Hydrothermal dolomitization,mixing corrosion and deep burial porosity formation: numerical results from 1‐D reactive transport models

Major corrosion has been found at depth in carbonate hydrocarbon reservoirs from different geologic provinces. Fluid inclusion microthermometry and stable isotopic compositions of carbonate cements, predating major corrosion, constrain the interpretation of the evolution of parental fluids during progressive burial and prior to the major corrosion event. Post‐major corrosion mineral paragenesis includes pyrite (‐marcasite), anhydrite, kaolinite (dickite) and fluorite. Although the post‐corrosion mineral paragenesis represents minor volumes of rock, it may provide valuable insights into the post‐corrosion brine chemistry. Using reactive transport numerical models, the roles of cooling and/or mixing of brines on corrosion have been evaluated as controls for dolomitization, deep burial corrosion and precipitation of the post‐corrosion mineral paragenesis. Modelling results show that cooling of deep‐seated fluids moving upward along a fracture may cause minor calcite dissolution and porosity generation. Significant dolomitization along a fracture zone and nearby host‐rock only occurs when deep‐seated fluids have high salinities (4 mol Cl kg^?1 of solution) and Darcian flow rates are relatively high (1 m³ m^?2 year^?1). Only minor volumes of quartz and fluorite precipitate in the newly formed porosity. Moreover, modelling results cannot reproduce the authigenic precipitation of kaolinite (dickite at high temperatures) by cooling. As an alternative to cooling as a cause of corrosion, mixing between two brines of different compositions and salinities is represented by two main cases. One case consists of the flow up along a fracture of deep‐seated fluids with higher salinities than the fluid in the wall rock. Dolomite does not precipitate at a fracture zone. Nevertheless, minor volumes of dolomite are formed away from the fracture. The post‐corrosion mineral paragenesis can be partly reproduced, and the results are comparable to those obtained from cooling calculations. Minor volumes of quartz and fluorite are formed, and kaolinite‐dickite does not precipitate. The major outputs of this scenario are calcite dissolution and slight net increase in porosity. A second case corresponds to the mixing of low salinity deep‐seated fluids, flowing up along fractures, with high salinity brines within the wall rock. Calculations predict major dissolution of calcite and precipitation of dolomite. The post‐corrosion mineral paragenesis can be reproduced. High volumes of quartz, fluorite and kaolinite‐dickite precipitate and may even completely occlude newly formed porosity.     

国民经济恢复时期北京的失业知识分子救济政策及其成效

国民经济恢复时期,面对失业和人才需求关系的矛盾,城市失业知识分子受到党和政府的高度关注。北京市的失业知识分子虽人数不多,但呈现出一定程度的复杂性。为此,北京市根据党和国家的政策,从首都社会秩序的稳定和首都建设的人才需求出发,在较短的时间内,有计划有步骤地对失业知识分子进行了必要的社会救济,达到了预期的目标。同时,实际操作中也遇到了一些不容回避的问题。     

郑州市南阳路家世界购物广场战国墓葬发掘简报

2003年10-12月,郑州市文物考古研究所配合基本建设,在郑州市南阳路家世界购物广场工程区发掘一批战国墓葬,出土大量随葬器物,以陶器为主,其年代为战国中、晚期。     

就石片台面研究问题答李炎贤

石片包括了各种类型台面的石片,石片台面的分类可以视为石片分类的一种。旧石器时代考古术语需要斟酌和规范。科学研究必须实事求是。     

从"资治"到"救国"--关于19世纪史学经世致用思想变化之研究

自19世纪40年代伊始,中国社会所发生的空前的沧桑巨变,直接推动了史学由古代史学向近代史学的转变。这种转变的重要标志之一,就是史学经世致用思想的变化,即史学经世致用思想从“资治”到“救国”,从着眼于王朝治乱兴衰到关注国家和民族前途命运之经世致用的宗旨和参照系的变化。同时,这种变化又对整个19世纪中国史学的发展及其走向产生了重大而深远的影响。     

当前高句丽史研究中的几个问题

本认为,经过百多年的研究,高句丽史研究已经有了雄厚的学术基础。在新的历史条件下,为了高句丽史研究的理论形态和实践形态发展得更充分,就应该在研究方法和研究手段上有所创新。进而从联系起来研究、专门化研究、献资料和考古资料的关系、“一史两用”和“双向继承”等方面阐明了对高句丽史研究的认识。     

"虚拟"先人与十九世纪新加坡华人社会--兼论海外华人的"亲属"概念

在东南亚殖民地时代,"虚拟血缘"的组织原则对于华人移民社会的重组重建及其运作,具有重要的意义.本文以19世纪的新加坡为个案,考察华人移民如何透过埋葬先人的坟山组织建构"社群共祖"以整合华人社会,讨论东南亚华人虚拟的"先人"或"祖先"概念,进而思考海外华人的亲属研究问题.本文也讨论与比较了"虚拟血缘"组织原则在明代华南宗族"联宗"形态、台湾汉人社会发展早期的"合约式"宗族和东南亚华人坟山组织的不同运用.     

《春秋·庄公三十二年》伐邢之"狄"考

《春秋》所载伐邢之"狄"应为商人.在邢国墓葬考古中,发现有"毁墓"现象,由年代和情势判断,只能是对邢有"亡国"之恨的商人所为.狄也叫戎.戎在金文中写作" ",最初是商王小乙之子"子 "的氏族徽志.这个氏族一部分居于王畿北境,今河北新乐一带,负守土之责.周公东征后逃匿太行山中.狄也作翟.翟,《说文》云"山雉尾长者",《赵世家》云"子姓".图腾和族姓皆与商人相同.     

Planting Roots,Making Place: Urban Autochthony in Port Vila Vanuatu

A contentious issue for Pacific Islanders, as well as researchers of the Pacific Islands, is ni-Vanuatu notions of ‘belonging’ to urban centres. Previous research in Vanuatu has shown that despite generations of people born and raised in Port Vila, the nation's capital, the urban centre is not generally perceived as a ‘place’ to which urban migrants can say they are from. For many, exclaiming that one is ‘from’ town is tantamount to admitting one has ‘no place’. This paper, based on fieldwork among a group of urban young men in Freswota, a residential community of Port Vila, argues that in contrast to this, Freswota young men are generating a new locative identity. Their urban community rather than their parents' home island places is emerging as their primary location of belonging and the source of their sense of self, personhood and social identification. As such, these young men are the urban autochthones of the country.     

民族互嵌视野下的畲族海外移民研究——基于浙南文成侨乡的田野调查

论文以浙南侨乡文成县为田野调查点,基于畲汉民族互嵌的视角,分析了文成畲族海外移民的历史背景、动力机制、发展现状,阐释了侨乡畲族海外移民的时代意义。浙江文成县畲族海外移民既是中国改革开放的时代产物,也是文成县侨乡文化强烈辐射和畲族与汉族良性互动的结果。其深层动因则源于文成畲汉民族关系由形式上的互嵌向结构性的互嵌之顺利转型。文成畲族海外移民案例,标志着畲族历史变迁中的时代飞跃,有利于缩小畲汉发展结构性差异和增强畲汉民族关系的和谐,对当今畲族乡村振兴和畲汉民族关系发展亦具有重要启迪意义。