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By B. B. Cox

The principal event during 1936 was the sale of Mosul Oilfields, Ltd. to Mosul Holdings, Ltd., a British company with French and American participation, and the expansion of its wildcat activities to untested structures on its West Tigris concession. Mosul Holdings continued the exploration of its low-gravity Qaiyarah-Najmah-Jawan-Qasab field. The Iraq Petroleum Company's systematic exploration and exploitation of its Kirkuk field was continued on a scientific unitized basis. Pressures and gas-oil ratios remained satisfactory. All wells were produced by flowing. A stabilization plant large enough to supply the 4,000,000-ton pipe line to the Mediterranean was completed at Kirkuk about the close of the year and only sweet oil is now being exported. The Khanaqin Oil Co., Ltd., a subsidiary of the Anglo-Iranian Oil Co., Ltd., continued the normal exploitation of its Naft Khaneh oil field, refining and marketing through the Rafidain Oil Co., Ltd. for local Iraq market. This field lies partly on the Iraq side of the boundary and partly on the Iranian side, the latter portion being known as Naft-i-Shah. Only the Iraq side is considered in this paper. Slightly more than 30,000,000 bbl. of crude was produced in Iraq during 1936. The I.P.C. exported all crude sold outside of Iraq and showed an increase of about 2,500,000 bbl. over the preceding year. Crude production in Iraq for export in 1934 was 7,096,669 bbl.'; in 1935 it was 27,014,904 bbl. and in 1936 it was 29,521,053 barrels.

Jan 1, 1937

By W. R. Wawersik, A. M. Starfield

The classical approach to room-and-pillar mine design in flat-lying, tabular ore bodies limits itself to the special case of an extensive and uniform system of pillars. Each pillar is then assumed to carry the same load, and this load is readily calculated from the extraction ratio e and the weight of the overburden : average pillar stress = [ ] where H is depth below surface, p is average density of overburden, and g is acceleration due to gravity. The average pillar load does not, in this case, depend on the mechanical properties of either the pillars or the surrounding rock mass. The only relevant physical property of the pillars is their compressive strength, (i.e., the maximum load-carrying ability) and the criterion for design is that the average pillar stress should not exceed this strength. The wider the pillar, the greater its strength, and the design of the system is concerned with reconciling this increase in strength to the requirements of roof control so as to optimize extraction.l Any departure from a uniform distribution of pillar loads invalidates the classical approach. Such departures may, for instance, be brought about by: (1) a nonuniform layout of pillars and remnants resulting from selective mining, (2) variations in geology which result in gross changes in the properties of part of the seam or the host rock, (3) deliberate use of abutment support in narrow panels, and (4) the use of yielding pillars for local roof support in conjunction with barrier pillars to carry the overburden load.

Jan 1, 1972

By Frank A. Wardlaw

My subject covers the effect that recent metallurgy has had on operations at the Utah-Delaware mine. This mine is the old Highland Boy mine of Bingham Canyon, Utah, one that has now been in operation for about 30 years. It was first operated by Messrs. Weir and Newhouse as a gold mine, under direction of the Highland Boy Gold Mining Co. The ore was oxidized gold ore and it was treated on the property in a cyanida-tion plant. During the process of development, sulfide ore was found assaying about 5 per cent. copper. It proved to be the discovery of what is yet the largest sulfide copper orebody in the State. The first shipment was made in December, 1896. A smelter was built in Salt Lake Valley to treat this ore and not long after the property was sold to the Utah Consolidated Mining Co. From 1900 to 1924, the mine was a large producer of direct-smelting ore which averaged for many years 4.5 per cent. copper, then later dropped to 2 per cent. copper. During the years 1912 to 1920, direet-smelting lead ore was also mined. In 1918 and 1919 ore developments at depth showed a decided increase in silica content and a porphyry sill so closely associated with the ore that it was impossible to mine the ore clean and it was found necessary to build a copper flotation concentrator at Tooele. The mill had a capacity of 1000 tons a day and made a recovery of 90 per cent., and would have been responsible for a continuance of profitable operations had it not been for a slump in the copper market and the necessary high cost of mining ore on the lower levels. Results of Selective Flotation In 1924 the mine was on the point of a shutadown which had all the earmarks of being permanent; it was being operated at a heavy loss and preparations were made to pull the pumps and salvage the machinery. The plant at Tooele was remodelled for selective flotation by the International Smelting Co. in order to treat custom ores, and incidentally to clean up a possible 10,000 tons of lead-zinc ore which it was thought possible to get in the Utah-Delaware before shutting the mine down. Results were so encouraging that an effort was made to develop more lead-

Jan 1, 1928

By E. L. Estabrook, H. H. Hill

This report summarizes the information that was obtained by the Committee on Unit Operation in Eastern United States and in the foreign countries. Letters and questionnaires were sent to all of the Eastern members of the Petroleum Division of the American Institute of Mining and Metallurgical Engineers and to those who are living outside of the United States, asking them to advise the Committee of any unit operations that are in effect in the various countries of the world and to furnish the names of men to whom inquiries should be directed for detailed information on the different projects. The response to the Committee's request is worthy of note. Practically all of the members who had knowledge of foreign operations replied to the questionnaire and not only furnished information that was of value to the Committee, but they evidenced a real interest in the subject of unit operations and assured the Committee of their willingness to assist in every way possible in order to make the study a success. The Committee wishes, at this time, to express its appreciation of the excellent cooperation that was received from the members of the A. I. M. E. to whom questionnaires were sent. Unfortunately, the limited time that has been given to this survey did not permit the collection of detailed data on the different unit operations that are now in effect. It required several weeks to get back replies from the members located in some of the foreign countries and as a result the men who were asked to furnish information on the various projects have not had sufficient time to submit the detailed data that were requested. The Committee has been assured, however, that information relating to a number of unit operations will be furnished in the near future. Part of the delay has been due to the fact that the purpose of the study was not understood and because the terms "unit" and "near-unit" operations were not clearly defined. In the foreign countries, practically all of the operations in noncompetitive fields are on concessions or leases that have been granted to a single company and for that reason

Jan 1, 1930

R. Schuhmann, Jr. (Purdue University)— Fulton and Chipman's results on rate of silica reduction from slags are analogous in many was to the results of Parlee, Seagle, and Schuhmann10 on rate of alumina reduction from alumina crucibles. Both investigations have given comparably low rates of reduction and slow approaches to equilibrium. Accordingly, we may hypothesize that the rate-determining step is the same in both kinds of experiments; that is, oxygen diffusion across the stagnant boundary layer on the liquid-metal side of the interface between the liquid metal and the oxide phase (slag or solid oxide). I suggest that silica reduction involves the following consecutive steps: I) At the slag-metal interface: SiO2(slag) Si+ 20 II) Transport of oxygen from slag-metal to gas-metal interface: a) diffusion across liquid-metal boundary layer at slag-metal interface. b) convection within the body of liquid metal. c) diffusion across boundary layer at metal-gas interface. 111) At the metal-gas interface: C +O- CO (gas) Iv) At the graphite-metal interface: C (graphite) -C At steelmaking temperatures it is reasonable to assume that equilibrium is attained in all three chemical reactions (I, 111, and IV) right at the respective interfaces. Convection within the stirred liquid metal (step IIb) is also rapid. Transport of Si and C should be orders of magnitude easier than transport of 0, because of the relatively high concentrations of Si and C. Accordingly, we might expect the overall reaction rate to be determined by boundary-layer diffusion of oxygen, either IIa or IIc. Fulton and Chipman's demonstration that bubbling CO through the system had no major effect on reaction rate indicates that IIc is not the slowest step. Therefore, it becomes logical to estimate the maximum rate for step IIa and to compare this theoretical estimate with Fulton and Chipman's experimental data. If oxygen diffusion across the liquid metal boundary layer at the slag metal interface (step IIa) is rate-determining, In this equation, dn sio, /dt is the rate of silica reduction in moles per sec,A is the area of slag-metal interface in sq cm, Do is the diffusivity of oxygen in sq cm per sec, 6, is the boundary layer thickness in cm, c,* is the oxygen concentration right at the slag-metal interface in moles per cubic cm, and co is the oxygen concentration in the body of the liquid metal, also in moles per cubic cm. Equilibrium data" on the silicon deoxidation reaction in liquid iron and steel at 1600°C indicate that the oxygen contents of the liquid metal in Fulton and Chipman's experiments at 1600°C probably fell in the range of 0.5 x10-3 x10-3wt pct. That is, the maximum conceivable value of co*-co for the system under consideration was on the order of 10"5 mole oxygen per cubic cm. On the basis of previously published data,1O,11 it is estimated that Do/0 will fall somewhere in the range from 10-3 to 10-1 cm per sec. The surface area A in Fulton and Chipman's experiments was approximately 20 sq cm, and the weight of metal involved was about 500 grams. Combination of all these figures with the above rate equation leads to an estimate that the rate of silica reduction should fall within the range from 0.002 to 0.2 wt pct Si per hr. This estimate is consistent with the experimental data. For example, Fulton and Chipman's Fig. 2 shows a change of about 0.3 pct Si in 10 hr, corresponding to an average rate of 0.03 pct per hr. According to the proposed hypothesis, increasing the temperature will increase the reaction rate ill two ways: 1) by increasing oxygen diffusivity and 2) by increasing the oxygen concentration (oxygen solubility) in the liquid metal. The combination of these two effects accounts for the high value of the observed activation energy. Summarizing, I propose that the rate of silica reduction, like that of the carbon-oxygen reaction, is diffusion controlled and that low oxygen concentration in the liquid metal is the major factor accounting for the very low observed rates of silica reduction. John Chipman (author's reply)—The authors thank Professor Schuhmann for his interesting contribution. His proposed explanation may well prove to be the correct one. There is clearly a need for much further experimental work on this problem, and further research is in progress.

Jan 1, 1961

By M. L. Requa

In the fall of 1910, the Nevada Petroleum Co., operating in the Coal-inga field in California, determined to drill a number of wells with rotary tools, in order to prove conclusively the relative value of the rotary as compared with the standard rig. At that time, the rotary was but little known in California and its proposed introduction met with considerable criticism on the part of the operators and quiet opposition among the standard drilling crews. There were few men available who were competent to handle a rotary outfit, and these few had had but little experience in California fields. Machines as then built were much inferior to those now used, being lighter in construction and of a poorer quality of material. The shells encountered at depths between 1,700 and 2,000 ft. seemed to be too hard to permit of successful drilling, and at these depths the rig was changed over to standard tools and by them completed. Because of the heavy depreciation, the time lost in converting from rotary to standard, and the comparatively small profit, it was concluded that unless in the future there was some material improvement in rotary rigs, nothing would be gained by drilling with rotary tools upon this property. Little or no drilling has been done upon the property since that time, but in the meantime a large number of men have been trained in the use of the rotary; in fact, many standard-tool men have abandoned standard drilling and, starting in as roustabouts, have become thoroughly competent rotary operators. The improvements in the machinery have been such as to remove many of the objections and the rotary drilling of to-day is in every way superior to that of 1910. In contrast, a well drilled recently by the Kern Trading & Oil Co., in the east side Coalinga field may be cited. The first 2,500 ft. was drilled in 24 days and it is confidently expected that the water string will be set with a rotary at 3,400 ft.—a record obviously far beyond that made in 1910 by the Nevada Petroleum Co. The records herewith are published with the hope that some one having more recent data will publish them so that comparison may be

Jan 1, 1915

By T. Sterry Hunt

I HAVE in a previous communication called the attention of the Institute to the geognostical relations of the crystalline iron ores belonging to the Eozoic rocks of North America, at which time I noticed (1) those associated with the gneisses of the Laurentian series, (2) those of the crystalline schists of the Huronian, as seen in Northern Michigan and in many localities along the Appalachians ; (3) those of Southeastern Missouri associated with petrosilex porphyries and schistose rocks, and presumed to be nearly of the same age with those of the Huronian schists; and (4) the highly titaniferous ores of the Norian or Labradorian series from Essex County, N. Y., and from various parts of Canada. It may here be remarked that, although the presence of titanium is most marked in the Norian ores, this objectionable element is sometimes found in the schistose ores of the Huronian, and to a lesser extent in certain Laurentian magnetites. The ores of each of these geological divisions have their individual peculiarities, which serve to distinguish them to such a degree that the magnetites and specular ores of the Laurentian are as dissimilar to those of the Huronian as are the crystalline silicated rocks of the two series. As it happens that these mineralogical dissimilarities correspond to differences in composition and in adaptability to different processes of manufacture, which, in the present condition of the iron industry, are objects of special consideration to metallurgists, it will be seen that these geognostical distinctions become of great practical importance. During the past year I was desired by the Geological Commissioners of Pennsylvania to devote a few weeks to certain geological studies in the eastern part of the State, in the course of which I was enabled to make, with regard to its crystalline iron ores, some observations to which I desire to call the attention of the Institute. I may mention, in passing, that the great South Mountain belt, from the Schuylkill to the Delaware, is composed of Laurentian rocks, in which are found the characteristic ores of the series like those of the Highlands of New Jersey and New York, and of the Adiron-

Jan 1, 1876

By C. O. Brawner

INTRODUCTION Tailings dams up to about 200 ft. high are proposed to store tailings for a major mining operation on Marinduque Island in the Philippines. The original design of the dam utilized a compacted laterite starter dam followed by hydraulic placement of cycloned sands to form slime retaining dykes along the outer face of the dam. The upstream method of construction was proposed. In view of the failure of numerous tailings dams in Chile during the EL Cobre earthquake (I), an investigation was performed to assess the earthquake stability of the proposed dam. This included a soil investigation on the first cycloned sand dyke, which had been built to a height of 45 ft. Results indicated that the density of the sand was much lower than existing empirical criteria consider to be necessary for resistance to liquefaction. As a result, the dam was redesigned. The downstream method of construction was selected and a yearly construction program was developed to make use of sand available by cycloning. To increase shear strength, improve resistance to liquefaction, and to utilize steeper slopes, compaction of all sand in the dam was specified. A special underdrainage layer and toe drains were incorporated in the design. Details of the decant system and surface erosion alternatives are described. SITE CONDITIONS The mining project is located in the Philippine Islands. At the present annual rate of production, about 4,230,000 cu.m. of tailings will be produced yearly. The volume requirements for tailings storage design for the first 10 years of operation are in the order of 45,000,000 cu.m. The topography near the mine is mountainous with many gullies and canyons carved out by high intensity rainfall and runoff. The bedrock, which is generally shallow and weathered for a considerable depth, is overlain by laterite soils. Vegetation is comprised largely of palms, banana trees, and tropical shrubs and grasses. Precipitation is heavy. The average yearly rainfall over 24 years is 65.2 in. and the maximum recorded 24 hour rainfall is 9.0 in. High intensity rainfall is associated with typhoon storms, which are a seasonal threat inthe Philippines. Fig. 1 shows a summary of monthly precipitation.

Jan 1, 1972

By K. J. Reid, H. A. Lex, I. Iwasaki, K. A. Smith

The effects of autogenous grinding and conventional grinding on the floatabilities of copper-nickel sulfides from Duluth gabbro were investigated. At the same mesh-of-grind copper, nickel, and cobalt recoveries were higher and residual sulfur in the flotation tailings was lower with the autogenously ground pulps. With the ball-mill ground pulps the residual sulfur in the tailings could not be lowered to the level attained by the autogenously ground pulps even at increased levels of the collector addition. From mineralogical examinations of concentrate and tailings samples, an electrochemical interaction between grinding media and sulfide minerals was thought to have a greater effect on sulfide mineral flotation behavior than the breakage characteristics of the ore samples in these two types of mills.

Jan 1, 1984

By Kendall E. Born

PRoduction of crude oil in Tennessee during 1938 was slightly more than 41,000 bbl., an increase of about 5000 bbl. over 1937. The production by counties and by fields is shown in Table 1. The increased production has resulted from continued activity in the Upper Cumberland district, especially in Clay County. The "Mississippi lime" production in Scott and Morgan Counties continued to show a further decline with a 1938 production of 12,379 bbl. as against 14,644 bbl. during 1937. Small scattered production from some half dozen wells in Clay, Pickett, and Fentress Counties, on which there are no accurate figures, is estimated at 500 bbl. during the year. The only natural gas marketed off the lease in Tennessee during 1938 was in Morgan County, where a small amount was furnished for the town of Sunbright and immediate vicinity. The gas occurs with the oil in the Boone Camp field and small amounts were put on the line from the near-by Coon Hollow and Seabolt pools. Developments There were 88 wells spudded in during 1938, of which 10 were drilling or only temporarily shut down on Dec. 31, 1938. Eighty wells were completed during the year; 16 produced oil and 3 were gas wells of undetermined quantity. The total footage drilled on 1938 completions was 63,385 ft. Flush production during the year totaled 850 bbl. per day. The more important wildcats are listed in Table 2; the distribution of oil and gas tests drilled during the year, according to physiographic divisions, is given in Table 3. Cumberland Plateau There were no completions in the producing pools in Scott and Morgan Counties. The decline in production in these areas has been steady for the past several years. In an effort to revive production, present plans include a repressuring program in the Boone Camp field in Morgan County early in 1939. There was one completion in Morgan

Jan 1, 1939

By A. B. Kinzel

A PREVIOUS study1 of the relations of impact strength to inclusions showed that the dynamic strength of steel is lowered by the presence of visible counted inclusions, but that other factors comprised in the term "body" have a marked influence. The previous work was carried out on selected steels from a single source, so that the body factor was purposely minimized, but even under these conditions it was found that inclusion counting or the use of the commercial inclusion rating is not satisfactory. The tensile-impact test, however, was indicated as a satisfactory measure of dynamic strength. It was further suggested that the tensile-impact test should be so standardized as to be suitable for use in specifications, and that the hardness factor should be worked out over a sufficient range to admit ready commercial use of the tensile-impact test. In accordance with these suggestions, and in view of the fact that the steels reported in the previous paper were selected and treated so as to have a minimum variation in body, hardness and structure, further work has been performed on a variety of steels which are not limited by these conditions. The word "body" is used here for want of a better term. It is simply a convenient expression which comprises the effect of the various unknown factors that modify the dynamic strength of the steel. Thus at our present state of knowledge, the writers have chosen to consider hardness, structure and counted inclusion content as factors not comprised in the term "body," and such factors as raw materials, process of melting, fabricating, etc. as comprised in the term "body." Numerous grades of steels made in several ways have been taken from different sources and have been heat-treated to varying hardness by normalizing and by quenching and drawing. The results, therefore, may be considered to be generally applicable to current engineering steels. A certain limitation with respect to the hardness at which steel should be

Jan 1, 1931

By Kendall E. Born

PRoduction of crude oil in Tennessee during 1938 was slightly more than 41,000 bbl., an increase of about 5000 bbl. over 1937. The production by counties and by fields is shown in Table 1. The increased production has resulted from continued activity in the Upper Cumberland district, especially in Clay County. The "Mississippi lime" production in Scott and Morgan Counties continued to show a further decline with a 1938 production of 12,379 bbl. as against 14,644 bbl. during 1937. Small scattered production from some half dozen wells in Clay, Pickett, and Fentress Counties, on which there are no accurate figures, is estimated at 500 bbl. during the year. The only natural gas marketed off the lease in Tennessee during 1938 was in Morgan County, where a small amount was furnished for the town of Sunbright and immediate vicinity. The gas occurs with the oil in the Boone Camp field and small amounts were put on the line from the near-by Coon Hollow and Seabolt pools. Developments There were 88 wells spudded in during 1938, of which 10 were drilling or only temporarily shut down on Dec. 31, 1938. Eighty wells were completed during the year; 16 produced oil and 3 were gas wells of undetermined quantity. The total footage drilled on 1938 completions was 63,385 ft. Flush production during the year totaled 850 bbl. per day. The more important wildcats are listed in Table 2; the distribution of oil and gas tests drilled during the year, according to physiographic divisions, is given in Table 3. Cumberland Plateau There were no completions in the producing pools in Scott and Morgan Counties. The decline in production in these areas has been steady for the past several years. In an effort to revive production, present plans include a repressuring program in the Boone Camp field in Morgan County early in 1939. There was one completion in Morgan

Jan 1, 1939

By Theron Wasson

The discovery of two new fields—the Reed City area of Osceola County and the Headquarters field, of Roscommon County —and the important development in Winterfield township, Clare County, again demonstrate the fact that it is the unknown and unexpected that enter very definitely into the oil-producing history of Michigan. This is particularly true in the area of thick glacial drift in the north central part of the state, where the new prolific fields have been discovered this year. This shifts the interest from the southwestern part of the lower peninsula, where a number of pools were rapidly developed during 1939 and 1940, back into the Central Basin area. As a result of strict proration in the new areas, the production for the state of Michigan for the year has not been as great as in 1940 or 1939. In 1941 the total production was 16,300,000 bbl., in 1940 it was 19,551,000 bbl., and in 1939, which was the peak year, it was 23,300,000 bbl. However, the discovery of the new fields this year nearly doubles the estimated reserves for Michigan reported at the end of 1940 In 1941 about 12,000,000 bbl. of oil was produced from the older fields, in which the individual well productions were so small that proration was not an important factor. The total production for the state from the discovery of oil in 1925 through 1941 now stands at 161,205,000 barrels. ActIVe Oil Fields Reed City Field.—In the Reed City field, Lincoln township, Osceola County, only small oil wells were completed during 1939 and 1940. The discovery of much larger production in wells drilled somewhat deeper, by The Pure Oil Co. and the Weber Oil Co., in the early part of 1941, led to the rapid development in this area. Some wells have had initial productions as high as 10,000 bbl. By the end of the year III producing wells were completed, with an average depth of 3600 ft., from the Detroit River formation of Devonian age. The entire development of the field to the end of 1941 was on 20-acre spacing. Headquarters Field.—The Headquarters field, which lies along the line between Clare and Roscommon Counties, was one of the most important discoveries of 1941 and will be the scene of vigorous development during 1942. Production so far has been from the Traverse lime at about 3400 it., and development has indicated that this is probably one of the most productive Traverse pools yet discovered. One well had been given a potential of 10,000 bbl. per day. Dry holes well located in relation to big producers indicate that it is a typical Traverse development. Winterfield Field.-This field, in Winter-field township, Clare County, was discovered late in 1940. By December 1941, 14 Dundee and 5 Traverse producers had been completed. The Dundee lime is found at a depth of 3750 it. and the Traverse lime at 3070 it. Producing conditions in the Dundee seem to be erratic because of varying porosity in the dolomit-ized limestone. Kawkawlin Field.—The Kawkawlin field, which was discovered by the Gulf Refining Co. in 1938, is in Monitor and Kawkawlin townships, Bay County. Small production

Jan 1, 1942

By Theron Wasson

The discovery of two new fields—the Reed City area of Osceola County and the Headquarters field, of Roscommon County —and the important development in Winterfield township, Clare County, again demonstrate the fact that it is the unknown and unexpected that enter very definitely into the oil-producing history of Michigan. This is particularly true in the area of thick glacial drift in the north central part of the state, where the new prolific fields have been discovered this year. This shifts the interest from the southwestern part of the lower peninsula, where a number of pools were rapidly developed during 1939 and 1940, back into the Central Basin area. As a result of strict proration in the new areas, the production for the state of Michigan for the year has not been as great as in 1940 or 1939. In 1941 the total production was 16,300,000 bbl., in 1940 it was 19,551,000 bbl., and in 1939, which was the peak year, it was 23,300,000 bbl. However, the discovery of the new fields this year nearly doubles the estimated reserves for Michigan reported at the end of 1940 In 1941 about 12,000,000 bbl. of oil was produced from the older fields, in which the individual well productions were so small that proration was not an important factor. The total production for the state from the discovery of oil in 1925 through 1941 now stands at 161,205,000 barrels. ActIVe Oil Fields Reed City Field.—In the Reed City field, Lincoln township, Osceola County, only small oil wells were completed during 1939 and 1940. The discovery of much larger production in wells drilled somewhat deeper, by The Pure Oil Co. and the Weber Oil Co., in the early part of 1941, led to the rapid development in this area. Some wells have had initial productions as high as 10,000 bbl. By the end of the year III producing wells were completed, with an average depth of 3600 ft., from the Detroit River formation of Devonian age. The entire development of the field to the end of 1941 was on 20-acre spacing. Headquarters Field.—The Headquarters field, which lies along the line between Clare and Roscommon Counties, was one of the most important discoveries of 1941 and will be the scene of vigorous development during 1942. Production so far has been from the Traverse lime at about 3400 it., and development has indicated that this is probably one of the most productive Traverse pools yet discovered. One well had been given a potential of 10,000 bbl. per day. Dry holes well located in relation to big producers indicate that it is a typical Traverse development. Winterfield Field.-This field, in Winter-field township, Clare County, was discovered late in 1940. By December 1941, 14 Dundee and 5 Traverse producers had been completed. The Dundee lime is found at a depth of 3750 it. and the Traverse lime at 3070 it. Producing conditions in the Dundee seem to be erratic because of varying porosity in the dolomit-ized limestone. Kawkawlin Field.—The Kawkawlin field, which was discovered by the Gulf Refining Co. in 1938, is in Monitor and Kawkawlin townships, Bay County. Small production

Jan 1, 1942

By C Gunther

In deposits in which the secondary zones are well defined a layer of rich oxidized ore is frequently found immediately to overlie the enriched sulphides, from which it is derived by direct oxidation in place. In deposits that contain oxidizing precipitants particles and masses of residual oxidized ore are likely to be scattered through the leached zone, having been precipitated during migration before reaching the zone of enrichment. This precipitation hinders secondary enrichment and in extreme cases prevents the formation of such concentrations. Residual ores are precipitated by various reagents. Carbonates are formed through the action of the carbonic acid contained in surface waters, and also directly through the replacement of calcite, especially where the containing rock is limestone. Native metals, such as copper, gold, and silver, are formed by the action of reducing agents, among which organic matter and ferrous sulphate are prominent. Kaolin, gouge, and certain shales occasionally act as powerful precipitants through adsorption. Silver is often found as residual chloride, formed through precipitation by the chlorine contained in surface waters. Residual ores are often the result of incomplete solution, the relatively insoluble minerals being left behind during the migration of associated metals; incomplete oxidation and solution often leave residual masses of unaltered, or partly altered, sulphides in the oxidized zone. Such residual particles or masses have commonly been enriched by additions from circulating, metal-bearing solutions. During oxidation under conditions that permit reprecipitation, such as the oxidation of sulphide deposits in limestone, a scab

Jan 1, 1932

By Ernest Burchard

A RECONNAISSANCE Of the manganese-and chrome-ore deposits of Cuba was made by the writer, as a representative of the U. S. Geological Survey, in company with Mr. Albert Burch of the Bureau of Mines under instructions of the Secretary of the. Interior, in the Spring of 1918. The object of the study was to obtain authentic information for the use of the United States Government as to the location, character, quantity, and availability of the manganese and chrome-ore deposits in Cuba. Accordingly, the work comprised the examination of such deposits as seemed to be of promise, without regard to stage of development, with a view to determination of the quantity and quality of ore likely to become available for shipment during 1918 and 1919, and of the tonnage of ore in reserve. While it was possible to visit most of the deposits that seemed to be of promise, there was not sufficient time to visit all that were brought to our attention, some of which may have merit. Manganese ore is found in Cuba in Oriente, Santa Clara, and Pinar del Rio Provinces, but in Oriente Province only does it occur in large commercial quantities. There, the deposits are in three areas: one north of Santiago de Cuba, one south of Bayamo and Baire, and one on the Caribbean coast between Torquino Peak and Portillo. In Santa Clara Province, a little ore has been found near the Caribbean coast west of Trinidad; and in Pinar del Rio Province, manganiferous material occurs north of the city of Pinar del Rio and farther west near Mendoza. The manganese ores of Cuba occur, principally, in sedimentary rocks, such as limestone, sandstone, and shale, that are in places metamorphosed, and. in beds that originally may have been water-laid tuff

Jan 3, 1919

JESSE L. JONES,* Pittsburgh, Pa. (written discussion?).-As the die-casting process is so very different in character from the process of making sand molds, it is often considered that entirely different methods of pouring, gating, venting, etc. should be used. There is really, however, no essential difference in the making of (lie castings and sand castings, and similar methods should be used in each process. In the matter of gating, the metal should be introduced at a central point, as nearly as possible, so that it will have an equal distance to flow from the point of entrance to the most distant points of the mold. This will cause a uniform rate of congealing of the casting and prevent streaks and cold shuts. The venting should be done in such a way that a free exit of the air in the molds can occur. It should be less difficult to take care of the venting of a die-casting mold than to vent an ordinary sand mold. In the case of a sand mold, the venting is left, to a considerable extent, to the judgment of the molder, and it is possible that no two molds will be vented in a similar manner. Further than this, after a vent has been made in a sand mold, it may become clogged by the sand and for this reason be inefficient. There is also quite a variation in the pressure of the metal entering a sand mold, due to varying heights of the pouring gate. In a die-casting mold these factors can be controlled more closely. The vents should be so disposed that the air in the mold compressed by the entrance of the metal may be able to leave the mold at a uniform rate and by exits located symmetrically. These exits are made quite small on molds at first, as they can he easily enlarged if necessary, and they are tapered so that a free flow is guaranteed without danger of the metal spurting out from the die. Uniformity of pressure of the metal as it enters the mold is very important and, as the pressure is mechanically applied, its control is not difficult. It is true that a sand mold has much less of a chilling effect on the metal poured into it than has the die-casting mold, but, outside of this point, there is a great similarity between the die-casting process and the process of making castings in sand folds. It is suggested that much would be gained by regarding these two processes as not essentially different.

Jan 4, 1919

By Ben B. Cox

Oil produced in Iraq for export during 1938 was 31,354,090 bbl., or a daily average of 85,901 bbl; This is an increase of 182,614 bbl., or 0.5 per cent over 1937. All oil exported was produced from the Kirkuk field. The Khanaqin Oil Company, Ltd., a subsidiary of the Anglo-Iranian Oil Company, Ltd., continued to supply local market requirements from its Naft Khaneh field in the Transferred Territories. Slightly more than 32,000,000 bbl. was produced in Iraq, a small part of which was used in field operations. During the year 12 wells were completed and 9 wells were drilling at the end of the year. Of the completions, 5 were producers and 1 was an oil-water level observation well in proved fields, and 6 were listed as failures. Basrah Concession The outstanding event of the year was the granting, by the Kingdom of Iraq, of a 75-year concession embracing approximately 89,000 sq. miles to the Basrah Petroleum Company, Ltd., a British company with French and American participation. The concession covers all parts of the Kingdom, its territorial waters, islands, submerged lands, and its interest in the Neutral Zone separating Iraq and Saudi Arabia that

Jan 1, 1939

By Ben B. Cox

Oil produced in Iraq for export during 1938 was 31,354,090 bbl., or a daily average of 85,901 bbl; This is an increase of 182,614 bbl., or 0.5 per cent over 1937. All oil exported was produced from the Kirkuk field. The Khanaqin Oil Company, Ltd., a subsidiary of the Anglo-Iranian Oil Company, Ltd., continued to supply local market requirements from its Naft Khaneh field in the Transferred Territories. Slightly more than 32,000,000 bbl. was produced in Iraq, a small part of which was used in field operations. During the year 12 wells were completed and 9 wells were drilling at the end of the year. Of the completions, 5 were producers and 1 was an oil-water level observation well in proved fields, and 6 were listed as failures. Basrah Concession The outstanding event of the year was the granting, by the Kingdom of Iraq, of a 75-year concession embracing approximately 89,000 sq. miles to the Basrah Petroleum Company, Ltd., a British company with French and American participation. The concession covers all parts of the Kingdom, its territorial waters, islands, submerged lands, and its interest in the Neutral Zone separating Iraq and Saudi Arabia that

Jan 1, 1939

By Theron Wasson

The oil and gas fields of Michigan that have been under development since 1925 are in an area that extends across the middle of the lower peninsula from northeast to southwest, a distance of about 200 miles, and with a width of about 80 miles. In 19 years 70 fields have been discovered. Most of these are relatively small when compared with other oil-producing areas. This is borne out by the fact that since the first wells were drilled these fields have produced a total of only 204,000,000 bbl. However, Michigan is still maintaining its production, for during the past five years the annual production has remained fairly constant at approximately 20,000,000 bbl. Production for 1943, as reported by the Bureau of Mines, was 20,682,000 barrels. Roughly, one third oi Michigan's production in 1943 came from the Reed City field, which was discovered in 1941. During the year, 237 oil wells were completed in Michigan in 1943. The decrease of 56 from the 1942 total is probably due to the continuance of Government regulations requiring a 40-acre spacing pattern over most of the state. Fig. I shows the principal oil and gas fields of Michigan, and the columnar section, Fig. 2, shows the principal producing horizons in relation to the section drilled. The data of Table I and Table 2 have been carefully checked with previous reports to eliminate errors. Six new producing areas were discovered during 1943 and five areas discovered in 1942 were developed during the year. Both the new discoveries and the 1942 discoveries that were developed appear to be small and relatively unimportant. Goodwell Field.—The best discovery of the year is the Goodwell field, T. 14 N., R. 11 W., Goodwell township, Newaygo County. This small structure was located by core testing done by The Pure Oil Co. in 1942 and early 1943. The first producing well, C. R. Harris No. I, was completed on July 5, 1943, ill the Traverse limestone at a total depth of 2742 ft., with ail estimated potential of 1100 bbl. per day. By the end of the year, 18 wells had been completed in this field and approximately 281,000 bbl. of oil produced. The field operated under proration of 262 bbl. per day per well from Oct. I to Dec. I; 150 bbl. per day per well after that date. Woodville Field.—The small Woodville pool, T. 15 N., R. 11 W., 3 miles north of the Goodwell field, was discovered by core testing by the Ohio Oil Co. The discovery well was completed on May 5, 1943, flowing 650 bbl. of fluid, including 18 per cent salt water the first 18 hr., from the Traverse limestone at a depth of 2810 to 2815 ft. Seven wells had been completed by the end of the year and 67,000 bbl. of oil had been produced. Development is now practically at a standstill because further drilling does not aDDear economically iustified.

Jan 1, 1944