bluuebunny/crossref_metadata_2025 huggingface dataset:
The Graniteville Granite and High Heat Production Granites in the St. Francois Terrane of Southeastern Missouri*
Authors: Kisvarsanyi Eva B.
Published: August 2024

Granites and rhyolites of the Middle Proterozoic St. Francois terrane are among the most uraniferous igneous rocks in the United States. They are only partly exposed, as islands in a “sea” of sedimentary rock, in a 3,500 mi2 area in the St. Francois Mountains of southeastern Missouri, but underlie thousands of square miles in the midcontinent. The terrane formed in an anorogenic tectonic environment through subcontinental-scale melting of older crustal rocks. The anatectic melts were enriched in LIL (large-ion lithophile) and radioactive elements, rose to high crustal levels, and were emplaced through explosive volcanism as ash-flow sheets. and associated subvolcanic granitoid ring complexes.
Two Distinct Ore Fluids in the Viburnum Trend
Authors: Viets John G. , Leach David L. , Mosier Elwin L.
Published: August 2024

The stable carbonate platform of the U.S. midcontinent is host to the largest concentration of Mississippi Valley-type (MVT) zinc-lead mining districts in the world. Of these districts, the Southeast Missouri Lead District which includes the main Viburnum Trend and Old Lead Belt subdistricts, is unique in several ways. Lead dominates over zinc and the ores have significant amounts of copper, silver, cobalt, and nickel. Hosted in the Upper cambrian Bonneterre Formation, above the basal Cambrian Lamotte Sandstone which is underlain by felsic Precambrian basement, the Viburnum Trend is situated very low in the carbonate section when compared to the other districts of the region. Of the Ozark districts, the Southeast Missouri Lead District is also unique in its proximity to the Reelfoot Rift which is concealed beneath the Mississippi Embayment. The possible importance of the Reelfoot Rift as a pathway for brine migration from a southerly source has recently been demonstrated by Farrand Land (1985) and Farr (1987). Detailed descriptions of the mines of the Viburnum Trend are given in a special issue of ECONOMIC GEOLOGY (V. 72, NO. 3, 1977). Other informative background papers on the ore deposits of the Southeast Missouri Lead District include those by snyder and Gerdemann (1968), Gerdemann and Meyers (1972), Davis (1977) and Sverjensky (1981).
Applications of Ore Microscopy to Processing of the Ores in the Southeast Missouri Lead District
Authors: Hagni Richard D.
Published: August 2024

The significance of applied or process mineralogy in the minerals industry has been fully recognized only in the last ten years. The various mineralogical techniques that are routinely applied by economic geologists and mineralogists to the study of ores can be very usefully applied to the solution of a wide variety of industrial problems and to the improvement of the efficiency of those industrial processes. Publications dealing with applications of process mineralogy have been connected principally with presentations before three professional organizations.
Geology of the Cadillac Tectonic zone
Authors: Desrochers Jean-Philippe , Hubert Claude , Robert François
Published: August 2024

The Cadillac fault is generally thought to be coincident with a highly schistose zone, a few tens of meters thick, composed of chlorite-carbonate and talc-chlorite-carbonate schists (Gunning and Ambrose, 1940; Norman, 1946). However, outcrops on the Orenada zone noo2 property indicate that deformation related to the Cadillac fault has affected different rock types over a width of more than 200 m. It is therefore more appropriate to refer to the Cadi11ac tectonic zone (CTZ) than to the Cadi11ac fau1t. This outcrop zone exposes a lithological succession that can be extended using outcrops and drill hole data for more than 10 km. This succession differs from the one presented on the available compilation maps and has important implications for the regional “stratigraphy”.
Geology of the Belmoral (Ferderber) Gold Mine Val D’OR, Quebec
Authors: Vu Lan
Published: August 2024

The Belmoral (Ferderber) gold mine, owned by Société Les Mines Belmoral Ltee, is situated 10 km NE of Val d’Or (Fig.1) in Bourlamaque Twsp., northwestern Quebec, near the centre of the Bourlamaque batholith. This contrasts with the location of other gold mines that are situated near the margin of the batholith, such as the Perron and Courvan mines at the eastern contact, the Sullivan mine at the western contact, and the Bras d’Or (Dumont) mine at the southern contact (Fig.1).
The Cactus Gold Mine Kern County, California
Authors: Brady Jim , Marsh Tim , McKitrick Scott
Published: August 2024

The Cactus Gold Mine is located in the eastern Mojave Desert part of Kern County, California, about sixty air miles north of the city of Los Angeles and 9 miles southwest of the town of Mojave. The mine is at Middle Buttes, an isolated peak of Miocene volcanic rocks and Cretaceous intrusives surrounded by alluvium. Operated by CoCa Mines Inc. of Denver, Colorado, the mine is a joint venture between CoCa and MinVen Gold Corporation of Lakewood, Colorado.

The mine is an open pit, heap leach operation with an average 10,000 ton per day ore and waste extraction from the Shumake Pit. Crushing output to the heaps is 5,000 tons per day with recovery by Merrill-Crewe.
Introduction to the Salton Trough Rift
Authors: McKibben Michael A.
Published: August 2024

The Salton Trough rift, manifested geomorphically as the Imperial Valley in southern California and the Mexicali Valley in northern Baja California (Figure 1), possesses an abundance of natural resources. These valleys are major areas for agriculture, game fish, and waterfowl migration and management. Major nonrenewable resources include metallic minerals (primarily gold) and industrial minerals (primarily gypsum and aggregate). Finally, two of the world’s largest liquid–dominated geothermal energy fields are located in the rift: the Salton Sea field in California and the Cerro Prieto field in Mexico. The rift is therefore of major economic importance to the population of southwestern North America. The purpose of this field trip is to introduce economic geologists to the diversity of hydrothermal mineralization in this modern continental rift environment.

Viewed in the simplest way the Salton Trough consists of an active continental rift, underlain by a fragmented oceanic ridge spreading system, into which has been deposited the delta of the Colorado River. Deposition of the delta has significantly influenced the character of economic mineralization in the rift. The combination of magmatic heat sources, thick porous sediments, tectonic activity, and saline lakes have provided a unique environment for the accumulation and movement of metalliferous hydrothermal brines. Before considering these aspects, a summary of the tectonic evolution of the Gulf of California and Salton Trough is presented.
The Salton Sea Geothermal Brines
Authors: McKibben Michael A.
Published: August 2024

The sediment—hosted Salton Sea geothermal system (SSGS) contains some of the most saline, metal—rich hydrothermal fluids known from an active system (White et al., 1963; Skinner et al., 1967; Helgeson, 1968). Recent extensive scientific and commercial drilling into this system has provided a wealth of new samples and data relevant to understanding this unique hydrothermal system and its metalliferous brines (Elders and Sass, 1988; McKibben et al., 1988a, 1988b; Williams, 1988; McKibben and Eldridge, 1989; McKibben and Williams, 1989; Williams and McKibben, 1989; McKibben et al., 1990). Only a brief overview of the SSGS is presented here.
Geology, Alteration and Mineralization of the Modoc Hot Springs Gold Prospect, Imperial County, California
Authors: Hillemeyer Frank L. , Johnson Michael D. , Kern Richard R.
Published: August 2024

The Modoc prospect is a Plio-Pleistocene epithermal gold-bearing hot springs system located in the northwestern Salton Trough. To date, Modoc offers the best preserved and developed fossil analogue of the currently active geothermal systems in the continental rift. A surficial hot springs origin for the system is evidenced by interbedded, nearly flat-lying chalcedonic sinter beds exhibiting a strong layered morphology, hummocky pool structures and well preserved fossil reed casts.

The primary structural control on the hot springs system is a major ENE-striking, southerly dipping, oblique-slip fault system separating Jurassic granodiorite on the north from Plio-Pleistocene continental sediments on the south. This “Truckhaven” fault system appears to be coincident with the edge of a large basin related to crustal thinning and progradation of the Colorado River Delta into the proto Gulf of California.

Gold mineralization occurs as electrum and native gold (8 to 1800 microns) and is associated with sheeted and banded chalcedony veins, silicified and adularized sandstone and conglomerate, and siliceous sinter beds. Gold and chalcedony precipitated simultaneously in numerous episodes and preliminary fluid inclusion data indicate temperatures ranging from 90 to 135°C. Gold mineralization is locally high grade (up to 1.4 ounces of gold per ton over a 20′ (6.1 m) width) and is found in highly anomalous concentrations over an area measuring 8,000′ (2,438 m) long by up to 2,000′ (610 m) wide. Correlation coefficient data indicate a strong gold, silver, copper affinity. The typical hot springs pathfinder elements As, Sb and Hg are present in unusually low concentrations.

The Modoc hot springs system is more akin to the active geothermal fields situated on the margins of the rift than those in the center of the Trough. It is strikingly similar to the high-silica Dunes geothermal system, which has no surface expression largely due to the development of hydrothermally induced caprocks. The rediscovery of the Modoc hot springs gold prospect leaves exploration geologists wondering how many other such occurrences underlay the seemingly barren sediments of the Imperial and Mexicali Valleys.
An Overview of the Keweenaw Peninsula Native Copper District, Michigan
Authors: Bornhorst Theodore J.
Published: August 2024

The Keweenaw Peninsula segment of the Midcontinent rift system 1s host to the world's largest native copper mining district (Fig. 1). Cumulative production between 1845 and 1968 was about 5 billion kg of refined copper (Weege and Pollack, 1971) . Although about 96 % of the production came from a 45 km long belt in vicinity of Houghton and Calumet, small uneconomic amounts of native copper occur in basalt flows throughout the exposed Midcontinent rift, including Isle Royale (Michigan), Wisconsin, Minnesota, and Ontario (Canada) (see Cannon and McGervey, 1991). Lenticular, blanket-like orebodies, locally designated as lode deposits, are found along brecciated and amygdaloidal tops of lava flows and interflow conglomerate units within the Portage Lake Volcanics. Minor copper production was from vein orebodies. Economic deposits of native copper are stratigraphically restricted to the Portage Lake Volcanics, but uneconomic amounts of native copper do, occur in younger rift formations. In the White Pine area significant native copper occurs within the Nonesuch Shale (Mauk et al., this volume).
The Origin and Significance of High-Grade Metamorphic Xenoliths, Clear Lake Volcanics, California
Authors: Stimac Jim
Published: August 2024

The Clear Lake Volcanics (~2.1 to 0.01 Ma) are the youngest of a series of volcanic fields in the nothern Coast Ranges of California whose ages roughly parallel the timing of northerly migration of the Mendocino triple junction (Dickinson and Snyder, 1979; Johnson and O’Neil, 1984; Fox et al., 1985). There is compelling chemical, isotopic, and textural evidence that partial melting of crustal rocks played a major role in magmatism at Clear Lake (Futa et al.,1981; Hearn et al., 1981; Johnson and O’Neil, 1984). Physical evidence includes the presence of high-grade metamorphic xenoliths in many basaltic to andesitic lavas of the area (Brice, 1953; Hearn et al., 1981). The xenolith suite is dominated by high-T, low-P granulite facies schist and gneiss, but also includes mafic igneous inclusions interpreted as cognate with the Clear Lake Volcanics (Stimac, 1991). Together, this suite is thought to represent fragments of mid- to lower-crustal mafic intrusions and their contact aureoles (Stimac et al., 1992a).

Exposed basement rocks in the Clear Lake area include the Late Jurassic to Late Cretaceous Franciscan Complex (FC), the Middle Jurassic Coast Range ophiolite (CRO), and the Late Jurassic to Early Cretaceous Great Valley sequence (GVS) (McLaughlin, 1981; McLaughlin and Ohlin, 1984). The metamorphic xenoliths do not resemble exposed graywackes of the FC and GVS, although they could represent the residuum of partial melting and recrystallization of graywacke and intermediate to mafic igneous rocks of the FC or GVS. This indicates that either the exposed country rocks are metamorphosed to higher
Gas Geochemistry and Guide for Geothermal Features in the Clear Lake Region, California
Authors: Goff Fraser , Janik Cathy J.
Published: August 2024

Thermal/mineral waters of the Clear Lake region, California are among the most challenging geothermal fluids in the world to study because they display enormous chemical and isotopic diversity and do not geochemically resemble fluids in typical, high-temperature (≥200°C) geothermal systems (Goff et al., 1993a, 1993b). The Clear Lake region contains no boiling hot springs, hot fumaroles, or springs actively depositing sinter, features commonly linked with high-temperature reservoirs. Regionally, the fluids display tremendous variations in chemical and isotopic composition, caused more by variations in bedrock composition than by subjacent magmatic heat sources (Goff et al., 1977; Thompson et al., 1981a; 1992; Donnelly-Nolan et al., 1993). The distribution of fluids is roughly coincident with the late Tertiary and Quaternary Clear Lake volcanic field (2.1 Ma to 10 ka; Donnelly-Nolan et al., 1981; Hearn et al., 1981). The region lies northeast of The Geysers steam field, the largest geothermal field in the world, yet drilling of approximately 25 exploration wells has not found a commercially exploitable geothermal system. Because conditions in most of these wells are very hot (≥200°C at 2000 m) but relatively impermeable, the Clear Lake region is rated as one of the best hot dry rock geothermal prospects in the United States (Goff and Decker, 1983).

Gas geochemistry is becoming more widely used for geothermal prospecting, especially in areas where spring chemistry is ambiguous or where spring waters are not directly derived from deep reservoirs (Goff et al., 1985; 1991; Janik et al, 1991; 1992). Geothermal gases commonly originate from
The Genesis of the Mclaughlin Mine Sheeted Vein Complex, Fluid Inclusion and Stable Isotope Evidence
Authors: Sherlock Ross L.
Published: August 2024

The McLaughlin Mine is a hot-spring type gold-mercury deposit located in the Coast Ranges of northern California. The “sheeted vein complex” is the center of the hot-spring system that formed the McLaughlin deposit. The sheeted vein complex merges from a subaerial siliceous sinter into a bilaterally symmetric, subparallel, multistage vein swarm. The precious metals are well zoned with gold largely restricted to the upper 200 m of the deposit. Silver can dominate anywhere in the system but is always more abundant than gold below 200 m. Below 350 m, silver is rare, gold has not been observed and mineralization is dominated by base metal sulfides. Fluid inclusion analysis suggest that the ore forming fluids were low salinity NaCl dominated, low CO2 fluids. The deepest samples (> 800 m below the paleosurface) have an average temperature of 235°C. The ascending hydrothermal fluid intersected the hydrostatic boiling curve at ~400 m below the surface and paralleled the hydrostatic boiling curve to the surface. Boiling of an ascending hydrothermal fluid accounts for the metal zoning observed in the sheeted vein complex. During boiling CO2 is partitioned into the vapor phase faster than H2S, resulting in the deeper portion. 3f the ore body being enriched in silver with respect to gold and the shallow portions of the ore body enriched in gold with respect to silver. On the basis of the physical and chemical conditions of the ore forming fluids, gold grade, as well as silica and temperature gradients the hydrothermal fluid is undersaturated with respect to gold prior to the onset of boiling. There is a strong trend for increasingly light δ18Oqtz with depth. The most isotopically enriched samples are from the subaerial sinter and the lightest sample are from the deepest samples. This trend is a temperature effect and is the result of increasing fractionation with decreasing temperature. The oxygen isotopic composition of the hydrothermal fluid remained fairly constant at ~93%o. The oxygen and deuterium composition of the hydrothermal fluids are consistent with a meteoric water origin. The hydrothermal fluids have a pronounced oxygen shift due to water/rock interaction but do not have a deuterium shift. The water/rock ratios are low but similar to other geothermal systems in the Coast Ranges and other epithermal deposits emplaced within sedimentary sequences.
Carlin Trend Geologic Overview
Authors: Christensen Odin D.
Published: August 2024

The Carlin trend is a 60-kilometer-long line of predominantly sedimentary-rock-hosted gold deposits, which has already yielded 477 tonnes of gold production from a total resource exceeding 2500 tonnes of gold. Deposits are hosted predominantly within sedimentary rocks deposited on the Paleozoic continental margin and subsequently compressed through Late Devonian continent-arc collision to form an allochthonous siliceous deep-water stratigraphic assemblage overlying an autochthonous shelf carbonate assemblage. A sequence of compressional, transpressional, and later extensional tectonic events has further shaped the geologic architecture. Gold mineralization is characterized by sub-micron sized “invisible” gold as discrete grains and incorporated within iron sulfides . Deposits are localized within rock volumes rendered sufficiently permeable by primary lithology, chemical alteration, or structural preparation. Alteration styles spatially associated with gold mineralization include decalcification, silicification, argillization, sulfidation, and introduction of the minerals barite and alunite and geochemically anomalous concentrations of As, Sb, Hg, Ag, and Tl. The age of gold mineralization is poorly constrained but believed to be Oligocene. While descriptive models for this type of deposit are well developed, genetic models remain strongly contested.
Geology of the Post Deposit, Eureka County Nevada
Authors: Thoreson Ronald F.
Published: August 2024

The Post deposit is located in Eureka County, Nevada, Section 19, T36N, R50E, approximately 40 km (26 miles) northwest of the town of Carlin and 7 km (4.5 miles) northwest of the Carlin #1 mill (Figure 1).

The Post deposit is located along a spur of the Tuscarora Mountains that also hosts the Blue Star/Genesis and Deep Star deposits. Host rocks for the Post orebody are the sandstones, siltstones, calcareous mudstones, and limestones of the Siluro-Devonian Roberts Mountains and Popovich Formations, and the siliceous mudstones and siltstones of the Devonian Rodeo Creek unit. The Goldstrike diorite intrusion irregularly penetrates the sedimentary rocks as dikes, sills, and stocks producing local hornfels, skarn, and marble.

Gold mineralization occurs along the northern margin of the Goldstrike intrusion in a structural domain dominated by a NW-striking antiform. The eastern limb of this antiform is truncated by the N20W high-angle Post Fault (Figure 2). Gold mineralization, occurring west of the Post Fault, is structurally-controlled along high-angle NE and NW-striking faults, and is stratigraphically-controlled within arenaceous lenses of the Rodeo Creek unit, and within breccias of the lower Popovich and the upper Roberts Mountains Formations. Mineralization is limited within argillized diorite sills and metamorphic rocks to zones that have been structurally-prepared.

Gold mineralization is subdivided into three zones based on geology, morphology, grade, and metallurgical character: Upper Post, Lower Post, and Deep Post. Upper Post represents oxide ore (averaging 0.040 to 0.050 oz/st) hosted in argillized and silicified mudstones, siltstones, and sandstones of the Rodeo Creek
Introduction to the Iberian Pyrite Belt
Authors: Barriga Fernando J.A.S. , de Carvalho Delfim , Ribeiro António
Published: August 2024

This Guidebook contains information to support the three SEG field trips included in the SEG Neves Corvo Field Conference 1997 (Lisbon, May 11–14, 1997). Collectively, these field trips cover the whole Iberian Pyrite Belt and beyond. Given that the Conference is aimed primarily at participants unfamiliar with the geology of the Belt, it was considered appropriate to introduce the subject prior to the field guides. Many studies have presented the overall characteristics of the geology and mineral deposits of the IPB (e.g. Carvalho et al., 1976; Strauss et al., 1977; Carvalho, 1979; Routhier et al., 1980; Barriga, 1990). Very recently, Carvalho et al. (1997) have summarized rather thoroughly the present state of the art concerning the IPB geology and metallogenesis. The present introduction is drawn largely from this.

The Iberian Pyrite Belt (IPB) corresponds to an area of Devonian-Carboniferous volcanic and sedimentary rocks containing massive polymetallic sulfide deposits. This area forms an arcuate belt, about 250 km long and up to 60 km wide, trending westwards from near Seville in Spain to west-northwest in South Portugal. Both the eastward and westward extents of the belt are covered by Tertiary sedimentary rocks (Figure 1).

The IPB is arguably the largest and most important volcanogenic massive sulfide (VMS) metallogenic province in the world. Some of its mineral deposits have been known and mined since the Chalcolithic era such as the Rio Tinto deposit, renowned for its historical role in the study of ore deposits. Only after the discovery of the large and
Deep Regional Resistivity Structure Across the Carlin Trend
Authors: Rodriguez Brian D.
Published: August 2024

The genesis of gold deposits along the Carlin trend is not fully understood. Many of the significant mineral deposits in the Carlin trend were formed during the Tertiary as a result of interrelated high-angle basin-and-range faulting, intrusive igneous activity, and hydrothermal processes (Radtke, 1985). According to Shawe (1991), the linearity of the gold deposits along the Carlin trend and the sub-parallel Battle Mountain-Eureka trend suggests that deep-penetrating regional structures controlled the emplacement of magmas generated in the lower part of the crust or upper mantle, and either provided hydrothermal fluids or caused heating of ground waters that were responsible for transport and deposition of the gold ores. To investigate crustal processes that may have contributed to the genesis of gold deposits along the trend, a regional southwest to northeast profile of magnetotelluric (MT) soundings was acquired in 1996 (line MT-MT′, Fig. 1). Two-dimensional resistivity modeling of the MT profile is being used to place constraints on possible heat or magma sources and possible tectonic controls on the linear distribution of mineral deposits.
Ore Fluids at the Getchell, Carlin-Type Gold Deposit, North-Central Nevada
Authors: Cline Jean S. , Hofstra Albert , Landis Gary , Rye Robert
Published: August 2024

The Getchell gold deposit is one of several Carlin-type gold systems located along the Getchell Trend in north-central Nevada. Deposits located along this trend exhibit all of the characteristics typical of Carlin-type systems including the presence of submicron-sized gold particles in arsenic-rich pyrite. Although Carlin-type deposits have been mined for thirty years and are currently responsible for Nevada being one of the leading gold pr~ducers in the world, there is little consensus concerning the geological processes that concentrated gold in these deposits.

The lack of understanding of formation conditions stems from the submicron size of the gold particles, a paucity of ore stage fluid inclusions in most systems, and a lack of readily datable minerals that are unequivocally related to gold mineralization. The lack of visible gold, even under the microscope, has made it difficult to identify minerals and textures associated with gold precipitation, complicating determination of gold precipitation mechanisms. Fluid inclusions are sparse or absent in the fine-grained replacement ore present in most systems, making it difficult to determine system pressure and temperature, and ore fluid chemistry. The lack of datable minerals has prevented identification of key geological events responsible for gold concentration.

The Getchell deposit is somewhat unusual in that a significant amount of open-space-filling mineralization is hosted within the Getchell fault zone. This mineralization exhibits cross-cutting and textural relationships that provide constraints for the ore paragenesis. Additionally, these slightly more coarse-grained minerals trapped several populations of fluid inclusions, including primary inclusions contained within growth zones. Examination of
Gold Paragenesis in Intrusion-Marginal Sediment-Hosted Gold Mineralization at Eureka, Nevada
Authors: Margolis Jacob
Published: August 2024

The Archimedes gold deposit, discovered in 1992 by Homestake Mining Company, is about 1 mile northwest of Eureka, Nevada in the northern part of the Eureka minin district (Nolan, 1962). The deposit, described in further detail by Dilles et al. (1996), is a largely stratiform body of silicification within non-carbonaceous, cherty Ordovician limestones of the Pogonip Group. This zone, West Archimedes, is approximately 2600 feet long at N60°W, and averages 260 feet inwidth and 75 feet in height; the zone plunges gently east. Gold mineralization has low concentrations of Ag-Pb-Zn-Cu and correlates strongly with silicification, which is generally surrounded by decalcified but unsilici:fied limestone containing lower grade. Published reserves for the western zone are 7.62 million short tons grading 0.099 ounces per ton (opt) Au; the mineralization is oxidized. Values above 0.25 opt Au are common in the central part of the zone. This stratiform silicification is concealed by as much as 500 feet of alluvium and locally intersects the bedrock surface. No intrusive rocks or calc-silicate alteration are present within the West Archimedes deposit, although an altered sill lies more than 1000 feet below. This gold-bearing silicification is herein referred to as Type A. North-northeast and west-northwest trending normal faults are thought to have provided ingress for hydrothermal fluids in the deposit area (Dilles et al., 1996); however, the lack of bedrock exposure at the deposit has precluded thorough analysis of the structures.

More strongly brecciated gold-bearing silicification (Type A) on the east side of West Archimedes is underlain
Petrochemistry and Emplacement History of the Wasatch Igneous Belt
Authors: Vogel Thomas A. , Cambray F. William , Feher Leeann , Constenius Kurt N.
Published: August 2024

Exposures in and around the mid-Tertiary Wasatch Igneous Belt (WIB) provide an opportunity to investigate the mechanisms associated with the emplacement of the stocks. They are associated in time and place with northeast-trending dikes, indicating that the area was undergoing extension at the time. Studies elsewhere show that at best, distortion of the country rock around igneous intrusions can only account for 40 percent of the space required. We propose a model in which part of the space is made available where faults associated with the extension change strike (releasing bends) or dip (releasing steps). Evidence for this is in the form of kinematic indicators associated with minor intrusions, the map scale geometry of the stocks and the pattern of dikes. The Little Cottonwood, Alta, and Clayton Peak stocks are chemically distinct, lending support to the concept of separately generated and separately emplaced magma bodies. The eastern stocks and the Keetley Volcanics have some similarities with the Alta stock. The stocks and volcanic rocks of the WIB are all high-K calc-alkaline rocks with K2O, εSr and εNd values that are difficult to generate from the mantle wedge overlying a subducting plate, but are consistent with magmas derived by partial melting of the lower crust (Proterozoic meta-igneous). The intrusive and volcanic rocks in the WIB range in age from 30.5 ± 0.6 Ma (Little Cottonwood) to 35.5 ±1.5 Ma (Clayton Peak) with most of the intrusions and volcanic deposits occurring in the 32 to 36 Ma range.
Alteration, Metal Zoning, and Ore Controls in the Bingham Canyon Porphyry Copper Deposits, Utah
Authors: Phillips C.H. , Smith T.W. , Harrison E.D.
Published: August 2024

The Bingham Canyon porphyry copper deposit has been a world class producer of copper and other metals since 1904. Sulfide mineral distribution is typical of many porphyry copper deposits, with an outer, low-grade zone of pyrite and chalcopyrite and an inner zone of chalcopyrite. Molybdenite occurs in the center of the deposit. A late bornite-gold episode overprints part of the earlier mineralization. The deposit occurs principally within the composite Bingham stock, consisting of an equigranular monzonite phase that is intruded by a wide, dike-like body of quartz monzonite porphyry and younger latite porphyry and quartz latite porphyry dikes.

Propylitic, potassic, and phyllic alteration are recognized. Pervasive actinolite-chlorite alteration in the monzonite phase of the Bingham stock was followed by biotite veinlets, with little associated sulfide mineralization, which fill crackle fractures in the monzonite. These veinlets are crosscut by quartz-biotite veins containing chalcopyrite with strong biotite and K-feldspar selvages. As the veins evolve to more planar, continuous stockworks, chalcopyrite becomes more abundant and then decreases as molybdenite appears. Quartz-molybdenite veins contain minor chalcopyrite and weak biotite. The zone of >0.7 percent copper forms an annulus in which copper grades locally exceed 1.0 percent within at least four distinct pods. One of these high-grade areas, located in the southwestern part of the deposit, may represent a separate center of mineralization. Gold grades of four to five times the average in the copper orebody occur within the gold-bornite zone (>0.02 oz/t Au) on the north side of the deposit, where blast hole assays of up to 0.1 oz/t gold are not uncommon. Bornite mineralization is associated with a set of quartz-K-feldspar veins with selvages of K-feldspar/silica flooding and perhaps clay/sericite alteration. This gold-bornite zone appears to overprint earlier chalcopyrite mineralization, and may be a variant of potassic alteration. Phyllic alteration consists of quartz-sericite-pyrite veins, mainly in a zone peripheral to the orebody. In the higher-grade copper zone, veins are found that are similar to quartz-sericite-pyrite veins except that the predominant or only sulfide is chalcopyrite.
Field Stops
Authors: Watanabe Koichiro , Taguchi Sachihiro
Published: August 2024

Figure 1, looking to the northwest, shows a profile and view of Kami-Kometsuka, which is a basaltic cinder cone. The reddish color of most scoria is due to high-tempera- ture oxidation. A nice view of Kometsuka (also shown in Fig. 2), another cinder cone, can be seen to the northwest.
Otake-Hatchobaru Geothermal Field
Authors: Taguchi Sachihiro
Published: August 2024

The Otake and Hatchobaru geothermal field is located on the northwestern slopes (900-1,100 m above sea level) of the Kuju Volcano, 4 to 5 km to the north of the fumarolic area of Kuju Iwo-yama. The geothermal system of the field is a water-dominated type and is controlled by fracture systems. The field is one of the most productive geothermal fields in Japan; Otake (12.5 MW), Hatchobaru Unit I (55 MW), and Unit II (55 MW) geothermal power plants have been operating since 1967, 1977, and 1990, respectively.

In this field, we can observe shallow geothermal phenomena such as argillic and advanced argillic alteration, steaming ground, hot springs (steam-heated water), veins, and spectacular mineralization in pipelines.
Field Trip Day Three
Authors: Delorraine William F.
Published: August 2024

The Underground tour will examine Proterozoic Zn sulfide deposits of the Balmat Zn mine, described by deLorraine and Dill (1982) and in this volume by deLorraine (2001). The evening preceding the tour will feature a talk on Balmat geology. This talk will involve a slide show presentation with maps, cross sections, and mine models made available for inspection. The latest structural interpretations will be reviewed and there will be in-depth discussions regarding the response of massive sulfides to high-grade, near granulite- facies metamorphism in a sequence of interlayered silicated dolomitic marbles and pure marble units of extremely high ductility contrast. We will demonstrate that ore was tectonically remobilized 600 m and more laterally, by over 2000 m in the down-plunge dimension. This happened in several parent-daughter pairs. The degree and extent of remobilization of massive sulfide at Balmat appears to be unique anywhere in the world.
Geochemical Settings of Mine Drainage in the Vermont Copper Belt
Authors: Seal Robert R. , Kornfeld Jeannie M. , Meier Allen L. , Hammarstrom Jane M.
Published: August 2024

Elizabeth and Ely, which exploited Besshi-type massive sulfide deposits, are the two largest abandoned mines in the Vermont copper belt. The ore mineralogy of the deposits and their mine wastes are dominated by pyrrhotite with minor chalcopyrite and sphalerite. Gangue minerals include quartz, muscovite, biotite, amphibole, and minor carbonate. The watersheds of the Vermont copper belt away from the mines are characterized by neutral waters, with significant alkalinity and hardness due to the presence of carbonate rocks in the watersheds. The Elizabeth mine site discharges into the West Branch of the Ompompanoosuc River at three points, in order going downstream: the Air Vent, which drains the underground mine workings; Copperas Brook, which drains the area with most of the mine wastes; and Lord Brook, which drains an area impacted by drainage from two smaller mine workings. The Ely mine site is drained by Ely Brook, which empties into Schoolhouse Brook, which flows into the East Branch of the Ompompanoosuc River. Mine drainage from Elizabeth and Ely is characterized by low pH (1.9 to 6.9), high specific conductance (0.16 to 5.69 mS/cm), and elevated concentrations of Fe (0.286 to 1,000 mg/L), Ca (10.9 to 498 mg/L), Al (0.011 to 236 mg/L), Cu (6 to 200,000 μg/L), Zn (5 to 38,000 μg/L), Co (<0.2 to 7,200 μg/L), Cd (0.5 to 400 μg/L), and sulfate (92 to 4,900 mg/L). The chemistry of the drainage is linked to the physical and chemical character of the mine wastes, the stoichiometry of pyrrhotite weathering reactions, and the hydrologic and climatic settings of the sites, among other factors.
EFFECT OF CURRENT RATIO AND DEBT TO EQUITY RATIO ON NET PROFIT MARGIN IN THE COMPANY PT ADHI KARYA (PERSERO) Tbk. WHICH IS LISTED ON INDONESIA STOCK EXCHANGE IN 2017-2021
Authors: Maharani Eka , Hasibuan Daniel Roland , Nainggolan Ringkot P
Published: August 2024

ABSTRACT
The purpose of this study is to determine the effect of current ratio and debt to equity ratio on net profit margin both partially and simultaneously. The research method used is a quantitative research method with a descriptive approach. The population used in this study is the financial statements of PT Adhi Karya (Persero) Tbk. The sample used in this study is the financial statements of PT Adhi Karya (Persero) Tbk. for 2017-2021. The analytical methods used in this study are descriptive data analysis, classical assumption test (normality test, multicholinearity test, heteroskedasticity test, and autocorrelation test), hypothesis test (multiple linear regression test, coefficient of determination test, t test, and f test). The results of this study show that the Current Ratio partially affects and is not significant on Net Profit Margin with a calculated value of -3.510 with a significance level of 0.072 > 0.05. Debt to Equity Ratio partially negatively and significantly affects Net Profit Margin with a calculated value of -5.886 with a significance level of 0.028 < 0.05. Current Ratio and Debt to Equity Ratio simultaneously have an effect and significantly affect Net Profit Margin with a significant value of 0.019 < 0.05.
ANALISIS PENERAPAN PERHITUNGAN, PENYETORAN DAN PELAPORAN PAJAK PERTAMBAHAN NILAI (PPN) PADA PT. ARKSTARINDO ARTHA MAKMUR
Authors: Naila Romana Rati , Simangunsong Timbul , Saprudin Saprudin
Published: August 2024

This study aims to determine whether the application of the calculation, deposit and reporting of Value Added Tax (VAT) at PT. Arkstarindo Artha Makmur by adjusting Tax Law No. 42 of 2009. Data collection methods used are Observation Studies, Interview Studies, and Documentation Studies. The data analysis method used is descriptive qualitative and quantitative analysis. The results of the research show that the implementation, calculation and reporting of VAT by PT. Arkstarindo Artha Makmur cannot be said to be effective and efficient due to several inhibiting factors in the collection of VAT on Taxable Goods and Services. The company has issued an electronic Tax Invoice, performed calculations from the Tax Imposition Basis, deposited and reported Periodic VAT SPT. Company. Application of VAT calculation, deposit and reporting by PT. Arkstarindo Artha Makmur has not been effective due to differences in implementation between consumers and companies.
INTENSI KONTINUITAS PENGGUNAAN DIGITAL PAYMENT: PERAN MAHASISWA SEBAGAI WARGA KEUANGAN DIGITAL
Authors: Erlinda Sholihah  , Diyah Ariyani
Published: August 2024

This study aims to determine the factors that influence the level of continuance intention in using digital payments by students with the Expectation Confirmation Model (ECM) theory approach. The study used primary data from 100 students who use digital payments. The analysis in this study used SEM-PLS to analyze the relationship between exogenous variables and endogenous variables with the help of SmartPLS version 3. Overall, this model accounts for 54.7% of the variance in the continuity of digital payment usage intentions.  An element substantially influenced by factors such as Perceived Usefulness and Satisfaction. Of these factors, Satisfaction is the most powerful predictor of continuance intention. Along with Confirmation, Perceived Usefulness also greatly affects Satisfaction. These findings will assist stakeholders in strategizing policies to offer more innovative and flexible technology products to the wider community as digital finance citizens.
THE INFLUENCE OF LEADERSHIP STYLE, WORK DISCIPLINE, AND JOB SATISFACTION ON EMPLOYEE PERFORMANCE AT PT. KELOLA KARYA BERSAMA
Authors: Saputri Dian , Adrian Adrian , Frederick Henry Waidan
Published: August 2024

This study aims to analyze Leadership Style, Work Discipline, and Work on Employee Performance at PT. Kelola Karya Bersama. The variables studied are Leadership Style, Work Discipline, Job Satisfaction, and Employee Performance. The type of research used is a quantitative research type, and the kind of data is primary data through the questionnaire method with the sampling technique used is purposive sampling with the number of respondents forty-six (46) respondents. Data analysis in this study used SPSS version 26.0. The analysis used in this research is the Validity Test, Reliability Test, Multicollinearity Test, Heteroscedasticity Test, Normality Test, Multiple Linear Analysis, Correlation Coefficient Analysis Test, T-test, F-test, and Coefficient of determination (R2). The results of testing and analysis of this research show that leadership style, work discipline, and satisfaction work simultaneously or together significantly affect employee performance. Suggestions for Kelola Karya Bersama in the future are to improve an excellent and fair leadership style further and enforce employee discipline in doing work to create employee satisfaction and increase company productivity.
PENINGKATAN KAPASITAS SUMBER DAYA MANUSIA PADA BIDANG PANAS BUMI DI KEMENTERIAN ENERGI DAN SUMBER DAYA MINERAL
Authors: Lestari Suci , Alexandra Esther Tiara , Tobing Erie Hotman H
Published: August 2024

This study aims to find out the obstacles and to find the strategies in capacity building of human resources in geothermal. This research uses quantitative research with descriptive approach. In this study, the method of data collection is documentation, the data used in the form of interviews. Data analysis carried out in this study was qualitative data analysis, where data analysis was carried out in a non-statistical way, namely research carried out by describing the data obtained in words or sentences and literature studies. The results of this study indicate that Indonesia still lacks human resources who have specific competencies to work in geothermal projects
ANALYSIS OF THE IMPACT OF COVID 19 AND THE POLICY OF IMPLEMENTING COMMUNITY ACTIVITIES LIMITATIONS ON MSMEs Central Jakarta in 2021
Authors: Situmeang Farida P , Dewi Diana Setiyo , Alexandra Esther Tiara
Published: August 2024

This study aims to determine the impact of covid 19 and the policy of limiting the application of community activities (PPKM) on MSMEs in Central Jakarta in 2021. The Covid 19 and the policy of limiting the application of community activities as an independent variable, while MSMEs as the dependent variable. The population of this research is MSME actors. The type of research used is a quantitative type and the data used in this study is primary data in the form of respondents' answers to the questionnaire and processed using SPSS software version 28. Furthermore, the sampling technique used is census or total sampling with the number of respondents obtained by 100 actors. umkm in central jakarta. The results of the study based on the t test (Partial) proved that covid 19 and the policy of limiting the application of community activities to MSMEs had a significant positive effect. The calculated F test showed that the F Count was 7.340 and the sig. 0.001. When compared with Ftable 1.984, Fcount > Ftable and Sig value < 0.05. Thus showing that COVID-19 and restrictions on the application of community activities (PPKM) simultaneously affect MSMEs.
PENGARUH KEPUASAN NASABAH DALAM PENGGUNAAN KARTU KREDIT PADA PT BANK UOB JAKARTA
Authors: Zahrina Lutfiana  , Agus Sriyanto  , Ismail Habib
Published: August 2024

The rapid development of technology is very influential on economic conditions in a country. Especially in the banking sector. The impact is a shift in people's behavior in consuming a good or service. The existence of this technological transformation must be addressed wisely, especially banks by innovating, efficiency and effectiveness of service services to customers. Banks need to improve Trust, Service Quality and Brand image in order to be competitive. This bank continues to strive to provide services in order to satisfy its customers. Bank UOB is a company engaged in banking that has its head office in Jakarta and branch offices in several other cities in Indonesia. The more advanced technological developments, many people are looking for an item or tool that is flexible, efficient and can be used whenever needed without having to waste so much time. In this era, banking increasingly refers to efforts to achieve social, economic progress, by making new products, providing better service quality and instilling trust and a good brand image in customers.This study aims to prove and analyze the effect of trust, service quality, brand image on the satisfaction of Bank UOB Jakarta credit card users. The study population is all UOB Bank credit card users, sampling is carried out by probability sampling with the random sampling method, Data analysis using SPSS 23 the number of samples used was 70 respondents from 230 populations. The results proved that trust has a significant positive effect on UOB Bank credit card user satisfaction, service quality has a significant positive effect on UOB Bank credit card user satisfaction, brand image has a significant positive effect on UOB Bank credit card user satisfaction.
DAMPAK KECANDUAN BELANJA ONLINE YANG DIALAMI GENERASI MUDA TERHADAP IKLAN FLASH SALE SHOPEE DI TELEVISI DI ERA PASCA PANDEMI COVID 19
Authors: Rochmansyah Erwin , Putri Depi , Ikrom Muhammad , Sopiyan Wawan
Published: August 2024

Perubahan gaya hidup masyarakat dalam melakukan interaksi sosial melalui internet khusunya aktivitas penggunaan komunikasi massa seperti media televisi sering digunakan pada masa pandemi Covid-19. Adanya physical distancing, pembatasan sosial dan penerapan protokol kesehatan membuat masyarakat lebih memilih untuk memanfaatkan internet sebagai pendukung pemenuhan kebutuhan hidup sehari-hari. Gaya hidup yang dirasakan oleh masyarakat saat ini adalah gaya hidup konsumtif karena banyaknya media massa yang turut campur dalam membentuk konstruksi gaya hidup dalam masyarakat. Dengan prinsip masyarakat Indonesia yang masih banyak menganut ideologi patriarki, tentu menempatkan perempuan sebagai seorang yang dengan mudah dipengaruhi oleh permainan kapitalisme. Hasil dari kontruksi gaya hidup ibu rumah tangga Melalui penelitian ini, melihat bahwa bagaimana penerimaan Ibu rumah tangga terhadap tayangan iklan flash sale Shopee di televisi di era pandemi saat ini. Penelitian ini menggunakan metode penelitian reception analysis. Hasil dari penelitian ini adalah Generasi Muda (laki-laki dan perempuan) masih dijadikan sebagai sebuah objek bahkan target sasaran dari industri kapitalis dengan adanya penerimaan dari perempuan terhadap budaya konsumerisme melalui perilaku konsumtif belanja online. Sedangkan media sampai saat ini masih menjadi alat yang digunakan untuk menjadikan kiblat informasi.