南岭地区两种类型盆地的压实流体系统及其矿化作用

盆地构造演化—流体系统—矿化作用是矿床学研究的前缘课题。盆地演化的特征直接影响盆地沉积建造的结构特征。建造结构和地球化学特征对压实流体系统的温度场、动力场、地球化学场和矿化作用产生决定性的影响。滇东南白牛厂早古生代盆地是典型的裂谷式凹陷盆地,上万米厚的黑色页岩与上部碳酸盐岩和砂岩组合有利于矿化的压实流体系统的形成,形成了白牛厂式超大型银多金属矿床。粤北晚古生代盆地为地台型浅海盆地,沉积物主要由透水性较好的粗碎屑物质和碳酸盐岩组成,沉积建造厚度较薄。数字模拟结果表明,粤北盆地压实流体系统难以形成较高的地热储和流体势,流体只能在沉积层的特殊部位汇聚并形成红岩型低温黄铁矿矿床。     

Marine debris accumulation in the nearshore marine habitat of the endangered Hawaiian monk seal, Monachus schauinslandi 1999-2001

Large amounts of marine debris are present in shallow reefs adjacent to beach haulouts of the critically endangered Hawaiian monk seal, Monachus schauinslandi. These areas serve as seal pup nurseries, and injury and death caused by entanglement in marine debris are undermining population recovery efforts. We investigated the extent of this threat by measuring the accumulation of potentially entangling derelict fishing gear in nursery zones, 1999-2001. Plots of reef 1.0-1.3 km2 at three Northwestern Hawaiian Islands were initially cleaned of derelict fishing gear in 1999 then resurveyed in 2000 and 2001. Submerged debris densities across sites ranged from 16 to 165 debris items/km2. Resurveyed sites yielded annual marine debris accumulation rates from 0 to 141 debris items/km2. This large range was attributed to the physiography of reef areas surveyed. Trawl net webbing was significantly more common than other types of debris recovered and represented 84% of all debris encountered, suggesting that much of the debris originated from distant North Pacific Ocean fisheries. The likely source of most debris is the multinational trawl fisheries of the North Pacific Ocean. An international solution to this problem is needed. Targeted marine debris removal is a short-term, successful, entanglement mitigation strategy.     

吉林海沟金成矿预测新思路——控矿构造层次

深部成矿预测已成为海沟金矿当务之急。为进一步加强区内,外找矿工作,本文提出金矿预测新思路－控矿构造层次。依据金矿产出地质条件的不同,将金矿控矿构造划分为中部,浅部,浅－表部和表部四个层次,每个层次都有特征性的控矿鉴别标志,分别反映出是大陆张裂、隆－滑和拆离构造等多种大陆壳动力学机制转变过程中的产物。最后通过纵、横向不同层次控矿构造特征变化规律进行成矿预测。     

云南耿马县老厂地区发现银、铅新矿点

老厂地区行政属于云南省耿马县勐简乡。地理坐标为东经99°2 1′4 6″—99°2 3′4 3″,北纬2 3°39′11″—2 3°4 1′2 0″,面积约为2 0km2 。山区最高海拔186 5m ,相对高差4 0 0m至千余米,工作条件较差。工作区绝大部分地段为山林植被覆盖,仅局部露头可辨别出下古生界浅变质     

成功的深部矿体定位预测——以山东夏甸金矿为例

山东夏甸金矿位于胶东招平断裂带中段。该地区不同时代多种典型构造动力机制交互叠置 ,构造岩复杂多样 ,岩浆活动发育 ,矿产丰富。运用复合成矿系统思想对该地区进行矿体定位预测 ,取得了初步成效 ,复合成矿系统的思想是翟裕生 (1992 )根据大宝山、铜官山等成矿实例提出 ,并认为不同时代成矿系列间的叠加复合是造成多成因矿床的重要原因 ,在我国多构造旋回区 ,这种成矿系列复合现象有更多的表现 ,可以作为区域成矿分析和成矿预测的一个重要思路。将复合成矿系统定义为 :在一定的成矿区带中 ,在不同地质时期形成的成矿系列间存在着复合关系 ,…     

胶东花岗-绿岩带金矿构造成矿动力学模型

微量元素与同位素地球化学反映胶东花岗-绿岩带金矿成矿物质具有多来源,尤其是地幔来源特征。地震波场、磁场与重力场揭示壳-幔结构与耦合机制是成矿系统物质、能量交换、聚集的根本动力学原因。在此基础上,结合构造环境演化史,将其构造成矿动力学模式表述为:太古宙—元古宙绿岩带产生、形成——金的矿源系统雏形;古生代构造环境稳定——金成矿作用间歇;中生代绿岩带强烈活化-改造——构造成岩成矿;新生代构造继承性活动——后期构造破矿作用。其中印支中晚期郯庐断裂带深切上地幔,通过壳-幔相互作用,将含矿流体系统输运到更高层位,蚀变、矿化作用发生。     

Crust-Mantle Structures and Gold Enrichment Mechanism of Mantle Fluid System

Gold enrichment mechanism of ore-forming fluid is the essence of gold metallization.This paper summarizes the distinguishing symbols of mantle fluid and effect of crust-mantle structure on fluid movement. Fluid moving processes include osmosis, surge, gas-liquid alterna-tion and mutation of fluid speed. During fluid movement, gold will be enriched gradually. Final-ly, a layered circulatory system is illustrated in this paper.