and William F. Mercer, a clerk in the judge's court. The lease was to run for a period of 10 years and the significant part reads as follows: 'Rafael Garcier, as party of the first part and owner of the land, and James A. Shorb and William F. Mercer parties of the second part...' The lease was to cover '..all that tract or parcel of land known as the ranch to the party of the first part and called or named Ponta lastera de Malo, for all the limeing and timber and wooded purposes.' The lessees were to have the privilege of building lime kilns; and the entire privilege of the rancho. In exchange for these privileges, the parties of the second part were to give one-third of all the lime burned in the "kiln or kilns that they may erect or cause to be erected." At this point it seems quite clear that had any other kilns been present, notation of them would certainly have been made in this rather carefully worded document. It is further mentioned that '.the party of the first part is to furnish oxen, carts, and Indians to haul all the lime burnt in the kiln or kilns to the Embarcadero and assist in loading or putting the lime in the vessels. Also the party of the first part may receive his one-third at the kiln or Embarcadero.' According to Mr. Brown, the Embarcadero mentioned was probably the one at Bolinas Lagoon, a point from which lumber was being shipped at that time. He suggests that the landing may have been the one located at Inverness Park, as this was but a short distance from the Garcia home. However, the Bolinas Lagoon was closer to San Francisco.

Figure 1. General ground plan and elevation of the Olema Creek kilns. General ground plan and elevation of the Olema Creek kilns
Diagram showing details of Kilns
Figure 2. a, Profile of kiln 2, showing barrel shape and heavy fire-clay lining in both backs and front of kiln. Kiln 2 has only a single arch in fire box, but has retaining shelf at back of arch, and sloping floor in fire box. b, Profile of kiln 1. Interior casing composed of large blocks of limestone cut to follow exact contour of burning shaft so a consistent coating of fire clay or fire bricks could be applied. Backing material between inner and outer casings consists of irregular chunks of limestone set in mud and a small amount of mortar. Brick lining runs about halfway around inner casing, covering rear of kiln. Front of shaft is lined with about two inches of coarse tempered fire clay applied like plaster. This difference indicates a higher temperature at the back, necessitating use of brick. c, Detail showing structure at north end of kilns, probably used for storing burned lime. d, e, Profile and top view of kiln 1, showing manner in which shaft was hand-packed to produce a flue leading directly from fire box into read of shaft. As unloading was done through fire box, it was necessary to cease firing and to cool kilns.
Fig. 3. Photographs showing kiln 2, a, Inside of kiln, showing inner casing and fire arch; mason work has been carefully done. b, c, Outer casing and fire arch. Stone masonry on outside casing proved resistant to weathering, but inside chunky "fill" is crumbled and slumped. d, Front view of fire arch and grate; floor (grate) is composed of 8-inch layer of rock set in mortar or fire clay. Photos by J. Quast. Photographs showing kiln 2

"As indicated by all the evidence from historical records and excavation, the lime kilns were operated for a very short period. On March 15, 1852, the land west of the kilns was leased by Gregorio Briones to George R. Morris to cut wood and timber. In this lease the kilns were mentioned, as they constituted one of the boundary markers; the lease also stated that the kilns were being operated by a Spaniard, who may have employed by Shorb and Mercer. The description, however, did not suggest any large-scale operation. On September 25, 1856, Garcia sold the tract of land containing the kilns to Daniel and Nelson Olds. This sale was made 4 years before the lease to Shorb and Mercer was to have expired, yet there is no mention in the deed of any transference of the lease. From all indications, it would appear that the financial venture by Shorb and Mercer was a failure. Material evidence also militates against the idea of any large-scale operations for any length of time. By trenching the dumps in front of the kilns and by counting the sequence of layers of charcoal-ash and overburned limestone, it has been determined that no one kiln has been fired more than four times, and that there have probably been no more than 12 firings for all the kilns. When abandoned, the smallest of the kilns (no. 1) was loaded but had not been fired. The amount of material removed from the face of the quarry is of not great significance. Taking into account the large amount of limestone used in the actual construction of the kilns, it is evident that very little stone was quarried and prepared for firing. Thus, both the source of material and the reject from firing indicate that there was no large-scale operation.

"The greatest obstacle in dating the kilns has been the presence of the Douglas fir trees. One of these trees, 6 feet 5 inches in circumference, has grown directly out of the floor of kiln 3. A larger tree, 11 feet 4 inches in circumference and 40 inches in average diameter, has grown up between the outer retaining wall (casing) and the central kiln. In 1935 the Marin County Agricultural Commissioner attempted to determine the age of the larger tree by taking a core boring and counting the annual growth rings. Unfortunately, the increment auger could take only an 8-inch sample, thus leaving about 12 inches to the center of the tree in which the number of rings had to be estimated. Inasmuch as rings are very compact and narrow near the outside of a tree, but increase in width as the center is approached, any estimate as to the number of rings contained in the unsampled inner 12 inches would be subject to considerable error.

"In 1949 the author was able to obtain a much larger increment auger. With it two samples were taken - a complete one from the small tree, and one within 2 ½ inches of the center of the large tree. The one from the big tree was taken on the same level and just to the side of the 1935 test. The samples are now in the Museum of Anthropology, University of California. They were examined by Dr. Cockrell, dendrologist at the University of California; he estimated the age of the tree to be 70 to 80 years. Two distinct methods were used to estimate the number of rings on the unrecovered 2 ½ inches. In the first method, the number of rings contained on the last inner inch of the sample were counted and multiplied by 2.5; the result, added to the known 59 rings, gave 70 years as the age of the tree. In the second method, the inner 2 ½ inches of the small tree was substituted for the 2 ½ inches not obtained from the big tree. Since the two trees grew under almost the same environmental conditions, their growth patterns should be approximately the same. Through this method an age of 69 years was obtained. Since the tree was sampled about 4 feet above the ground level, the loss of about 10 rings could be assumed. Taking into consideration possible errors, a safe estimate of the age of the large tree would be 70 to 80 years. According to Dr. Cockrell, the growth rate of the tree was not unusual, considering that there was sufficient water, little competition, and certainly no calcium deficiency.

"The trees, spectacular as they appear, can henceforth be eliminated as a confusing factor in determining the age of the lime kilns. As nearly as can be ascertained, the kilns were last in operation in 1852, some 97 years ago. Allowing the large tree its maximum age (80 years), there remains a period of 17 years between the time the kilns could have been abandoned and the time the seedling fir took root. It therefore seems most certain that the lime kilns along Olema Creek date from 1850.

"Excavation in and around the base of the kilns did not produce a single cultural object of any consequence. However, the rubbish dump associated with the house was located and partially excavated. From this dump was recovered a great quantity of broken porcelain, glass, iron objects, square nails, and the stem of a clay tobacco pipe. All the material recovered appeared to be characteristic of the post-1850's. This would be in accordance with the known historic date of the kilns, assuming the occupants of the house were also the operators of the kilns. Directly across the creek from the kilns the hillside adjacent to the water has an unnatural appearance, suggesting possibly that some sort of structure might once have occupied the area; however, test pitting failed to produce any cultural material.

Fig. 6. Front of kiln 2. Photo by Mary Rae Hill. Front of kiln 2. Photo by Mary Rae Hill
Fig. 4. a, Fire box of kiln 2. Single arch is 7 ½ feet high and 7 feet deep. Sides and top slope in, so that arch where it joins kiln is 2 ½ feet wide and 4 ½ feet high. b, Sketch showing small Douglas fir growing out of kiln 3 (left), and large Douglas fir (only trunk is shown) growing between kilns 1 and 2. c, Detail of fire box of kiln 1, showing double arch. Outer arch is 6 feet high, with passage 3 feet deep. Inner arch is 4 ½ feet high; passage, which is 2 feet deep, presumably served as retainer for burned lime out of the fir box. d, Sketch of kilns 1 and 2, showing also the undetermined structure at the north (left of picture). A sketch depicting details of three kilns
Fig. 5. Photograph taken inside kiln 3, showing small Douglas fir growing in kiln. Stone mason work of inner casing has been carefully done. Photo by J. Quast. Photograph taken inside kiln 3

"At present (circa 1950) the greater part of the kilns still stands intact, though through natural agencies and vandalism by people seeking moss-covered garden stone, some of the more important features have been destroyed. Someone has torn down and hauled away the vertical walls of an undetermined structure at the north end of the kilns. Also missing is the entire front casing and fire arch from kiln 3. The large Douglas fir growing out of the top of the wall in front of kiln 2 has so weakened the structure as to place it in immediate danger of total destruction. Since 1913 the roots of this tree have pushed out an entire section of the front retaining wall and have partially destroyed the inner part of the fire box in kiln 2.

"Though the gross features of the kilns are rustic, it is nevertheless apparent that the builder was an experienced stone-mason well versed in the building of kilns suitable for burning limestone. Judging from the consistency throughout the structural detail, the kilns were erected as a well-planned unit under the direction of one person. Considerable time and labor must have been expended on the construction.

"The structure consists of three barrel-shaped kilns surrounded by angular casings. The angular offsets on the front façade are the result of building around the contour of the hill, and for structural support. On the north end joining kiln 3 is a rectangular structure of uncertain use, which probably served as a storage bin for burned lime. It is a passageway 4 feet 3 inches wide, 11 feet long and 32 inches deep, which extends back to the outer casing of the northernmost kiln. The sides of this structure are built up with stone and lined with lime mortar. At one time there were straight vertical walls rising along both sides of the passage.

"Following traditional form, the quarry is located above the top of the kilns. This provided easy access for loading the shafts. Examination of the quarry face indicated no drilling, or use of powder; instead, a stripping technique following the dip and strike of the fracture zones along a near-vertical face was apparently used. The talus debris gives every indication of having been reduced to a fairly uniform size by means of a sledge hammer. The quarry is in a fine-grained dark-gray limestone lens in the Franciscan formation. Some of the specimens on the talus slope below the quarry face contain impurities, but the material in the loaded kiln was fairly uniform and relatively pure grade.

"The practice of burning limestone to obtain lime is an extremely ancient one. It was not until very early in the twentieth century that any radical or new improvements were introduced into the industry. With the exception of the method used to remove burned lime from the shaft, the Olema Creek lime kilns were remarkably like kilns operating in 1913 in the eastern United States.

"A stipulation in the Mercer and Shorb lease called for the lime to be transported to an Embarcadero by means of ox carts and Indian labor. At the waterfront it was loaded on vessels and shipped, presumably to the port of San Francisco. That lime from the Olema kilns ever reached San Francisco or any other destination is, however, unlikely, for only a brief period of operation is indicated, which probably resulted in considerable financial loss to the original builders and operators."

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