A critical evaluation of the use of hydrocarbon gases in rocks as a pathfinder for base-metal mineralisation in Shannonbridge, central Ireland

This paper discusses the results of a light hydrocarbon gas (LHG) lithogeochemical survey carried out at Shannonbridge in central Ireland. Two methods of LHG extraction (dry grinding and sample solution in EDTA) are compared with a heat extraction method developed by Carter (1981). The results show that due to a more complete breakdown of the sample, LHG contents of up to an order of magnitude greater are released by grinding and sample solution, with no apparent decrease in precision. As a result, a potential problem related to the generation of additional gases by the thermal breakdown of organic matter during heating, can be avoided.Similar LHG component distribution patterns are produced by dry grinding and EDTA extraction suggesting that both methods could be useful alternatives to the heating technique. This is strengthened by the identification of a possible target zone in Shannonbridge based on the distribution of samples depleted in methane and enriched in butyl gases, C4 (butane plus butene plus their associated isomers). However, this empirical interpretation was not supported by the results of heating. Furthermore, subsequent exploration failed to establish the presence of a significant mineral occurrence at Shannonbridge. Evidently, the LHG patterns were either misinterpreted or they reflect hydrocarbon sources which are not related to mineralisation.Further evaluation of the data showed that LHG component distributions are significantly influenced by variations in lithology. Once this effect was reduced, it became apparent that the patterns are principally controlled by regional faulting. Since fault structures would be permeable to hydrocarbon gases formed from a variety of processes (such as maturation of organic matter in the host limestones), no relationship with buried mineralisation is necessary to explain the patterns observed.By using the Shannonbridge data as an example, this paper attempts to emphasise the equivocal nature of data collected using prospecting methods of this type. The aim is not to refute innovative and quality research already carried out in this field because the association of hydrocarbon gases with mineralisation is too frequent to be simply classified as coincidental. However, anomalous levels of LHG can be attributed to other processes which, in many cases, are too easily overlooked.     

皖南上震旦统蓝田组中银铅锌等多金属矿床成因探讨

皖南地区上震旦统蓝田组，是银铅锌等多金属矿床的重要赋矿层位，区域地质，矿床地质和地球化学特征研究表明，银铅锌等多金属矿床是由于热水沉积作用而形成，热水沉积作用受断裂控制明显，主要呈带状沿着祁门－三阳坑一万家桥深断裂NE方向展布，热水学沉积形成了银铅锌等多金属矿床，铁锰矿床以及蓝田组底部数千平方千米含锰碳酸盐岩，这一认识不仅为皖南地区矿床的成因给予了新的解释，也为今后该区矿产资源的勘察工作提供了新的思路。     

米易大槽铜镍铂矿地质特征及找矿前景

米易大槽铜镍铂矿位于扬子地台西缘，康滇地轴中段西测，矿体受超基性岩体及南北向断裂控制。本文对该矿床的控矿构造，岩体特征，矿体特征，矿物组合，矿床类型，找矿标志，找矿前景等。进行了研究和论述，预测在岩体底部及接触带深部有找到品位较高的铜镍铂矿的可能。     

加强非金属矿产工作促进社会经济可持续发展

二十一世纪是我国全面推进工作化、市场化、科技化和国际化进程的时期，作为国民经济与社会发展基础的非金属矿产资源的调查评价、开发利用与保护面临新的机遇和挑战，存在着资源的有效供给、综合利用、深度加和环境保护等方面的矛盾，为此，本文通过对非金属矿产资源的特性和国内外开发研究现状等方面的分析，提出了进一步工作的建议；开放新资源，探索新用途，提出资源的综合利用程度；重视非金属矿产地质工作，增强矿产资源战略储备，加强非金属矿产资源管理，实现矿产秩序根本好转；搞好矿山生态环境建设，促进资源开发与环境保护协调发展；依靠科学技术进步，提高矿产资源利用效率。     

试论胶东花岗岩—绿岩地体剪切带超大型金矿

从产出地层、构造和岩浆岩的特点，论证胶东地区的金矿为花岗岩－绿岩地体剪切带超大型金矿。     

云南会泽铅锌矿床构造控矿规律及其隐伏矿预测

对会泽铅锌矿成矿构造体系、构造控矿型式进行研究，认为小江深断裂带和曲靖-昭通隐伏断裂带为矿床形成提供了有利的构造背景，矿床严格受北东向压扭性断裂控制，“阶梯状”和“多字型”构造是矿区具有普遍性的控矿构造型式，北东构造带是主要的成矿构造体系，提出麒麟厂矿床主矿体向南西向侧伏，通过工程验证新增铅锌矿金属储量近100万t。     

离子色谱法测定硫化矿中高含量硫和砷

选定了混合熔剂的比例及用量,试样经半熔后制备成与淋洗液匹配的试样溶液,结合色谱条件的选择成功地将离子色谱法应用于硫化矿中高含量S和As的测定。含As 42.44％和含S20.97％的试样其相对标准偏差(n=8)分别为0.53％和0.47％     

黄沙脉钨矿床银的赋存状态及其综合利用

通过对黄沙脉钨矿床银的赋存状态研究,发现银主要赋存于铅铋矿物中,阐述了铅铋矿物的种类、嵌布特征和银的主要载体矿物及其分布规律,并提出了银应以生产银-铅-铋精矿的形式加于回收。     

利用大数据挖掘矿石中主要矿物之间的关系

近年来,借助于大数据技术的发展,地质学迎来了新的发展机遇,但目前利用大数据技术来分析矿物之间关系的研究还比较少。矿物是岩石、矿石的基本组成要素,通常都是以共存集合体的形式产出。矿物的产出不是随机的,而是按照一定的规律共生、伴生在一起。通过大数据技术挖掘出这种矿物的共伴生规律,能够更好地认识矿物之间的关系,对于指导找矿实践有积极作用。本文利用频繁模式挖掘、关联规则、网络分析以及社团检测这些常用的大数据挖掘方法进行了矿石主要组成矿物的大数据分析。所使用的矿石矿物组成数据来自于美国地质调查局的全球矿产资源数据系统(MRDS),该数据集收集了来自于全球的大量矿床中矿石的矿物组成数据。研究结果显示,通过关联规则可以挖掘出隐藏在矿石矿物成分大数据集中的频繁矿物组合,对于找矿勘查和认识矿物之间的关系有积极作用;关联规则挖掘出的规则是一种量化的推理规则,通过兴趣度度量指标能够定量地表征规则的强弱,这种规则相比于经验总结的规律更加定量化和精细化;通过网络分析能够对矿石中主要矿物之间的关系和共伴生规律进行动态、多维、定量的可视化;再结合社团检测可以从矿石矿物数据集中发现隐藏在其中的矿物之间的关系。     

陕西旬阳地区志留系铅锌矿矿集区特征及其成因初探

通过十多年的勘查及研究，在陕西旬阳—白河一带的志留系中新发现了大型铅锌矿矿集区。该矿集区东西长约100km，南北宽10—50km。区内有中志留统双河镇组和下志留统梅子垭组两个含矿层位及泗人沟—南沙沟、红土坡—韩氏沟—小沟、西营—黄石板三个成矿带。在成矿带内已发现20余处铅锌(铜)矿床(点)，资源丰富，找矿潜力较大。该矿床成因为细碎屑岩沉积—改造型铅锌矿床。