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By C. D. Allman

Specifications for coal at the Grand Lake thermal electric station read in part: "Coal will be Rom Minto Bituminous (strip operation). Maximum lump 3x3x4 ft. Very corrosive, abrasive and when damp, sticky. Coal may consist of frozen lumps of coal, snow and ice." To maintain quality control it was necessary to develop an automatic sampling system capable of: 1) sampling from one 10-ton truckload every 1½ min; 2) permitting an operator to automatically take a sample from each truckload; 3) depositing the sample in a pre-selected container, one of a possible 10; and 4) performing the sampling operations in accordance with latest ASTM specifications for sampling coal with an ash content of 35%. This paper tells how these and other problems were resolved and describes the equipment used. The New Brunswick Electric Power Commission issued detailed specification No. 5351-5009 outlining the scope of work and general requirements for a mechanical coal handling system to be installed at the Commissions Grand Lake Generating Station. The thermal station is located at Newcastle Creek, some 40 miles east of Fredericton, N.B. Canada, on the shore of Grand Lake. This particular location is immediately adjacent to the Minto strip mining coal area of New Brunswick. Contained in the specifications, but not detailed specifically was an automatic coal sampling system. The system outlined, was to be designed and specified by the individual equipment tenderers. In conjunction with the Hardinge Co., the Barber-Greene Co. designed a sampling system which was contained in the general contract proposal. The system as designed originally, however, presented certain limitations to a continuous coal handling system and was ultimately changed. However, it was only through preliminary study and design that problems created by the specifications were determined, and these problems discussed and finally negotiated with the NBEPC engineering staff created the subsequent sampling system now being installed by Barber-Greene. It must be considered that where the original specifications did not detail the mechanical equipment, it was necessary to present a system which would correspond to the intent of specification and for which Barber-Greene would be responsible as to function, but remain in a competitive position with regard to the tender considered primarily on a price basis. The system now being installed, contains basically all the components which were detailed originally, with the exception of the holding bin arrangement, which was changed to allow a continuous operation of the entire coal handling system. SPECIFICATIONS The specifications covering the sampling system follow. 4.5 Sampler: An automatic sampling system shall be installed capable of sampling one-truck load of coal every 1½ min. When the coal is dumped into the receiving hopper, the operator shall push a button and the sampler shall automatically take a sample of that particular coal when it reaches the sampler. Then the sample taken shall be crushed and reduced in quantity to a workable sample and deposited in a pre-selected container, one of a possible ten. All samples and sampling operations shall be in accordance with the latest edition of ASTM designation 492 for sampling coal with an ash content of 35%. The coal for the initial sample shall have maximum sized lumps of about 3/4 in. and the final sample shall be adjustable from 2 to 5 lb per sample and capable of passing through a sieve with 1/8-in. diam openings. It should be noted that, because of the time delay between the time the sample is requested and when it is actually taken, the operator may call for one or two additional samples from different coal before the first sample is completely refined and in the final sample can. Coal is received from a number of different suppliers on the same day, therefore, the system shall be designed so that there is no possibility of mixing or contaminating the coal from the different suppliers. All coal rejected from the sample shall be returned to the main conveyor. All chutes, hoppers, etc. shall be designed in accordance with Section 4.6 of these specifications. 4.6 Chutes, Hoppers, etc. All chutes and hoppers

Jan 1, 1963

By W. Bonfield

The microstrain characteristics of a polycrystal-line Cu 1.9 wt pet Be precipitation-hardening alloy have been determined for various conditions of aging. The friction stress remained constant for all the conditions investigated, whereas the microscopic yield stress (the stress to produce a plastic strain of 2 x 10-8 in. per in.) and the three-stage stress-strain curve in the microstrain region were sensitive to changes in dislocation and precipitate distribution. Correlations between the measurements of microplasticity and electron-nzicroscope observations of substructure are considered. ALTHOUGH the macroscopic mechanical properties of Cu 1.5 to 2.0 wt pet Be precipitation-harden ing alloys were established' in some detail, there has been no previous investigation of the nature of microyield-ing in these alloys. This paper describes a high-sensitivity extensometer determination of microplasticity in polycrystalline Cu 1.9 wt pet Be, in which the friction stress, the microscopic yield stress (the stress to produce a plastic strain of 2 x 10-6 in. per in.), and the rate of strain hardening in the micro-strain region were measured for various conditions of precipitation. The structural changes accompanying aging in this alloy were examined using transmission electron microscopy, a study which differed from previous investigations as, in order to minimize grain boundary precipitation effects,' the solution-treated alloy was cold-rolled to 40 pet reduction prior to aging. Hence the extent of recovery and recrystalliza-tion, as well as the variation of precipitate morphology and distribution, were assessed. From these results possible correlations between the microstrain characteristics and the observed precipitate and dislocation structure are considered. EXPERIMENTAL PROCEDURE The material investigated was a commercial copper beryllium alloy (Berylco 25), which had a com- position of 1.9 wt pet Be and 0.2 wt pet Co. The alloy was solution-treated at 800°C, quenched in water, and then cold-rolled to 40 pct reduction. Tensile specimens of gage length 1 in. and rectangular cross section of 0.18 by 0.06 in. were prepared from the solution-treated, cold-rolled material and aged for 15 min, 2, 24, and 100 hr at 315°C and 24 hr at 425°C to produce a range of precipitate structure. The hardness values associated with these conditions are listed in Table I. It can be seen that a maximum value is obtained after 2 hr at 315oC, which decreases with continued time at temperature to a minimum after 24 hr at 425°C. For comparison some as-solution-treated specimens were also aged for 2 hr at 315°C. The specimens heat-treated to a given condition were examined in two ways. First, the nature and distribution of the precipitate and dislocation structure was characterized using transmission electron microscopy. Thin foils were obtained from the specimens by electrolytic polishing in a 30 pet nitric acid-alcohol solution at -20oC, and were examined in an RCA EMU 3 electron microscope. Second, the mi-croplastic behavior of the specimens was measured with a Tuckerman strain gage, using the load-unload technique previously described2, 3 to determine the friction stress, the microscopic yield stress, and the variation of plastic microstrain with stress. RESULTS 1) Structural Changes During Aging. a) Annealing Processes. The solution-treated, cold-rolled Cu 1.9 wt pet Be had an irregular dislocation-cell structure,

Jan 1, 1968

By Sidney Snook

FLUORSPAR production is the most important industry in a compact area in southern Illinois and western Kentucky bordering the Ohio River. Producers' activities do not usually figure much in the mining news of the country, so that few know that the last year or so has been an unusually active one. Mine shipments more than doubled in 1939 compared with the poor year 1938. The average price changed but little, though it is now about one-sixth higher than at the beginning of last year. The outbreak of war in Europe a year ago lent an immediate stimulus to the industry, though only about 15 per cent of the domestic consumption is normally imported, thanks to a tariff of $8.40 per ton, equivalent to about 30 per cent ad valorem. Be- cause of the increased production and many expansions and improvements in the mines and plants, the period since the beginning of 1939 has been the most important one for the industry in the last 15 years.

Jan 1, 1940

Meeting of Feb. 16, 1915.-The Committee on Membership was appointed with the following personnel: John H. Janeway, Chairman; Karl Filers, Lewis W. Francis, Louis D. Huntoon, and Thomas H. Leggett. President Saunders announced the appointment of the Committee on Increase of Membership, as shown on p. xxviii of this Bulletin. The reproduction by the anastatic process of 100 copies of Volume IX of the Institute Transactions was authorized. The sum of $50 and the exchange of the Bulletin. was awarded to the commission publishing the Annual Table of Constants. The sum of $49.07 was contributed to the expense of the John Fritz Medal Board of Award for the year 1914, and the Institute agreed in the future to share the annual expense for the John Fritz Medal Board of Award not to exceed one-quarter of $500 in the year. Upon the recommendation of the Committee on Membership, 36 Members, 1 Associate, and 13 Juniors were elected. The resignations of 26 members were accepted. L. D. Ricketts was elected a Vice-President of the Institute to serve the unexpired term of W. L. Saunders. George D. Barron was elected a Director to serve the unexpired term of L. D. Ricketts.

Jan 4, 1915

By Robert Peele

TWO outstanding members of the Institute will be honored at the Annual Meeting this month: Robert Peele, who will accept his election to the small group of Honorary Members; and Clinton Hoadley Crane, president of the St. Joseph Lead Co. and William Lawrence Saunders Medalist for 1936. Eminence in the profession character, interest in Institute activities, and general recognition as a gentleman and a friend by so many people, have contributed to the election of Professor Peele. The Saunders Medal is for "achievement in mining." In awarding it to Mr. Crane the citation reads "For distinguished achievement in the successful development and operation of low-grade lead mines."

Jan 1, 1936

By R. V. Whetsel, Valentin R. Garfias

Mexican petroleum production for 1928 was approximately 50,000,-000 bbl., the lowest in 12 years, showing a decrease from 1927 of over 14,000,000 bbl. The steady downward trend for the past 7 years has allowed Russia to outrank Mexico by a wide margin for third position and if the expected decline continues during 1929 it should place Persia ahead of Mexico as fourth in rank. The year 1928 was characterized by a continuation of the reentrench-ment previously begun by the oil industry in Mexico in an attempt to adjust itself to the adverse conditions caused by the steady depletion of the fields, the rapidly increasing competition from Venezuela and the United States and the as yet unsettled petroleum legislation and taxation situation. With the exception of the Isthmus of Tehuantepee, drilling in proved fields was considerably curtailed and although the number of wildcats completed exceeded those of the previous year, no extensive drilling programs were undertaken. Practically without exception, the major companies reduced personnel and operations to a point where they could meet existing conditions and mark time while awaiting a more stable basis for the future testing of unexploited regions. Many terminal and transportation facilities were abandoned during the year. Development Only 371 wells were completed during 1928, as against 583 in the previous year and 808 during 1926, and although the percentage of producers in 1928 was 34 per cent., compared to 26 per cent. in 1927, the initial production of -wells was considerably lower than during the previous year, a great number of the wells showing salt water and becoming "strippers" from the time they started to flow. Development is summarized in Table 1. Drilling in the Northern fields did not prove any new pools of importance, the most successful wells being located in the old producing areas of Cacalilao, Panuco and Topila. (Fig. 1 Very few of the producers made more than 1000 bbl. daily, and a great many less than 300 bbl. a day.

Jan 1, 1929

By AIME AIME

As already announced in the January Bulletin, this publication will be issued during the coming year monthly instead of bi-monthly as heretofore. Among other reasons for this change, it is desired to effect thereby the earlier transmission to members of important papers, lists of candidates for membership, and other items of timely information. Spokane Meeting and Excursions. Further details of the 97th meeting of the Institute have been sent to members in the Circular of May 8, 1909. The list of those intending to go on the excursion is filling up, and since preference in position of state-room or berth is given in the order of application, members and guests who expect to accompany the party and have not yet communicated with Mr.. Theodore Dwight, 29 West 39th St., New York, N. Y., are earnestly requested to do so without delay. For convenience of the members a summary of the additional information is here presented. A special train of Pullman cars will leave Chicago about September 15. This train will be side-tracked at all places visited, and the sleepers will be available for lodging and the dining-car for meals during the entire trip, except during the Yellowstone Park tour. The general cost of the trip per member will be $300, which includes transportation, berth, and meals for the entire trip from Chicago back to Chicago, almost 6,000 miles, and the tour through. Yellowstone Park, occupying in all about 30 days. Special, accommodations on the train will be furnished at the following rates

Jun 1, 1909

By Robert M. Grogan, James C. Bradbury

The Illinois-Kentucky mining district has, since 1880, accounted for 80 per cent of all U.S. production of fluorspar. The ore deposits are of two types: vein deposits formed by fissure fillings along faults and bedding-replacement deposits formed by the replacement of strata at certain favored stratigraphic positions along minor faults and fractures. Fluorite is the chief valuable mineral in the deposits. Sphalerite and galena commonly are present in small amounts but, in some ore bodies, may form a substantial part of the valuable constituents of the ore. Calcite is the chief gangue mineral; quartz and barite Exposed strata range from Devonian are present in various amounts. through Pennsylvanian in age. Igneous intrusive rocks occur as mafic dikes and sills and intrusive breccia dikes and plugs. Structurally, the district is situated on a generally northwest- trending arch that has been sliced into a series of long, narrow blocks by normal faults that trend northeastward. The structural The localization of the ore deposits by faults and fractures, the association of fluorite mineralization with intrusive breccias, and various lines of petrographic and geochemical evidence indicate that the fluorite-zinc-lead deposits were epigenetic and deposited by solutions emanating from a deep alkalic magma.

Jan 1, 1968

By AIME AIME

CHARACTERIZING the annual meeting as the biggest and best one yet has happened so repeatedly that some may suspect it has become a conventional phrase, like "good morning," and yet, what else can be said when not only one but all the many who express an, opinion use exactly those words, while the first of the two adjectives refers to a physical fact that is established by count. Perhaps there were hose who thought it not the best, but if so they were too tactful to say it out loud. So without further ado . let us admit that the one hundred and thirty-ninth general meeting of the A. I. M. E. held; as our By-laws provide, in New York during the third week of February, was the biggest and best of them all. Perhaps it is because we appreciate friendliness more as we grow older, but somehow the friendly atmosphere seems to rise slowly in temperature with the passing of the years. The actual atmosphere on the opening morning was quite the contrary, Feb. 17 being the coldest clay, so far, of this winter, and the suburbanites claimed that their thermometers had registered 5" below zero when they got up, though the official records of the weather man did not go that low. From that time the temperature steadily rose until Thursday afternoon, when the official record of 66" constituted a record high for Feb. 20 at New York. The weather man explained it by learned discussion of highs and lows, but we suspect the A.I. M. E. members must have had something to do with it.

Jan 1, 1930

RESOLUTION ADOPTED BY THE BOARD OF DIRECTORS AT ITS MEETING ON APRIL 17, 1936 Recognizing the fact that the problems of the committee named by the Board to prepare the " official ticket" for officers and Directors of the Institute are various and difficult; and desiring to assist this committee by setting forth some of the principles that should guide the committee and some of the qualifications that should be required of candidates, the following instructions are formulated and the Secretary is directed to publish them in MINING AND METALLURGY concurrently with the publication of the names of each newly appointed Nominating Committee and to send a copy to each member of the Committee. NOMINATIONS TO BE MADE Each year the Nominating Committee is to select "official" candidates for eight places, as follows: (1) President and Director (2) Vice-President and Director (3) Vice-President and Director (4) Director (5) Director (6) Director (7) Director (8) Director GEOGRAPHICAL DISTRIBUTION The Bylaws provide that "the Nominating Committee shall, so far as practicable, distribute representation on the Board geographically." Pursuant to this provision, the United States, Canada and Mexico have been divided into fifteen districts, as shown on the official map.* Districts 1, 5, 6, 10, 11, 12,13,14, and 15 are assigned one Directorship each; District 2, three Directorships; District 3, eight Directorships; District 4, two Directorships; and Districts 7, 8, and 9, two Directorships between them. It will be the duty of the Nominating Committee to make selections that will give effect to this allocation of Directorships. There is nothing to prevent a Director being named to succeed himself. Attention is called to the: fact that many Institute members now resident in New York formerly lived in the West, South, or North and still have intimate business connections that compel them to visit various parts of the country periodically. Such men are particularly valuable as Directors and their nomination and election tends to minimize the objection that a large number of Directors reside in New York.

Jan 1, 1940

By J. E. McConnell

No. 1 Electric Furnace and Billet Casting Shop, located in Plant No. 4 adjacent to our new 12 inch merchant bar mill, represents Inland Steel Company's first venture into both electric furnace steelmaking and continuous casting. Construction of the shop began in September, 1968 with excavation and foundation work, followed by awarding of general construction and major equipment contracts from December, 1968 to April, 1969. The first heat was tapped from No. 90 furnace on December 18, 1970, and the first cast attempted on December 29, 1970. The rated shop capacity is 500,000 tons per year of semi-finished billets and blooms, and was justified on the basis of approximately 85 percent of the product mix falling into the special bar quality category of steel grades. Auxiliary equipment has been designed into the shop to pursue free machining steels, including leaded and tellurized grades. The start-up and operation of the shop for the first year was essentially based on a two-part philosophy: 1. Initially operate with the "open stream" casting technique to accomplish machine shakedown and operator familiarization and training. 2. Operate with special bar quality, or "submerged casting", practices, make necessary refinements and gain customer acceptance

Jan 1, 1972

By William Mikulas

LITTLE work has been done in the field of the nickel-tin binary system. The complete diagram has been investigated on two occasions, but the results are in very poor agreement. The structure of a compound NiSn, and the solubility of tin in nickel have been determined by X-ray methods. Several investigations have been made of the liquidus curve, and the compositions of the eutectics have been determined. A study of the literature, however, shows that there is no satisfactory agreement between the data presented in the various papers. The present investigation was undertaken in an attempt to determine the equilibrium conditions, and to correlate X-ray with metallographic data. The equilibrium diagram was determined by thermal and metallo-graphic means, and the solubility of tin in nickel further investigated with X-rays. Powder diagrams were made of the intermetallic com-pounds, and three of the structures were partly determined. No attempt was made to determine the range of homogeneity of the inter-metallic compounds.

Jan 1, 1937

By E. L. Kinsella, F. S. White

Solids fluidization utilized in two ways for the commercial production of lime is described. Crushed —6 mesh limestone is dried and dedusted in a single bed reactor, then calcined in a 5-stage reactor. Construction, operation, and results obtained with both processes are given. THE solids fluidization process brought out by the Standard Oil Development Co. in the early forties for catalytic cracking of petroleum enabled rapid transfer of large quantities of heat from gases to solids under closely controlled temperature conditions. As the technique developed, it was natural that applications for the process outside the petroleum industry would be sought. The calcination of limestone to quicklime requires the transfer of a large quantity of heat at high and closely controlled temperatures. For these reasons, this possible application was one of the first to be investigated. Laboratory work conducted by the Dorr Co. indicated that lime produced by solids fluidization would be of exceptional quality. Calculation of theoretical heat balances showed that savings in fuel could be expected. Accordingly, a pilot plant of 10 tons per day capacity was erected by the New England Lime Co. at Adams, Mass., to substantiate the process. Operation of the pilot plant, previously described,' showed that excellent lime could be produced with a saving in fuel. The work also indicated the necessity of preparing feed to remove the finer fractions if dust losses were to be held to a tolerable level. A single-stage fluidized solids drier-stripper was developed to accomplish this sizing.' Subsequently a commercial lime reactor was erected at Adams, beginning operation in June 1949, followed by air sizer facilities completed in November 1951. This paper will describe these two applications of solids fluidization. The raw material for preparation of lime by the fluidizing process is a high calcium crystalline lime- stone having the approximate chemical composition shown in Table I. The stone is first prepared by crushing and grinding in conventional equipment to pass a 6-mesh sieve. After crushing, the material is sent to the FluoDry unit for drying and dedusting. Fluidized Drying and Sizing As shown in Fig. 1, the FluoDry unit consists of a -in. cylindrical steel shell, 9-ft ID by 22-ft 6-in. overall height. Attached horizontallv at the bottom is a 6-ft diam combustion chamber, approximately 7 ft 6 in. long. A refractory constriction dome, consisting of first-quality fire brick shapes, partitions the inside into two sections. The lower section is called the windbox and the upper the bed compartment. The vertical wall of the shell is lined with 6-in. first-quality rotary kiln blocks. In the bottom of the windbox a hoppered section is formed with castable refractory to permit the windbox to be readily cleaned via a 6-in. screw conveyor. The combustion chamber is similarly lined with refractory shapes. On the 6-in. diam section, 4 in. of insulating brick, HW-26, are used. The inner combustion chamber is lined with 4-in. Korundal brick to withstand the high flame temperatures encountered. An 8-in. steel feed pipe, entering vertically through the top and fitted with an air-operated cone valve,

Jan 1, 1953

By F. S. White, E. L. Kinsella

Solids fluidization utilized in two ways for the commercial production of lime is described. Crushed —6 mesh limestone is dried and dedusted in a single bed reactor, then calcined in a 5-stage reactor. Construction, operation, and results obtained with both processes are given. THE solids fluidization process brought out by the Standard Oil Development Co. in the early forties for catalytic cracking of petroleum enabled rapid transfer of large quantities of heat from gases to solids under closely controlled temperature conditions. As the technique developed, it was natural that applications for the process outside the petroleum industry would be sought. The calcination of limestone to quicklime requires the transfer of a large quantity of heat at high and closely controlled temperatures. For these reasons, this possible application was one of the first to be investigated. Laboratory work conducted by the Dorr Co. indicated that lime produced by solids fluidization would be of exceptional quality. Calculation of theoretical heat balances showed that savings in fuel could be expected. Accordingly, a pilot plant of 10 tons per day capacity was erected by the New England Lime Co. at Adams, Mass., to substantiate the process. Operation of the pilot plant, previously described,' showed that excellent lime could be produced with a saving in fuel. The work also indicated the necessity of preparing feed to remove the finer fractions if dust losses were to be held to a tolerable level. A single-stage fluidized solids drier-stripper was developed to accomplish this sizing.' Subsequently a commercial lime reactor was erected at Adams, beginning operation in June 1949, followed by air sizer facilities completed in November 1951. This paper will describe these two applications of solids fluidization. The raw material for preparation of lime by the fluidizing process is a high calcium crystalline lime- stone having the approximate chemical composition shown in Table I. The stone is first prepared by crushing and grinding in conventional equipment to pass a 6-mesh sieve. After crushing, the material is sent to the FluoDry unit for drying and dedusting. Fluidized Drying and Sizing As shown in Fig. 1, the FluoDry unit consists of a -in. cylindrical steel shell, 9-ft ID by 22-ft 6-in. overall height. Attached horizontallv at the bottom is a 6-ft diam combustion chamber, approximately 7 ft 6 in. long. A refractory constriction dome, consisting of first-quality fire brick shapes, partitions the inside into two sections. The lower section is called the windbox and the upper the bed compartment. The vertical wall of the shell is lined with 6-in. first-quality rotary kiln blocks. In the bottom of the windbox a hoppered section is formed with castable refractory to permit the windbox to be readily cleaned via a 6-in. screw conveyor. The combustion chamber is similarly lined with refractory shapes. On the 6-in. diam section, 4 in. of insulating brick, HW-26, are used. The inner combustion chamber is lined with 4-in. Korundal brick to withstand the high flame temperatures encountered. An 8-in. steel feed pipe, entering vertically through the top and fitted with an air-operated cone valve,

Jan 1, 1953

By R. J. Wagner, F. F. Craig, H. G. Riley, J. D. Griffith

Peripheral water injection has been underway in the Sholem Alechem Fault Block "A" Unit, Stephens County, Okla., since 1955. In the engineering planning of the flood, it was recognized that maintenance of pressure in the large, dry gas caps was vitally necessary to prevent the loss of an estimated 27 million bbl of oil through saturation of the gas caps by the oil banks moving updip on the peripheral flood pattern. The development of an abundant, low-cost water supply and the rising cost of makeup-gas purchases indicated that gas-cap control by water injection was desirable from an economic standpoint, provided an eflective water barrier could be placed without premature water breakthrough into downdip oil producers. A laboratory model scaled to the existing reservoir conditions was comtructed to evaluate the feasibility of gas-cap water injection. Model studies indicated that (I) water injected at the edge of the gar-oil contact would form a continuous barrier between the oil and gas zones, and (2) water would advance uniformly downdip without segregation due to gravity effects provided a specified, minimum water-injection rate was maintained. The model test results also indicated that it was not necessary to fill the gas cap completely with water. Water injection at the edge of one of the gas caps was initiated in March, 1958, to field test gas-cap water injection. Water breakthrough occurred at a downstruc-ture producing well in April, 1959, after approximately 2.5 million bbl of water had been injected into the gas cap. This was the volume calculated to be required to form the barrier between the oil zone and gas cap. This performance indicates that prevention of oil encroachment into dry gas caps in a peripheral water flood by water injection at the gas-oil contact appears practical and that the model studies provided a valid prediction of field performance. INTRODUCTION The Sholem Alechem Fault Block "A" Sims Sand Unit was one of the fist major waterflood projects in Oklahoma to utilize a peripheral injection pattern. Design of control measures to minimize oil encroachment into the large crestal gas caps was one of the greatest single problems during engineering planning of this flood. Engineering studies indicated that saturation of the gas caps with oil displaced by the peripheral water flood could result in a loss of about 27 million bbl of oil, or over one-half the estimated waterflood recovery. This estimate was based on a residual oil saturation after water flooding of 35 per cent pore volume, compared to the negligible oil saturation initially in the gas caps. The Sholem Alechem Springer field, located in Stephens County, Okla., is an elongated anticline with structural dips varying from 400 to 1,000 ft/mile. The structure contains numerous faults, some of which are sealing. The portion of the field considered in this paper is Fault Block "A", which is the largest of the five major fault segments in the field. A map of the unit is shown on Fig. 1. The unit is bounded on the east and west by major sealing faults, on the north by a water-oil contact and to the south by a deterioration of sand development. Two domes, each having gas caps, exist in the unit and are separated by a north-south fault as shown in Fig. 1. The sands being flooded are the Sims sand members of the Springer series of early Pennsylvanian age. The Sims sands average over 100 ft in thickness in Fault Block "A" and have a porosity of approximately 19 per cent. Core permeabilities average 160 md, with interstitial water saturation of about 23 per cent pore volume. Three different zones can be correlated over most of the area. However, they are commingled in most of the producing wells. The two upper zones, designated as First and Second Sims, are the most important. Both the First and Second Sims have gas caps in the east dome, while only the First Sims has a gas cap in the west dome. These gas caps, whose limits are also shown on Fig. 1, initially occupied nearly 11 per cent of the total reservoir volume. The major concern of this paper is the control of the two gas caps in the First Sims sand. Fig. 2 is a cross section, to scale, across the east dome of this formation. Notable features are the relatively shallow dip, the deterioration of the First Sims sand on the south side of the gas cap and the water-oil contact on the northern edge. The formation dip at the gas-oil contact in this cross section is approximately 5".

By Charles A. Anderson

Arizona and western New Mexico contain 17 of the 25 leading copper mines in the United States. Production of molybdenite, lead, zinc, and by-product gold and silver is important. Precambrian ore deposits are largely limited to the Yavapai Series in central Arizona and most of the metal production has come from massive sulfide deposits, dominantly pyritic but containing different amounts of chalcopyrite, tennantite, sphalerite, and galena. Their origin has been interpreted by some geologists as hydrothermal replacement of schist, and by others as syngenetic deposits later metamorphosed. Most of the important ore deposits are of Mesozoic and early Tertiary age, dominated by the porphyry copper deposits spatially related to stocks, plugs, sills, or dikes of quartzbearing porphyritic to granular rocks. Host rocks for these deposits include the associated intrusive rocks, Precambrian schist and granitic rocks, Paleozoic limestones, Mesozoic(?) porphyritic andesite, and Mesozoic arkose and siltstone. Chalcopyrite and pyrite are the dominant hypogene sulfide minerals in the porphyry copper deposits, accompanied by minor molybdenite. The Questa deposit in New Mexico is largely molybdenite. Supergene sulfide minerals are chalcocite and minor covellite. Some ore bodies consist largely of hypogene sulfides, some are dominantly supergene sulfides, and others are mixed hypogene-supergene sulfides. Supergene oxide-copper minerals locally are important. Intense hydrothermal alteration accompanied the metallization in all of the porphyry copper deposits; five types are recognized, ( 1) propylitic, (2) argillic, (3) potassic, ( 4) quartz-sericite (without clay), and (5) lime silicate. The origin of the closely spaced fractures that contain ore minerals in intersecting veinlets is debatable; some geologists favor tectonic forces and others suggest cooling of magma or shrinkage due to alteration. Breccia pipes, veins, and limestone replacements account for some important deposits of Mesozoic and early Tertiary age, and presumably these are genetically related to the various intrusive rocks of this age. The St. Anthony deposit of Cenozoic age in southeastern Arizona is unique, consisting of a lead-zinc vein associated with later molybdenum and vanadium oxide-minerals. Cenozoic manganese deposits in western Arizona are an important resource in the Artillery Mountains, but the extent to which they may be exploited is a metallurgical and economic problem.

Jan 1, 1968

By R. G. Bowman

LEAD is a dull and sober metal, and in times of economic stress it en- joys, or at least occupies, a position which partakes somewhat of its physical lethargy and stability. The past ten years have witnessed in this country a decline in the production of lead, and a shrinkage of ore reserves, following closely the general economic situation. Metal prices have not justified exploration and development of new sources. Momentary rallies in industry have brought no response from lead.

Jan 1, 1940

By GORDON H. FISHER

During the year 1945, the drilling pace in West Texas increased above that in the year 1944, and represented the highest number of well completions since 2941. The 1680 new wells drilled 8,287,958 ft. of hole for a per well average of 4933 ft. This depth is approximately 30o. ft. deeper than the average for the year 1944. Although the deepest well drilled in West Texas (Phillips Petroleum Company's Ada Price No. 1, in Pecos County) was completed during the year. 1944 to a depth of 15,279 ft. and tested the Ellen-burger horizon, the producing depth record for West Texas was set during the year 1945 with the completion of Amerada Petroleum Corporation's Jones No. I-A, in the Jones Ranch field, Gaines County, which now is producing at 11,422 ft. from the Devonian formation.

Jan 1, 1946

By S. Warren Hobbs

The section of the Northwestern United States that includes the northern Rocky Mountains and adjacent areas to the west and east is one of large mineral production and important mineral potential. The metallic ore deposits vary widely in age and type and their geologic settings are similarly diverse. A brief resume of the region's physiographic characteristics and geology sets the framework for the selected ore districts that are described in following papers and makes it possible to place these ore deposits in their proper reference to space and time.

Jan 1, 1968

By Harold Margolin

The Ti-Al system certainly merits the investigative attention it has been receiving and this latest contribution by Blackburn is therefore to be welcomed. The titanium-rich end of the phase diagram shown here, as well as the diagram by crossley,17 Clark et a1.,18 and Tsujimoto and Adachi,29 reveal no other intermediate phase than Ti3A1, although a previous work by Ence and Margolin20 had reported an additional intermediate phase. Since then, Buerger Precession pictures of single crystals of 10.5, 11.5, and 12.5 wt pct A1 were made at New York university21 and the extinctions were found to be typical of a D6h a Ti structure. Some superlat-tice spots and/or streaks suggesting the presence of an Mg3Cd structure, i.e., Ti3Al, were also found. Since these specimens had been quenched from the y region20 and had revealed a Ti, it was concludedz1 that y does not exist and the structures interpreted as m + y could not be so considered. The absence of normal two-phase behavior in these structures had been indicated in the paper. Accordingly, the two-phase region y + 6 becomes a + Ti3Al and there is some agreement between the results of Blackburn and of Ence and Margolin20 as to both shape and existence above 900°C of an a + Ti3Al field. Crossley 17 proposed that Ti3Al is a line compound which decomposes congruently at 900°C. It is difficult to discount entirely the fact that clear two-phase structures, varying in amount with position in the two-phase field, could be detected above 900°C by Ence and Margolin.20 Precipitation during quenching could not have been so regular and the twin-phase syndrome17 does not apply. The heat treatment and quenching technique was essentially the same as was used by Crossley, whereas Blackburn, who used a rapid quenching procedure, also showed a two-phase a + Ti3A1 field above 900°C. If the two-phase field exists above 900° C, it is easy to picture a two-phase field which could account for the data of Crossley below 900°C without invoking a line compound existence of Ti3A1. All that would be necessary would be an 0 + Ti3Al/Ti3Al boundary which curved sharply to higher aluminum contents below 900° C. It is clear that the controversy must be solved by techniques which obtain data at elevated temperatures without quenching. It is conceivable that the difference in width of the a + Ti3N fields reported by Blackburn and by Ence and Margolin is due to the longer annealing times used by the latter investigators. The criterion for establishment of equilibrium in our work20 was the

Jan 1, 1969