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Stripping of the Exotica open-pit mine, which is proceeding at about 120,000 tpd, is dwarfed by its proximity to the 500-million-ton Chuquicamata tailing pile. The excavating work is being carried on smoothly and efficiently and, as of the end of October, accounts for the removal of 77 million tons of total material of which some 200,000 tons is stockpiled ore. Diamond drilling has outlined an orebody 5900 ft long and 3400 ft wide containing an estimated 153 million tons of ore at 1.35% recoverable copper based on 80 % extraction.

Jan 11, 1969

By A. J. Erickson, W. W. Atkinson

Concepts developed in a geologic data recording system at the Victoria, Nevada breccia pipe-skarn copper mine, are not fundamentally new, but represents expansion of earlier ideas. The basic philosophy is that a high quality geologic data base is necessary and should be complete, clear, standardized, neat, quantitative, and readily useable. It may be multi-colored or simply black and white. Graphic, descriptive and quantitative recording of data is essential. A format for core logging is presented and discussed, as well as a mu1tiple overlay system for recording data gathered in surface mapping.

Jan 1, 1984

By Roger B. Alke

INTRODUCTION Request to Mine Beneath Bridge The Jakes Run Bridge is a reinforced Portland concrete arch filled bridge located on WV Route 7 near Pentress, WV. The bridge has a span of 22.9 m (meters) and a height of 4 m above normal pool elevation to the underside of the center of the arch (See Fig 1). The bridge is a two lane structure with a width of 6.86 m. The structure is over 50 years old having been built in 1929 and is owned by the Department (WV Department of Highways). [ ]

Jan 1, 1984

By Vernon Taylor

CANADA'S oil production is obtained almost entirely from the Turner Valley gas and oil field, in the Province of Alberta. This field, about 30 miles southwest of the city of Calgary and approximately 115 miles north of the United States border, supplied 92 per cent of production in Canada during 1937. In 1938 considerable development took place in this field and total production for the year amounted to 6,688,716 bbl., an increase of 3,922,146 bbl. over the production in 1937, which increased the percentage of production to approximately 97 per cent of Canada's total. In the British Empire, Canada's production is thus comparable to that of Bahrein Island and Burma, each of which produced approxi-mately 7,800,000 bbl. in 1937, being second to Trinidad's production of 15,500,000 bbl. The total production of the British Empire in that year amounted to 2.07 per cent of the world's total. HISTORY Development of the Turner Valley field commenced in 1913, when a well was started near a gas seepage on the banks of the South Fork of Sheep River in the central part of the Valley. This well found small quantities of a light crude oil in beds of Upper Cretaceous age and pre-cipitated a wild boom in 1913-1914 which ended with the beginning of the Great War in 1914. A small amount of drilling was done in the years from 1914 to 1922 and a few wells found small crude-oil production in the upper sands. In 1922 a few wells were started, including the Royalite Oil Company's No. 4 well (R, Fig. 1), which became the discovery well of naphtha pro-duction from the Paleozoic limestone. In October 1924, this well was completed at a depth of 3740 ft., being approximately 300 ft, in the lime-stone, with an initial flow of 600 bbl. of 72° A.P.I. gravity naphtha and 20,000 M cu. ft. of gas per day. Intense activity was not started until the latter part of 1928, when the Okalta No. 1 well (Q, Fig. 1) was drilled, with an initial production of 500 bbl. of naphtha per day. This well was only 1 ¼ miles from Royalite No. 4, but it was approximately 1300 ft.

Jan 1, 1939

By E. S. Shaw

Utah continues as a very unimportant factor in oil and gas production. During the year 1933 there were no developments of noteworthy significance. There were no completions of either producers or dry holes during the year. The only commercial production in Utah has been from the five fields listed in Table 1 and mentioned briefly in the following paragraphs. Virgin Field.—Oil was first discovered in 1907 in a well drilled in sec. 13, T.41S., R.12W. Of the first 15 wells drilled, all but three were failures. In 1920 production from four wells from 550 to 600 ft. deep was about 20 bbl. per day. San Juan Field.—The majority of drilling in this area was done during the years 1908 to 1911. Probably the first commercial well in the field was that drilled in NW.$i sec. 6, T.42S1 R.l9E., in 1909. Farnham Dome.—The discovery well was drilled by the Utah Oil Refining Co. in April, 1923. A number of years later a second well was drilled by The Carbon Dioxice a mica1 Co., the present operator, which markets the gas in the manufacture of "dry ice" and allied products. The eslimated production, as indicated in Table 1, includes 500 million cubic feet estimated to have been lost while drilling the discovery well. Cisco Dome.—The discovery well was drilled by The Utah Oil Refining Co. in November, 1924. The Crystal Carbon Co. markets the gas in the manufacture of carbon black. Ashley Valley Dome.—The discovery well was drilled by the Utah Oil Refining Co. in April, 1925. The Uintah Gas Co. markets the gas in Vernal, Utah, for fuel. Woodside Structure.—In February, 1924, gas was discovered in a well drilled by Utah Oil Refining Co. in sec. 12, T.l9S., R.l3N., on the Woodside structure. This gas is reported to contain an appreciable amount of helium. It is being held as a helium reserve by the United States Government. Salt Valley Structure.—The test of the Utah Southern Oil Co. in sec. 31, T.23S., R.21E., on the Salt Valley structure has been shut down for some time at 6120 ft. This test has passed through more than 5000 ft.

Jan 1, 1934

By Alan D. Hoagland

The Flat Gap mine, are important zinc deposit of the Appalachian type, is located in the Copper Ridge Belt in the Valley of Tennessee approximately 30 miles northeast of the Mascot-Jefferson City zinc district (Fig. 1). The ore is found in large stratigraphically linked deposits in solution and collapse breccias of the Kingsport, Longview and, to a minor extent, Mascot formations of Lower Ordovician age. The principal ore mineral is sphalerite and the principal gangue minerals are dolonmite and accessory pyrite. There is local minor galena and very rare barite and fluorite.

Jan 10, 1962

By Leon O. Hart

The nickel-chromium alloys of importance are those containing iron and those free from iron. The most important alloys containing iron, with regard to high tonnage, are the nickel-chromium steels. Straight nickel steel was introduced about the year 1889, but it was not until 1895, when it was found that the addition of chromium greatly increased the strength and resistance to shock, that nickel-chromium steels came into use. The three types of nickel-chromium steels developed at this time were: Type 1, containing 3.,50 per cent. nickel and 1.50 per cent. chromium; type 2, containing 2.00 per cent. nickel and 1.00 per cent. chromium; and type 3, containing 1.50 per cent. nickel and 0.50 per cent. chromium.

Jan 1, 1921

By Charles L. Elliot

Data for mining applications of geophysical activity in the Free World in 1963 has been collected by the Committee for Geophysical Activity of the Society of Exploration Geophysicists. This information has been made available to the AIME and is published here in abstract form with the kind permission of the SEG. The data is based or1 244 responses (51%) to the questionnaires circulated among 475 worldwide organizations engaged in mining geophysical operations and or research. It is believed that the data is a realistic appraisal of actual world geophysical activity.

Jan 8, 1964

By J. E. Warren

The mathematical problem considered by the author1 can be given another physical interpretation which is of some practical significance. The alternative physical problem involves the approximate behavior of a single well which is producing at a constant rate through an axially symmetric, horizontal fracture of infinite flow capacity which is located at the center, top or bottom of a uniformly thick, horizontal, homogeneous, anisotropic reservoir of infinite lateral extent which contains a single, slightly compressible fluid. Using Coats' asymptotic results, the wellbore pressure in the fractured system is given by the following equation.

Victor G. Hills, Cripple Creek, Colo. (communication to the Secretary): In continuation of the subject of the perform ance of "baby machine-drills," presented by Mr. Thane, I sub mit the following records of work done with these drills in the Cripple Creek district of Colorado. Two years ago, the Anchoria-Leland mine began to use baby drills ; and, to make the experiment more complete, began by purchasing two machines, of the same size, but of different make. The little drills were first used for stoping and up raising, in which they achieved at once an unqualified success. Soon after, they began to be used for the smaller branch-drifts and prospecting cross-cuts, while the large two-man drills were still used for the main drifts. Now they have almost entirely superseded the large drills, since it has been found that they will do any ordinary work in the mine at less cost, both for labor and for powder, per ton of rock broken. The large drills, of course, make more rapid progress; but it is only where time is a specially important factor that they are now used. The Portland mine, where, until within a year, only the large machines were used, is now using some small drills for stoping, and also for drifting. Mr. Thane speaks of having two men to operate a baby-drill; but in this district the baby-machine is always worked by one man without help. Again, in Prof. Christy's postscript, the quoted extract from a letter of Mr. L. T. Seymour, the South African engineer, mentions a " 2 1/2-inch Little Giant," as though that were the smallest machine used in that region. These statements leave some doubt as to just what Mr. Thane means by a " baby-drill." To avoid any such uncertainty as to the present communication, I will say that the large or two-man drill in common use at Cripple Creek has a 3 1/8-inch cylinder; while a few mines employ a 3-inch, and a few, in running large tunnels, a 3 1/2-inch drill. What we call a baby-drill here has a

Jan 1, 1900

By W. H. Hough, P. B. Leavenworth

Development in the upper Texas Gulf Coast during 1944 resulted in the discovery of 19 new fields as compared with 11 during 1943. These discoveries include 10 oil fields, one dry gas field, and eight gas-condensate fields. Drilling During the year 590 wells were drilled as compared with 418 drilled during 1943. Of these operations, 485 wells were drilled in proven fields, with the following results: 281 oil wells, 22 condensate wells, one dry gas well and 141 dry holes. The remaining 105 wells were wildcats, of which 19 were producers. The geological distribution of these discoveries was as follows: In 1944, production amounted to 178,-522,630 bbl., which was an increase of some 31,670,384 bbl. over the 1943 figure of 136,852,246 bbl. These figures include both condensate and oil production, as separate figures are not available. Wildcatting in the area was more successful during 1944 than in 1943 as the following comparison of number of wells drilled illustrates: Discoveries during 1944 Smith Point, Chambers County.—Standard Oil Company of Texas completed its No. I State, sec. 109, on Feb. 15, 1944, in a Frio sand at 8135 to 8146 ft. The well flowed 250 bbl. of 42º gravity oil through an 1/8-in, choke. Gas-oil ratio was 800 to I; tubing pressure, 1100 bbl. Four other oil wells and one gas well were completed during the year. This discovery does not appear to be of major importance. The producing area lies on the upthrown side of a large fault. North Winnie, Chambers County.—Sun Oil Co. completed No. I P. E. Dougherty on Apr. 27, 1944, from the Frio, through perforations at 8757 to 8759 ft. The initial production was 154 bbl. of 38.3º gravity oil through an 1/8-in. choke. Gas-oil ratio Was 2526 to 1; tubillg Pressure, 2280 1b.; casing Pressure, 1225 lb.; total depth, 9519 ft. Three other wells were drilled during the Year. This discovery is on the downthrown side of the major Winnie Stowell fault, and increases in magnitude the already large producing area along this fault. Mayes Field, Chambers County.—Humble Oil and Refining Company's No. I Mary Etta Mayes was completed on Dec. 24, 1944, in a Frio sand, at 8166 to 8169 ft. through 1/4-in. for 768 bbl. of 40.3º gravity

Jan 1, 1945

By P. Duwez, L. Zwell

In recent years, the problem of pressing metal powder in a die has received much attention. The question has been the object of a Symposium held in New York in March 1947 under the sponsorship of the AIME; an excellent review of the subject may be found in Ref. 1. Various experimental techniques have been used to study the behavior of the powder in a die cavity. Two methods have been particularly successful; one consists of measuring the density distribution²,³ and the other makes use of a lead grid in the powder during pressing.4 In the present study, the pressure at various points on the bottom and the sides of a die 1.50 in. in diam was measured by means of small piston dynamometers and resistance sensitive strain gauges. In order to correlate the results with previous investigations, the pressure distribution inside the compact has also been determined by an indirect method based on density measurements. Strain Gauge Measurements of Pressure on Side and Bottom of Die A schematic drawing of the die used for measuring side pressures is shown in Fig 1. The pressure gauge consists of a 0.25-in. diam piston A which transmits the pressure to a dynamometer B, on which two Baldwin Southwark type 4-14 strain gauges are fastened 180" apart. Because the installation of several dynamometer assemblies along the side of the die would have been difficult, the pressure distribution was obtained in successive tests in which the distance from the gauge to the bottom of the compact was adjusted to different values by changing the length of the bottom piston. The dynamometer, disassembled from the die, was calibrated under compressive loads and showed a 1.00 ohm change of resistance for every 15,300 psi change of pressure (750 lb load change). All the strain gauge measurements were made with a null type Leeds and Northrup Wheatstone bridge. The sensitivity of the method was better than 1 pct and the accuracy was within 2 pct. These values were considered satisfactory in view of the rather large scatter in the measurements introduced by the random variation in packing the powder in the die. The stable ambient conditions and short time involved in the taking of observations made temperature compensation unnecessary-. The pressure distribution on the bot-

Jan 1, 1950

By Ralph W. Smith

Development of the lime industry in Ste. Genevieve County began in a crude way in 1840. According to information furnished by the Missouri Bureau of Geology, in the early days small vertical kilns built of stone were used, and wood was the fuel. Modern development began in 1904 when one company introduced steel shells lined with firebrick. Within a few years two more companies erected similar plants, and in 1925 a fourth company began operations. Thus there arc today four lime companies at Ste. Genevieve, all operating at high capacity and with a gradually increasing production. Geology The limestone of Ste. Genevieve County, which has the chemical composition and purity required for lime burning, is the upper 80 or 90 ft, of Spergen formation. The Missouri Bureau of Geology, in its geological map of Ste. Genevieve County, gives the Spergen formation a total thickness of 160 ft., but only the upper portion is pure enough for lime burning, with an average raw-stone analysis of 98.7 per cent CaCo3; 0.35 SiO2; 0.3 R2O3; 0.35 MgCO3; 0.3 SO3. The Spergen, one member of the Meramac group, Iowa series, of the Mississippian system, underlies an area approximately 12 miles long north and south, by 5 miles wide east and west (Fig. 1) in Ste. Genevieve County. The entire eastern two-thirds of Ste. Genevieve County is sedimentary, the formations dipping gently toward the east on an average grade of about 4 per cent, or 2 1/2°. Thus the outcrops of the various sedimentaries run approximately north and south. A line running west from Ste. Genevievc crosses the outcrops of the sedimentaries, ranging from the top of the Mississippian to the Ozarkian geological system in a space of 12 miles. Thus with the gentle dip of 2 1/2° the 160-ft. thickness of the Spergen formation stretches out in its outcrop so that it is approximately one mile wide. The early quarry and lime developments at Ste. Genevieve mere in this easily obtained surface rock of the Spergen outcrop.

Jan 1, 1938

By Ralph W. Smith

Development of the lime industry in Ste. Genevieve County began in a crude way in 1840. According to information furnished by the Missouri Bureau of Geology, in the early days small vertical kilns built of stone were used, and wood was the fuel. Modern development began in 1904 when one company introduced steel shells lined with firebrick. Within a few years two more companies erected similar plants, and in 1925 a fourth company began operations. Thus there arc today four lime companies at Ste. Genevieve, all operating at high capacity and with a gradually increasing production. Geology The limestone of Ste. Genevieve County, which has the chemical composition and purity required for lime burning, is the upper 80 or 90 ft, of Spergen formation. The Missouri Bureau of Geology, in its geological map of Ste. Genevieve County, gives the Spergen formation a total thickness of 160 ft., but only the upper portion is pure enough for lime burning, with an average raw-stone analysis of 98.7 per cent CaCo3; 0.35 SiO2; 0.3 R2O3; 0.35 MgCO3; 0.3 SO3. The Spergen, one member of the Meramac group, Iowa series, of the Mississippian system, underlies an area approximately 12 miles long north and south, by 5 miles wide east and west (Fig. 1) in Ste. Genevieve County. The entire eastern two-thirds of Ste. Genevieve County is sedimentary, the formations dipping gently toward the east on an average grade of about 4 per cent, or 2 1/2°. Thus the outcrops of the various sedimentaries run approximately north and south. A line running west from Ste. Genevievc crosses the outcrops of the sedimentaries, ranging from the top of the Mississippian to the Ozarkian geological system in a space of 12 miles. Thus with the gentle dip of 2 1/2° the 160-ft. thickness of the Spergen formation stretches out in its outcrop so that it is approximately one mile wide. The early quarry and lime developments at Ste. Genevieve mere in this easily obtained surface rock of the Spergen outcrop.

Jan 1, 1938

By R. W. Lai, I. Iwasaki

Some physical as well as chemical aspects of the methods of dispersion of various corn starches and their derivatives are investigated and their effects as depressants in anionic silica flotation of iron ores ascertained. The adsorption behavior of starches on hematite and quartz is strongly affected by their molecular sizes as inferred from viscosity measurements. The implication of this behavior on flotation and flocculation is discussed. Mechanical treatment of causticized starch solutions is shown to reduce the starch requirements in flotation appreciably. Starches and starch products have been used as depressants for iron oxides both in amine flotation of siliceous gangue and in soap flotation of activated silica from iron ores. Cooke and his associates1,2,3,4 extensively studied the effects of certain starches and their derivatives in the amine flotation of iron ores at near-neutral pH and found that although most starches were good flocculants for hematite and de- pressed that mineral more or less selectively1,3 they did not flocculate quartz suspensions. Further, that replacement of active groups in corn starch modified its behavior as a flocculant for hematite or quartz suspensions1 and as an iron oxide depressant. Schulz and cooke2 showed that many starches and their derivatives, except aminoethyl starch, were abstracted more effectively by Brazilian hematite than by quartz and that the adsorption of a starch product was strongly dependent on pH and on the presence of calcium ion. In soap flotation of calcium-activated quartz, certain starches and their products have been used to depress iron oxides.5'6 The behavior of these substances in flotation appears at times to be at variance with those previously reported and especially with results obtained in the Mines Experiment Station laboratories. This is attributed, at least in part, to differences in flotation procedure and flowsheets and in the method of preparing the depressant. Most of the investigators referred to above, solubilized the starch products by autoclaving at 120°C. Others have used acid,7 alkali8 or oxidizing agents.9 In view of the limited knowledge of the depressing action of starches and their derivatives in iron ore flotation, particularly in soap flotation of calcium-activated silica at high alkalinity, an extensive study

Jan 1, 1965

By J. W. Freeman, R. F. Decker

A microstructural investigation was pursued to establish the mechanism of the pronounced benefits of traces of boron and zirconium on creep properties of a 55 Ni-20 Cr-15 (20-4 MO-3 Ti-3 A1 alloy at 1600°F. The mechanism of improvement of creep properties was found to be a pronounced stabilizing effect of traces of boron and zirconium on the grain boundaries of the alloy. The alloy with low boron and zirconium was subject to rapzd agglomeration of M23 C6 and in the grain boundaries, followed by depletion of y ' and intergranular microcracking at the grain boundaries transverse to applied stress. Brittle fracture then occurred by linking of microcracks. However, additions of zirconium, boron, and boron plus zirconium decreased this tendency in that order, allowing longer creep exposure and higher creep defor.mations before fracture occurred. VERY little information has been published describing the mechanism by which trace amounts of boron or zirconium improve the creep properties of complex nickel-base heat-resistant alloys, although the effect is now well recognized.1-4 Because the phenomenon is so important to properties and the effects are so striking, a study was made of the mechanism in a 55 Ni-20 Cr-15 Co-4 Mo-3 Ti-3 A1 alloy. It was believed that such a mechanistic approach would increase knowledge in theory of alloying and give a more basic understanding of alloy design to resist creep. The basic premise of the study was that boron or zirconium would alter the microstructural characteristics controlling creep and fracture to the extent that the effects could be identified by light and electron microscopy and by electron diffraction techniques. Characteristic of the microstructure of the Ti + Al-bearing nickel-base alloys is the dispersed precipitation of the intermetallic compound Ni,(Al, Ti), the ? ' phase, which is generally con- sidered to be the major source of high creep resistance.5-7 In addition, carbide phases have been identified8-10 and these can alter creep properties markedly.11 Since both the ?' and carbide transformations have been found to control properties, careful attention was paid to the effect of boron and zirconium on these transformations.

Jan 1, 1961

By T. B. Counselman

An iron blast furnace of 1000 tons daily capacity will produce a 100,000 cu. ft. per minute of blast-furnace gas. This contains a 25 per cent of carbon monoxide, and has a B.t.u. value of about 95. gas is used primarily for heating the stoves of the blast furnace, secondarily, under boilers, for steam production. Occasionally it is used in gas engines. The raw gas coming out of the furnace carries about 10 grains of dust per cubic foot of gas, under best operating conditions. With furnace "rolling" or slipping, this quantity may temporarily be gre increased. This dust would, of course, deposit on the checkers o: stoves, or plug the burners under the boilers; therefore the gas : be cleaned. Flow Sheet The first step in the cleaning operation, as shown by the flow s Fig. 1, is a dry dust catcher, of which there are several forms, partially cleaned gas next goes to a primary wet washer, where v sprays knock down most of the solid particles. If further cleani desired, the gas may then go to electrical precipitation. Again, the removed is collected in water. Dry dust catchers reduce the dust col from 10 grains to between 4 and 6 grains per cubic foot, and rec roughly half of the total flue dust in the gas. The wet washers rea most of the remaining dust, reducing the dust content to about 1/4 per cubic foot. Electrical precipitators, if used, further reduce the content to about 0.01 grain per cubic foot of gas. The flow sheet s the dust content of the gas at various steps in the treatment and als content of solids in the water. It should be noted that some plant less water on the primary wet washer than indicated, and that ofte solids content of the scrubber water will be 300 grains per gallon, or much higher. Reasons for Recovering Flue Dust.—There are two main incentive recovering flue dust from the scrubber water: (1) the value of the (2) stream or lake pollution, where such a reason applies.

Jan 1, 1937

By Olin G. Bell

The year 1934 in Southwest Texas was marked by aggressive development and exploratory work and resulted in the finding of five new fields and a new producing horizon in one of the older fields. This activity is the result of a reasonable market outlet for production, on both oil and gas, and the fact that drilling and operating costs are reasonable and that possibilities of finding new productive areas are rather high. A large part of the area is prospective and very little, if any, satisfactory surface geological work can be done. This, together with the possibility of finding new productive areas, stimulates wildcatting throughout the counties under discussion. Development work continued actively in all of the newer fields. Exploratory work was most intense in Duval, McMullen, Starr and Zapata counties. The activity in Duval and McMullen counties was the result of persistent efforts to find new trends of production similar to and perhaps associated with the Government Wells group of fields. The activity in Starr and Zapata counties was stimulated by the discovery of the Sam Fordyce field in Hidalgo County as well as the continued effort to find new productive trends southeastward from some of the older fields in northeastern Zapata County and western Jim Hogg Comity. Statistics on production are shown in Tables 1 and 2. New Fields Lopeno.—The Lopeno gas field in the southwestern part of Zapata County was opened in August, 1934, by R. B. Morrison No. 1 Ramirez. This is an anticlinal structure mapable in Claiborne beds and the producing horizon is the Queen City sand at 2100 ft. in the Upper Mt. Selman. At the close of the year only two gas wells had been completed but drilling operations were in progress on several other wells and a gas line was being laid to the field so that withdrawals from the area will begin early in 1935. Comilas.—The Comitas field was opened by Merle Gunby No. 1 Haynes in a sand at 800 ft. in an area southwest of the Escobas field. The discovery well had an initial production of only about 16 bbl. of oil

Jan 1, 1935

By David N. French

In a recent paper, Miyoshi, Hara, and sugimotoL have shown that hardness increases and crack resistance decreases with polishing time in tungsten car-bide-cobalt alloys. They attribute the changes in hardness and crack resistance to cold working in these alloys. More recently Exner2 explains the decrease in crack resistance with the amount of material removed (polishing time) by suggesting that polishing removes a high compressive residual surface stress due to the initial grinding operation. He cites previous work on steel to show grinding can induce surface compressive stresses but offers no direct experimental measurements to support this in cemented tungsten carbides. In recent work we have observed changes in residual stress in the W C phase as measured by X-ray diffraction techniques with changes in polishing conditions.3 As a result of the work of Miyoshi et al.,L a brief study was undertaken to investigate the effects of polishing and grinding on the residual stress in the WC phase and have been reported.4 A single composition of tungsten carbide —10 wt pct Co was used. Two initial conditions were studied: an annealed condition with about -30,000 psi residual stress from the differences in thermal coefficients of expansion of WC and cobalt and, on the same specimen, a surface ground with a 150 grit diamond wheel. Stress was measured in the WC phase using X-ray diffractometry as a function of the amount of material removed by metallographic polishing with 6 diamond paste. The results are shown in Fig. 1. Two things are noted, 1) polishing with 6 p diamond paste has little effect on the annealed sample and 2) the magnitude of the grinding stress is markedly reduced as material is removed. By the time 0.1 mil is removed the surface has a metallographic polish satisfactory for light microscopy examination. Thus the surface, even though polished, can still retain most of the stress due to grinding. Since WC is itself slightly ductile, it seems reasonable that high compressive stresses can be generated in the surface by the plastic deformation accompanying grinding. Exner2 suggests, by analogy with steel, that as a result of grinding both WC and cobalt in the

Jan 1, 1970

By Alfred H. Bell

Drilling activity in the eastern interior coal basin, which includes Illinois, southwestern Indiana and western Kentucky, decreased greatly in 1931. Only 521 wells were drilled as compared with 1438 in 1930.' The decline in oil production (Fig. 1) was due partly to the failure of new production to make up for the natural decline of the old wells and partly to artificial curtailment of production to meet a decreased demand. During the year prices trended sharply downward until July, after which they made a partial recovery (Fig. 2). The average price of Illinois crude, which is the same as that for southwestern Indiana, was $0.852 per barrel in 1931 as compared with $1.616 in 1930, or slightly more than one-half. The cost of drilling has declined only slightly. The 25 per cent curtailment of production which was adopted by agreement of the southeastern Illinois operators on Sept. 1, 1930, ended on June 3, 1931. It was effective for five months in 1931 as compared with four months in 1930. The outlook for 1932 is for drilling activity in the whole area to continue at about the same rate or to decrease somewhat unless it is stimulated by a substantial rise in crude oil prices or by the discovery of extensive new productive territory. Discoveries of new productive areas and new sands during the year were few. A new gas area was discovered early in the year in Busseron township, Knox County, Indiana, in which the producing sand is in the Pennsylvanian at depths of 630 to 730 ft. The wells had a total initial open-flow capacity of 7 or 8 million cubic feet per day but are shut in for lack of marketing facilities. An exceptionally large gas well which was drilled in Gibson County between Oakland City and Francisco reached a total depth of 1490 ft. and produced from the Brown sand of Chester age. The initial open-flow capacity was reported as 13 million cubic feet per day. In western Kentucky a number of extensions to oil and gas-producing areas are reported. The most active drilling campaign was in Hart County, where 124 wells were drilled, most of them in the

Jan 1, 1932