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By Hans Lundberg

IN last year's report on the progress of geophysics, the airborne magnetometer was the featured new development. At that time only a relatively small number of surveys had been made. During 1947, the airborne magnetometer was used in making many surveys and is again one of the high lights of the year in geophysics. This report is mainly concerned with geophysics as applied to the search for minerals exclusive of petroleum. In 194,5 and 1946, the use of the magnetic method reached a peak, partly because of an active period of prospecting brought on by an active mining market, particularly in Canada.

Jan 1, 1948

By Thomas T., Read

DESIRABLE as it is to summarize what has been set forth in preceding chapters, the task can only be approached with great hesitation. What follows represents the personal views of the author at the moment of writing, reserving the privilege to change them on more mature reflection or in the light of further evidence. With that reservation they may be stated somewhat as follows. Education for the mineral industries falls into two categories; general education and technical vocational, using the word vocational not in its usual sense but to signify preparation for specific activities, in which sense a law school is a vocational school. Even at the beginning, as indicated in the first chapter, mineral industry education was partly general and, partly technical and that relationship still persists, because technical education requires a firm basis of general education. Our general American system is to provide free public' general education through the twelfth grade, or completion of high-school work, though there are already many technical vocational high schools, and even in a community where nearly all the young people are preparing for entrance to college there will be some who wish to qualify for employment at the end of the high-school course, or even on completing junior high. Our educational system, therefore, has not only to provide education for those who intend to proceed beyond the twelfth grade but also for those who, for a variety of reasons, may wish or be forced to cease full-time education at any level between the first and twelfth grades. This study has been chiefly concerned with the problem of what kind and how much technical education to provide for those who have completed the twelfth grade and who wish to make their living in the mineral industries. The obvious fact that the mineral industries employ all sorts of trained persons,

Jan 1, 1941

By T. S. Lundy, J. I. Federer

Chemically purified Zr95and Cb95 have been used in determining self-diffusion coefficients in the bcc phase of iodide zirconium over the temperature range of 900o to 1750°C. The temperature dependence of the diffusion coefficients could not be described by the usual Arrhenius-type equation over the entire temperature range. Values of the apparent frequency factors (D0)a and activation energies (Q)A for ZR95 varied from 4.8 x 10-6 to 2.5 x 10-2 sq cm per sec and 20,700 to 46,900 cal per mole, respectively, between 900°and 1750°C. Similarly, for Cb95, values of (Do) a and (Q)A varied from about 2.4 x 10'5 to 0.25 sq cm per sec and 26,500 to 56,800 cal per mole, respectively. The data may be described in terms of the a to ß transition temperature of 1136 °K and the absolute temperature of the diffusion anneals by the following eauations: SEVERAL studies on the diffusion of Zr95 in zirconium have been reported.1"5 The values of the constants contained in the usual Arrhenius-type equation for describing the temperature dependence of the diffusion coefficient, D = Do exp [- Q/(RT)], are summarized in Table I. The reported values of Do, the frequency factor, and Q, the activation energy, are seen to vary by factors of about 60 and 1.6, respectively. Examination of the data from any one study indicated reasonable consistency of measurements. The large discrepancies of over-all results, therefore, cannot be explained on the basis of experimental scatter. One possible explanation for the differences in results could be a varying impurity content of the zirconium. Another possibility is that the radioactive daughter, Cb95, influenced the values of some of the determined diffusion coefficients. Therefore, the first of the three purposes of this study was to reconcile the large differences in diffusion results that have been obtained. Several empirical relations have been proposed to relate the diffusion coefficients in solids with physical properties, such as the absolute melting point, the heat of fusion, and the heat of sublimation.

Jan 1, 1963

By J. Brian Eby

The Gulf Coast of southern Louisiana during the year of 1940 was subjected to an extensive exploration and development campaign, as a result of which 16 oil fields and about 38 new producing sands were found. Although this record of discovery appears in keeping with the rate of 1939 actually in amount of new proven reserves, it may fall short of that of the previous year. Only five or six of the discoveries rated as first-class or important fields at the close of the year. The most prominent new fields opened during the year were Neale field in Beaure-gard Parish, the West Cote Blanche field in St. Mary Parish, the Stella field and the West Bay field in Plaquemines Parish, and the Lake Salvador field in St. Charles Parish. There were many important oil-sand discoveries in proven fields, such as in the Bayou Perot field, the Golden Meadows field, the Iowa field, West Lake Verrett field, and the Venice field. During the year, 1047 weUs were drilled in southern Louisiana, of which 768 were completed as oil-producing wells, 17 as gas wells and 262 as dry holes. The Neale field in northwest Beauregard Parish is considered one of the most important discoveries of the year. The f~eld centers around the north half of sec. 26, 'Y.3 S., R.I I W., just north of the town of Neale. It was discovered by the Atlantic Refining Co., using reflection seismograph to locate the structure. Production was found in the second well drilled in the Wilcox sand on the downthrown side of a fault. The structure is known as the "Tepetate" type, being similar to that of the well-known Tepetate field. There were 12 oil wells and 3 dry holes drilled during the year. The Wilcox sand in this field occurs between 8350 and 8400 ft. and averages 30 ft. in thickness. The West Cote Blanche Bay field, in West Cote Blanche Bay, St. Mary Parish, is a 1940 discovery by the Texas Company, credited to reflection seismograph exploration. The oil is from two sands occurring at 3110 to 3140 ft. and from 4950 to 5020 it. Four wells were drilled during the year, three oil wells and one dry hole. The deepest hole drilled reached 9491 ft. without encountering salt or dome material. In Plaquemines Parish, south of New Orleans, the California company has a new field known as the Stella field. The sand was found at a depth of 7485 ft., and 5 ft. of perforations made a well capable of producing 486 bbl. of oil in 24 hr. through a 9.is-in. choke. The oil is 42" gravity. The discovery well was drilled to a total depth of 10,258 ft. and other producing sands were indicated. A good field appears assured, although only one well was completed within the year. The Lake Salvador field, in the center of Lake Salvador, St. Charles Parish, gives promise of being one of the most important discoveries of the year. The discovery well was perforated at 9775 to 9800 ft. making 850 bbl. of 33.7° gravity oil daily through a 1/4-in. choke. Three wells were completed in 1940 but few details have as yet been made available.he Gulf Oil Corporation apparently has a good field in its wildcat discovery in West Bay, Plaquemines Parish. This well found

Jan 1, 1941

By J. Brian Eby

The Gulf Coast of southern Louisiana during the year of 1940 was subjected to an extensive exploration and development campaign, as a result of which 16 oil fields and about 38 new producing sands were found. Although this record of discovery appears in keeping with the rate of 1939 actually in amount of new proven reserves, it may fall short of that of the previous year. Only five or six of the discoveries rated as first-class or important fields at the close of the year. The most prominent new fields opened during the year were Neale field in Beaure-gard Parish, the West Cote Blanche field in St. Mary Parish, the Stella field and the West Bay field in Plaquemines Parish, and the Lake Salvador field in St. Charles Parish. There were many important oil-sand discoveries in proven fields, such as in the Bayou Perot field, the Golden Meadows field, the Iowa field, West Lake Verrett field, and the Venice field. During the year, 1047 weUs were drilled in southern Louisiana, of which 768 were completed as oil-producing wells, 17 as gas wells and 262 as dry holes. The Neale field in northwest Beauregard Parish is considered one of the most important discoveries of the year. The f~eld centers around the north half of sec. 26, 'Y.3 S., R.I I W., just north of the town of Neale. It was discovered by the Atlantic Refining Co., using reflection seismograph to locate the structure. Production was found in the second well drilled in the Wilcox sand on the downthrown side of a fault. The structure is known as the "Tepetate" type, being similar to that of the well-known Tepetate field. There were 12 oil wells and 3 dry holes drilled during the year. The Wilcox sand in this field occurs between 8350 and 8400 ft. and averages 30 ft. in thickness. The West Cote Blanche Bay field, in West Cote Blanche Bay, St. Mary Parish, is a 1940 discovery by the Texas Company, credited to reflection seismograph exploration. The oil is from two sands occurring at 3110 to 3140 ft. and from 4950 to 5020 it. Four wells were drilled during the year, three oil wells and one dry hole. The deepest hole drilled reached 9491 ft. without encountering salt or dome material. In Plaquemines Parish, south of New Orleans, the California company has a new field known as the Stella field. The sand was found at a depth of 7485 ft., and 5 ft. of perforations made a well capable of producing 486 bbl. of oil in 24 hr. through a 9.is-in. choke. The oil is 42" gravity. The discovery well was drilled to a total depth of 10,258 ft. and other producing sands were indicated. A good field appears assured, although only one well was completed within the year. The Lake Salvador field, in the center of Lake Salvador, St. Charles Parish, gives promise of being one of the most important discoveries of the year. The discovery well was perforated at 9775 to 9800 ft. making 850 bbl. of 33.7° gravity oil daily through a 1/4-in. choke. Three wells were completed in 1940 but few details have as yet been made available.he Gulf Oil Corporation apparently has a good field in its wildcat discovery in West Bay, Plaquemines Parish. This well found

Jan 1, 1941

E. K. Landis, Philadelphia, Pa. (communication to the Secretary) : Mr. Firmstone's paper is of great interest; but he has unfortunately otnitted to state the most important point, viz., the percentage of sulphur in the two materials he compares; and this omission vitiates the conclusions which he draws. Comparing by grade, instead of silicon-contents (as in his Table III.), the iron made using limestone with that made using dolomite, we find for gray-forge the average of four analyses under limestone to be, Si, 0.644; S, 0.089 ; while one analysis under dolomite gives Si, 0.508 ; S, 0.070. For No. 2 iron, the limestone flux gives, as an average of 19 analyses, Si, 1.107; S, 0.051; while the average of 4 analyses made with dolomite flux gives Si, 0.630; S, 0.056. It will be observed, that no No. 1 pig is given under limestone, while 14 analyses appear under dolomite, averaging Si, 0.950 ; S, 0.028. As nothing is said about changed conditions, it is Fair to presume that the ore and fuel, as well as the blast-temperature (which is stated to have been uniform at about 750' F.) remained practically the same; and since the sulphur in the two fluxes is not given, it is impossible to know whether the lower sulphur for equal silicon-contents is due to the use of dolomite or to other conditions. The use of dolomite would produce a more fusible cinder, and the furnace would be hotter than when using limestone; therefore, we might expect to see a grayer iron. The amount of So. 1 iron made with dolomite seems to confirm this supposition; and, under these conditions, we might expect more of the sulphur to be volatilized, and to pass off in the gases. The easier fusibility of the cinder would also permit more rapid driving; and this should reduce the amount of silicon and sulphur in the iron, as the amount of reduced metalloids in the pig is directly proportional to the length of time it remains in the reducing-zone.

Jan 1, 1895

Jan 1, 1931

By S. A. Mahon

AN interesting feature among the mining structures, on the Mesabi. iron range is the iron ore stacker erected in 1934 at the Mesabi Chief washing plant at Keewatin, Minn. It is built of structural steel, and carries a system of belt conveyors which collects the washed product of the plant and places it on a stockpile for subsequent shipment. Although the only one of its kind in the Lake Superior iron district, installations of similar nature have been used elsewhere in the handling of coal and gravel and in earthwork construction. The reasons for stocking Lake Superior iron ores may be as various and diversified as the methods used in building the piles. At the under¬ground mines the existence of the huge piles in evidence at each active shaft is due, principally, to climatic conditions in this north country where the shipping period is much shorter than the operating season. Conversely, at the washing. plants it may be desirable to stockpile washed ores because the shipping season is commonly of longer duration than the period during which the plants may be operated. Washed ores, and mixtures of which washed ores are a component part, have found high favor with the oper

Jan 1, 1935

By David R. Mitchell, R. M. Fleming

MANY trends were evident in the coal industry during 1951. Some were favorable for the industry; others were not. Probably those having the most far-reaching consequences are those affecting coal's markets. The rapid dieselization of many railroads and the continued trend toward oil and natural gas for home heating has caused serious dislocations in various mining districts. Mines have been forced to close down or to work on a reduced time basis. Conversely the increased activity in the metallurgical industries has increased the demand for coking and special purpose coals, and the growing production of electric energy has increased the demand in certain areas for steam coals. The increased demand for metallurgical coal and for steam raising by the large utilities is more than equal tonnage-wise to the loss of coal to railroad dieselization and conversions to oil and gas in the domestic market. Since much of the expansion is at captive mines of large corporations, many commercial operators supplying railroad and domestic users have had their markets curtailed without any compensating demand from other sources. Feverish activity was in evidence in many areas by commercial operators attempting to find new markets. The Norfolk and Western Railway is the, only major American railroad committed to the burning of coal. It has an exceptionally good cost record. During 1951, fifteen additional modern coal-burning steam switching locomotives were authorized for construction in the company's Roanoke shops at a cost of about $1,450,000. When the new order is completed the road will own a total of sixty locomotives of the modern-switcher type, including thirty acquired by purchase last year. The Norfolk and Western today is the only American railroad building its own motive power. All of these locomotives burn coal. Production Coal production in the year 1951 will approximate 570 million tons of anthracite, bituminous coal, and lignite. Of this, approximately 7 pet is anthracite. Total production is approximately 30 million tons more than in 1950 and reflects the increase in general industrial activity. Exports are expected to be close to 50 million tons. The industrial stockpile is close to 75 million tons, the highest it has been since 1943. With the exception of the usual local stoppages the year 1951 was unmarked by labor disputes. It was a year of good labor-management relations with a negotiated wage increase unmarred by a work stoppage. This may be the beginning. of an era of sensible negotiations to find agreeable settlements of disputes without the usual protracted bickering and industry-wide strike. The United Mine Workers of America has condemned wildcat strikes, stating that in nearly every, instance proper grievance procedures have not been instituted. Government defense organizations, perhaps profiting by their experiences during World War II, are pursuing a more enlightened program with regard to the fuel requirements of the nation. Many prominent officials have stated that wherever possible coal should be considered the primary source of fuel in all defense expansion. With the increased consumption of steel by defense projects, approval of transportation facilities for liquid and gaseous fuels have been refused where these fuels would enter a coal producing area. Liquid and gaseous fuel producers also have failed to provide satisfactory evidence that they have sufficient reserves and are capable of supplying their product in adequate amounts for the periods of time required. Realization has at last become prevalent that the hydro-electric power installations in several areas are insufficient to handle increased demands.' Steam generating plants are being constructed in these areas and equipped to burn coal. Most notable of these, is the TWA area whose supplemental steam power plants are expected to consume 10 million tons of coal per year when completed. The Pacific Northwest is another area which is expected to follow the same pattern. Nearly all new steam-power generating plants are being equipped to burn coal either as a primary fuel or as an emergency measure. Metallurgical Coal The steel and other metallurgical industries are expanding rapidly to meet increased industrial demands and defense orders. Since these industries are dependent on coke, coke has had a year of high production and can be expected to break all existing records when steel-plant expansions are completed. Most notable of the expansion projects is that of the Delaware River area where the iron ore will be received by ship from Canada and South America. U. S. Steel is only one of several steel corporations that are planning on putting integrated steel producing units in this area. The Defense Solids Fuels Administration announced in December that through. November 30, 1951. 29 projects in eight states, with a total cost of

Jan 1, 1952

By H. W. Gillett

MAINTENANCE of membership by the technical so¬cieties and the activity of these societies in spite of the adverse business situation have been noteworthy. This forcibly brings home the fact that industry recognizes that sound technical guidance is well worth its cost. The numerous difficulties and losses due to defects of various kinds arising from gas-metal reactions are now generally recognized and interest in these problems is widespread. The forthcoming A. I. M. E. round-table discussion of gas-metal problems will do much to clarify the situation and will permit us to assay our present knowledge and to suggest the proper direction for profitable future research. "The Age Hardening of Metal" was the title of the annual I. M. D. lecture delivered by Dr. Paul D. Merica. A critical review of the known facts relating to age-hardening phenomena was first given, followed by the presentation of a theory correlating the detailed observations which have been made regarding the mechanism of the hardening.

Jan 1, 1933

DAVID COLE, El Paso, Tex. (communication to the Secretary*).-I notice that Mr. Callow takes issue with me on certain points I have previously contributed to the Transactions, to which I would reply," follows: Regarding Inspiration: Mr. Callow's refinements of gravity methods made just prior to the advent of flotation in the Southwest were intended to be "down to the minute," and the gravity flow sheet for Inspiration ores which he brought out at that time as the result of his long campaign of experimentation was regarded by many as the last word in wet gravity work. It was not my intention to discredit this good work when I said "he threw small light on slime treatment." "Minus 200 mesh," however, is not-synonymous with "real slime." Repeated treatments by gravity methods will result in the separation of a very large percentage of the fine granular sulphides in sizes much finer than 200 mesh, and I gave him due credit for that. The unavoidable losses were made in the "real" slime which I mentioned in the paragraph which Mr. Callow refers to as my "statements on page 1871," and his refinements were not a solution to the real slime problem. Mr. Callow has called attention to the fact that his best results at. Inspiration in gravity work were obtained on Joe Bush ore and he presents a table, viz., Tests Nos. 68, 71, and 72; and asks us to consider and compare these results, made by his refined gravity methods, with the results obtained by 'flotation methods in the new mill "during the second half of 1915 and in August, 1916." Of course, the ore treated in the mill was what happened to come. It was not Joe Bush ore, and therefore comparisons of detail figures are of no value. In regard to Mr. Callow's statements under the caption "Callow Cells Adopted by Arizona Copper Company," I would say that those who have been sufficiently interested to read my paper and' his remarks will notice what amounts to contradictory statements on several points which I cannot allow to go unchallenged. I was on the ground constantly and got my information at first hand. The tables published were the official ones. Mr. Callow was not present during the period and has been laboring under that disadvantage.

Jan 5, 1917

By I. R. Kramer, L. J. Demer

Aluminum single crystals were pulled in an electrolytic cell allowing surface removal during the deformation. The extent of Stages I and 11 of the stress-st-aitz curve was increased and the slope decreased as the rate of metal removed from the surface was increased. An increase of the strain rate caused a decrease in the effectiveness of the metal removal. The data indicate that the work-hardening coefficient in Stage I is determined primarily by the conditions which exist on the surface of the crystal. In Stages 11 and 111, both surface effects and internal barriers are important. ALTHOUGH numerous investigations have been conducted on the plastic flow characteristics of metals in an attempt to explain the mechanism of work-hardening, relatively few studies have taken into account the influence of the surface. In all current theories of work-hardening it is assumed that the impediments to the movement of dislocations are within the crystal. The barriers due to the surface and the existence of solid and liquid films have been neglected even though it has been demonstrated that the surface exerts a large effect. A number of investigators1-l8 have shown that solid films on the surface of single crystals markedly affect their mechanical behavior. In general, the presence of a solid film tends to increase the yield stress and increase the work-hardening rate. Often, on single crystals, Stage I and, at times, Stage II regions are completely suppressed. Various mechanisms have been offered for the effects of oxide and metal films as well as the influence of electrolytes. Of these, concepts concerned with the locking of surface dislocation sources and the blocking of dislocations at the surface resulting in pileups appear to be actively considered at present. Barrett,11 Takamura,6 Gilman,19 Lipsett and King,20 Shapiro and Read,10 and Weiner and Gensamer21 are among those who have interpreted their results in terms of piled-up dislocations at the surface, while Adams.22 and Chalmers and Davis23 have explained their experimental observations in terms of locking of surface dislocation sources. In general, the change in plastic flow properties due to electrolytes has been explained in terms of the unblocking or unlocking of dislocations by the removal of the oxide films. In considering the two proposed mechanisms, it appears that the locking of sources of surface dislocations by a solid film should exert a primary influence only on the critical resolved shear stress for flow and not on the slopes of Stages I and 11. However, the blocking at the surface of dislocations from internal sources may also affect the critical resolved stress and furthermore exert an influence throughout the whole plastic range. In certain cases it does not seem feasible to explain the results of experimental observations in terms of locking of surface dislocation sources. The abnormal aftereffects found by Barrettll,12 by removing the oxide by an acid treatment are excellent evidence of the blocking of dislocations at the surface. Additional evidence in favor of a blocking due to a pileup of dislocations at the surface may be found from the observations that the critical resolved shear strength continues to increase with the thickness of the oxide layer until very heavy oxide layers are formed. If the locking of surface dislocations sources were the dominant factor, the critical resolved shear stress would not be expected to increase after all of the surface sources were locked by the formation of the oxide. This may be expected to happen after a few atomic layers of the oxide are formed. In spite of the above evidence on the strong influence of the surface on the plastic flow characteristic, this has been ignored in current theories of work-hardening. Seeger24,25 suggested that most of the dislocations may slip out of the crystal only when the specimen axis is within certain areas of the orientation triangle. In other areas the resolved shear stress in other glide systems is large enough to generate dislocations which can form Lomer-Cottrell locks, thereby decreasing the average slip distance in some directions and causing a larger hardening rate. Friede126 assumed that at the beginning of Stage 11, a large number of Lomer-Cottrell dislocations are formed by a catastrophic process which used up all the Frank-Read sources on the secondary slip-planes. In this manner a fixed number of Lomer-Cottrell locks is formed which act as barriers against which the dislocations can pile up. In Stage 111, Seeger24 and Diehl, Mader, and Seeger25 proposed that Lomer-Cottrell barriers are circumvented by the cross slip of extended screw dislocations. Cottrell and Stokes,27 Friedel,26 Cottrell,26 and stroh29 suggest that the Lomer-Cottrell dislocations collapse under the stress field of the dislocation pileup. It is the purpose of this paper to report the changes in Stages I, II,and III of the deformation process in

Jan 1, 1962

Jan 1, 1901

By John M. Cigan

Samples of copper-lead concentrates from the mine of Cia Minerals Santander, Inc., a Peruvian subsidiary of the St. Joseph Lead Co. were recently subjected to special analysis. This concentrate was known to contain bismuth which, under some circumstances, might have incurred a smelter penalty. In this case, customers for the concentrate accepted it and requested a higher concentration of bismuth. Although chemical analysis would disclose the presence of the metal, it was not possible with equipment available at the mill in Peru to determine the mode of occurrence in the fine grained ores.

Jan 11, 1964

By W. A. Ver Wiebe

Spurred on by the very high demands for new crude supplies resulting from World War 11, the oil men of Kansas strained every effort in 1943 to find as many new pools as possible. In all, 1761 test wells were drilled, ,of which 895 were successful in finding new oil supplies and 32 in finding new gas supplies. The total number of wildcat wells drilled in Kansas was 577, including the so-called "extension wildcats," which are located less than 2 miles from production. As a result of the very determined effort to find new oil reserves, 49 of the wildcat test wells found new oil pools in western Kansas and 7 found new oil pools in eastern Kansas. There were 289 rank wildcat tests, and among these 28 were successful ventures. They are responsible for 26 of the new oil pools recorded for the year and 2 of the new gas pools recorded. The ratio of dry holes to producing wells among such rank wildcats is thus approximately 10 to I (289 dry and 28 good). This compares with a ratio of II: I in 1942 and 6:1 in 1941; the same in 1940 and 5:Iin 1939. With nearly all wells flowing to their maximum economic capacity, the total production for Kansas during 1943 reached a new high; that is, 107,700,000 bbl., compared with 97,000,000 during the previous year. Similarly, the amount of gas sold during 1943 made a new high point on the production curve. The total amount was 122 billion cubic feet, compared with about 98 1/2 billion cubic feet for the year previous. As usual, the large Hugoton field of south- western Kansas accounted for approximately half of the total gas production. Highlights of the Year Despite the fact that 56 new pools were found in Kansas during 1943, it must be admitted that the future reserves of the state have not been increased greatly. Most of the new pools seem to be of minor value, although it is admittedly impossible to gauge the future production of any pool in Kansas with any exactitude. Judging by the later performance of some of the pools found in 1942 and in 1941, less than five of the new pools are likely to make any great contribution to the state's future oil reserves. Taking up the counties of Kansas in alphabetical order, the following statements summarize the highlights of the year. In Graham County, the Morel pool was extended to the southeast and this pool now promises to become one of the important pools of western Kansas. Several of the older wells have already contributed more than I000,000 bbl. of oil, and such a figure is considered very satisfactory in Kansas. In McPherson County, important new reserves were found by persistent drilling in township 17 S., R. I. W., the most northeastern township of the county. Many new wells in older pools and discovery wells in new pools make this region look promising. The Lindsborg pool, which had a sensational revival during 1942, was also extended in a number of directions and has now become a rather large producing area with a fairly high future potential capacity.

Jan 1, 1944

By W. A. Ver Wiebe

Spurred on by the very high demands for new crude supplies resulting from World War 11, the oil men of Kansas strained every effort in 1943 to find as many new pools as possible. In all, 1761 test wells were drilled, ,of which 895 were successful in finding new oil supplies and 32 in finding new gas supplies. The total number of wildcat wells drilled in Kansas was 577, including the so-called "extension wildcats," which are located less than 2 miles from production. As a result of the very determined effort to find new oil reserves, 49 of the wildcat test wells found new oil pools in western Kansas and 7 found new oil pools in eastern Kansas. There were 289 rank wildcat tests, and among these 28 were successful ventures. They are responsible for 26 of the new oil pools recorded for the year and 2 of the new gas pools recorded. The ratio of dry holes to producing wells among such rank wildcats is thus approximately 10 to I (289 dry and 28 good). This compares with a ratio of II: I in 1942 and 6:1 in 1941; the same in 1940 and 5:Iin 1939. With nearly all wells flowing to their maximum economic capacity, the total production for Kansas during 1943 reached a new high; that is, 107,700,000 bbl., compared with 97,000,000 during the previous year. Similarly, the amount of gas sold during 1943 made a new high point on the production curve. The total amount was 122 billion cubic feet, compared with about 98 1/2 billion cubic feet for the year previous. As usual, the large Hugoton field of south- western Kansas accounted for approximately half of the total gas production. Highlights of the Year Despite the fact that 56 new pools were found in Kansas during 1943, it must be admitted that the future reserves of the state have not been increased greatly. Most of the new pools seem to be of minor value, although it is admittedly impossible to gauge the future production of any pool in Kansas with any exactitude. Judging by the later performance of some of the pools found in 1942 and in 1941, less than five of the new pools are likely to make any great contribution to the state's future oil reserves. Taking up the counties of Kansas in alphabetical order, the following statements summarize the highlights of the year. In Graham County, the Morel pool was extended to the southeast and this pool now promises to become one of the important pools of western Kansas. Several of the older wells have already contributed more than I000,000 bbl. of oil, and such a figure is considered very satisfactory in Kansas. In McPherson County, important new reserves were found by persistent drilling in township 17 S., R. I. W., the most northeastern township of the county. Many new wells in older pools and discovery wells in new pools make this region look promising. The Lindsborg pool, which had a sensational revival during 1942, was also extended in a number of directions and has now become a rather large producing area with a fairly high future potential capacity.

Jan 1, 1944

By John E. Murphy, Ernest L. Ohle

Hematite-magnetite ore bodies at Iron Mountain, Missouri, have produced nearly 9 million tons of iron ore concentrates since 1844. The ore minerals occur principally as open-space filling in fractured and brecciated andesite porphyry with very minor replacement of the wall rocks. The enclosing rocks are Precambrian in age and consist of a series of dacite, rhyolite, and andesite flows aggregating about 2000 feet in thickness. All of the ore is in andesite and the mineralization is Precambrian in age. The shape of the ore bodies, the breccia character of the ore, and the gangue mineralogy are believed to be unique. One of the two main ore bodies is crudely dome-shaped with a tendency for development of concentric mineralized shells; the other is an elongated lense in plan but hook-shaped in cross section. Both have strong linear elements striking northeast, east-west, or northwest. Various modes of origin for the structures and for the tension breccias have been suggested, but none is completely satisfactory. Hematite is the main ore mineral; magnetite is subordinate. Important gangue minerals are andradite, quartz, calcite, actinolite, apatite, epidote, and chlorite. Although some evidence favors injection of an iron-rich melt, other evidence suggests ore formation by a high temperature, water-rich solution.

Jan 1, 1968

By C. S. Yust, Lida K. Barrett

The change in shape of the void in a sirzterir~g copper mass has been investigated as a juntction of' density. A serial sectioning' technique was used to eoaltrate the irregular shape of the void at two levels qf density. A measure of the void size and configuration, the proximity number, is defined and used to describe the progress of void removal. The process of. void removal deduced front the observations of this study contrasts with current sintering models in that it takes into account the irregularity of structure of a sintering mass and demonstrates that isolated Porosity does not occur first as spherical pores, but as large, definitely nonspherical sections of the void void volume. The process of sintering, about which there is much practical and theoretical knowledge, has evaded a direct and thorough analysis despite the intensity with which it has been studied for 60 years or so. This is due, of course, to the complex structure of a sintering mass and the inability to observe directly the development of a fully dense solid from the initial particulate arrangement. Extensive theoretical analyses have been based on the adoption of one or another of several model systems, that is, by visualization and analysis of some sort of regular assembly or arrangement of geometric "particles" approximating the conditions of a sintering mass. It seems appropriate at this time to try to examine experimentally in some detail the extent to which a sintering mass of irregular particles dlffers from these models. Many models deal with neck growth and the initial stage of sintering and follow the direction established by ~ucz~nski' in 1949 for the sintering of spheres to flat plates. Recently Johnson and cutler2 have adapted these models to sintering of powder masses. coble3 has presented a mathematical model for sintering that applies to the middle and final stages of the process. These papers, without exception, assume a regular geometry, generally spheres in contact in a regular array. Rhines~ and coworkers, however, are studying the sintering process by applying a model based on the topological concept of genus which permits them to consider an irregular structure. whites has described the various models with the exception of that of Rhines et al., and the assumptions on which they are based and their shortcomings. The present paper examines the geometric changes that occur in the powder mass during sintering by examination of the void. The method is to analyze a series of partially sintered structures and to propose from this analysis the sequence of events which occur in the removal of the void space as a sintering mass progresses from a collection of individual particles to a solid body. The irregular nature of the stacking of particles and of the particles themselves will be taken into account. The significant points derived from this study are: first, accurate reconstructions of the irregular void shapes are presented; second, it is clearly established that closed porosity occurs first as widespread volumes of interconnected porosity, definitely nonspherical in shape; and third, a new factor, the proximity number, is defined, which serves in this paper as a tool for describing the void shape changes observed, and which will be used in a later paper as part of the basis of a mathematical model for sintering. While the specific material studied is copper, the observations are thought to be relatively general as indicated by comparison of the results with partially sintered structures in other materials presented in the literature, both metallic and nonmetallic. EXPERIMENTAL PROCEDURE Four series of specimens representing progressive stages of the sintering process were prepared by sintering high-purity copper powder for various time periods. A relatively large particle size was used so that the void-solid interface could be readily distinguished at low magnification. In three series of specimens a loose stacking of particles was obtained by pouring powder into an alumina mold and lightly tapping the mold. The green density of such compacts was approximately 40 pct of theoretical density. Two of these three series utilized irregularly shaped particles in the size range -230 +325 mesh, one series sintered in vacuum and one in hydrogen at 950°C. The third series of loosely stacked particles consisted of spherical particles in the size range -270 +325 mesh, sintered in hydrogen at 950°C. A fourth series was prepared from compacted irregular particles sintered in hydrogen at 950°C. The specimens for this series were formed by lightly pressing the irregularly shaped particles in a steel die; the green density of the pressed pellets was approximately 60 pct. The irregularly shaped particles used in this study are shown in Fig. 1. The density of these particles, measured by a toluene picnometer technique, is 98.2 pct of theoretical density. Each particle is highly convoluted, and in some instances appears in cross section to contain internal porosity. The density measurement, however, indicates that completely enclosed porosity is very small so that the individual particles have a highly irregular surface but are essentially fully dense copper. Therefore, most of the void space that appears in two dimensions to be isolated within the particle is actually at the particle surface and connected to the external void in the dimension not included in the plane of the cross section. The void space that appears as void surrounded by the par -ticle or within folds in the particle w~ll be r~fc\r?

Jan 1, 1968

By R. M. Asimow, J. J. Svitak

Tile crilical resoll,r,d shear stress, CRSS, for slip of slow1y cooled Ag-All single crystals was measured at 201K. Tlze importance of short-range order and Suzuki sogregalion was inrestigated by deter~rlining llze ciic.cl of quenching on the CRSS. Thr obserz.ed rfrtenching effects were generally small and indicate that short-range ordcr and Slczuki srgregation do no1 account for n significant portion of the solid-solution strengthening in this system. However, all alloys slzozcwi yield drops ulhich rilere heat- lreat nrenl-sensiline THERE have been a number of mechanisms proposed to explain alloy strengthening in the Ag-Au system. The effectiveness of some of the proposed mechanisms, especially those that depend on Suzuki segregation1" or on short-range order,2-6 SRO? should be strongly dependent on heat treatment. Since internal friction investigations in this system indicate that there is stress-induced order,' we must also consider the possibility of local atomic rearrangement or short-range ordering in the stress field of a dislocation. There is not complete agreement whether these mechanisms should be most effective in raising the flow stress, in causing yield drops. or some combination of these two effects. This work was undertaken to determine the effects in the Ag-Au system of mechanisms that depend on segregation or order by using known but drastically different cooling rates following a high-temperature treatment. By comparing the critical resolved shear stress, CRSS, for slip measured after a very slow cool and again after a fast cool (quench) of the same crystal, it is possible to determine the effect of cooling rate on CRSS* and on yield drops. The single-crystal CRSS was determined at several compositions because there has been no data published across the phase field since the publication of room-temperature flow stress by Sachs and Weerts.' EXPERIMENTAL PROCEDURE Starting with materials of 99.999 pct purity, single-crystal specimens of random orientation 1.25 mm square by 4 cm long were prepared with 0, 10, 14, 25, 30. 50, 70. 75. 80, 90. and 100 at. pct Au. Crystals were grown in an inert atmosphere using a modified Bridgman technique with a growth rate of 1.5 cm per hr in a gradient of 3°C per cm. To obtain a maximum practical degree of SRO, the crystals were cooled at a rate of 275'C per hr to about 310°C and then cooled at 6°C per hr to approximately 200°C. Specimens were tested in tension immersed in an alcohol bath at -72°C (201°K) at a strain rate > = 0.003 mm"1 to determine the CRSS (7). The activation volume of several crystals was determined from the flow stress increment (72 - T1) for a tenfold increase in strain rate. The total shear strain varied from 0.05 to 2.3 pct but was generally less than 0.4 pct. After testing, each crystal was then held at 500°C for 10 min, quenched into brine at -35°C and. after storage at -71°C for 1 day, retested in tension using a procedure identical to that of the first test. The quenching apparatus, see Fig. 1, was designed to enable accurate temperature control and rapid quenching while preventing specimen contamination and accidental deformation. Test data from a specimen with a fine thermocouple spot-welded to it indicated a cooling rate of 104C per sec. The relatively low heat-treatment temperature was chosen to minimize quenching defects caused by a large vacancy

Jan 1, 1970

Jan 1, 1897