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981.
982.
川滇密西西比河谷型铅锌矿床成矿流体来源研究:流体Na-Cl-Br体系的证据 总被引:11,自引:1,他引:11
应用流体包裹体滤液分析方法,测定了川滇7个MVT铅锌矿床成矿流体的Na,Cl,Br含量,结果表明成矿流体的x(Na/Br)和x(Cl/Br)的平均值分别为185和73,并与高度蒸发浓缩的残留海水的x(Na/Br)和x(Cl/Br)相近。成矿流体的Na,Cl含量呈正相关,在lgNa-lgCl图解中呈线性分布。根据这些事实以及矿床地质特征,认为原始成矿卤水起源于蒸发浓缩的残留海水,原始含矿卤水与富含有机质的大气降水混合导致矿质沉淀而成矿。 相似文献
983.
984.
我国铝土矿资源合理开发利用的探讨 总被引:14,自引:3,他引:14
分析我国铝土矿开发利用的现状以及存在的问题 ,指出我国铝土矿的特点是多为一水硬铝石型矿石 (占 98.4 6 % ) ,且是高铝高硅低铁 ,用其生产氧化铝成本高 ,矿石开采难度大。探讨今后合理开发利用铝土矿的途径 相似文献
985.
详细研究了燕山东段地区花岗岩类的侵入时代、产出形式和成因类型 ,指出该区与花岗岩有关的三个金属成矿系列。 相似文献
986.
987.
A stochastic channel embedded in a background facies is conditioned to data observed at wells. The background facies is a fixed rectangular box. The model parameters consist of geometric parameters that describe the shape, size, and location of the channel, and permeability and porosity in the channel and nonchannel facies. We extend methodology previously developed to condition a stochastic channel to well-test pressure data, and well observations of the channel thickness and the depth of the top of the channel. The main objective of this work is to characterize the reduction in uncertainty in channel model parameters and predicted reservoir performance that can be achieved by conditioning to well-test pressure data at one or more wells. Multiple conditional realizations of the geometric parameters and rock properties are generated to evaluate the uncertainty in model parameters. The ensemble of predictions of reservoir performance generated from the suite of realizations provides a Monte Carlo estimate of the uncertainty in future performance predictions. In addition, we provide some insight on how prior variances, data measurement errors, and sensitivity coefficients interact to determine the reduction in model parameters obtained by conditioning to pressure data and examine the value of active and observation well data in resolving model parameters. 相似文献
988.
This paper assesses the agricultural land resources of Guiyang City by means of GIS,on the basis of the pressure-state-response model in which soil heavy metal contamination is selected as a pressure indicatror.he results suggest that most of the agricultural land resources are of good quality,However,there are 17.11km^2 dry land and paddy field,which belong to the region of serious heavy metal contamination and are not fit for planting crops.At the same time,the high quality plowland,which is suitable for cultivation,has decreased nearly by 1/3 due to soil heavy metal contamination.These findings may improve our understanding that it is very important to prevent and cure heavy metal contamination of Guiyang City. 相似文献
989.
Groundwater-flow modeling in the Yucatan karstic aquifer, Mexico 总被引:1,自引:0,他引:1
Roger González-Herrera Ismael Sánchez-y-Pinto José Gamboa-Vargas 《Hydrogeology Journal》2002,10(5):539-552
The current conceptual model of the unconfined karstic aquifer in the Yucatan Peninsula, Mexico, is that a fresh-water lens
floats above denser saline water that penetrates more than 40 km inland. The transmissivity of the aquifer is very high so
the hydraulic gradient is very low, ranging from 7–10 mm/km through most of the northern part of the peninsula. The computer
modeling program AQUIFER was used to investigate the regional groundwater flow in the aquifer. The karstified zone was modeled
using the assumption that it acts hydraulically similar to a granular, porous medium. As part of the calibration, the following
hypotheses were tested: (1) karstic features play an important role in the groundwater-flow system; (2) a ring or belt of
sinkholes in the area is a manifestation of a zone of high transmissivity that facilitates the channeling of groundwater toward
the Gulf of Mexico; and (3) the geologic features in the southern part of Yucatan influence the groundwater-flow system. The
model shows that the Sierrita de Ticul fault, in the southwestern part of the study area, acts as a flow barrier and head
values decline toward the northeast. The modeling also shows that the regional flow-system dynamics have not been altered
despite the large number of pumping wells because the volume of water pumped is small compared with the volume of recharge,
and the well-developed karst system of the region has a very high hydraulic conductivity.
Electronic Publication 相似文献
990.
The composition of quartz inclusions and trace elements in ore indicate that gold-bearing fluid in the Xiadian gold deposit,Shandong Province,stemmed from both mantle and magma,belonging to a composite origin.Based on theoretical analysis and high temperature and high pressure experimental studies,gold-bearing fluid initiative localization mechanism and the forming environment of ore-host rocks are discussed in the present paper.The composite fluid extracted gold from rocks because of its expanding and injecting forces and injecting forces and flew through ore-conducive structures,leading to the breakup of rocks.The generation of ore-host faults and the precipitation of gold-bearing fluid occurred almost simultaneously.This study provides fur-ther information about the relationships between gold ore veins and basic-ultrabasic vein rocks and intermediate vein rocks,the spatial distribution of gold ore veins and the rules governing the migration of ore fluids. 相似文献