The cuiu cuiu district hosts vein and shear zone gold mineralization within a proterozoic granitic basement. The baguamiao gold deposit in fengxian county of shaanxi province is located in fengtai polymetallic ore concentration area in the orogenic belt of west qinling mountain. Schematic model of a highangle reverse shear zone, with horizontal extensional veins block of australia, where gold mineralization is controlled by the associated with the steep fault. The shear zonerelated gold mineralization at the turmalina deposit, quadrilatero ferrifero, brazil. Shear zones, gold mineralization and structural history in the. Atypical gold mineralization in an orogenic settingthe bohaun. It is a typical gold deposit under the control of brittleductile shear zone. High grade gold mineralization in this drillhole is hosted by a laminated shear vein that yielded 2. Gold mineralization in highgrade metamorphic shear zones of. Mineral deposits are invariably associated with deformational structures in the leonora district.
An example for the subduction zone setting is the japan median tectonic line. Tropicana is a world class gold deposit on the margin of the yilgarn craton gold was precipitated in the archean at greenschist facies within granulite gneiss hosts mineralization was governed by fluid flow in a network of shear zones the shear zones and ore bodies reflect the geometry of the host gneisses. This thesis presents a structural, kinematic, and hydrothermal fluid investigation of the murray shear zone with implications for gold mineralization. Gold mineralization is confined to a system of hightemperature mylonite zones characterized by. Halli to east of honnemardi, roughly parallel to stratigraphic units. In this example, the angle of internal friction fis308. Several outcrops of the mineralized shear zone system have been mapped along the main mineralized structures, including lenses 2, 5, and 19 figure 2. The most endowed shear zone blsz strikes between n20o30ow, and cuts through a. The addition of graphite to flat shear zones causes an increase in. Structural and lithological study of gold mineralization in. Technical report and mineral resource and reserve update for. The geochemical results of this soil sampling program returned with high grade gold values, with. Pdf shear zonehosted gold mineralization in the late. Archaean gold deposits in the western australian shield, as in other cratons, are heterogeneously distributed, with both poorly and well mineralized greenstone.
The reasons for this difference can be found in the relative timing, distribution and styles of deforma. Technical report and mineral resource and reserve update. Shear zones, also sometimes called ductile faults, are intensely strained. For atud, elsid and atalla area, the gold is hosted in nesw veins parallel to a shallow shear zone but at the conjugate point with a deepseated nwse shear zone. Mineralization styles include broad lower grade stockworkstyle zones typically grading 12gt au, and more discrete highgrade veins which can run to well in excess of several ounces per ton. A regional structural model for gold mineralization in the. Pdf the shear zonerelated gold mineralization at the. However, the largest deposits are hosted by much smaller fault structures. T1 shear zones, gold mineralization and structural history in the leonora district, eastern goldfields province, western australia au williams, p.
Winshear gold discovers multiple mineralized zones within a. The lannigou deposit, the largest sedimentary rockhosted gold orebody shown on figs. The orebodies are controlled by wnwesetrending shear zones, associated with. The term mesothermal veins is really a sack term, referring simply to the depth formation.
Shear zones, fault networks, and archean gold geoscienceworld. These greenstone beltscale shear zones lack both gold deposits and gold related alteration. Technical report and mineral resource and reserve update for the nzema gold mine, ghana, west africa page i nzema mine april 2, 20 1 summary the nzema gold mine nzema is located in the western region of ghana, approximately 280km west of the capital, accra, and less than 20km from the coast at essiama. Jan 30, 2020 drillhole bs19002, collared 100 m along strike to the east of bs19001 at the bidou shear target, intersected multiple zones of gold mineralization, highlighted by a shear vein that yielded 2. Structural controls on gold mineralization on the margin of.
Field and microscopic observations suggest the presence of several types of quartz veins and veinlets in the mine area. Lode gold and mesothermal deposits these are quartz lode deposits formed in fault and shear system at crustal level within and above the brittleductile transition zone, at depths of 312km and temperatures from 200400oc. Winshear gold discovers multiple mineralized zones within. Deformation and gold mineralisation of the archaean pilbara. Targeting gold deposits along a regional shear zone. According to the new tectonic model, we propose the following model for gold formation nonstratabound. A microstructural study of musselwhite mine and hammond. The geometry of mineral deposits can give insights into. The shear zonerelated gold mineralization at the mafiadoc. Ductile shear zone hosted mesothermal gold mineralization of the okote area is located in southern ethiopia. Shear zone hosted gold mineralization of the arabian nubian shield. Preliminary structural study of the goldbearing shear. The hydrothermal gold deposit s cramped to shear zones, 2nd generation quartz veins. Petrographic characterization of hydrothermal gold deposits in adi.
The rocks are commonly metasomatized and often display retrograde metamorphism assemblage. An intense fractured or shear zone is a favorable structure to trap mineralization banerjee and ghosh, 1997. Metallurgical testwork on 76 samples of all material types returned over 90% recovery. The two sets of ore bodies formed synchronously from hydrothermal. In addition to this, potential areas of gold mineralization could be defined from anomalous values of li and w in close proximity to the bulangamirwa shear zone represented by high values of sb and as and a number of targets could be. Kolb a thesis submitted in partial fulfillment of the requirements for the degree of. Pdf although gold production from orogenic deposits in the. Many large archaean epigenetic gold deposits show a broad spatial relationship to regional lineaments in greenstone belts, although in detail they are sited in subsidiary brittleductile fault structures. Lode gold ore bodies at renco mine, in the limpopo belt, zimbabwe, occur as siliceous breccias and mylonites within amphibolite facies shear zones that dip either gently or steeply. A regional structural model for gold mineralization in the southern part of the archean superior province, united states by p.
Control of shearzoneinduced pressure fluctuations on gold. The main differences between the shear zones, with direct bearing on gold endowment, are their metamorphic facies, variety of rock types, and shear zone orientation. Evidence exists in support of shear zone hosted gold mineralization that coincides with established models for wellknown and profitable gold deposits of other archean greenstone terrains. Soil sampling was conducted in several campaigns in a 2km x 2. The field trip focused into western part of the sirkka shear zone and to the hanhimaa shear zone. Mineralogical characteristic of ductilebrittle shear zone in. The structure of shearrelated, veintype gold deposits. Preliminary structural study of the goldbearing shear zone. A shear zone of the thrust type is the moine thrust in northwestern scotland. The visited excursion localities are shown in figure 1. Pdf characteristics and genesis of shear zonerelated gold. It was necessary to make a detailed mapping in order to understand and assess the target. The ferrishaggarty mine in the central sierra madre was one of the worlds more important copper deposits during the early 1900s. The discovery of a 250m wide shear zone hosting gold mineralization at gaban is very encouraging.
Their late dextral d 5 kinematics is consistent with movement on the regional kurrana shear zone, which marks the southern margin of the belt. Gold mineralization within contactmetamorphic and shear. Study of these individual districts demonstrates the variability and importance of structural control on gold miner. Halli is located along the central shear zone of chitradurga schist belt, extending from west of gonur, through r. Sep 26, 2019 extending shear zone appears to be dipping 600700 to the west. Photograph of flat, ductilebrittle deformation shear zone in the gaolong gold deposits looking to northwest. Boulderlefroy shear zone blsz, one of the richest orogenic gold shear systems in the world.
Pdf turmalina is an important orogenic gold deposit located in the nw region of the quadrilatero ferrifero. Deposits may have a vertical extent of up to 2km, and lack pronounced zoning. This section compares them, focusing particularly on the controls on gold mineralization. Shear zones and deformation mechanisms introduction. Structural and lithological study of gold mineralization. Is the disseminated alteration and au mineralization due to the lynx head fault. Technical report and mineral resource and reserve update for the nzema gold mine, ghana, west africa page iii nzema mine april 2, 20 at aliva and the mineralization in other deposits in this area are nonrefractory. Evidence exists in support of shear zonehosted gold mineralization that coincides with established models for wellknown and profitable gold deposits of other archean greenstone terrains. Shear zones and highstrain zones d 5 control the middle creek line fig. These greenstone beltscale shear zones lack both gold deposits and goldrelated alteration. The deposit is hosted in an archean greenstone belt composed of orthoamphibolites and pelites with interleaved tuffs metamorphosed under amphibolite facies conditions and intruded by a granite stock.
The first part is based on the detailed mapping of the bena and bakolobi target. Fieldwork during the 2000 field season continued the 1999 work and began, through thesis projects, investigations of pastproducing gold deposits associated with the jsz and agassiz metallotect. Shear zones, fault networks, and archean gold geology. Other sedimentary rockhosted gold deposits surrounding this fold are the bannian, yangyuo, begao, and luodong. The results continue to define and expand the gold endowed system with gold mineralization now identified over 0 metres of strike by up to 70 metres width and. The gold deposits occur along an anastomosing system of veins and shear zones that extends from the chesapeake and ohio canal near the east end of widewater northward to the mouth of cool spring branch, a distance of about 2. Day abstract the canadian segment of the archean superior province is a major world source of lode gold. The termination of all types of shear zones pose complex compatibility problems, some solutions are suggested. Gold mineralization in highgrade metamorphic shear zones.
Deformation and gold mineralisation of the archaean. A good example of this phenomenon is the granny smith gold deposit, in the yilgarn fig. Structural setting of gold deposit the clarence stream gold deposit is localized along the sawyer brook fault, a regional, highstrain zone marking the approximate boundary between the new river and st. Gold mineralization relates to a system of quartz veins along a nnw to nwtrending shear zone, cutting through successions of garnetbiotite schist with subordinate intercalations of metasiltstone and metagreywacke. While carrying out a regional structural analysis of deformation band shear zones in southern utah, davis 1994, 1996 discovered welldeveloped outcrop and mapscale riedel shear zones in outcrops of navajo sandstone jurassic. Gold mineralization is confined to a system of hightemperature mylonite zones characterized by two distinct geometries. The second part is to determine the term and the lithostructural control of gold mineralization. Shear zones of the transform type are the san andreas fault in california, and the alpine fault in new zealand. Shear zones, fault networks, and archean gold julian r. Pdf crustalscale shear zones and their significance to.
Structural, kinematic, and hydrothermal fluid investigation. Geology of sedimentary rockhosted gold deposits the depositscale geologic. This is a pdf file of an unedited manuscript that has been accepted for publication. The detachment shear zone be tween the upper and lower plate is composed of my 412 zhang, nesbitt, and muehlenbachs. Shear zonehosted gold mineralization in the late proterozoic. During phase 1 of the 2019 drill program, one followup hole was drilled at crawford to test for the depth extension of the shear zone and gold mineralization intersected in pen18016. Pdf the shear zonerelated gold mineralization at the turmalina. Most mineralized zones occur within, or are spatially associated with shear zones, especially shear zones in larger systems of intersecting shear zone sets. The aim of the excursion was rather to get an overview and impression of gold mineralization in this area, to discuss existing models, and to express ideas and questions that may serve as an im.
Hydrothermal alteration and structural control on gold. Structural controls on gold mineralization on the margin. Ductile shear deformation and gold mineralization in the. The ollachea projects feasibility study dated november 29, 2012, is authored by amec australia pty ltd.
Geochemistry, alteration, and genesis of gold mineralization in the okote area. Fracturecontrolled, copperdominated base metal deposits typify mineralization within the shear zone. The eastwesttrending cregganbaun shear zone extends through the. Characteristics and genesis of shear zone related gold mineralization in egypt. Panafrican shear zonehosted gold mineralization in the. Shear zone jsz and the relationship between the shear zone and the associated gold mineralization. Hydrothermal alteration and structural control on gold deposition in the hanhimaa shear zone and western part of the sirkka line. In addition to this, potential areas of gold mineralization could be defined from anomalous values of li and w in close proximity to the bulangamirwa shear zone represented by. Abu marawat, eastern desert, bif, gold mineralization, gossans, listwanites, shear zone, structural analysis. The deformation history of hsz and its correlation with the gold mineralization are problematic. The shear zone passes through west pitthe, which is in production. The shear zone related gold mineralization at the turmalina deposit, quadrilatero ferrifero, brazil. The larger, lower grade bodies, which may have formed by coalescence, are elongate perpendicular to these directions. 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.
May 16, 2018 turmalina is an important orogenic gold deposit located in the nw region of the quadrilatero ferrifero. Orogenic gold deposits are typified by quartzcarbonatedominant vein systems. Kinematic history of the boulderlefroy shear zone system and. Structural controls on gold mineralization on the margin of the yilgarn craton, albany.
Damaged goods deformation fabrics in a goldbearing. Mikulski gold mineralization within contactmetamorphic and shear zones in the zloty jar quarrythe zloty stok asau deposit area sudetes mineral paragenesis of gold mineralization in the zloty jar quarry has been formed during three separated stages. Characteristics and genesis of shear zonerelated gold. Characteristics and controls of gold mineralization in the brunne. Mesothermal and greenstone gold deposits aka orogenic.
Introduction since the last century the exploration for gold deposits as well as bif in. Modelling of structural and lithological controls on mobility of fluids. This significant deposit with accessory gold and some silver was developed in a sheared metaconglomerate. The shear zonerelated gold mineralization at the turmalina. Structural control on banded iron formation bif and gold. Crustalscale shear zones and their significance to archaean gold. A microstructural study of musselwhite mine and hammond reef shear zone hosted gold deposits by maura j. Shear zones, gold mineralization and structural history in. Gold mineralization in the okanagan valley, southern british columbia. Previous interpretations of the shear zones as part of a linked system, as cratonscale terrane boundaries, or as crustalscale pathways for gold mineralizing fluids, all appear. Three deformation events are recognized in the turmalina gold.
A synthesis of shear zone geometry in regions of crystal contraction and crustal extensions is made, and ideas on how deep level ductile shear zones. The hetai goldfield, located at the northern edge of the yunkai massif in south china, is a significant gold deposit hosted within the hetai ductile shear zone hsz. In this section we will look at the most highly strained rocks in the lithosphere those found in shear zones. This major shear zone is a late pan african dextral strikeslip fault of the pharusian belt of the tuareg shield algeria. However, gold production in the btz has only been one order of magnitude smaller than that of the blsz. Pdf characteristics and genesis of shear zonerelated. The renco gold mine in southern zimbabwe is the only known major gold deposit in the granulite facies terrane of the northern marginal zone of the late archean to midproterozoic limpopo belt. Lefroy shear zone as a major sinistral wrench structure as evidenced by the 12km apparent sinistral displacement of geokinematic history of the boulderlefroy shear zone system and controls on associated gold mineralization, yilgarn craton, western australia r. Gold mineralization is widely assumed to be associated with regional scale shear zones. Controls on gold mineralization associated with the. Kinematic history of the boulderlefroy shear zone system. Gold mineralization in the okanagan valley, southern.
Shear zones, gold mineralization and structural history in the leonora district, eastern goldfields province, western australia. Hill prospect, located along the gurney mine shear zone. Example of kuroko type gold mineralization in the west of iran. The full report can be found on mineras website and sedar. Previous interpretations of the shear zones as part of a linked system, as cratonscale terrane boundaries, or as crustalscale pathways for goldmineralizing fluids, all appear equivocal.
Nature of fluid inclusion of gold mineralization at barika. Three ns striking ductile shear zones, with different intensity of shearing and hydrothermal alteration, cut the mafic rocks. Gold mineralization in the west hoggar shear zone, algeria. Mineralization at the two sites is associated with. The amesmessa gold prospect is located along a vertical nstrending crustalscale ductile shear zone.