Reported in this paper are K-Ar dates of volcanic rocks, biotite-granite and greisen from Lianhuashan tungsten ore deposit in Guangdong Province. Isotopic dilution method is adopted in this work. The whole-rock isochr...Reported in this paper are K-Ar dates of volcanic rocks, biotite-granite and greisen from Lianhuashan tungsten ore deposit in Guangdong Province. Isotopic dilution method is adopted in this work. The whole-rock isochron ages of volcanic rocks are within the range of 120.4±12.1m.y. The petrogenetie age of biotlte-granite and the minerogenetic age of the tungsten ore deposit are close to those of the volcanic rocks. The apparent ages of various types of rocks in the mining district generally bias towards younger values, which may be attributed to the effects of late thermal events which took place in the eircum-Paeific mctallogenetic belt.展开更多
Risk quantification in grade is critical for mine design and planning.Grade uncertainty is assessed using multiple grade realizations,from geostatistical conditional simulations,which are effective to evaluate local o...Risk quantification in grade is critical for mine design and planning.Grade uncertainty is assessed using multiple grade realizations,from geostatistical conditional simulations,which are effective to evaluate local or global uncertainty by honouring spatial correlation structures.The sequential Gaussian conditional simulation was used to assess uncertainty of grade estimates and illustrate simulated models in Sivas gold deposit,Turkey.In situ variability and risk quantification of the gold grade were assessed by probabilistic approach based on the sequential Gaussian simulations to yield a series of conditional maps characterized by equally probable spatial distribution of the gold grade for the study area.The simulation results were validated by a number of tests such as descriptive statistics,histogram,variogram and contour map reproductions.The case study demonstrates the efficiency of the method in assessing risk associated with geological and engineering variable such as the gold grade variability and distribution.The simulated models can be incorporated into exploration,exploitation and scheduling of the gold deposit.展开更多
文摘Reported in this paper are K-Ar dates of volcanic rocks, biotite-granite and greisen from Lianhuashan tungsten ore deposit in Guangdong Province. Isotopic dilution method is adopted in this work. The whole-rock isochron ages of volcanic rocks are within the range of 120.4±12.1m.y. The petrogenetie age of biotlte-granite and the minerogenetic age of the tungsten ore deposit are close to those of the volcanic rocks. The apparent ages of various types of rocks in the mining district generally bias towards younger values, which may be attributed to the effects of late thermal events which took place in the eircum-Paeific mctallogenetic belt.
文摘Risk quantification in grade is critical for mine design and planning.Grade uncertainty is assessed using multiple grade realizations,from geostatistical conditional simulations,which are effective to evaluate local or global uncertainty by honouring spatial correlation structures.The sequential Gaussian conditional simulation was used to assess uncertainty of grade estimates and illustrate simulated models in Sivas gold deposit,Turkey.In situ variability and risk quantification of the gold grade were assessed by probabilistic approach based on the sequential Gaussian simulations to yield a series of conditional maps characterized by equally probable spatial distribution of the gold grade for the study area.The simulation results were validated by a number of tests such as descriptive statistics,histogram,variogram and contour map reproductions.The case study demonstrates the efficiency of the method in assessing risk associated with geological and engineering variable such as the gold grade variability and distribution.The simulated models can be incorporated into exploration,exploitation and scheduling of the gold deposit.
