【作者】 陈远荣；

【导师】 戴塔根；

【作者基本信息】 中南大学 ， 矿产普查与勘探， 2001， 博士

【摘要】 国内外大量地质、地球化学工作者研究发现，许多金属矿床的成矿均或多或少存在有机质的参与，而目前国内外将有机烃气测量法应用于金属矿产勘查尚处于初级试验阶段，是一个前沿性的气体测量研究领域，为了进一步完善该方法技术，使其由试验研究阶段上升到推广应用研究阶段，促进对成矿作用、成矿过程、成矿规律、气体运移规律和找矿预测的全面认识，并促进有机地球化学和无机地球化学、固体地球化学和气体地球化学、勘查地球化学和矿床学等不同领域的相互渗透。笔者选择“有机烃气新方法寻找有色、贵金属矿床的研究”为本人的博士研究生毕业论文。 通过对有机物与金属成矿、各类金属矿床烃类异常源分析、典型矿床方法有效性试验、最佳野外工作方法、异常模式与成因机制、干扰因素认识与消除和未知区的应用评价等方面进行近三年的研究，获得了如下主要成果和认识。 1、首次系统地对各类矿石、岩石、矿物气液包裹体等进行了烃类组分分析，结果发现，各种金、银、锡、铅、锌、铜、锑等金属矿床（包括岩浆期后中高温热液矿床）的成矿过程均不同程度地存在有机物的参与，至今仍存在很高的烃气含量，甚至高达几万μl/Kg。相对地，烃类在不同矿种之间，其含量具有金矿＞锡矿＞铅锌矿、锑矿＞铜钼矿＞铁、锰矿的变化规律。另一方面，对矿体周围不同空间区段的围岩进行烃类测量的结果表明，即使是象个旧、大厂这样的中高温热液锡多金属矿床，或是象马鞍桥那样的剪切带热液交代变质型金矿，矿体周围现今仍存在以矿体为中心的烃类晕圈异常（可为空心，也可为实心）。这充分表明利用有机烃气测量法寻找有色、贵金属矿床具有坚实可靠的理论基础。 2、众多研究证据表明，有机质参与金属成矿的作用极为广泛，从矿质的初始富集到活化转移（包括热卤水淋滤活化转移，岩浆重熔作用活化转移等各种转移方式）、富集成矿，直至矿体形成后的变质改造整个成矿过程，均存在有机物的“身影”。只是由于有机物在不同温度条件下的激烈相变，即在矿质初始富集阶段，温度低，有机物大多表现为原始有机碳；成矿元素活化、迁移和中低温热液阶段表现为残留有机质、烃气、有机络合物，岩浆和中高温热液阶段表现为烃类气体、残留碳质和沥青；超高温阶段（温度高达600℃以上时）时表现为纯甲烷气甚至碳质、H₂和CO₂。而气体类极易散失，难于捕捉。以致于人们很难相信，在中高温矿床成矿中存在有机物的参与，利用有机烃气测量寻找金属矿的研究也因此被长期忽略。 3、有机物不仅是金属元素活化和迁移的重要介质和催化剂，而且有机物热降解产生的大量气体可使内压激增，导致岩石产生微裂隙，或引起原已存在的微裂隙反复开张与闭合，为矿源层中的成矿元素捧出和汇聚提供通道和动力，继而进一步共同运移到有利的空间沉淀、富集成功。 4、研究表明，在金属矿产勘查中，大多数情况下以土壤酸解烃测量法最为合适。该方法野外工序简单，样品运输方便，获取的异常信息结果稳定，重现性好。 5、首次论述了土壤烃气测量的野外工作方法在金属矿产勘查中与油气勘查中的异同点。共同点是最佳取样深度均为60～80cm，用于分析烃类的最佳富集粒度均是40～120目，差异点主要网密度，以详查评价为例，金属勘查中的点线距以 Zffe50X 10M00米居多，而油气勘查中的点线距以25(k400X50pe75米为主。 6、经十几个典型矿床的试验研究表明，从地表景观看，无论是北方高原黄土覆盖区、云南高山红壤、黄壤区，还是南方中低山、丘陵的红土、黄上、水稻田分布区，在大多数金属矿床上方均不同程度地存在有机烃气异常反映；从矿种看，金银矿、锡矿、铅锌矿、铜铝矿、铜镍矿、锑矿等矿种均存在有机烃气的踪迹：从矿床类型看，无论是层控矿床（如泅顶铅锌矿）、海底喷流沉积矿床（如庆丰铅锌矿）、中低温热液矿床（如康家湾铅锌金银矿）、中高温热液矿（如个旧锡矿、大厂锡矿）、沉积变质型铜矿（如水泄铜、桐木沟铜矿）、韧性剪切带型金矿（如金山金矿）、石英脉型金矿（如柴胡栏子金矿）、矽卡岩型铜钥矿（如铜陵某铜钥矿）等等，其地表亦都有烃气异常显示：从埋藏深度看，不仅在地表矿和浅埋矿上方有异常显示，而且在埋深达60ffe700米的盲矿（如中条山桐木沟铜矿、个旧松树脚锡矿），其地表依然有良好的烃类异常。由此充分表明了有机烃气测量法在金属矿产勘查中适用范围非常广阔。笔者深信，在寻找深埋藏盲矿方面，它具有其它传统地球化学勘查方法无法比拟的独特优势，并将在今后金属矿产勘查中发挥更大的作用。 7、初步研究表明，在各类金属矿床上方，有机烃气和汞在剖面上存在五大类综合异常模式。即不对称对偶双峰式，对称对偶双峰式，顶端单峰式，烃类双峰、汞单峰混合式，多峰（峰丛）式。其中，以对偶双峰式（可为对称，亦可不对称）居多。 8、经初步研究表蛙．金属矿床上方形成各类烃汞异常模式的主要决定因素有四个：一是烃汞运移的通道：二是成矿期的热差效应；三是金属硫化物的氧化作用；四是地温差异。 9、提出了就某一矿区或矿田而言，烃类含量的高低?更多还原

【Abstract】 Organic materials had been participated more or less in the whole mineralization process of metallic ore deposit were discovered by many geologists and geochemists at home and abroad. But at present, the organic hydrocarbon survey for metallic ore deposit prospecting belongs to the first test period yet and is a forward research field of gas geochemical prospecting. The main goals of writer to select the title of "Study on A New Method of Organic Hydrocarbon for Exploration of Nonferrous and Precious Metal Deposits" as the dissertation of doctor degree are: a. To consummate this new technique further, and to lead it up to popularization from test. b. To promote the overall understanding about the genesis, process and regularity of mineralization, the migration of gas and the forecast of prospect, c. To impel to infiltrate each other between organic geochemistry and inorganic geochemistry, solid-earth geochemistry and gas geochemistry, exploration geochemistry’ and study of mineral depositAfter study for three years on the organic mass and metallization, the genesis of hydrocarbon anomalies of different metallic deposits, the test effectiveness of the method upon typical metallic deposits, the suitable fieldwork plan, the anomaly patterns and their mechanism of formation, the discernment and prospecting appraisal in unknown area, some achievements have been gotten as follows:1. After analysis of hydrocarbon to different kinds of ore, rock and inclusion, it is discovered that organic materials had been more or less participated in the mineralization process of AurAg,Sn,Pb,Zn,Cu,Sb deposits (include some mid-high temperature deuteric hydrothermal deposits). At the same time, higher content of hydrocarbon has been well preserved to present, even more than tens thousands uu I/kg. Comparatively speaking, the contents of hydrocarbon among different metallic deposits have the law of gold>tin>zinc lead and antimony>copper and molybdenum>iron and manganese. More over, it is discovered that there is a hydrocarbon halo till now around the ore body at middle-high temperature hydrothermal deposit (such as Gejiu and Dachang tin-multi-metallic deposits), or ductile shear zone deposit (such as Maanqiao gold deposit),by the hydrocarbon survey to the wall rocks of ore body in different spatial sections. These results show us fully that the hydrocarbon survey for exploration of nonferrous and precious metal deposits has a firm and reliable theoretical basis.2. Many evidences show that the organic materials exist in whole process of mineralization, from the initial concentration of mineral elements to mobilized migration (include leached out by hot brine, remobilized by remelting of magma, etc.). mineralization epoch and super imposition andreconstruction period. But organic material will changed its phase state intensely under different temperature conditions: a. In the period of initial concentration of mineral elements, the temperature is lower, and the organic material shows raw organic mass. b. In the stage of mobilization and migration of elements, and the stage of low-middle temperature hydrothermal activity, it will be transformed to hydrocarbon, organic complex and debris, c. In the period of magma formation and middle-high hydrothermal contribution, it shows hydrocarbon, carbon and asphalt, d. In the super high temperature (over 600"C) period, it shows methane, even changes to carbon,H2 and CO2. Because gas is easy to disperse away and difficult to capture, so, it is unbelievable that the organic material had been participated the mineralization process of middle-high temperature metallic deposits, and this lead organic hydrocarbon survey for prospecting of metallic deposits to be neglect for a long-term.3. The organic material is the important media and catalyst of mobilized migration of metallic elements. A huge amount gas which is produced by heat degradation from organic materials will increase the inner pressure sharply, lead the rock to produce micro-fissures, an更多还原