The Structure of Ore-controlling Strain and Stress Fields in the Shangzhuang Gold Deposit in Shandong Province,China

The Shangzhuang altered-rock type gold ore deposit is located in the middle segment of and controlled by the Wang＇ershan fault zone in the northwestern part of the Jiaodong gold province, China. The deformation evolution, the structure of strain and stress fields and its ore-controlling effect in the Shangzhuang deposit are discussed in this paper. It is revealed that the deformation evolution has mainly undergone four phases： the early ductile deformation, the second NE-striking horizontal simple shear, the third NE-striking compression-shear and the final NW-striking compression. The mineralization happened during the third stage in which the maximum principal stress gradually transited from NE to NW. The 3-D numerical simulations of the stress field show that, on the condition that the maximum principal stress is NE-striking, the fracture development in the fault zone is favored, while when the maximum principal stress is NW-striking, the fault zone is relatively extensional and it is suitable for the influx and emplacement of ore-forming fluids. The compression-shear strain field during the mineralization is characterized by the λ-type structure, the positive flower structure, etc. Orebodies are mostly equidistantly located in the dilatational spaces, which are distributed in the integral compressional circumstances. And the dilatational spaces are developed where the fault attitude changes or shear joint systems develop. In the overall compression-shear stress field, the strain field bears self-similarity at multiple scales, including the orebody, ore deposit and orefield. The selfsimilarity of the structure comprises the subequidistant distribution of fractures at the same scale and the similar shape of the fractures at various scales. Yet, due to the special geological structure, the orebodies are mostly located in the hanging wall in the Shangzhuang deposit, which is different from most deposits in the Jiaodong gold province. Analyses of the ore-controlling stress and strain fields in the deposit provide an important basis for deposit seeking.

Electronic structure and flotability of gold-bearing pyrite:A density functional theory study

Various incorporation of Au in pyrite and its effects on the geometrical structure,electronic structure and flotability of pyrite were theoretically investigated and fully discussed by performing density functional theory(DFT).The calculated incorporation energy shows that gold would most likely exist in pyrite via incorporating into interstitial lattice sites in the absence of As impurity.As a result of incorporated Au,the covalence levels of the S—Fe and S—S bonds are changed,and the tonicity of Au—S bonds and antibonding of Au—Fe bonds are found to form in the pyrite,which would change the natural flotability of pyrite.The Au impurity energy levels are introduced into the energy band and result in the transformation of pyrite semiconductivity type.The calculated band-gap value suggests that the incorporated Au significantly decreases pyrite semiconductivity level,which enhances the formation and the adsorption stability of dixanthogen during pyrite flotation.The DOS results reveal that the stability and depression difficulty level of pyrites increases in the following order:Fe_(32)S_(63)As<Fe_(32)S_(64)<Fe_(32)S_(63)As Au<Fe_(32)S_(64)Au.

Analysis of the Ore-Controlling Structure of Ductile Shear Zone Type Gold Deposit in Southern Beishan Area, Gansu, Northwest China

The ductile shear zone-type gold deposit is a kind that both the ore-forming mechanism and ore-controlling factors are closely related to the ductile shear zone and its evolution. Ductile shear zone develops in Beishan area, Gansu of Northwest China, and develops especially well in the south belt. The controls of the ductile shear zone on gold deposits are as follows. （1） The regional distribution of gold deposits （and gold spots） is controlled by the ductile shear zone. （2） The ductile-brittle shear zone is formed in the evolution process of ductile shear zone and both are only ore-bearing structures and control the shape, attitude, scale, and distribution of mineralization zones and ore-bodies. （3） Compresso-shear ductile deformation results in that the main kind of gold mineralization is altered mylonite type and the main alteralization is metasomatic. （4） Ore-bearing fracture systems are mainly P-type ones, some D-type and R-type ones, but only individual R＇-type and T-type ones. （5） Dynamic differen- tiation and dynamic metamorphic hydrothermal solution resulting from ductile deformation is one of the sources of ore-forming fluid of gold mineralization, and this is identical with that ore-forming materials are mainly from metamorphic rocks, and ore-forming fluid is mainly composed of metamorphic water, and with the fluid inclusion and geo-chemical characteristics of the deposit. （6） There is a negative correlation between the gold abundance and susceptibility anlsotropy （P） of the altered mylonlte samples from the deposit, which shows that the gold mineralization is slightly later than the structural deformation. All above further expound the ore-forming model of the ductile shear zone type of gold deposits.

Interpretation of Geological Structures Hosting Potential Gold Deposits in the Konongo Gold Mine Using Airborne Magnetic, Electromagnetic and Radiometric Datasets

The renewed interest in the reactivation of the defunct National Konongo Gold Mine located in the Ashanti Greenstone Belt, calls for a further probe into its geology and the associated mineral hosting structures to discover its mineralization potential. In order to achieve this, airborne magnetic, radiometric and electromagnetic datasets were interpreted to determine the potential gold hosting features in the studied area. The results show the area to consist of the metasediment, the metavolcanic, Tartwaian Formation and their associated granitoids. Results also show that the Tarkwaian sediments, observed largely in the north-eastern side of the site;widen out substantially and truncate in the south. The analysis of the structure lineaments using a rose diagram reveals three main tectonic structures trending in N-S, NNW-SSE, and third the structure trending in the NNE-SSW to NE-SW directions in the area. The dominant structures in the area, form 90% of all the delineated structures and trend in the NE-SW and NNE-SSW direction with the remaining 10% trending in the N-S and NNW-SSE. These structures are associated with the major shear and fracture zones located mainly at the contact between the basin sediments and volcanic belt and also associated with the Tarkwaian Formation. The mapped potential gold mineralization zones located mainly at the contact between the metasediment and the metavolcanic units of the Birimian Supergroup, as well as the Tarkwaian Formation, were mapped by integrating the structures, alteration zones as well as the complex dyke systems. This paper delineates the prominent geological structures with the potential of hosting economic gold mineralization in and around the Konongo Gold Mine.

An SCF－MS－Xα Study of the Electronic Structures of Binuclear and Trinuclear Gold（Ⅰ） Compounds

The SCF-Xα-SW molecular orbital calculations were carried out on the modelcompounds of binuclear and trinuclear gold(Ⅰ)using starting potential of Au atom and the Watson sphere.The energy level order of the frontier orbital of a binuclear gold model compound is in agreement with the experimental result.The calculated ionization potential of the binuclear model compound is consistent well with the photoelectron spectrum of Au (Me)(PMe_3).The metal-metal interactions are discussed.The calculated electronic absorption spectra of binuclear and trinuclear gold(Ⅰ)are basically in agreement with experimental results.

Analysis of Ore-controlling Structure in the Qifengcha-Detiangou Gold Deposit,Huairou County,Beijing

The Qifengcha-Detiangou gold deposit is a medium-sized deposit recently found in Huairou County, Beijing. It belongs to the altered mylonite type with superimposed quartz vein type and is related to the early Yanshanian magmatic activity. Characterized by multiperiodic activity, the NE-trending Qifengcha fault is a regional ore-controlling structure in the area, and gold mineralization develops only in its southeastern part. Meanwhile, gold mineralization is controlled by the Yunmengshan metamorphic core complex. The nearly N-S- and E-W-trending low-angle detachment faults, reformed by the Qifengcha fault in the northwestern part of the core complex, are the main ore-bearing faults. All discovered gold deposits are located within an area 1.5–4.0 km away from the boundary of the upwelling centre. The N-S- (NNE-) and E-W-trending ore-bearing faults are ductile-brittle structural zones developing in shallow positions and subjected mainly to compressive deformation. The structural ore-controlling effects are as follows. (1) The attitude, shape, and distribution of gold orebodies are controlled by faults. (2) There is a negative correlation between the gold abundance and the magnetic anisotropy (P) of the altered mylonite samples from the deposit, which shows that the gold mineralization is later than the structural deformation. (3) Quartz vein type mineralization is superimposed on altered mylonite type mineralization. (4) In mineralized mylonite, the stronger the ductile shear deformation, the easier the late-stage gold mineralization to occur and the higher the gold abundance. The richest gold mineralization occurs only around the centre of the fault subjected to the strongest deformation.

Structure and Luminescence Property of a Linear Tetranuclear Gold(Ⅰ)-thiolate Complex through Au-Au Interaction

The synthesis,structure and luminescent property of a tetranuclear gold（Ⅰ）complex with doubly bridging diethyldithiocarbamate（Et2dtc）and 1,1-bis（diphenylphosphino）ethene（（Ph2P）2C=CH2）are described.The complex crystallizes in monoclinic space group C2/c with a=26.785（7）,b=25.654（6）,c=12.277（3）A,β=106.879（5）°,V=8073（4）A^3,Z=8,C31H32Au2F6NO3P2S2Sb,Mr=1222.32,Dc=2.011 g/cm^3,F（000）=4592,Rint=0.0529,T=293（2）K,μ=8.157 mm^（-1）,the final R=0.0464 and wR=0.1444 for 5804 observed reflections with I〉2σ（Ⅰ）.The intramolecular and intermolecular Au¨Au distances are 2.8670（9）and 3.2367（9）A,respectively.Weak emission appears at 517 nm at room temperature in the solid state.

The geology, structure and mineralisation of the Oyu Tolgoi porphyry copper-gold-molybdenum deposits, Mongolia： A review

The Oyu Tolgoi cluster of seven porphyry Cu-Au-Mo deposits in southern Mongolia,define a narrow,linear,12 km long,almost continuously mineralised trend,which contains in excess of 42 Mt of Cu and1850 t of Au,and is among the largest high grade porphyry Cu-Au deposits in the world.These deposits lie within the Gurvansayhan island-arc terrane,a fault bounded segment of the broader Silurian to Carboniferous Kazakh-Mongol arc,located towards the southern margin of the Central Asian Orogenic Belt,a collage of magmatic arcs that were periodically active from the late Neoproterozoic to PermoTriassic,extending from the Urals Mountains to the Pacific Ocean.Mineralisation at Oyu Tolgoi is associated with multiple,overlapping,intrusions of late Devonian（～372 to 370 Ma） quartzmonzodiorite intruding Devonian（or older） juvenile,probably intra-oceanic arc-related,basaltic lavas and lesser volcaniclastic rocks,unconformably overlain by late Devonian（～370 Ma） basaltic to dacitic pyroclastic and volcano sedimentary rocks.These quartz-monzodiorite intrusions range from earlymineral porphyritic dykes,to larger,linear,syn-,late- and post-mineral dykes and stocks.Ore was deposited within syn-mineral quartz-monzodiorites,but is dominantly hosted by augite basalts and to a lesser degree by overlying dacitic pyroclastic rocks.Following ore deposition,an allochthonous plate of older Devonian（or pre-Devonian） rocks was overthrust and a post-ore biotite granodiorite intruded at～365 Ma.Mineralisation is characterised by varying,telescoped stages of intrusion and alteration.Early A-type quartz veined dykes were followed by Cu-Au mineralisation associated with potassic alteration,mainly K-feldspar in quartz-monzodiorite and biotite-magnetite in basaltic hosts.Downward reflux of cooled,late-magmatic hydrothermal fluid resulted in intense quartz-sericite retrograde alteration in the upper parts of the main syn-mineral intrusions,and an equivalent chlorite-muscovite/illite-hematite assemblage in basaltic host rocks.Uplift,facilitated by syn-mineral longitudinal faulting,brought sections of the porphyry deposit to shallower depths,to be overprinted and upgraded by late stage,shallower,advanced argillic alteration and high sulphidation mineralisation.Key controls on the location,size and grade of the deposit cluster include（i） a long-lived,narrow faulted corridor;（ii） multiple pulses of overlapping intrusion within the same structure;and（iii） enclosing reactive,mafic dominated wall rocks,focussing ore.

Interpretation of remote sensing of geological structures and prediction of gold mineralization in Mohe area and its adjacent region

The authors took the ETM+ multi-spectra data as the data information and correlation coefficient for each band and carried out their information volume statistics.According to certain criteria,the authors also determined the optimum band-combined image.The image clarity is improved by various enhancements and fusions method.Based on remote sensing geological interpretation in detail,the relationship between remote sensing geological characters and gold mine were analyzed systemically.Using all kinds of remote sensing structure information,combining other research data,the authors determined mainly ore-controlling ore structure.Several prospective areas of gold ores were determined and furthermore significant finding mine target areas was confirmed.

Controlled coupling and characterization of oyster (Crassostrea gigas) ferritin with gold nanostars

Ferritin has good thermal stability,resistance to certain acids and bases,and targeting,and has broad application prospects in the synthesis of gold nanostars(AuNS).In this study,we screened monodisperse AuNS with uniform particle size and morphology through a one-step synthesis method and coupled the synthesized AuNS with oyster ferritin(GF1).The results showed that the surface plasmon resonance(SPR)peaks of the coupled GF1@AuNS changed signifi cantly,and the changes in infrared spectra and potential confirmed the success of the synthesis,while the microscopic morphology showed an increase in particle size and surface peak coverage.Furthermore,GF1@AuNS does not induce cell death in the 100µmol/L range,is highly stable in physiological environments,and exhibits good X-ray attenuation in micro-computed tomography.Due to the unique functional activity of ferritin and AuNS,GF1@AuNS has potential applications in food detection and drug development in the future.

Analysis of Ore-Controlling Structures of the Xincheng-Hexi Gold Deposit,Shandong Province,China

Based on quantitative and semi-quantitative mathematical and mechanical analysis of the shape, motion, structural factors, stress field and deformation field of the ore-hosting faults in the Xincheng-Hexi gold deposit, the ore-controlling features of faults and mineralization mechanism are discussed. It is concluded that the mineralization is controlled by the main faults, subsidiary fractures, joint density, mechanical features and deformation of the faults. The ore bodies are mainly located in the lower part of the convex crest and upper part of the concave trough of the main undulating fault surface. Mineralization is positively correlated to the development of subsidiary fractures and joints, which correspond to zones of low internal stress and high body strain and shear strain. They are favourable positions for mineralization and alteration.

Ab Initio Molecular Orbital Calculation on Dinuclear Gold(Ⅰ) Complexes──Metal-Metal Interaction and Electronic Structure of Binuclear Gold(Ⅰ) Complexes with Bridging Bidentate Ligands

The electronic structure and electronic absorption spectra of binuclear Au(Ⅰ) complexes with bidentate phophines and a bidentate ylid ligand have been studied using quasirelativistic pseudopotential ab initio calculations at the HF and MP2 levels by the LANL2DZ basis sets. The electronic properties of the spectral transition and Au(Ⅰ)—Au(Ⅰ) interaction were also discussed.

CRUSTOBODY STRUCTURE OF CHINA AND DISTRIBUTION OF ROCK GOLD ORE DEPOSITS

CRUSTOBODY STRUCTURE OFCHINA AND DISTRIBUTION OFROCK GOLD ORE DEPOSITSHuang Ruihua(Changsha Institute of Geotectonics, Academia Sinica, 410013, Hunan, China)rock gold ore deposit, crustobody structure, China.China continent is divided into four crustobodies from east to west. There is well-known Jinguashi rock gold deposit in East Asia continental margin crustobody. Gold met-allization is very well developed in East Asia crustobody. There are mainly rock gold ore de-posits related to Archean greenstone formation and Mesozoic-Cenozoic rock gold ore deposits in it. There are mainly Palaeozoic rock gold ore deposits of geosynclinal type and Cenozoic rock gold ore deposits of diwa (depression) type in Central Asia crustobody. South Asia crustobody possesses great potential in rock gold metallization. As a whole, prospecting exploration and exploitation of rock gold are very well of future in China.

Facile Synthesis of Micro/Nano Binary Dendritic Gold Structures for SERS and Superhydrophobic Applications

Via a galvanic displacement reaction, well-defined micro/nano binary dendritic gold structures were prepared on silicon wafers in fluoride acid solution containing HAuCI4 at 50 ℃. The gold deposits were characterized with scanning electron microscopy （SEM）, energy-dispersive X-ray （EDX） spectrum and X-ray diffraction （XRD）. The investigation of the surface-enhanced Raman scattering （SERS） reveals that the film of gold dendrites was an excellent substrate with significant enhancement effect. Also, the gold dendritic structured surface exhibited a remarkable superhydrophobic property with a contact angle of approximately 165° and low contact angle hysteresis after further simple surface modification with n-dodecanethiol.

A New Mechanism of Formation of the Silver-Rim Structure on Primary Gold Grains

Gold minerals in the Baochun skarn\|type gold deposit are Au\|Ag alloys with Ag contents within the range of 15-35.5 wt% and the minerals vary from 5μm to 50μm in size. As viewed from the electron microprobe images, most gold grains show silver rims with a high Ag content as compared with the core, ranging generally from 2 to 3μm in width. From dynamic calculations based on the mass action and mass balance constraints on the crystallization of native gold, it is considered that the enrichment of silver in the rim of gold minerals is due to gradual enrichment of silver in the ore\|forming solutions with its evolution from the early to the late metallogenic stage.

GEOCHEMICAL REASERCH ON ORE-CONTROLLING STRUCTURE IN LIAODONG LUOQUANBEI-BAIYUN GOLD MINERAL BELT

In recent2 0 years,because of the finding ofmany large- superlargegold deposits,we re- new the theories for prospecting and gain many things and conceptions.The current geo- chemical and gold- forming theories underline the importance of the early submarine volcano- sedimentation,metamorphic differention,sedimentation of terrigenous clastics,thermal spring and it’s sedimentation,syngenesis process and other hypergene supplying the source for metallogenic materials.According to the study for source bed(rock) and depsitional for- mation of gold,we find that gold will be gradually enriched and mineralized in source bed (rock) ,because of variousgeologicprocesses,such as regional metamorphism ormigmatiza- tion,geothermal bittern,volcanism. The ore- control of deep and giant fault and ductile shear beltand tectono- flash space is emphasized,especially,we should notice the long- term, succession and multistage of the

THE CHARACTERISTICS AND MODELLING EXPERIMENTS ON THE DEPOSIT-CONTROLLING STRUCTURE OF SHEAR-ZONE GOLD DEPOSIT IN CHINA

THE CHARACTERISTICS ANDMODELLING EXPERIMENTS ON THEDEPOSIT-CONTROLLING STRUCTUREOF SHEAR-ZONE GOLD DEPOSITIN CHINAWu Xueyi(Institute of Geochemistry, Academia Sinica, Guiyang, 550002, China)shear zone, gold-controlled structure, modelling experimentThe shear-zone gold deposits found in China can be divided into four types: (1) gold deposits controlled by the ductile shear-zones; (2) gold deposits controlled by the brittle-ductile shear zones; (3) gold deposits conntrolled by the ductile-brittle shear zones; (4) gold deposits controlled by the brittle shear zones. These gold deposits mostly occurred in the regions with higher abundance of gold, which underwent a long and complicated evolution-ary process and had obvious zoning and multiperiod metallogenic feature. The modelling exper-imental result of gold-controlled structure shows that the thermodynamics of compresso-shear structures made gold mobilizing and migrating in the earlier stage of shear zone; and that the extension process did

A Structural Principle as William Golding's Hallmark:Polarities Expressed in Moral Tension

Golding thinks we live in " two worlds", one physical and the other spiritual, and that the experience of the " two worlds" is basically emblematic of our nature. For Golding who most often uses the conventional religious terms, "physical" and "spiritual", to identify the polarity, the "physical" is equated with the rational. He sees the rational view of experience as denying the irrational, the mysterious or the "spiritual". All this leads to a structural principle that has become Golding's hallmark-polarities expressed in moral tension.

Structural geometry of orogenic gold deposits： Implications for exploration of world-class and giant deposits

With very few exceptions, orogenic gold deposits formed in subduction-related tectonic settings in accretionary to collisional orogenic belts from Archean to Tertiary times. Their genesis, including metal and fluid source, fluid pathways, depositional mechanisms, and timing relative to regional structural and metamorphic events, continues to be controversial. However, there is now general agreement that these deposits formed from metamorphic fluids, either from metamorphism of intra-basinal rock sequences or de-volatilization of a subducted sediment wedge, during a change from a compressional to transpressional, less commonly transtensional, stress regime, prior to orogenic collapse. In the case of Archean and Paleoproterozoic deposits, the formation of orogenic gold deposits was one of the last events prior to cratonization. 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 significant post-gold orogenic overprint. Within the host volcano-sedimentary sequences at the province scale, world-class orogenic gold deposits are most commonly located in second-order structures adjacent to crustal scale faults and shear zones, representing the first-order ore-forming fluid pathways, and whose deep lithospheric connection is marked by lamprophyre intrusions which, however, have no direct genetic association with gold deposition. More specifically, the gold deposits are located adjacent to ～10°-25° district-scale jogs in these crustal-scale faults. These jogs are commonly the site of arrays of ～70° cross faults that accommodate the bending of the more rigid components, for example volcanic rocks and intrusive sills, of the host belts. Rotation of blocks between these accommodation faults causes failure of more competent units and/or reactivation and dilation of pre-existing structures, leading to deposit-scale focussing of ore-fluid and gold deposition.Anticlinal or antiformal fold hinges, particularly those of ＇locked-up＇ folds with ～30° apical angles and overturned back limbs, represent sites of brittle-ductile rock failure and provide one of the more robust parameters for location of orogenic gold deposits.In orogenic belts with abundant pre-gold granitic intrusions, particularly Precambrian granitegreenstone terranes, the boundaries between the rigid granitic bodies and more ductile greenstone sequences are commonly sites of heterogeneous stress and inhomogeneous strain. Thus, contacts between granitic intrusions and volcano-sedimentary sequences are common sites of ore-fluid infiltration and gold deposition. For orogenic gold deposits at deeper crustal levels, ore-forming fluids are commonly focused along strain gradients between more compressional zones where volcano-sedimentary sequences are thinned and relatively more extensional zones where they are thickened. World-class orogenic gold deposits are commonly located in the deformed volcano-sedimentary sequences in such strain gradients adjacent to triple-point junctions defined by the granitic intrusions, or along the zones of assembly of micro-blocks on a regional scale. These repetitive province to district-scale geometrical patterns of structures within the orogenic belts are clearly critical parameters in geology-based exploration targeting for orogenic gold deposits.