Abstract: The study of metallogenic epoch is a very important branch in the study of deposits.The Carlin-type gold deposits in Nevada is a typical deposit.Therefore，the exploration on its metallogenic age will surly generate important implications for forth-coming researches conducted in the same field.This paper will analyze the problems which may exist in the study of metallogenic epoch through reviewing the previous researches of Carlin-type gold deposits in Nevada which are conducted by using methods like Rb-Sr，K-Ar，Ar-Ar，FT and U-Th/He.It is argued that different closure temperatures of isotope dating systems is applicable to different genetic types of ore deposits，and that accurate metallogenic age can be obtained only with the combination of the researches of metallogenic epoch and those of metallogenic temperature，closure temperature and cooling rate.
Distinctive plant communities can extract metals from metal-rich soils.This method can economically mine metals from low-grade ores，mineralized soils and mining tailings that are too poor for conventional mining of metals，besides，new prospecting areas can be indicated.Phytoextraction can generate bio-ores which are virtually sulphur free and have greater metal content than conventional ores.It is a green and economical metallurgy way.The study of gold phytoextraction technology has been mature in aborad，but little related research in China.This paper reviews the study of gold accumulation in plants and introduces mechanism of gold uptake by plants.Economic assessment and future scopes of gold phytoextraction are discussed.
Laoyachao gold deposit is located in the famous Shuikoushan orefield，the exposed strata are the upper Devonian to lower Cretaceous，the lithology is carbonate，paralic clastic rocks and terrigenous clastic rock.The Indosinian fold and the SN trending fracture are developed，magmation is rather strong.The ore-forming material enriched in the axle of the overturned anticline，the fault zone and surrounding the rock.Laoyachao gold deposit occurs in cryptoexplosive breccia pipe，which is controlled by F1 fault and No.4 granodiorite，alteration of the wall rock is developmend，silicification，pyritization，zinc mineralization has a close relationship with mineralization.Gold mainly exists as native gold，distribute in the gaps of quartz，pyrite，sphalerite and the particle clearances.Mineralization can be divided into skarn stage，hydrothermal stage and supergene stage，hydrothermal stage is the main mineralization stage.Quartz-pyrite-sphalerite-native gold stage is the main stage of mineralization.The main prospecting mark is cryptoexplosive breccia，silicification，sphalerite and pyritization is closely associated with mineralization.
Xingfucun gold deposit of is located in Huade County of Inner Mongolia，the tectonics of which locates in the east of north edge of North-China Platform, Baiyunebo rift belt.The gold vein distributes in the central area， and mainly exists in the Bayan Obo group Bilute fabric phyllite.The geochemical features，geophysical features，approximately equal in distances of orebodies and contrast of typical gold deposit in adjacent regions are studied in this paper，through summarizing geological characteristics of mining area, doing research in geological， physical and chemical data.The results show that ore body shape the approximately equidistant distribution from the plane，and from the vertical，ore body shape characteristic of expansion and contraction，pinch reproduction. Combining actual conditions of mining area，quartz vein altered rock type gold orebody should by the main prospecting direction in future.
Pangkaimen gold-silver deposit located at Aihui-Huma metallogenic belt， and the ore body mainly hosted in volcanic rocks of the Ganhe formation of Jurassic.The ore body was formed with veins and distinctly controlled by fault structure.Many fault structures occurred in the study area， and were classified into five trending directions of NEE，NNE，NNW，NWW and NS.There are mainly four tectonic epochs in the study area and the tectonic directions are NEE，NNE，NNW and NWW in time order.The fault structure in NEE direction showed inherited activities，and provided a great channel for Yanshanian volcanic eruptions and deep ore-bearing hydrothermal.The extrusion fracture in NNE direction controlled the distribution of the mineralized belt in the study area.The tenso faults in NNW provided large space for precipitation and enrichment of ore-bearing hydrothermal.
With geological conditions more favorable and good prospecting potential，the Ershiyizhan area is located on the southern margin of upper Heilongjiang Basin.The preliminary study of the geochemical features in Fukeshan area was based on the 1∶50 000 stream sediment survey.Studied of the elements distribution features，the correlation analysis and factor analysis，the author thinks that the area has the potential of searching for Au，Cu ore deposit and mineralized bodies.Combined with the ore-forming geological conditions and existing mine information，one of the metallogenic types is probably gold mineralization related to quartz veins in volcanic rock，and the other is gold deposit produced in contact zone between intrusion and sandstone of Ershierzhan group； another is probably copper deposit related to rocks（granodiorite porphyry），in which the anomalies have great scale，high peak value，obvious concentration centre and good registration，gold or copper ore bodies may be found in Ershiyizhan Au-Cu metallogenic prospect area.
In order to strengthen quantitative prediction for regional and geological work，based on the dimension geochemical dispersion patterns，combined with ore forming body evaluation model and method for available metal component，using the exploration results of Shabaosi and Baoxinggou gold deposit，the two large-scale gold deposits in Heilongjiang Basin，to conduct a quantitative evaluation.The results point out the expectation exploration resource for Baoxinggou area，Balifang area，and Shiwuliqiao area.We also proposed the concept of block of formation ore in the specific application of quantitative assessment method，namely the anomaly within the range of drop 500 meters deep geological range.And through the evaluation of the Shabaosi and Baoxinggou deposit calculation，confirmed that block of formation ore can evaluate and predict the deposit scale and reserves better.
The method of soil geochemical survey can achieve clear prospecting，narrow the scope of prospecting，and determine the target area of prospecting.Through the soil geochemical survey in Iquique HN mining area，we finally found 9 integrated anomaly areas, including 4 anomaly areas mainly with copper，3 anomaly areas primarily with gold，2 anomaly areas mainly with zinc and molybdenum，respectively.The mining area within main abnormal was controlled by F1 fracture.Gold anomaly region with the distribution pattern of “satellite” was primarily located out of the copper（molybdenum） anomaly area. In addition, the mining area was similar to the horizontal zonal characteristics of porphyry copper deposits on the whole, and the abnormal horizontal zonal presented the order of Cu （Mo）-Au-（Zn-Pb-Ag） from inside to outside.Moreover，the anomalies showed that the area has the great potential of finding vein and porphyry copper deposits.Some of anomaly areas especially for gold anomaly region with high intensity exhibited that the gold deposit may exist, therefore，the evaluation of gold can’t be ignored during the work.
Based on the huge demand for gold in the world and the urgency of exploring new gold resources is increasing，taking Web of Science database as the data source，using TDA software to quantitatively analyzed the research 3 061papers published during 1980—2013 about gold exploration and metallogenic.By bibliometric analysis,we reveals the distribution of international leading coutries and institutions engaged in gold exploration and metallogenic researches in the world，and comparatively analyzes their influence from the perspective of average cited times per paper.At the same time，we analyze the distribution of disciplines and research hotspots in the field of gold exploration and metallogenic，and discusses its driving factors.
It is remain an enormous and difficult problem to improve the efficiency of stoping the gentle dip and filminess ore body.If the resuming fill is applied to stope ore body according to the conventional rules，it will lead to lower efficiency and higher loss impoverishment rate，especially，the slip of mine system arrangement can not effectively solve the problem for gentle dip and filminess ore body.Aiming at the problem above，thus the resuming-fill mining method is optimized.Using the chute instead of sneaking underground ore，both sides of the chute with rubble wall，all of which can make the staff enter the chute to solve the blocking phenomenon，additionally，it improves the mining efficiency.Making use of cemented backfilling materials filling in caving on the basis of rubble，and playing a layer with enough strength of cementation plane can not only reduce the dilution loss rate，but also greatly improve the efficiency of ore mining.These optimization measures have been widely applied in Wangershan sub-ore of Jiaojia gold mine，which has brought good economic benefit for the mine.
Based on the analysis of ore mineralogy，through the optimization of gravity separation and process table concentrator operation facilitie，implementation of continuous operation of table concentrators，and simultaneously taking diversified measures，strengthening the effection of the jigging and gravity separation，the total recovery rate was increased by 0.45%.Using a variety of means，including remote control of the production and omnibearing monitoring about the table running，achive the table concentrators unattended operation and gold closed-off management in order to ensure the production safety of the gold.
In order to obtain false color digital mine model construction taking an open pit mine in Shandong as the case，by making the point cloud pre-processing，the traditional three-dimensional modeling，and then giving false color information via traditional point cloud data on the three-dimensional model，re-modeling，and finally formed the entire mining and false color three-dimensional model of the building’s largest mining.The model also be used to conduct a detailed application aspects of the practice of calculating mine reserves.The point transport data generated by TLS，point cloud data generated by IDL programming process，using geomagic software modeling methods，the false-color three-dimensional model was construct which can finally get a good guide to the actual production.Get the point cloud data from research to final spending five days to build the model，false color three-dimensional model of the ultimate resolution of two meters to build a traditional digital topographic maps a month workload can not be achieved，fully demonstrated by constructing a three-dimensional scanning mine the way the model can greatly reduce the computational workload and working hours，and more realistic.
The public data of EGM2008 Earth Gravity Field Model from National administration of surveying， mapping and geo-information is used in measuring and balancing the elevation control survey data of Beijinshan gold deposit.Two measurement methods（GPS control survey and conventional optical leveling） and three common gravity field model（DQM94a，EGM96 and EGM2008） are used in the study，and we compared its effect by three different methods，which are ECEF，error ellipse component and ellipse equilibrium diagram.The results show that the height accuracy of EGM2008 Earth’s gravity field model is 6.9 cm in Beijinshan gold deposit，EGM2008 Earth’s gravity field model has a higher accuracy than the traditional gravity model EGM96 and DQM94，the efficiency and accuracy is better than conventional lead levels，EGM2008 Earth’s gravity field model is proved suitable for mine surveying work of mountainous areas of Southern Gansu.
HF-HNO3-H2SO4+aqua regia system was applied to complete sample digestion.National Primary Reference Material instead of standard solution of the measured elements was employed to make the standard work curve，and then we used inductively coupled plasma mass spectrometry（ICP-MS） to determination of rare earth elements in geological samples.The results indicated that the accuracy，precision，detection limit of the method are conform to the requirements of the specification，meanwhile，it greatly reduces the matrix effect in the practical application of interference to some degree，and eliminate of errors that were introduced during the period of making standard work curve.In addition，the method had the advantage of accurate results and easy operation，which can be widely applied to determination of amounts of rare earth elements in geological samples.
The germanium in polymetallic ores was dissolved by HNO3+ HF+H2SO4+ HClO4 and was measured by hydride generation-atomic fluorescence spectrometry（AFS）.The effects of some parameters such as the H3PO4 concentration and KBH4 concentration，working parameters of the AFS instrument on the determination were studied and optimized by experiments.The allowable quantities of the interference elements were also invested.The detection limit of this method was 0.024 μg/g，RSD was in the range of 4.79% to 5.53% and the recovery of standard addition was 93.5% to 107.3%.The method was validated by determination of Ge in National Standard Reference Materials and the results were in agreement with certified values.
It is the most important factor to ensure the quality of analytical data for analysis method of the regional geochemical survey samples.In this paper，11 mineral elements （V，Cr，Cu，Zn，Co，Ni，Ba，Ti，Mo，W，Pb） of the regional geological survey samples in a region of Xinjiang were jointly determined by Inductively Coupled Plasma Mass Spectrometry and X-ray Fluorescence Spectrometer.The results of same batch samples for ICP-MS and XRF were compared，and the best analysis method for different elements was optimized，the analytical method precision and accuracy were evaluated too.Finally，a set of scientific matching program was established which apply to analysis the regional geochemical survey samples.The detection limit and the precision of the method meet DZ0130.4-2006 and supplemental instructions for 1∶50 000 geochemical samples standards.The reliability of the method has been tested by elements determination in Standard Reference Materials and the results are in agreement with the certified values.The matching program（ICP-MS and XRF） is rapid and high sensitivity，and it can be used to geochemical mapping samples analysis.
In order to improve the mineral recovery rate of a gold mine in Gansu Province，two technology schemes were applied to processing ores which include the flotation-concentrate cyaniding and the all slime cyaniding.By comparing the overall metallurgical recoveries of them，the technology schemes of flotation and concentrate was ultimately determined，which have been considered from the aspects of technical and economic.The tests show that under the premise of ensuring the total flotation time in 20 minutes，the slurry concentration of 33% and the grinding fineness -200 above 55% were set at the production site.The pharmacy conditions also was butyl xanthate 100 g/t and butyl aerofloat 80 g/t.And the concentrate cyaniding conditions should be kept at the mesh fineness -400 above 90%，the cyanide concentration of 65‰，the cyanide leaching time of 36 hours，and the slurry concentration of 30% to 35%.Finally，it can obtain good indicators of the cyanide overall recovery of 95.43%.
The extraction raffinate pretreatment can avoid environment pollution.Moreover，it is likewise an effective way of recovering valuable elements.This work proposes a new extraction raffinate pretreatment that is the ammonia precipitation.Principle of the new extraction raffinate pretreatment is to apply ammonium hydroxide to make pH≈7.5 of the raffinate，which can result in the valuable elements（Zn，Cu，Pb，Fe） forming precipitations of hydroxide and then the precipitations separate out quickly，however，the element As forms the FeAsO4 precipitation.After solid-liquid separation，adding Na2S into the filtrate can make some of the trace metal elements begin to precipitate.Finally，the goal that all valuable elements of the extraction raffinate can be recycled effectively comes true.It is found that treatment fluid can be used as a kind of the slurry in roasting cyanide during the process of acid leaching.
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