The formation of explosive volcanos at the circum-Pacific convergent margin during the last century

Journal of Oceanology and Limnology - The circum-Pacific convergent margin is known as “the Ring of Fire”, with abundant volcano eruptions. Large eruptions are rare but very disastrous....     

Galvanic interaction between grinding media and arsenopyrite and its effect on flotation: Part I. Quantifying galvanic interaction during grinding

The Magotteaux Mill® system was used to quantify the galvanic interaction between four types of grinding media (mild steel, 15% chromium, 21% chromium, and 30% chromium media) and arsenopyrite, in situ of the mill. The galvanic current was determined from the polarization curves of individual electrodes, in situ of the mill. The high chromium media had a significantly weaker galvanic interaction with arsenopyrite, and produced a very much lower amount of oxidized iron species in the mill discharge than mild steel medium. Increasing the dissolved oxygen in the mill slurry enhanced galvanic interaction. A theoretical model was developed to describe the relationship between galvanic current and oxidized iron species in the slurry, as measured by EDTA extraction. The electrochemical data were correlated with the measurement of oxidation products after grinding under different conditions. The stronger the galvanic interaction, the higher the amount of hydrophilic oxidized iron species in the mill discharge.     

韧性剪切构造成岩成矿作用及对金矿化的控制--以内蒙古武川县后石花金矿为例

本文以内蒙古中部后石花金矿为例,简述了"韧性剪切构造成岩成矿作用"的新观点.研究表明,韧性剪切成岩过程包括细粒化作用、热流体作用、酸碱交代作用;韧性剪切带这种深层次断裂构造形成过程中,其推覆演化是逐渐减压过程,降压效应和剪切带本身的膨胀渗透作用,引起了剪切带内部积累的能量梯度(压力、温度、物质),导致弥漫于大面积围岩中和下地壳的液体进入韧性剪切带中."节流阀"作用形成韧性剪切成岩成矿热液系统.韧性剪切构造对金矿的控制核心是成岩成矿为统一的热动力系统,早期以成岩为主,中晚期以蚀变和矿化为主.     

藏北高原现代火山的航空象片与地图分析

本文应用航空象片和地形图分析了藏北地区现代火山和分布,对研究藏北高原火山活动有一定参考价值。     

龙门山陆内复合造山带的四维结构构造特征

位于扬子陆块和松潘陆块过渡带上的龙门山造山带,是在印支期中国大陆主体拼合和秦岭造山带形成过程中开始发育、燕山期陆内构造活动中继承发展、喜马拉雅期印-亚碰撞和青藏高原隆升过程中遭受改造并定型的。现今构造面貌是扬子陆块向北漂移过程中产生的北西向推挤力、源自秦岭造山带的南北向推挤力和源自青藏高原的东西向推挤力三者联合作用的结果,因此是一个典型的陆内复合造山带。其陆内复合结构构造特征具有下列特点。 1）倾向上,龙门山造山带由茂县-汶川断裂、北川-映秀断裂、安县-灌县断裂和广元-大邑（隐伏）断裂4条主干断裂分隔显示出明显的分带变形特征,由北西向南东具有层次渐浅、强度递减、卷入层位变新的趋势,总体上呈前展式扩展。 2）走向上,龙门山造山带呈现北、中、南段三分格局,它们在基底性质及展布、地层发育及演化历史、变形特征、沉降与隆升特征、活动构造等多个方面具有差异。 3）垂向上,龙门山造山带发育多层次滑脱构造,最重要的滑脱界面是15～20 km深处的低速层和中下三叠统富膏盐岩层,由此控制了深浅构造不一致的变形幅度和变形样式。 4）时间演化上,龙门山造山带表现出倾向上的前展式扩展和走向上的分段式递进性或序次性演化的趋势：印支期,龙门山中北段活动较强,由北东向南西逐渐扩展,主要为挤压逆冲和左旋走滑作用; 燕山期,构造活动总体上趋于相对平静,具有南北分段、由北东向南西迁移的特征; 喜马拉雅山期,龙门山中南段活动较强,由南西向北东逐渐扩展和递进,主要为挤压逆冲、隆升和右旋走滑作用。     

西藏冈底斯成矿带东段中、新生代斑岩成矿系统岩石地球化学与年代学测试数据集

西藏冈底斯成矿带东段中—新生代斑岩成矿系统岩石地球化学测试数据集基于冈底斯成矿带地质矿产调查项目“西藏冈底斯东段中新生代斑岩成矿系统与找矿预测”资助,进行岩石测试分析整理而得。岩石地球化学与地质年代学数据可以全面地反映岩石与矿床成因、成岩与成矿年龄等重要信息,为西藏冈底斯成矿带东段中、新生代斑岩矿床成矿背景与成矿模式研究提供科学依据和基础数据支撑。本数据集为Excel表格型数据,包括3个.xlsx类型文件（majorelement_Gangdise.xlsx,traceelement_Gangdise.xlsx,reos-upb_Gangdise）分别记录主量、微量、测年数据,其中majorelement_Gangdise.xlsx包含141条记录和105个字段,traceelement_Gangdise.xlsx包含273条记录和166个字段,reos-upb_Gangdise包含208条记录和100个字段。其中,主量、微量元素数据涉及与邦铺、达布、程巴、甲玛4个矿床有关的5个岩体。测年数据包括邦铺钼多金属矿床黑云母二长花岗岩等4组锆石U-Pb年龄数据,达布铜（钼）花岗岩体等3组锆石U-Pb年龄数据,甲玛铜多金属矿床5组Re-Os年龄数据,邦铺钼多金属矿床2组Re-Os年龄数据。本库提供全部测试均在国家知名测试数据实验室进行,数据质量可靠。     

基于房地产价格空间溢出的广州城市内部边界效应

中国行政区经济导致市场分割的现象普遍存在,从房地产价格空间溢出角度,采用2005 年广州市房地产价格数据,通过扩展的Hedonic 模型,在分析价格的空间自相关和价格溢出程度的基础上,对城市内部区一级的边界效应进行了检验。研究结果表明：2005 年广州区与区之间的行政区边界效应显著存在,并存在着市场分割现象,中心老城区之间的边界效应小于城乡结合部地区的边界效应,自然条件和城乡历史对边界都有显著的影响。     

Water Soluble Gas in Deep Carbonate Reservoir,Sichuan Basin,Southwest China

Based on temperature and pressure of fluid inclusion,phase of organic inclusion in calcite and quartz filled in vug in the deep carbonate reservoir and the natural gas composition in Weiyuan (威远) gas field in Sichuan (四川) basin,research indicates that water soluble gas exists in deep carbonate reservoir,which reconstructs development and effusion process of water soluble gas.The overpressure formed during oil thermal cracking can reach 105-170 MPa in Sinian and Cambrian reservoir in Central Sichuan and 78-86 MPa in Cambrian reservoir in Southeast Sichuan.The high temperature caused by deep burial and overpressure caused by thermal cracking make thermal cracking gas dissolve in water so that it becomes water soluble gas.The ratios of gas to water can reach 50-90 m3/m3and 10-30 m3/m3,respectively,in deep carbonate reservoir in Central and Southeast Sichuan.Methane dissolving in water exists in form of liquid phase.Until now,the decreases in temperature and pressure due to the uplift during 74 Ma make water soluble gas separate from water,water soluble gas pool or mixed gas pool of thermal-cracking gas and water soluble gas are modified or even destroyed in varying degrees.This may be the case of Weiyuan gas field.     

Fluid flow and mineralization of Youjiang Basin in the Yunnan-Guizhou-Guangxi area,China

Comprehensive studies, based on isotope geochemistry of C, H, O, S and Sr, chronology, common element and trace element geochemistry of fluid inclusions for the epithermal Au, As, Sb and Hg deposits in the Youjiang Basin and its peripheral areas, suggested that the ore fluid was the basin fluid with abundant metallic elements and the large-scale fluid flow of the same source in the late Yenshan stage was responsible for huge epithermal mineralization and silicification. The ore fluid flowed from the basin to the platform between the basin and the platform and migrated from the inter-platform basin to the isolated platform in the Youjiang Basin. The synsedimentary faults and paleokast surface acted respectively as main conduits for vertical and lateral fluid flow.