In addition, although little is known about the au supergene mineraliza. The fire ant social chromosome supergene variant sb shows low. Intensive lateritic weathering of bedrock under tropical or subtropical climatic conditions can form a variety of secondary, supergene type deposits. Supergene enrichment of silver ores with special reference. These secondary deposits may range in composition from aluminous bauxites to iron and niobium, and include rare earth elements ree.
Supergene mimicry is a striking phenomenon but we know little about the evolution of this trait in any species. The reaction produces secondary sulfides with metal contents higher than those of the primary. Nearsurface oxidation produces acidic solutions that leach metals, carry them downward, and redeposit them, thus enriching sulfide minerals already present. Definition secondary or supergene enrichment where leaching of materials occurs and precipitation at depth produces higher concentrations. Nico laterites are supergene deposits of ni co formed from the pervasive chemical and mechanical weathering of ultramafic rocks.
Below the water table is a zone of supergene enrichment in which secondary sulfide minerals such as covellite and chalcocite form from chalcopyrite and copper sulfate in solution. Supergene enrichment occurs at the base of the oxidized portion of an ore deposit. Hreeenrichment in some peripheral zones can be attributed to an increase in the abundance of secondary ree phosphates rhabdophane group, monazite, and fluorapatite, while hreeenrichment in other zones is a result of hree. Initial products of supergene oxidation, copiapo mining. Oxidation and secondary enrichment of gold deposits.
Finally, we test whether the supergene region can be divided into strata with different levels of divergence between sb and sb. Results of numerical calculations suggest that the enrichment blanket may be subdivided into three distinct zones. The evolution of supergene enrichment in the morenci by. Q for geologists about supergene enrichment supertopo. The first event is represented by oxidation of hypogene sulfides to form chrysocolla as the main cu oxide mineral phase, followed by a second and late supergene stage characterized by the formation of abundant atacamite. Residual mineral deposits an existing mineral deposit can be turned in to a more highly concentrated mineral deposit by weathering in a.
Bjorlykke cited rather limited data for six of these deposits, which. Pin a and thrum b flowers of primula vulgaris are controlled by a supergene. Definition of supergene enrichment a mineral deposition process in which nearsurface oxidation produces acidic solutions that leach metals, carry them downward, and reprecipitate them, thus enriching sulfide minerals already present. Intensive lateritic weathering of bedrock under tropical or subtropical climatic conditions can form a variety of secondary, supergenetype deposits. Lindgren, 1933, a concept that has since become entrenched in the literature e. On the other hand, the residual gold enrichment, under supergene conditions, can be formed by ag dissolution from au ag hypogene particles bowell, 1992. Largescale evolutionary analysis of genes and supergene. However, harvesting microorganisms from the supergene zone and using them. Regions covered include many different settings and an eclectic range of topics.
Oof 1q4 supergene enrichment of precious metals by natural amalgamation in 2 the las cruces weathering pro. Largescale development of supergene anataserich soils on carbonatiteassociated pyroxenites in brazil abstract anthony n. Similar to our findings for genomewide tandem duplicate fractions across all analyzed genomes, the significant enrichment for supergene clusters holds up for all organisms except c. Chlorine isotope fractionation recorded in atacamite. Supergene definition and meaning collins english dictionary. Supergene definition is a group of linked genes acting as an allelic unit especially when due to the suppression of crossingover. The descending meteoric waters oxidize the primary sulfide ore minerals and. Pdf weathering processes and supergene ore deposits conditions that. Oxidation that occurs in sulfide deposits which can concentrate valuable elements like copper. Supergene zinc and residual lead enrichment processes peter k. Please check your proof carefully and mark all corrections at the appropriate place in the proof e. In the atacama desert of northern chile, large amounts of the copper hydroxychloride mineral atacamite cu 2 cloh 3 are formed in the supergene oxidation zone of cu deposits.
Supergene enrichment of silver ores with special reference to. The enrichment zones, generally, can be geochemically divided into three intensities of development based on mineralogic and paragentic relationships as strong, moderate, and weak enrichment. Supergene environments, processes, and products in. Dokuchaev the zonality of soils, the weathering crust, continental deposits, ground waters, and so on. Degenerative expansion of a young supergene molecular. Pdf a simulation of the supergene copper enrichment process. Assistant professor, salt lake community college, salt lake city, utah view all posts by chris. Supergene sulfide enrichment, also called secondary enrichment, in geology, natural upgrading of buried sulfide deposits by the secondary or subsequent deposition of metals that are dissolved as sulfates in waters percolating through the oxidized mineral zone near the surface. Ree fractionation, mineral speciation, and supergene. At barreal seco, two supergene events were identified. Supergene alteration of norwegian sulphide deposits a query. Learn the translation for supergene in leo s english. Supergene enrichment of precious metals by natural. Supergene enrichment occurs when oxidizing acids dissolve metal ions from the protore and re deposits it.
Unravelling the genes forming the wing pattern supergene. Here, by studying genomes of butterflies from a recent radiation in which supergene. However, the oftencomplex mineralogy of supergene ores poses serious challenges to extractive metallurgy or mineral processing, and many supergene enrichment blankets will remain unmined or unprocessed until such time as viable metallurgical processes can be developed. Supergene enriched, intrusion related low suphidation deposit. Supergene enrichment is essential for the economic viability of many porphyry copper deposits reich and vasconcelos. Supergene enrichment of copper deposits since the mafiadoc. Tracing the origin and evolution of supergene mimicry in. A first principles approach to supergene enrichment of a porphyry. Preface for thematic issue on supergene ore deposits pdf. The paleoclimatic signatures of supergene metal deposits. Gold behavior in supergene profiles under changing redox.
The first and most important factor is the parent rock e. The supergene enrichment of gold in deposits may take place by a simple mechanical process, by chemical means, or by a combination of these. Supergene processes include the predominance of meteoric water circulation with concomitant oxidation and chemical weathering. Pyrite is a ubiquitous mineral in quartz veins and its oxidation can contribute strongly to the oxidation and hydrolysis of iron or ferrolysis mann, 1984. Since atacamite requires saline water to form and is commonly preserved under hyperarid conditions, it has been proposed as a climatesensitive mineral marker that can also provide relevant. A unified description of supergene enrichment of a porphyry copper protore is presented based on the principles of metasomatic zoning. A first principles approach to supergene enrichment of a.
The descending meteoric waters oxidize the primary sulfide ore minerals and redistribute the metallic ore elements. The fire ant social chromosome supergene variant sb shows. With nounverb tables for the different cases and tenses links to audio pronunciation and relevant forum discussions free vocabulary trainer. Supergene enrichment is essential for the economic viability of many porphyry copper deposits reich and vasconcelos 2015 this issue, and determining when and how supergene enrichment has occurred is important when exploring for enriched and exotic copper deposits mote et al. Supergene sulfide enrichment, in geology, natural upgrading of buried sulfide deposits by the secondary or subsequent deposition of metals that are dissolved as sulfates in waters percolating through the oxidized mineral zone near the surface. Metals that have been leached from the oxidized ore are carried downward by percolating groundwater, and react with hypogene sulfides at the supergene hypogene boundary.
Ree fractionation, mineral speciation, and supergene enrichment of the bear lodge carbonatites, wyoming, usa. It forms during the supergene sulphide ore enrichment, when weakly acid surface water perloctaes through the mineral deposit. Because they lack evidcnce of metamorphism, are typically related to present erosion surfaces, and contain abundant hydrous fe oxides, these hematitegoethite ores are generally accepted as resulting from supergene enrichment. Porphyry copper deposits result from the complex interactions and feedbacks of many processes. Supergene metal deposits form when common rock types or d eeply buried primary ore bodies are exposed at or n ear the earths surface and undergo oxidation, dissolution and reconcentration of the. Since then, the role of prevolcanic enrichment has been questioned cook, 1994. Pdf a simplified simulation of copper precipitation during supergene enrichment processes was carried out to study the feedback behaviors of.
Supergene processes and enrichment supergene processes are controlled by three basic factors. The cornubian batholith is a large mass of granite rock, formed about million years ago, veins of cassiterite tin oxide and wolframite a mineral containing iron, manganese and tungsten are found associated with the greisens, the former one theory is that the kaolinization. Arizona geological survey open file report 007, 69 pp. The green mineral atacamite cu2cloh3 is a major constituent of supergene zones in the atacama desert, and increasing evidence suggests that atacamitebearing oxide assemblages are late products of supergene enrichment, likely to have formed by the replacement of preexisting oxide assemblages during the passage of saline water cameron et. A mineral deposition process in which nearsurface oxidation produces acidic solutions that leach metals, carry them downward, and reprecipitate them, thus enriching sulfide minerals already present. The social chromosome supergene system may give insight into the early stages of degeneration of a nonrecombining region zhou et al.
In ore deposit geology, supergene processes or enrichment occur relatively near the surface. First, the enrichment may be primarily the result of the chemical removal of a large part of the gangue minerals, in which case the gold migrates slowly downward by gravity or is left behind as a residual. As host for the largest and richest porphyry copper deposits. Supergene ores lecture notes 8 environmental geology. Mathematically this formulation represents the supergene weathering process as a moving boundary problem. This publication brings together 12 papers and 3 abstracts of talks presented at the seg symposium, advances in the understanding of supergene processes, convened by m. Supergene processes article about supergene processes by.
The present study is the first detailed report of supergene au mineralization in the iberian pyrite belt. Consequently, this descriptive model uses a working definition of a porphyry copper deposit. Supergene definition of supergene by merriamwebster. During the early decades of the 20 th century, several eminent investigators proposed that silver sulfide enrichment beneath zones of oxidation is a widespread and economically important supergene process in silveronly and other silverrich deposits e. The differential expression within the supergene was generally more marked than in the rest of the transcriptome, as revealed by gene set enrichment analysis see additional file 1.
The mineral assemblages of supergene enrichment zones and their related gossans for a selected group of vms deposits are presented in table 121. Understanding the evolution of supergene enrichment at morenci is of critical importance, not only because of this deposits economic significance, but also in terms of our understanding of the evolution of porphyry copper systems in general. Owing to the complexity, a succinct definition that includes the essential attributes of this deposit class is elusive. By a stony creek in a valley, a blackclad young man was holding a black beetle with a metallic sheen that looked like a cross between a crab and a hercules beetle. The formation of secondary concentrations of ni co significant enough for an economic resource requires a protolith lithology that is primarily enriched in ni.
A study and application of the process of supergene. Supergene minerals such as sulfides, clays, hydroxides and sulfates are formed in the supergene zone as secondary minerals by the alteration of primary sulfide minerals from the oxidized zone above the water table. However, comparison of duplicate frequencies within different functional modules of terpenoid biosynthesis. The ore thus enriched forms the secondary, or supergene sulfide, zone and overlies the primary, or hypogene, zone. Supergene metal deposits form when common rock types or d eeply buried primary ore bodies are exposed at or n ear the earths surface and undergo oxidation, dissolution and reconcentration of. In such deposits, some of the widely proposed enrichment zones were reinterpreted as products of. A supergene is a group of neighboring genes on a chromosome which are inherited together because of close genetic linkage and are functionally related in an evolutionary sense, although they are rarely coregulated genetically. Supergene definition of supergene by the free dictionary.
The term is used to refer to several closely linked gene loci that affect a single trait or a series of interrelated traits, such as the genes coding for the expression of pin and thrum flower phenotypes in the primrose and other species of the. This is so because it denotes a concretion of iron hydroxides that has formed on top of sulphide mineral vein, where it reaches the surface. Gossan or the iron cap supergene sulphide ore enrichment. Nevertheless, the volumetric and economic importance of supergene silver sulfide enrichment was extensively debated during the early decades of the last century, and some experts downplayed its significance, especially in epithermal vein deposits e. Supergene enrichment occurs when oxidizing acids dissolve metal ions from the protore and re deposits it in more reducing, basic areas, i.
A chromosomelevel assembly of the atlantic herring genome. Bjorlykke 1960 gave some interesting facts regarding the diminution of copper content with depth in certain norwegian caledonian massive sulphide deposits. Supergene enrichment how natural processes have transformed lowgrade copper mineralization into economic ores by david f. For illustrative purposes, a diagram compiled by boyle 2003, based on supergene mineralization at numerous deposits in the bathurst mining camp, captures. The development of a supergene enrichment zone along with its overlying gossan in vms deposits produces a distinctive paragenetic sequence. Using a previous estimate that the sb supergene region represents 4. Chlorine isotope fractionation recorded in atacamite during. In an attempt to quantify the amount of genetic exchange across the supergene, we tallied both diagnostic, defined as having allele frequency 90% in one group and enrichment. The ore thus enriched forms the secondary, or supergene sulfide, zone and overlies the primary, or. Within the p interval, 30 and 24 of the transcripts mapping to the supergene were indeed differentially expressed among morphs at the prepupa and day1.
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