His major expertise is in the area of the geochemistry and geology of ore deposits, with emphasis on phanerozoic orogenic gold. Orogenic lode gold deposits of middle archean to tertiary age are arguably the predominant gold deposit type in metamorphic belts, and include several giant 250 t au and numerous world. How then do scientists reckon geologic time, and why do they. University of british columbia abstract geophysical inversion methods offer an opportunity to remotely explore for archean orogenic gold deposits. Fluid inclusion and hospb isotope geochemistry of the. Common or evolving fluid and metal sources through time, abstract \circledc 2015. According to, there are important factors regarding orogenic gold deposits definition after, such as the. Gsf giant gold provinces sga student chapter prague. Castle and propose an orogenic model for the genesis of this unique deposit. If it continues, it will eventually form extremely high mountains in the mediterranean. Carlintype gold deposits in nevada, usa, although characterized by aqueouscarbonic.
Timing, nature and characteristics of orogenic gold. These deposits form in response to major orogenic events caused by accretion or changes in subduction direction or dip. Distribution of orogenic gold deposits in relation to. Even within this single style of mineralisation, different resource evaluation approaches are needed for each orebody. Geology, geodynamics and orogenic gold prospectivity. Distribution of orogenic gold deposits in relation to fault zones and gravity gradients. Orogenic gold mineralization in the qolqoleh deposit. Geological survey, where he has been employed for more than 32 years. If all orogenic gold deposits define a coherent mineral system, there are only. Claiming your author page allows you to personalize the information displayed and manage publications all current information on this profile has been aggregated automatically from publisher and metadata sources.
The qolqoleh gold deposit is located in the northwestern part of the sanandai. Geological survey, box 25046, ms 964, denver federal center, denver, co 802250046, usa b state key laboratory of geological processes and mineral resources, school of earth sciences and resources, china university of geosciences, beijing 83, china. A new perspective on the relationship between orogenic gold mineralization and crustal shearing is presented in this case study on the gold deposits along ailaoshan. Carbonic fluid inclusions hydrogeological model of the crust. Phillips, 20, continues largely because it is difficult to reliably identify the source of gold. Orogenic gold deposits form in accretionary and collisional orogenic belts dominated by extrusion, and strikeslip deformation is associated with relatively lowstress areas, such as secondary fractures 1, 2. The jiaodong peninsula in eastern china is the third largest gold mining area and one of the most important orogenic gold provinces in the world. Orogenic gold mineralization of the eastern cordilleran gold belt, british columbia. Anatomy of an orogenic gold hydrothermal system with the key parameters. Jul 12, 2018 zak k, durisova j, strnad l, golias v, leach d, snee lw, viets j, stein hj 1998a the evolution of pressure, temperature and composition of hydrothermal fluids in a regional shear zone during retrograde metamorphism, regional uplift, and cooling. The sinistral ductile shearing along the zone occurred from ca. Greenstonesedimentary rock sequences now exposed in interior australia, northwestern africa.
Orogenic gold deposits in midto subgreenschist facies metamorphic belts of the neoarchean eastern goldfields superterrane egst, yilgarn craton, can be subdivided into proximal oxidized intrusionrelated and distal sourcerelated classes, based on the key silicate mineral muscovite, biotite, actinolite, albite of the proximal alteration zone. Battery metals, orogenic gold, hydrothermal, ore deposits, cobaltite. An assumption built into this analysis is that the pattern of structures we currently see at this regional scale of analysis also existed at the time of mineralization. Physicochemical parameters and geochemical features of oreforming fluids for orogenic gold deposits throughout geological time. Gold mineralization in the qolqoleh deposit is almost entirely confined to a series of steeply dipping ductilebrittle shear zones generated during late cretaceoustertiary continental collision between the afro. Together with event was the enrichment of gold related to mountainbuilding process profoundly refers to. Ensure your research is discoverable on semantic scholar. Red river shear zone arsz, southeastern tibetan plateau. Geoscience bc report 201715 1 orogenic gold mineralization of the eastern cordilleran gold belt, british columbia. The inherent variation caused by geological complexity within the. Within the mining industry, all phases of the operation are dependent on the resource model.
The sizhuang gold deposit, located in northwestern jiaodong, is characterized by orebodies of different occurrences. As all of the deposits studied in this thesis are classified as archaean orogenic gold deposits, the specific conclusions may only be pertinent to this style of mineralisation. The conceptual representation is based on a systemic analysis approach, where the formation of an orogenic gold deposit, from bottom to top and in time, requires a succession of processes for providing key parameters. The mediterranean ridge is the result of the african plate subducting sliding underneath the eurasian plate and other smaller microplates. Most orogenic gold deposits are formed under greenschist facies metamorphic conditions 36. Predictive targeting in australian orogenicgold systems. Crowe a comparison of australian and global examples. Parameters for the formation of orogenic gold deposits. This vast span of time, called geologic time by earth scientists, is difficult to comprehend in the familiar time units of months and years, or even centuries.
Orogenic gold deposits have formed over more than 3 billion years of earths history, episodically during the middle archean to younger precambrian, and continuously throughout. As all of the deposits studied in this thesis are classified as archaean orogenic. Geologic map of the sheep creek gold camp, after matthews 1953. Models and exploration methods for major gold deposit types. Gold has historically been a key strategic commodity, and the study of gold deposit formation has long been investigated. Predictive targeting in australian orogenicgold systems at the deposit to district scale using numerical modelling. Structural ore controls in the cariboo 093ah, cassiar 104p and sheep creek 082f mining districts. The recent increased applicability of global paleoreconstructions, coupled with improved geochronology from most of the worlds major gold camps, allows for an improved understanding of the distribution pattern of orogenic gold in space and time.
For orogenic gold deposits, the giants appear to have. Composition and origin of fluids associated with lode gold deposits. We invite contributions on all aspects of geochemistry applied to these intriguing deposits. Orogenic gold deposits represent by far the most economically important primary gold mineralisation in victoria, accounting for almost all primary gold production more than 1100 tonnes and include most of the known and potential resources. Minerals free fulltext geostatistical determination. The time of gold mineralization is recorded in pyrite by a chemically distinct growth zone containing arsenic, and nickel and cobalt zones with.
Mesoarchaean lode gold deposits despite contrasting fluidrock. Metamorphic belts are complex regions where accretion or collision has added to, or thickened, continental crust. Mesothermal gold deposits form half way up through the rise of the melt from the deep crust to the surface usually at a depth of less than 10 km but greater than 1 km. Structural ore controls in the cariboo 093ah, cassiar. Fluid inclusion and hospb isotope geochemistry of the yuka. Scribd is the worlds largest social reading and publishing site. The focus of the mining operation is a model, which is often based on incomplete or flawed data. A scaleintegrated exploration model for orogenic gold deposits. Pdf orogenic gold deposits have formed over more than 3 billion years of earths history, episodically during the middle archean to younger. Schematic cross secti on showing the key geologic elements of the main gold systems and their crustal depths of emplacement. The spacetime diagram showing the geodynamic synthesis of the birimian supergroup, ghana, west africa. Gold deposits in polydeformed metasedimentary rocks. Pdf distinguishing intrusionrelated from orogenic gold.
Aspects of resource geology in archaean orogenic gold. The jiaodong peninsula in eastern china is the third largest goldmining area and one of the most important orogenic gold provinces in the world. Bsc hons university of wales, cardiff msc university of wales, cardiff in december 2005. Distribution of orogenic gold deposits in relation to fault.
Orogenic gold deposits have formed over more than 3 billion years of earth s history, episodically during the middle archean to younger precambrian, and continuously throughout the phanerozoic. A rare phanerozoic amphibolitehosted gold deposit at danba. The term mesothermal veins is really a sack term, referring simply to the depth formation. Chronology of the kasperske hory orogenic gold deposit. Orogenic gold deposits have formed over more than 3 billion years of earths history, episodically during the middle.
Santoshb,c,d, acentre for exploration targeting, uwa, crawley 6009, wa, australia b centre for tectonics resources and exploration, department of earth sciences, university of adelaide, sa 5005, australia c state key laboratory of geological processes and mineral. Deposits can range from single small quartz veins to large and commonly highgrade, faultshear controlled systems containing in excess of 25 million ounces of gold. Distinguishing intrusionrelated from orogenic gold systems. Vein, stockwork and disseminated gold deposits are very common within orogenic belts, providing a large percentage of total historical world and australian gold production.
A rare phanerozoic amphibolitehosted gold deposit at. Goldrich deposits can be formed at all stages of orogen evolution, so that evolving metamorphic belts contain diverse gold deposit types that may be juxtaposed or overprint each other. 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. Groves di, goldfarb rj, gebremariam m, hagemann sg, robert f 1998 orogenic gold deposits.
Archean orogenic lode gold deposits are the result of large, complex mineralizing systems that have developed within many archean terrains. Debate on the genesis of socalled orogenic gold deposits 75% of gold recovered through history. Timing, nature and characteristics of orogenic gold deposits. The orogenic gold deposits in southeast guizhou are an important. Orogenic gold deposits have formed over more than 3 billion. Victoria hosts one of the worlds largest orogenic gold provinces. Relationship between orogenic gold mineralization and. Minerals free fulltext geostatistical determination of. Introduction to orogenic gold deposits investing news network november 23rd, 2014 orogenic deposits are the source of much of the worlds gold.
Using orogenic gold deposits as an example, geostatistical techniques are. Rich is a senior research geologist with the minerals program of the u. Pdf a proposed revision of the orogenic gold class. The vast majority of orogenic gold excluding witwatersrand, south africa is from three periods in geologic time. Abdusalam 1, marc anselme kamga 2, ernest serge djou 2. Mesothermal and greenstone gold deposits aka orogenic. This cited by count includes citations to the following articles in scholar. Optimizing geophysical inversions for archean orogenic gold. Diversity of gold deposits, geodynamics and conditions of formation. Geologic time the earth is very old 412 billion years or more according to recent estimates. Teale2 1 pmdcrc, school of geosciences, monash university, vic 3800, australia. Aspects of resource geology in archaean orogenic gold deposits. There are few wellpreserved blocks of middle archean midcrustal rocks with. Models and exploration methods for major gold deposit types robert, f.
The third global episode of orogenic goldvein formation occurred at ca. It is proposed that the orogenic event that gave rise to carlow castle is related to the initial assembly of the pilbara craton during the archean. Age and metal source of orogenic gold deposits in southeast. Geology, geochemistry, and genesis of orogenic goldantimony. The andean orogeny has been occurring for the past 200 million years, although the andes have only arisen in the past 65 million years. Cassidy proterozoic lode gold and ironcoppergold deposits. On the source of orogenic gold geology geoscienceworld. The third global episode of orogenic gold vein formation occurred at ca. Optimizing geophysical inversions for archean orogenic gold settings mitchinson, d. Gold in 2000 contents gold in 2000an introduction s.
The ones marked may be different from the article in the profile. An orebody is commonly a poorly understood geological entity, and the resource model is generated from samples taken from this orebody. Diversity of gold deposits, geodynamics and conditions of. These include gold dominated orogenic and intrusionrelated deposits, but also particularly controversial gold deposits with atypical metal associations. This partly explains the high level of controversy on the origin of some deposit types. Ore shoots plunging in specific orientations are a ubiquitous feature of the jiaodong lode deposits. Minerals free fulltext physicochemical parameters and. Orogenic gold deposits of all ages, from paleoarchean to. Geologic cycle free download as powerpoint presentation. Geology, geochemistry, and genesis of orogenic gold. Orogenic gold deposits have formed over more than 3 billion years of earths history, episodically during the middle archean to younger precambrian, and continuously throughout the phanerozoic. When compared to other orogenic gold provinces goldfarb et al.
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