山东大尹格庄金矿床深部三维定量成矿预测

大尹格庄金矿是胶西北招平断裂带中段的大型金矿床,但随着逐渐的开采其保有资源量不断下降,急需在矿床的深边部区域开展接续资源找矿工作。本文以大尹格庄金矿为研究对象,以区域成矿理论和找矿勘查模型为指导,利用三维地质建模技术构建了相关地质体的三维模型,在此基础上,采用定量化的方法提取地质体与成矿相关的控矿因素指标和矿化指标,并建立了三维定量成矿预测模型,并应用该模型圈定了3个找矿靶区。研究表明,该方法能够适用于大中型矿山的深边部找矿工作,其三维及定量化的预测结果能够为后续的勘探及开采工作提供重要参考。     

Groundwater transformation of a low-sulfur to a high-sulfur coal, the Harlem coal of the northern Appalachian basin

The Harlem coal is postulated to have been deposited in raised-bog settings. It was initially deposited as low-sulfur peat, but groundwater of a later origin altered portions of it to high-sulfur coal. The total sulfur content of 172 samples from 31 locations on a moisture- and ash-free basis have a quadrimodal distribution with two major modes at 0.75% S and 2.0%S. Multiple sampling and analyses at specific mine sites indicate that the addition of sulfur of a later origin occurred either laterally adjacent to sandstone channels or vertically adjacent to faults. Significant sulfur addition also occurred above clay partings at these sites. The original low-sulfur nature is preserved where the coal bed is isolated from descending groundwater by a thick impervious layer. Trace-element analyses show high concentrations of mobile elements such as Na and Mn in the high-sulfur coals.     

地质标准物质的回顾与展望

我国地质物料化学成分标准物质的研究始于七十年代的后期.地矿部西北地质研究所等首先研制了超基性岩和铬铁矿标准物质,继后由物化探研究所和岩矿测试研究所牵头,在区域化探全国扫面的推动下,先后研制了水系沉积物、土壤和岩石三个系列标准物质.稍后核工业部、冶金部和化工部也着手研制了相应专业的地质标准物质.八十年代是地质标准物质研制的全盛时期,在这个阶段之后地质标准物质基本上形成了比较完整的体系.根据1992年国家技术监督局公布的国家一级标准物质目录^[1],在样品数量上冶金类标准物质居第一位,地质类标准物质居第二位,约占四分之一;依发布的标准值项目数计^[2],地质类标准物质居于首位,占50%以上.我国地质标准物质与外国相比,在数量、品种类型和系列性方面均占世界领先地位,在定值的元素和定值精度方面亦为国际先进水平.     

既找矿又开矿搞活地勘单位：赴疆考察的认识和体会

“六五”和“七五”期间,新疆地矿局强化了地质找矿的科学管理,充分发挥了地质科技在找矿中的先导作用,争取到了一个好的外部环境,取得了地质找矿的重大突破。他们既找矿又开矿,以找矿促开发,走找矿与开矿结合的道路,实行探、采、工、贸一体化,创造了搞活地勘单位,振兴地方经济的成功经验。     

山东地质环境中砷的分布特征

山东地质环境砷含量一般为(10^-6)：各类岩石4．87～7．89，土壤10．89，水系底泥6．23。根据砷的分布特点。总体上可将山东分为鲁中南-鲁东山地丘陵区、鲁西北-鲁西南平原区2个大的砷的地质环境(背景)区及7个亚区。每个亚区内，山地丘陵区砷的地球化学背景较低，而平原区砷的背景相对高些。但总体上，全省处于正常的和相对比较低的背景，还未发现原生地质环境形成高砷背景对人体危害的案例。     

内蒙古西乌旗沙尔哈达晚侏罗世A型花岗岩：地球化学特征、岩石成因与动力学背景

内蒙古西乌旗沙尔哈达花岗岩侵入于贺根山缝合带蛇绿岩中。LA-ICP-MS锆石测年指示,沙尔哈达花岗岩岩株于晚侏罗世(154.6±1.2 Ma)侵位,矿物组合以石英、碱性长石和斜长石为主,富SiO2(74.86%~75.97%)、K2O(4.4%~4.95%),贫MgO(0.044%~0.22%)、CaO(0.38%~0.77%)、TiO2(0.046%~0.18%)和P2O5(0.007%~0.042%),A/CNK=1.03~1.09, 小于1.1,强烈亏损Ba、Sr、Eu、P、Ti,具有典型的右倾“海鸥型”稀土元素分配模式,表现出典型的铝质A型花岗岩的矿物组合及地球化学特征。沙尔哈达A型花岗岩具有低的(87Sr/86Sr)i值(0.7014~0.70374)、低正εNd(t)值(+3.96~+4.31)、高的εHf(t)值(+10.54~+14.72)。同位素地球化学特征指示,沙尔哈达花岗岩可能源于新生的中基性地壳物质部分熔融及其后的结晶分异作用。沙尔哈达A型花岗岩为晚侏罗世蒙古-鄂霍茨克洋闭合后造山伸展作用的产物,和蒙古-华北北部地块散布的其他A型花岗岩共同指示中晚侏罗世广泛的中下地壳伸展。     

岷县地质灾害易损性模糊综合评价

岷县地形多变、地貌多样、地质环境复杂,近年来地震、滑坡等地质灾害多发.基于易损性影响因素,结合岷县具体情况,选取人口密度、国内生产总值、公路、房屋、林地和耕地6个指标,以乡镇为基本单元,利用模糊综合评判法构建评价体系,将研究区易损性划分为不同等级.结果表明,高易损性地区占研究区总面积的20.62％,中易损性地区的占比为...     

Use of cartographic images by expert and novice field geologists in planning fieldwork routes

Topographic maps and aerial photographs are particularly useful when geoscientists are faced with fieldwork tasks such as selecting paths for observation, establishing sampling schemes, or defining field regions. These types of images are crucial in bedrock geologic mapping, a cognitively complex field-based problem-solving task. Geologic mapping requires the geologist to correctly identify rock types and three-dimensional bedrock structures from often partial or poor-quality outcrop data while navigating through unfamiliar terrain. This paper compares the walked routes of novice to expert geologists working in the field (n = 66) with the results of a route planning and navigation survey of a similar population of geologists (n = 77). Results show clearly that those geologists with previous mapping experience make quick and decisive determinations about field areas from available imagery and maps, regardless of whether they are or not physically present in the field area. Recognition of geologic features enabled experts to form and verbalize a specific plan for travel through a landscape based on those features. Novices were less likely to develop specific travel route plans and were less likely to identify critical landscape cues from aerial photographs.     

矿区三维地质建模与地裂缝成因分析

为了分析在复杂地质条件下采煤引起的大规模地表裂缝的形成原因,本文以某矿区地裂缝为研究对象、数字化软件SURPAC为技术平台、岩体为主要区域变量,建立关于开采工作面、火成岩、地裂缝及断层的三维地质模型,并进行开采沉陷影响预计,通过分析裂缝成因中各相关地质条件的作用影响,得出了煤炭开采导致地下应力平衡被打破后造成地裂缝的主要因素,为预防和治理地裂缝提供了参考。