Proved Oil Land.

The present extent of proved oil land in California has been determined recently by the State Mining Bureau in the most accurate and detailed study ever given to the subject. The total is 126 square miles, or 80,702 acres, of which 55,842 acres are in Kern County alone. Fresno County is second on the list with 12,218 acres, and Santa Barbara County third with 6,030 acres. The other counties in order of their rank are Orange, Los Angeles, Ventura, San Luis Obispo, and Santa Clara. It is worthy of notice that the total area of proved oil land is most insignificant in comparison with the area of the entire state, being less than one one-thousandth part, and yet the oil business is one of the state's most important industries.

Estimates of the total amount of oil which can be recovered from the land are little better than pure guesses but it does seem most probable that the average acre will ultimately yield much less than fifty thousand barrels.

The areas of the various fields are as follows:

CHAPTER THREE.

METALS.

The total value of metals produced in California during 1915 was $34,577,214. The chief of these is, and always has been, gold, followed in order in 1915 by copper, zinc, quicksilver, tungsten, silver, lead, manganese, antimony, platinum and iron. Deposits of ores of molybdenum, nickel and vanadium are also to be found in the state, although for 1915 there was no commercial output of these materials.

California leads all states in the Union in her gold production and the precious metal is widely distributed throughout the state. Thirty of the fifty-eight counties contain actively operated gold mines or dredges.

Copper, which is second in importance among the metals of the state, occurs in the following general districts: the Shasta County belt, which is by far the most important; the Coast Range deposits, extending more or less continuously from Del Norte in the north to San Luis Obispo County in the south; the Sierra Nevada foothill belt, starting in Plumas and running in a general southerly direction through the Mother Lode counties and ending in Kern; the eastern belt in Mono and Inyo counties; and the southern belt, in San Bernardino, Riverside, and San Diego counties.

Silver is not generally found alone in the state, but is associated to a greater or less extent with gold, copper, lead, and zinc. Quicksilver has for many years been one of the state's staple products and California supplies about 80 per cent of the nation's output of this metal. Tungsten is found in but few other localities of importance.

Large deposits of iron ore have long been known in many sections of the state, but for various economic reasons this branch of the mineral industry is still in its infancy here.

A comparison of the metal output with that of 1914 is afforded by the following table:

ALUMINUM.

Bibliography: Bulletin 38.

No deposits of pure bauxite have been discovered in the state, although from time to time small quantities of the impure material have been the foundation of extravagant reports regarding such discoveries.

ANTIMONY.

Bibliography: State Mineralogist Reports XII, XIII. Bulletin 38. Antimony is known to exist in a number of places in California, having been reported from Kern, Inyo, Riverside, San Benito, and Santa Clara counties. The Kern County deposits, some of which carry metallic antimony, are possibly the best known, and efforts were made to work some of them before California was a part of the United States. The commonest occurrence is in the form of the sulphide, stibnite. No continuous production, however, has been maintained, the output for 1915 being the first reported since 1901.

From the low point of 5.44¢ to 7.11¢ per pound, according to brand in July, 1914, the price of antimony rose gradually, though not steadily to 40¢ at the end of 1915. American antimony, for the first time in many years, appeared on the market in competition with the Chinese and Japanese product. From $1.00 to $2.10 per unit was paid for ore, and at first a minimum of 50% accepted; but, later, some lower grade ore was smelted.

During 1915 in California there was mined and sold a total of 510 tons of antimony ore, valued at $35,666, by five producers in Kern County and one each from Inyo and San Benito counties. The Wild Rose mine in Inyo County made the largest individual output. The production by years since 1887 has been as follows:

Bibliography: State Mineralogist Reports VII, XIII. Bulletins 23 and 50.

Copper is one of the staple mineral products of the state, being produced chiefly in Shasta County, with smaller amounts coming from Calaveras, Placer and Plumas counties. In 1915, some yield in greater

or less amount, was reported from a total of 25 counties. The total production for the year was 40,968,966 pounds, valued at $7,169,567; which is an increase in both amount and value over the previous year. The European war caused a decrease in copper mining for a short time, but followed by renewed activity. The same cause has also raised the price from the 1914 average of 13.3¢ to 17.5¢ per pound for 1915, the closing December figure being 23.5¢, and still rising.

Further efforts have been made during the past year in the improvement of method of handling the smelter smoke. Flotation concentration is being successfully employed by the Engels Copper Company in Plumas County, and by the Calaveras Copper Company in Calaveras County.

Distribution of the output, by counties, for 1915, was as follows:

Amount and value of copper production in California annually since such records have been compiled by the State Mining Bureau is given in the following tabulation:

Bibliography: All State Mineralogist Reports. Bulletins 36, 45, 57.

Gold is one of the most important mineral products of California, and its early discovery undoubtedly was the prime cause of the rapid development of the state. There is a marked tendency toward increased activity in gold mining, as investors realize that many of the mines and prospects have not been exhausted. It is absolutely necessary that owners of prospects and small mines, who wish to dispose of their property or see it developed, should realize that most large investments of that sort are made only after thorough investigation. Frequently, demands for large cash payments have turned away capitalists who would otherwise have been willing to risk an equal amount in development work. Increased activity is noted in practically all of the gold districts.

The State Mining Bureau has never independently collected statistics of gold, platinum and silver production, as there is no necessity for duplicating the very thoroughly organized work of the U. S. Geological Survey covering those metals. The data here given relative to these three metals has been received through the courtesy of Mr. Charles G. Yale, Statistician in charge of the San Francisco branch office of the Division of Mineral Resources. Anyone wishing fuller details of the production of these metals may obtain the same by applying to the