The strata present at qiuling are, from old to young, the upper devonian lengshuihe and nanyangshan formations, the lower carboniferous yuanjiagou formation of and middle. Epithermal gold deposits part ii geology and gold deposits of the oatman district, northwestern arizona by ed dewitt, jon p. Much of the gold in orogenic deposits is tied up in the crystal structure of sulphides such as pyrite and arsenopyrite cook et al. This means it can be viewed across multiple devices, regardless of the underlying operating system.
It is the orogenscale processes during these times that control release of gold and related elements. Pdf file or convert a pdf file to docx, jpg, or other file format. Transport and coarsening of gold nanoparticles in an orogenic. Jun 15, 2019 the term orogenic gold deposits has been widely accepted, but there has been continuing debate on their genesis. General setting geological and structural setting the pilbara craton western australia is a wellexposed 3. This article explains what pdfs are, how to open one, all the different ways. Most electronic documents such as software manuals, hardware manuals and ebooks come in the pdf portable document format file format. Reserves and resources as at june 30, 2017, see news release dated july 26, 2017. The temporal division of orogenic gold deposits into. Gold ore deposits are found in rocks throughout the earths geological history, from the earliest precambrianmore than 3.
Orogenic gold deposits are epigenetichydrothermal au base metal deposits which form in response to elevated heat and fluid fluxes during compressional to transpressional deformation in metamorphic belts of accretionary and collisional orogens. Sawyertype hightonnage mesozonal orogenic deposits the newly defined sawyertype mesozonal orogenic gold deposits include mineralization. Golden promise deposit lies within the badger map sheet nts 12a16 of central newfoundland. The socalled mesothermal gold deposits are associated with reginally metamorphosed terranes of all ages. Pdf supergene gold mobility in orogenic gold deposits. Pyrite compositions from orogenic gold and vhms deposits.
The term orogenic is used because these deposits likely form in. Jul 01, 2018 the orogenic gold deposits are confined to this jog and are sited in a number of d2 shear zones at, or close to, their intersection with the crossfault arrays. Pdf is a hugely popular format for documents simply because it is independent of the hardware or application used to create that file. If your pdf reader is displaying an error instead of opening a pdf file, chances are that the file is c. Ores were formed during compressional to transpressional deformation processes at convergent plate margins in accretionary and collisional orogens. For orogenic gold deposits at deeper crustal levels, oreforming fluids are commonly focused along strain gradients between more compressional zones where. Knoxrobinson, 2000 and are sited in accretionary or collisional orogens of all ages. For orogenic gold deposits, integrated terrane to district scale tectonic, structural and geochronological studies worldwide have demonstrated a latekinematic timing of gold mineralization related to a change from compression normally annotated d1d2 to.
Examples of such gold deposits subset developed are, intrusionrelated gold deposits 7, bulk mineable gold deposit 8, the epithermal gold deposits, or 9 the epigenetic archean gold deposits 1110 stated that a rational geological classification of the commonly recognized lode gold deposits is not feasible if it. Orogenic gold deposits have become attractive exploration targets because of the potential for relatively high grades. Orogenic gold deposits are somewhat unique relative to other ore systems because they can form at various stages of orogenesis e. The gold bearing, orogenic quartz vein system comprising the jaclyn deposit a. Parameters for the formation of orogenic gold deposits. For orogenic gold deposits at deeper crustal levels, oreforming fluids are commonly focused along strain gradients between more compressional. Prospectivity analysis of orogenic gold deposits in saqez. Orogenic gold deposits are the only important type of gold deposit for which many economically important examples are preserved throughout the geological record. The initial discovery in 2002 consisted of coarsegrained, combtextured and stylolitic quartz boulders exposed on subcropping, bedrockcored ridges. Pdf orogenic gold deposits are the main source of gold for humanity. These deposits formed from the archaean to phanerozoic at crustal depths of. The objectives of this paper are to provide an update on gold deposit models, and what new approaches and techniques can now be used to find gold deposits. This study presents data on the geological setting and ore mineralogy of these deposits.
Uniform elements in orogenic gold mineral systems from archean to phanerozoic ages are as follows. Smith2 abstract mines in the oatman mineralized district, near oatman in northwestern arizona, have produced more than 1. Sawyerkeystone trend of auagas deposits in randolph. However, many gold deposits classed as orogenic carry signatures suggesting a magmatic fluid component. The orogenic gold deposits are confined to this jog and are sited in a number of d2 shear zones at, or close to, their intersection with the crossfault arrays. This work will contribute linking regional scale deformations and localscale structural controls on orogenic gold mineralization in the guiana shield. Pataz lodegold deposits are in an equivalent situation to a large number of orogenic gold deposits hosted by granitoids. In both types of orogen, hydrated marine sedimentary and volcanic rocks have been added to continental margins during tens to some 100. Phanerozoic orogenic lode gold deposits gold in 2000. The new yahoopowered ads for adobe pdf service makes it easy to place payperclick ads in your pdf files. There are six worldclass settings for magmatichydrothermal gold deposits. Gold deposits can still be seen today forming in some active geothermal areas. Then click on the link to know more about this document and view some samples you can use freely now.
By michelle rae uy 24 january 2020 knowing how to combine pdf files isnt reserved. Igneous intrusions, volcanicrich sequences and the possible correlation of tertiary lavas with other new england volcanic fields also have exploration significance. On the source of orogenic gold geology geoscienceworld. Orogenic gold deposits are the main source of gold for humanity. General characteristics of orogenic gold deposits orogenic gold deposits are a widespread coherent group of epigenetic mineral deposits controlled by a similar set of factors groves, 1993. Orogenic gold deposits of china society of economic.
The temporal division of orogenic gold deposits into archean, proterozoic, and phanerozoic follows closely the. Orogenic gold deposits could be subdivided into two groups based on asand te contents of pyrite. Orogenictype coppergoldarsenicbismuth mineralization at. Typically formed early during the tectonic history of a greenstone belt. Oreforming fluid source of the orogenic gold deposit. Gold has historically been a key strategic commodity, and the study of gold deposit formation has long been investigated. Orogenic gold deposits bohlke, 1982 dominantly form in metamorphic rocks in the mid to shallow crust 515 km depth, at or above the brittleductile transition, in compressional settings that facilitate transfer of hot gold bearing fluids from deeper levels. Oct 05, 2020 the qiuling deposit, which is assigned to be an epizonal orogenic gold deposit chen et al.
Orogenic lode gold deposits formed from deepseated hydrothermal. These deposits formed from the archaean to phanerozoic at crustal depths of more than 4 km. I paid for a pro membership specifically to enable this feature. Richard goldfarb, kunfeng qiu china univeristy of geosciences, beijing, china, email. Orogenic gold deposits, or gold deposits in metamorphic rocks, are the spatially and temporally most widespread gold deposit type, defining important exploration targets in precambrian shields and in phanerozoic orogen ic belts. Because of this, it is suggested that the gold ores simply be classified as orogenic lode z. Gold occurs in a wide range of deposit types and settings, but this paper is concerned with deposits in which gold forms the main economic commodity or a coproduct. Transport and coarsening of gold nanoparticles in an.
Orogenic gold deposits are commonly vertically extensive, goldonly deposits that formed in broad thermal equilibrium with their wall rocks from. Detailed material for this globally important deposit type will be provided on tectonic and structural controls. Pdf parameters for the formation of orogenic gold deposits. To combine pdf files into a single pdf document is easier than it looks. Implications for exploration of worldclass and giant deposits david i. Phillips and powell 2011 either as the erosion of primary gold. Rethinking deposit models for phanerozoic orogenic gold deposits. Making a pdf file of a logo is surprisingly easy and is essential for most web designers. A remaining problem is whether to classify many intrusionrelated gold deposits within this group of z. Oreforming processes of the daqiao epizonal orogenic gold. A holistic model for the origin of orogenic gold deposits.
Orogenic gold deposit theresia lekatompessy academia. Early synsedimentary or synvolcanic models and hydrothermal meteoricfluid models are now invalid. Archean orogenic lode gold deposits are the result of large, complex mineralizing systems that have developed within many archean terrains. China produces about 500 t au per year and has stated reserves of approximately 10, 000 t au. A peculiar feature of these deposits is the association of gold with a variety of copper sulfides and the rare copper arsenides domeykite and koutekite which is atypical for orogenic type gold deposits. A pdf file is a portable document format file, developed by adobe systems. Existing published models for orogenic gold deposits are based heavily on the worldclass late archean deposits, especially those in the abitibi belt in canada and the yilgarn province in southwest australia. Poster session no registration fee for more information visit register and contact b l a c k f o r e s t a l p i n e s g a s t u d en t c h a p t e r keynote speakers orogenic gold workshop. Ophir district, randolph and montgomery counties, north. Importantly, the lodes may be located on one side of a cross fault, but not consistently displaced to the other side of the fault. This includes classic lowsulfidation mesozonal orogenic narrowvein lode gold deposits, represent by mines of the gold hill district gold hilltype and similar deposits along the gold hill fault zone moye, 2016. Auriferous intrusionrelated sheeted veins and orogenic. In particular, the forward looking statements in this document include among others those relating to the damang exploration target.
Diversity of gold deposits, geodynamics and conditions of. These deposits formed from the archaean to phanerozoic at crustal. Depending on the type of scanner you have, you might only be able to scan one page of a document at a time. A brief introduction to orogenic gold deposits gold fields. Instead, the unique temporal and spatial association of this deposit type with orogeny means that the vein systems are best termed orogenic gold deposits. By richard morochove, pcworld practical it insight from tony bradley todays best tech deals picked by pcworlds editors top deals.
Introduction to the orogenic gold mineral systems mineral. Orogenic gold mineralization in the qolqoleh deposit. Rethinking deposit models for phanerozoic orogenic gold. The saramacca gold deposit, a new orogenic gold discovery. Laminated quartz gold veins predate the formation of regional cleavage and stretching lineation in the wawa gold camp.
Pdf contrasting geochemistry of orogenic gold deposits. Magmatichydrothermal models fail because of the lack of consistent spatially associated granitic intrusions and inconsistent temporal relationships. Glendon and robbins aes alignments in the carolina terrane. Glendon and robbins aes alignments in the carolina terrane of. A holistic model for the origin of orogenic gold deposits and its. Metallogenesis of mesozoic orogenic gold deposit in. Pyrites from auas ores pyrite aste200 generally have pbbi5, sete5, pbsb 100 and major part of au is refractory inthe pyrite structure. In particular, the projects were acquired on the basis of past gold production at bleka from historic mining activities and the documentation of outcropping gold mineralization in orogenic style veins at vekselmyr. The saramacca gold deposit, a new orogenic gold discovery in. Gold mineralization is characterized by highgrade hydraulic breccias b and c ores that overprint an earlier tectonic breccia a ore. Orogenic gold deposits, or gold deposits in metamorphic rocks, are the. Receiving a subpoena that urges you to provide a statement for a deposition regarding a c.
The late timing of orogenic gold deposits within the structural evolution of the host orogen implies that any earlier structures may be mineralized and that the current structural geometry of the gold deposits is equivalent to that at the time of their formation provided that there has been no signi. Mineralizing systems are defined to include all geologic factors that control the generation and preservation of mineral deposits and emphasize the processes responsible for deposit formation at a variety of scales. Symbols indicate deposits, prospects or showings associated with orogenic, vmsrelated and other epigenetic gold systems. Jun 10, 2020 tourmaline from 18 orogenic gold deposits and districts, hosted in varied country rocks and metamorphic facies, was investigated by epma electron probe microanalyzer and laicpms laser ablationinductively coupled plasmamass spectrometry to establish discriminant geochemical features to constrain indicator mineral surveys for gold exploration. Geological and structural setting, age, and geochemistry of the. Focus paper structural geometry of orogenic gold deposits. This gold in 2000volume is organized around a classification of hypogene gold deposits that emphasizes their tectonic setting and relative time of formation compared to their host rocks and other gold deposit types e.
Luckily, there are lots of free and paid tools that can compress a pdf file in just a few easy steps. Pyrite compositions from vhms and orogenic au deposits in. Orogenic gold, or gold deposits in metamorphic rocks, and associated placer deposits, comprise. Pdf contrasting geochemistry of orogenic gold deposits in. Phillips and powell 2011 either as the erosion of primary gold deposits or from hydrothermal. The gold mineralization at wasamac has similar characteristics to both intrusionrelated gold systems and structurally controlled orogenic gold deposits. The findings of the study at grass valley have significant implications for the model for orogenic gold deposits, as the reconstruction of the paragenetic relationships provides evidence for the occurrence of two discrete events of gold introduction that occurred at different conditions during the evolution of the hydrothermal system. Metallogenesis of mesozoic orogenic gold deposit in bangong.
Orogenic gold deposits are associated with regionally metamorphosed terranes of middle archaeantertiary age goldfarb et al. The past producing bleka and vekselmyr orogenic gold. It was discovered in the 1930s and is characterized by highgrade ore zones with coarse gold. These deposits form in response to major orogenic events caused by accretion or changes in subduction direction or dip. Goldfarbb, liang zhangb aorebusters pty ltd, gwelup 6018, western australia, australia b state key laboratory of geological processes and mineral resources, china university of geosciences, beijing 83, china. A holistic model for the origin of orogenic gold deposits and. Chemical composition of tourmaline in orogenic gold deposits. Turbiditehosted, auriferous, orogenic quartz veins at the. Since the first official discovery of gold in 1852, gold has been mined in new zealand from three main types of deposits.
Mcqueen crc leme, australian national university, canberra, act 0200 and school of. Feb 26, 2019 orogenic gold deposits are the main source of gold for humanity. Veins and deposits record most or all the tectonic events that affected the greenstone belt. Some of the properties are available for option from prospectors or as joint ventures with junior mining companies. Debate on the genesis of socalled orogenic gold deposits 75% of gold recovered through history.
New deposits and perspectives black forest alpine sga student chapter in collaboration with nancy sga student chapter location. An oversized pdf file can be hard to send through email and may not upload onto certain file managers. These gold deposits are hosted by a variety of mafic igneous, felsic igneous, and sedimentary rocks in precambrian cratons and late neoproterozoicphanerozoic fold belts. Most veinhosted gold deposits form by fluid injections and fracture systems that evolve over time. The late timing of orogenic gold deposits within the structural evolution of the host orogen implies that any earlier structures may be mineralized and that the current structural geometry of the. These projects are greenstonehosted gold systems in southern norway see figure 1. In the above orogens, isotopegeochronological estimates suggest that the ore deposits were formed late in the orogenic history or even after orogeny had demonstrably ended 3,4,10,11.
Auriferous intrusionrelated sheeted veins and orogenic veins. Once youve done it, youll be able to easily send the logos you create to clients, make them available for download, or attach them to emails in a fo. Sawyerkeystone trend of auagas deposits in randolph county. Orogenic gold deposits are gold lodes within and associated with metamorphic belts 1,7,8,9. Models and exploration methods for major gold deposit types. If your scanner saves files as pdf portbale document format files, the potential exists to merge the individual files into one doc. Metallogenesis of mesozoic orogenic gold deposit in bangongnujiang suture belt. Orogenic gold deposits account for an estimated 75% of the gold extracted by humans phillips 20, including the tonnage of witwatersrand, the worlds largest district. In contrast to typical orogenic gold deposits displaying textures indicating brittle. Hydrothermal and structural crosscutting relationships at wasamac indicate that a structurally controlled hydrothermal event overprinted earlier potassic magmatichydrothermal alteration. The daqiao gold deposit is hosted in organicrich triassic pumpellyiteactinolite facies metamorphosed turbidites in the west qinling orogen, central china.
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