accounted for 249,074,000 bar., or 56-2 % of the total U.S. produc- tion. Pools are scattered throughout the area and new pools are constantly being discovered. Most of the oil produced in Kansas, Oklahoma and northern Texas is obtained from beds of sandstone in formations of the Pennsylvanian series (Upper Carboniferous). The oil produced in southern Oklahoma is mainly from several pools in beds of sandstone of the Pennsylvanian series, though some oil is found in the " red beds " of the Permian series (latest Carbonif- erous). The oil found in northern Louisiana and central Texas is obtained from sandstone or other porous rocks of the Cretaceous and Tertiary systems. The average oil from the mid-continent field is of about 35 Baum6 (0-8,485 sp.gr.), ranging from the thick black oil of some of the Louisiana fields, which has a gravity of 21 Baum6 (0-9,272 sp.gr.), to the high-grade Gushing oil of above 55 Baum6 (0-7,568 sp.gr.). The Glenn pool discovery in Creek county, Okla., in 1907 led to a great petroleum development in that state. This pool reached a maximum production of 125,000 bar. a day, sustained from Aug. 1907 to Feb. 1908. In 1912 the famous Gushing pool, also in Creek county, was discovered. In the latter part of 1913 a well in the Gushing pool was drilled to the Bartlesville sand at 2,600 ft., and resulted in a large gusher and the inauguration of an unprece- dented drilling campaign. The oil was the highest-grade crude yet discovered W. of the Appalachian fields. Gusher wells were brought in with frequency, and the production of the pool, which at the end of
1913 averaged about 25,000 bar. a day, was averaging at the end of
1914 over 225,000 barrels. There was a temporary decline early in 1915, but in April production had increased to almost 300,000 barrels. Subsequently it reached a maximum of 320,000 bar., sus- tained for a 6o-day period. The Gushing production was of such high grade and so large that it broke the oil market. In June 1915 the flush production of the field had been exhausted and a decline began. Gushing in 1915 yielded 17% of the total quantity of oil marketed in the United States. The Gushing pool early in 1921 was producing about 27,000 bar. a day.
In 1914 the rich Augusta pool in Butler county, Kan., was opened up, and in 1915 the El Dorado pool, also in Butler county, was discovered. In 1916-7 the Towanda extension of the El Dorado pool resulted in the district increasing its output from an average of between 15,000 and 20,000 bar. in the first five months of 1917, to 80,000 bar. in June and to nearly 100,000 bar. for a few days in September. The wells in the Towanda extension were of large capac- ity but proved to be short-lived, and the El Dorado-Towanda pool declined to about 50,000 bar. before the end of the year. The pool early in 1921 was producing about 29,000 bar. a day.
Late in 1917 the discovery of oil in a well 3,450 ft. deep, a mile and a half S. of the town of Ranger in central Texas, stimulated a most sensational development, covering possibly the widest " boom " area in the history of petroleum in the United States. This was gen- erally termed a " deep sand " development, and opened up exten- sive pools in Eastland county, Stephens county and a portion of Comanche county in 1918. Oil in the deep sand pools is obtained from several different horizons in the so-called Bend series, which is of Pennsylvanian and Mississippian age. In July 1918 a prolific well was drilled in at 1,735 ft. in the Burkburnett field in Wichita county, northern Texas, and Burkburnett was the scene of another great oil boom. The Ranger field reached a maximum capacity of about 75,000 bar. a day in the middle of 1919, but declined thereafter. It was producing 57,000 bar. on Jan. I 1920 and 14,000 bar. on Dec. 31 1920. The Stephens county pool (where development was slower) was producing about 37,000 bar. daily at the beginning of 1920 and had increased its production to close to 130,000 bar. at the end of that year, subsequently declining to about 90,000 bar. in May 1921. The Burkburnett pool, following the opening up of the Burkburnett extension, reached a maximum yield of over 100,000 bar. daily in 1919, from which peak it gradually declined in 1920. Early in 1921 it was producing about 60,000 bar. daily.
Another important development in the mid-continent field was the discovery in Sept. 1918 of oij in a shallow well near Homer, Claiborne parish, in northern Louisiana. A large gusher at greater depth was brought in in Aug. 1919, and the boom scenes of Ranger and Burkburnett were transferred to Shreveport, La. (the head- quarters of the Claiborne parish development), where late in 1919 and early in 1920 other large wells yielding as high as 30,000 bar. daily were brought in in the Homer pool. From a production of about 25,000 bar. at the beginning of 1920 the Homer pool reached a pro- duction of over 100,000 bar. in a few months. This output declined rapidly because of the quick decrease in production of the larger wells, but an average output of about 50,000 bar. daily was main- tained during the latter part of 1920 and the early months of 1921. Geologically the northern Louisiana producing area is in what is known as the Sabine Uplift, an uplift of considerable magnitude in the Coastal Plain sediments, the nature and age of which have not been definitely determined. One of the most important develop- ments of the early part of 1921 was the discovery of oil in commercial quantity in southern Arkansas. The discovery well was brought in near El Dorado in Union county, and rapid drilling of subsequent wells increased the potential production of the new pool to between 40,000 and 60,000 bar. a day by April 1921.
Several important pools were opened up in the Gulf coast field, which first came into prominence in 1901 when the Spindletop pool
in Jefferson county, Texas, was developed. The Gulf coast field includes southern Texas and southern Louisiana, and the petroleum is associated with masses of rock salt and gypsum in domes. The age of the oil-bearing strata ranges from Cretaceous to Quaternary. The field includes a great number of small scattered pools, some of which have developed wells of enormous productivity. The gravity of the oil ranges from 15 to 30 Baume (0-9,655 to 0-8,750 sp.gr.), an average of about 22 Baume (0-9,211 sp.gr.). Among the more important pools of the Gulf coast are the Goose Creek, Hull, Hum- ble, W. Columbia and Damon Mound pools. West Columbia at- tracted attention in 1920 when on July 20 the pool was extended by a well flowing at the rate of 26,000 bar. daily. This flow was practi- cally sustained until Aug. 28, when the well rapidly declined.
The Rocky Mountain field, which embraces the areas of produc- tion in Colorado, Wyoming and Montana, as well as prospective production in Utah and New Mexico, was stimulated by the drilling in of a large well in the Salt Creek pool, Natrona county, Wyo., in April 1912. This started a general boom in Wyoming, which state supplies the bulk of the Rocky Mountain production. Petroleum in the Rocky Mountain field is obtained from strata of the Carbonif- erous and Cretaceous age. Oils from older strata range in gravity from 18 to 24 Baume (0-9,459 to 0-7,865 sp.gr.) and are of paraf- fin base. The development of the richest part of the Wyoming fields was restricted until 1920, pending passage of legislation and issuance of regulations with respect to Federal public lands. The Wyoming field includes a large number of small pools, and the great- est production is obtained from the Salt Creek pool, which early in 1921 was producing about 50,000 bar. daily.
The California field, one of the most prolific in the United States, is divided into two geographic groups, one occupying two sides of San Joaquin Valley and commonly known as the valley fields, and the other occupying a large area along the coast and commonly known as the coastal field. All the valley fields, except one, lie on the west side of San Joaquin Valley, and the oil in most of them is ob- tained from porous Tertiary sandstone. The conditions in the coastal fields are in many respects similar. A very small part of the oil produced in California is obtained from Cretaceous formations. The oils range in gravity from 9-09 to 54 Baume (i-ooo to 0-7,609 sp.gr.), and heavy oils, containing little sulphur, predominate. A fair average gravity is about 21 Baume (0-9,272 sp.gr.). California for many years was the leading oil-producing state. It was sup- planted by Oklahoma in 1907 and 1908 but regained first place in 1909. California held this position until 1915 when its production declined, while Oklahoma's output, because of the Gushing produc- tion, greatly increased, Oklahoma again taking first place. Oklahoma held first place through 1920 with California a close second. The principal producing districts of California are: the Kern River, McKittrick, Midway-Sunset, Lost Hills and Belridge districts, all in Kern county; the Coalinga field, in Fresno county; the Lompoc and Santa Maria fields in Santa Barbara county; the Ventura and Newhall fields in Ventura county; and the Los Angeles and Salt Lake and Whittier-Fullerton fields in Los Angeles county. The larg- est production is obtained from the Midway-Sunset field, which in 1920 produced 37,917,010 bar., a daily average of 103,598 barrels. The Los Angeles and Salt Lake field produced 28,694,163 bar., a daily average of 78,399 bar.; the Coalinga field 15,464,198 bar., a daily average of 42,252 barrels. Important addition to production in the Midway-Sunset field was made in 1920 and 1921 by the de- velopment of the Elk Hills district, where large wells ranging from 2,000 to 6,000 bar. were brought in. Production of this district increased from 25,000 bar. per month during Dec. 1919 to 1,500,000 bar. during Dec. 1920.
Oil shale deposits are found in Colorado, Utah, Wyoming, Nevada, Montana, California, Texas, Kentucky and W. Virginia in the United States, but while extensive experimental work has been done on retorting and much chemical investigation has been conducted as to the nature, properties and behaviour of oil shale, the establish- ment of the industry on a commercial scale has not yet been accom- plished in the United States. By far the greatest attention has been paid to the oil shales of the western states.
Alaska. Oil has been found in several localities in Alaska, not- ably in the district between Icy Cape and Cape Yatag, 400 m. N. W. of Sitka; in the Kayak field, several miles inland from Cape Suckling; in the Gook's Inlet field, between Itimma Peak and Itimma Lake; and in the Cold Bay field, opposite Kodiak Islands. Wells were drilled in the early 'nineties in the Kayak, Cook's Inlet and Cold Bay regions, but oil was not found in commercial quantity. In 1920 interest in Alaskan fields was revived, but no important drilling operations were reported. Production was 56,000 barrels.
Canada. Canada's petroleum production declined steadily from 1908 to 1920. In 1920 the output totalled 198,425 bar. compared with 241,000 bar. in 1919 and 528,000 bar. in 1908. Virtually all of Cana- da's petroleum is produced in Ontario, and occurs in sandstone and limestone of Silurian and Devonian age. The gravity is about 30* Baume (0-828 sp.gr.). A small production is obtained in New Bruns- wick and Alberta. In Aug. 1920 oil was discovered on the Mackenzie River, 150 m. S. of the Arctic Circle in the Canadian North-west Territory. The well was located N.W. of Fort Norman, and on Aug. 23 1920 it began to flow over the top of the mast from a depth of 783 feet. After an uninterrupted flow of 40 minutes the well was capped.
