By Clarence A. Logan, California Journal of Mines and
Vol. 43, No. 3, July 1947, California Division of Mines,
San Francisco, California, pp. 175-357.
(Used with permission, California Department of Conservation,California Geological Survey.)
Uses of Lime and Limestone
"The uses of limestone and of lime, and lime hydrate made from it, fall under three major heads - agricultural, construction, and chemical industries. In addition, these products have a multitude of miscellaneous uses of every-day importance. It is likely that limestone affects human existence in many ways (many not commonly known) than any other mineral except water and common salt.
"It has been estimated that about 15 percent of the United States is underlain by limestone, but because it is usually so cheap, little limestone is mined underground. The opening of such a mine may be due to some location condition such as exhaustion of surface supplies near an established plant, or the need for stone of a particular quality. Cost of transportation is an important factor in the case of a cheap product and this restricts the distance it can be profitably shipped. Improvements in trucks, cheap Diesel-engine fuel, increased loads and speeds, and better roads have resulted in reducing ton-mile costs to the point where limestone in some cases has been hauled as much as 25 miles by truck, and lime from San Bernardino County is said to have been moved recently into the San Francisco market, a distance of over 400 miles by rail. A substantial tonnage of limestone and dolomite from southwestern Nevada goes into the Los Angeles area, a distance of near 300 miles, and marl from near Pyramid Lake in Nevada moves into north-central California. A producer of high-grade lime in Missouri has shipped carload lots into California. All of this business could and should be supplied from California properties.
"From the above it can be seen that no high-grade limestone deposit should be excluded from consideration if within reasonable distance of a railroad, in a state where manufacturing is increasing so fast.
"The largest consumers of limestone in the state are the portland cement plants which made $14,599,752 barrels, or 16 percent of all such cement made in the United State since 1944. Their consumption of limestone, oyster shells, and travertine has probably been between 2 ½ million tons and 5 million tons per year in the past decade, although no statistics have been published by the state to show the tonnage of raw materials used in cement.
"Other important uses in this state have been in agriculture, including use in processed feeds for poultry and stock, and as fillers in commercial fertilizers; in beet sugar making; for smelter flux, chiefly for iron and steel; and for making lime. Much of the lime used by sugar refineries goes back to the beet growers in the form of a low-grade calcium carbonate for use on their land, without coming on the open market. In the San Francisco area especially limestone is also used for macadam and concrete aggregate. The total reported for 'industrial uses' excluding aggregate in 1944 was 734,425 tons which included 164,494 tons used for lime, 102,220 tons used for all agricultural purposes, and 216,970 tons of fluxing stone. Sugar making requires 150,000 tons or more a year. The balance is used in a great many other industries, some of which are important consumers of limestone in other parts of the country, but are not yet sufficiently represented in California to consume much raw material. Among these are glass plants, paper mills, and chemical industries. The amount of limestone used for macadam and concrete aggregate, not included in the above, was 476,510 tons in 1944, according to the U. S. Bureau of Mines.
"The output of dolomite increased in California during the war on account of its use in producing magnesium, and due to the expansion of the steel industry. Most of the dolomite was burnt to lime, but some was used as carbonate for furnace flux and refractories, and for miscellaneous purposes where it was acceptable in place of high-calcium limestone. The commercial term 'dolomite' has a rather loose application, and some of the stone so described would be more accurately called magnesian limestone. Dolomite production in this state reached an all-time high in 1943 of 331,251 tons, dropping to 217,018 in 1944, the latter being 10 times the output for 1941...."
Uses in Building
"In California no limestone except marble and terrazzo is used directly for building (circa 1947). There are numerous large deposits of excellent marble in the state. Marble production began in the sixties and was carried on until 1942, when it may be said, for practical purposes, to have been suspended with the closing of the Columbia marble quarry in Tuolumne County, although there has been a very small output of crushed stone for terrazzo, and a little onyx and serpentine has been sold. California marbles have been widely used locally for interior work with excellent satisfaction. Marble has shared the same fate as sandstone and granite, both of which were once produced here in substantial quantities. These natural building stones, which require skilled labor at good wages, especially for cutting to finished size and polishing, have not been able to compete with cheaper products made and erected with a minimum of unskilled labor. In addition, marble must compete with that brought from other states or from outside the country.
"In many parts of the United States crushed limestone is widely used as aggregate in concrete, and in some cases plants have even been erected to make sand from limestone. Except for a few cases, concrete aggregate in California is supplied by silicate rocks of the 'trap' and 'granite' types, either quarried from deposits in place or dug as boulders and gravel from stream beds, often in the course of gold dredging. Sands used here are the natural stream deposits, composed almost entirely of quartz.
"Quicklime and hydrated lime for use in mortar, plaster, stucco, and masonry cement may be made either from high-calcium or high-magnesium limestone. The following are the standard specifications for quicklime for structural purposes, as issued by American Society for Testing Materials, C5-26:
"Maximum CO2 allowed is 3 percent if sampled at kiln; or 10 percent elsewhere...."
"High-calcium lime is favored by many because it slakes more rapidly and makes a greater bulk of hydrate than high-magnesium lime. Care is needed with the latter to be sure it is thoroughly slaked, but if this is done it is said to yield a superior mortar. The preparation of hydrate in commercial plants under proper controls is now common practice. Lime hydrate mixed with water to the proper consistency is prepared and aged under the Brooks patents issued in 1931, and is sold in several cities where large numbers of brick buildings are erected. It is commonly known as 'lime putty.' In such places it is also made up with sand into mortar and this is at times handled in transit mixers for delivery to the job in the same manner as ready-mixed cement.
Portland Cement *
(* Page 188 footnote: This section on Portland Cement and flow-sheet of the cement plant (fig. 1) were supplied by Permanente Cement Company.)
"Portland cement consumes more limestone than all other uses in California. All of it so used is 'captive' tonnage, and no state statistics have been published giving the tonnage or value. However, the record of cement production may be used to arrive at an approximate annual figure for limestone used for cement. In 1943 the total portland cement production in California was 18,515,085 barrels of 376 pounds each or 3,480,279 short tons. If it is assumed that the average lime content of all portland cement made in the state is 65 percent, and that all limestone so used will average 90 percent CaCO3, the total consumption of limestone for this purpose was about 4,488,000 short tons. Of course there are several varieties of cement made in which the analysis may vary from that of general-use, moderate heat cement, but it is believed this estimate is not more than 10 percent in error.
"As to a value that might be assigned to this limestone, this is a matter of bookkeeping. A variety of methods in mining or dredging the limestone of course leads to probably wide differences in raw material costs. The actual cost of producing crude limestone will vary from a few cents a ton for oyster shells to a maximum of possibly 80 cents a ton if present high wages in other industries ($10 to $11.50 a shift) have to be met. Incidentally, in the U. S. census figures of California manufacturers for 1939, when 10,984,033 barrels of cement was made in California the total cost of 'material and supplies' for the 10 cement plants then in operation was reported as $3,685,143.
"It is possible to use a rather wide variety of raw materials in making portland cement, if the mixture gives certain proportions of desired ingredients and does not exceed the limits set for some not wanted. Thus, in the Lehigh district, Pennsylvania, extensive use of an argillaceous limestone is made, requiring addition of little clay, and small amounts of high grade limestone. In California, cement companies in the past have generally used high-calcium limestones and no beneficiation of low grade material was attempted previous to the advent of Permanente Cement Company.
"A mild climate, cheap oil or natural gas fuel and plenty of high grade limestone have been basic advantages here. In 1940, California with about 1/20 of the country's population, produced over 1/10 of all portland cement made in the United States. In 1945, the last year for which details are available, five cement plants in northern California shipped 7,446,421 barrels and six plants in southern California shipped 8,417,713 barrels, a total of 15,864,134 barrels of cement, valued at $23,469,662. In 1946, the estimated total state production was 21,200,000 barrels of an estimated total value of $33,708,000. The total capacity of California cement plants was 27,740,000 barrels as of January 1, 1946. As noted herein, several of the plants have increased or are at present increasing their capacities. About 2300 men are employed in the state's cement mills."
Descriptions of Limestone Deposits by Counties - Age and Geographic Distribution of California Deposits*
(* For the description of the limestone in each California county, please go the individual county for the information.)
"It is of interest to note that in California the principal deposits of dolomite and of magnesian limestone are in the older rocks. In Monterey and San Benito Counties large deposits of dolomite are in the oldest rocks, being roof pendants on granitic rocks. In the desert region are numerous dolomite deposits and dolomitic limestones and many of these have been placed among the oldest rocks in the region. The largest of these, not utilized commercially because of remoteness, are the immense accumulations in the Death Valley region, ranging in age from lowermost Cambrian through Ordovician. Some of this is believed to be algal and much of it has evidently derived from limestone.
"In the western Sierra Nevada region from Tehachapi as far north as northern Plumas County, there are few outcrops of rock older than the Carboniferous. While there are numerous limestone deposits in this region that carry small percentages of magnesium, this is generally no higher than might be expected in rocks derived from most of the marine invertebrates. A great many analyses of such organisms found in other parts of the world have been made. In general, the percentages of MgCO3 found by analysis of the inorganic portions of their remains range from a fraction of 1 percent for some corals to nearly 16 percent in aleyonarians and some crustaceans. Analyses of globigerina ooze and pteropod ooze also show only small amounts of MgCO3, around 1 percent or less.
"The fossil evidence found in the high-calcium limestones of east-central California has been too meager to be of much assistance in determining the type of organism from which the deposits were derived. Only a few crinoids have been found. The limestone and the surrounding formations have been subjected to heavy compressive stresses, which is usually considered the cause of the obliteration of organic remains. The proof of organic origin of the limestone remains in the fact that practically every sample taken gives a fetid odor when struck by the hammer, even in cases where analysis shows 98 to 99 percent CaCo3. The uncombined carbon content is very low, though often sufficient to give the stone a gray color, ranging from dove color to near black.
"There appears to be an interesting geographic separation of limestones according to calcium-magnesium ratio along the Sierra Nevada front, which is probably a matter of difference in geologic age. Magnesian limestone is much the commoner from Calaveras County southward. From Amador County northward, high-calcium limestone predominates. The most extensive exposures are in Tuolumne County, and most analyses of samples taken there for this report a magnesium content, but not sufficient to justify the name dolomite In one case, however, where a width of 900 feet was sampled, it was possible to distinguish between the high-calcium and dolomitic beds accurately enough to cut separate samples showing on one side 600 feet of high-calcium limestone with less than 3 percent magnesium carbonate, and on the other 300 feet showing 35.45 percent MgCO3 and 60.77 percent CaCO3. This abrupt transition is difficult to explain as the beds appear to be in contact. However, it is no more remarkable than the abrupt change in the composition of core samples taken by drilling coral and coral rock on the atoll of Funafuti. In that case, the analyses of drill cores taken at depths from 55 to 598 feet yielded MgCO3 ranging from 0.79 to 5.85 percent, with only 1.06 percent MgCO3 at 598 feet. The sample from a depth of 640 feet contained 26.33 MgCo3 and from there to a depth of 1114 feet the content of MgCO3 was about 40 percent. At Funafuti, the principal organisms which contributed to the building of the atoll were, in the order of abundance, (1) Lithothamnion (algae); (2) Halimeda (jointed green algae); (3) Foraminifera; (4) Corals.
"The deposit in Tuolumne County and adjacent Calaveras County is exceptionally large probably because a combination of geological circumstances have preserved it. In the place where the above 600-foot and 300-foot samples were taken, the beds have been folded into an almost vertical position and the folds have then been truncated by erosion along Blanket Creek, in such a way as to expose the lower and older dolomitic limestone on the south. The cause of the folding was the intrusion of a batholith directly to the north, but actual proof of folding, which would be the finding of the strata repeated to the south, is concealed by detritus in the valley of Blanket Creek. On the north, the extent of erosion is controlled by a reef of hard buff and pink quartzite.
"On the Sierra Nevada slopes in Mariposa, Madera, and Fresno Counties there are fewer accessible limestone deposits than farther north, and the only important development has been the opening of a quarry on a large high-calcium deposit on the north side of Merced River, 3 miles northwest of Clearinghouse. This stone was hauled over the Yosemite Valley Railroad to Merced to make portland cement, but the cement plant has recently been removed (circa 1947).
"The Mother Lode gold belt (Jurassic) is terminated near the town of Mariposa and from there southward geologic mapping has been only fragmentary. The granite and related deep-seated rocks of the Sierra Nevada batholith become more prominent and turn nearer south, as erosion of the overlying rocks (slate, schist, shale, and sandstone) has been more active than farther north. In Madera, Fresno, and Tulare Counties many small limestone deposits have been noted on or near granitic contacts, where metamorphism has resulted in the formation of numerous small deposits of scheelite ore. These deposits are generally too remote from transportation, too small in tonnage, or too impure because of contact metamorphism to be of commercial value except possibly as a source of tungsten.
"In Tulare County the limestone which is near enough to railroads to be of interest is mostly different in character from that farther north. It represents the bottom zone, and occurs as roof pendants on the granitic rocks. It therefore shows greater variation in crystal size and a wider range in chemical composition due to localized, contact metamorphism, not only from the granite but from later intrusives.
"Limestone deposits near Tehachapi in Kern County for a long time supplied the southern California market. They are generally coarsely crystalline, occur on the granite and with interbedded schists and probably represent remnants of once much larger deposits. Except for one large deposit a few miles east of Tehachapi, which has been worked to make cement, no limestone or lime has been produced in Kern County since 1928. The Garlock fault, striking northeast a few miles south of Tehachapi, is recognized as the southern boundary of the Sierra Nevada geomorphic province.
"Northern California north of the Sacramento valley is divided into three principal geomorphic provinces. The western half, occupied by the Klamath Mountains and the Cascade Ranges is more important economically. The eastern half is covered by barren young volcanic rocks of the Modoc Plateau, and on the west by similar material from Lassen Peak and Mount Shasta. The remaining area of older crystalline rocks contains large limestone deposits of Devonian, Permian, and Triassic age. Shasta County contains most of these deposits that are near a railroad, and some of them have been worked in past years, though not recently active. Of the numerous deposits in Siskiyou County, only a few are near enough to a railroad to be of economic importance at present. One such deposits has been worked within the past two years.
"The Shasta County deposits are in a thinly populated region where there is not much local demand. The more populous parts of Sacramento Valley are 125 to 200 miles distant. The nearest lime kiln is in El Dorado County 50 miles east of Sacramento or about 250 miles from Redding. There are immense undeveloped deposits of lignite within a few miles of the limestone, and cheap electric power is produced at Shasta Dam with the population of the state increasing, these limestone deposits appear to have interesting future possibilities.
The Desert Region
"Mojave Desert covers most of San Bernardino County, the eastern half of Riverside County and parts of Kern and Los Angeles Counties. The northern portion contains part of the Great Basin; its boundary is indefinite. The southern portion includes the Colorado desert, and probably should include the entire portion of California east of the Sierra Nevada as far north as northern Mono County, and east of Cajon Pass and the San Jacinto fault to the Mexican line, (except for the land draining directly into Colorado River); for this is a land of interior drainage and limited rainfall, which fulfills the definition of a desert. Imperial County and northeastern San Diego County fall within this area.
"In this vast and sparsely inhabited region there are immense deposits of hard limestone, marble, and dolomite. San Bernardino County, larger than several of the Atlantic states combined, has many such deposits within reasonable distance of the two transcontinental railroads which cross it. Several thousand miles of dirt roads and state highways serve all parts of the county. The deposits range in age from Paleozoic (probably Carboniferous) in the west to Middle and Lower Cambrian. The older deposits are usually roof pendants on granite or related deep-seated intrusives. Dolomite is also of frequent occurrence.
"The most extensive dolomite deposits in the state are in Inyo County in the Death Valley region, and the only use so far made of them has been for marble and in a local chemical plant. They range in age from the Lower Cambrian Noonday dolomite, 1500 feet thick, through Middle Cambrian beds 5182 feet thick (mostly dolomite), Upper Cambrian, Lower and Upper Ordovician.
"Imperial County also contains several undeveloped limestone deposits which are not too far from railroad. The natural market for these and for deposits in eastern San Diego County would be in the city of San Diego.
Peninsular and Transverse Ranges
"These geomorphic provinces embrace the more populous sections of southern California, including the larger parts of Ventura and Los Angeles Counties, all of Orange and San Diego Counties and the important western parts of San Bernardino and Riverside Counties. In proportion to population and industries which require lime and limestone, this region has relatively few good deposits and has been supplied largely from other California districts and from Nevada and Arizona deposits. There is one portland cement plant in Riverside County and one in Los Angeles County, but the latter uses clinker made outside the county. In late years there has been only one producer in limestone in each of the counties in Los Angeles, Riverside, and Ventura, and there has been no recorded production from Orange and San Diego Counties. Central San Diego County contains several deposits of hard limestone and marble (probably Triassic) but along the coast only marl or other soft fossiliferous limestone has been produced. There is one good-sized undeveloped deposit of Paleocene algal limestone in Los Angeles County. The important limestone deposits of southwestern San Bernardino County which support portland cement plants at Colton, Victorville, and Oro Grande are in the border zone where the Mojave desert approaches the coast.
The Great Valley
"The central valley of California is about 400 miles long and from 35 to 65 miles wide, extending from the upper Sacramento river in Shasta County to southern Kern County. Most of this great area is covered by alluvium devoid of economic mineral deposits except sand and gravel. In the older sediments fringing both sides of the valley some deposits of marl have been noted. There has been little development of these deposits because they would be suitable principally for local use as fertilizer or soil corrective, and no great need has appeared for them so far. Ultimately, in regions of more than average rainfall and with good drainage, and especially where legumes are raised, such a need will develope (sic). This will be in the Sacramento Valley, where a few sales of marl from Nevada have already been reported. In the southern or San Joaquin Valley, because of scantier rainfall and poorer drainage, calcium carbonate has been retained in the soil, and further addition is not necessary. Gypsum is being used in great quantity in that region, principally for its sulfur content.
"The only commercial production of marl in the Great Valley has been in Fresno County, where output was reported between 1931 and 1939.
"Exploitation of limestone in the Coast Ranges has in general been confined to the region within 100 miles of San Francisco, and except for the travertine of Solano, Contra Costa, and Napa Counties, which has been used to make portland cement, most of the production has come from south of the bay. The deposits vary widely in age and character, from Recent oyster and other shells being dredged from the bay in San Mateo County for making cement, to the limestones and dolomites believed to be the oldest rocks of the Coast Ranges. Santa Cruz County produces much limestone, while Monterey and San Benito Counties have done so in the past. The dolomite deposits in Monterey County which were worked during the last war, and the adjoining dolomite and associated limestone of the Gabilan Mountains in San Benito County are roof pendants on granitic rocks. Santa Clara County has produced marl and shells and lately had been providing limestone for a large portland cement plant. About 200 miles south of San Francisco in San Luis Obispo County are large beds of limestone derived from shells; these have been used for beet sugar refining. In this county also are beds of oyster shells. The boundary of the Coast Range geomorphic province in this direction lies in southern Santa Barbara County.
"North of San Francisco in the Coast Range province there has been little limestone produced and there is evidently a lack of notably large deposits."