The Centennial Message:Retrospect and Outlook     

HOU Zengqian 《《地质学报》英文版》2022,96(1):1-2

The year 2022 marks the 100;anniversary for the founding of the Geological Society of China(GSC),one of the oldest scientific societies in China.The GSC was established to address a pressing need for like-minded people to exchange and disseminate ideas and knowledge of geology.  相似文献   

Hydrous Juvenile Lower Crust at the Western Yangtze Craton Margin as the Main Source of the Beiya Porphyry-skarn Au Deposit     

WANG Zixuan  ZHENG Yuanchuan  XU Bo  HOU Zengqian  ZHANG Aiping  SHEN Yang  MA Rui  WU Changd  XU Peiyan 《《地质学报》英文版》2022,96(3):972-992

The Beiya porphyry-skarn Au deposit is one of the largest gold deposits in China, temporally and spatially associated with Eocene intrusions in a post-collisional setting in western Yunnan, China. In this study, we report new whole-rock geochemistry, Sr-Nd isotope, zircon U-Pb geochronology and in situ zircon Hf-O isotopes of quartz-monzonite and biotite-monzonite porphyries from the Beiya deposit. The porphyry-skarn mineralization at the Beiya deposit is mainly associated with the quartz monzonite porphyry (35.8 ± 0.6 Ma), while the biotite-monzonite porphyry (34.3 ± 0.5 Ma) represents a post-mineralization intrusion crosscutting the main orebodies and the quartz-monzonite porphyry. Both intrusions have high-K and adakitic composition and are characterized by high Sr/Y ratios, high SiO2 and Al2O3 concentrations (SiO2 = 69.80–73.86 wt%; Al2O3 = 14.11–15.19 wt%), and low MgO, Cr, and Ni concentrations (MgO = 0.2–1.0 wt%; Cr = 1.76–11.13 ppm; Ni = 2.52–11.72 ppm). Their Sr-Nd isotope compositions (87Sr/86Sr = 0.7066–0.7077; εNd(t) = ?5.3 to ?1.5) are consistent with the lower crustal-derived amphibolite xenoliths (87Sr/86Sr = 0.7060–0.7100; εNd(t) = ?10.0 to 0.0), indicating that they might be derived from a thickened juvenile lower crust beneath the Yangtze Craton. The biotite-monzonite porphyry has lower zircon δ18O values of +5.3‰ to +6.8‰ and higher εHf(t) values of ?2.3 to +5.5 than those of the quartz-monzonite porphyry with δ18O values of +7.1‰ to +8.2‰ and εHf(t) values of ?3.8 to +1.5, implying that they were derived from different parts of the lower crust. High Ba/La and Pb/Ce ratios suggest that the quartz-monzonite porphyry is derived from a volatiles-rich reservoir. Relatively higher La/Yb, Sm/Yb and Dy/Yb ratios of the biotite-monzonite porphyry indicate residual garnet in the source, indicating a deeper source than that of the quartz-monzonite porphyry. The hydrous components should be represented by the amphibole-rich lithologies, which has relatively shallower depth than that of the garnet-bearing mafic thickened lower crust. Our data suggest that the mineralized quartz-monzonite porphyry at the Beiya deposit is derived from partial melting of amphibole-rich lithologies in the upper part of the thickened juvenile lower crust beneath the Yangtze Craton, while the post-mineralization biotite-monzonite porphyry is derived from the basal, and volatiles-poor, part of the juvenile lower crust.  相似文献   

Repeated Wildfires in the Middle Jurassic Xishanyao Formation (Aalenian and Bajocian Ages) in Northwestern China     

HOU Haihai  SHAO Longyi  LIANG Guodong  TANG Yue  ZHANG Huajie  ZHANG Jiaqiang 《《地质学报》英文版》2022,96(5):1752-1763

The coal-bearing strata in the southern Junggar Basin in northwestern China have recently attracted the attention of coal geologists. Its abundance of coal resources is of great interest as there is a potential of unlocking details about the palaeoclimatic information. Coal deposits have the capacity to record wildfire events, even those with inefficient combustions. To characterize wildfire events and palaeoclimatic history of the Middle Jurassic Xishanyao Formation (Aalenian and Bajocian ages), 22 coal samples from borehole cores and coal mines in the southern Junggar Basin were collected and their macerals were analyzed. The results indicated that fusinite and semi-fusinite were the dominant components of inertinite with proportions of 35.27% and 54.67%, respectively. The presence of inertinite is an indicator that wildfires occurred at the time of peat land development, and the widespread occurrence suggests large scale wildfires during the Middle Jurassic. This study proposes a new parameter for the evaluation of wildfire features by combining burning frequency and burning temperature. The comprehensive evaluation index (CEI) was influenced by the lacustrine basin level and ancient plant types from a sequence framework. During the Middle Jurassic, most wildfires were surface fires with low level and ground fire with high level. High oxygen levels were estimated in the lower, middle, and upper members of the Xishanyao Formation with corresponding to 26.78%, 24.55%, and 23.55%, respectively. The high oxygen levels would be the primary cause of repeated wildfires in the Middle Jurassic. These results are helpful for understanding palaeoclimatic changes in the Middle Jurassic.  相似文献   

基于SPAC法探测松科二井深层地热储水构造     

应恒成  李洪强  张玉敏  靳中原  张家铎  符伟  高磊  安栋召  潘宗栋  汪伟  侯贺晟 《地球学报》2022,43(6):909-916

微动探测技术作为一种获取地下地层速度结构和探测隐伏断裂构造的方法, 具有无须人工源、勘测过程便捷、抗干扰能力强的优势, 在城市、村庄浅层勘探中很受青睐。为进一步探索松辽盆地北部深层地热资源潜力, 在黑龙江省安达市南部松科二井及周边, 布设了一条微动探测剖面, 以获取该区嫩江组至坳陷层底部登娄库组地层的横波速度结构。基于空间自相关法(SPAC)从微动信号的垂直分量中提取S波频散曲线, 通过内插、光滑与反演计算, 获得了一条长9 km、探测深度达到地下4000 m的二维S波速度结构剖面。探测结果表明: 研究区地下S波速度总体呈现西高东低的趋势, 在松科二井西侧100 m、东侧2300 m、东侧3700 m处, 深度1400~2800 m范围内存在三个明显的低速异常带, 推测这些位置很可能存在断层或隐伏断裂构造。结合地层分层资料, 在该深度范围内以泉头组和登娄库组为主, 岩性多为砂岩和泥岩互层, 是良好的水热储层。本研究探索了基于空间自相关法的微动探测在识别深层地热储水构造的适用性, 为松辽盆地北部清洁能源调查指明方向。  相似文献   

辽东新岭铅锌银矿床成因：来自锆石U-Pb年龄、闪锌矿Rb-Sr年龄和H-O-S-Pb-He同位素证据     

何军成  刘军  王晓彤  侯可军 《矿床地质》2023,42(2):331-346

辽宁新岭铅锌银矿床位于华北克拉通东北缘,矿体赋存于古元古代辽河群变质岩中,受断裂构造控制。为了确定新岭矿床的成岩成矿时代、成矿流体和物质来源及其与中生代岩浆活动的关系,文章对新岭矿床开展了详细的矿床地质特征、年代学及同位素地球化学研究。结果表明,新岭矿床内与成矿有关花岗斑岩的LA-ICP-MS锆石U-Pb年龄为(227.3±1.5)Ma。5件闪锌矿样品的Rb-Sr等时线年龄为(222.9±2.9)Ma,初始Sr同位素比值为0.7104,确认新岭成岩成矿时代为晚三叠世。成矿流体的δ¹⁸O_W值介于4.7‰～7.6‰,δD_W值介于-97.7‰～-82.0‰,指示成矿流体主要为岩浆热液。黄铁矿³He/⁴He值介于0.15～0.21 Ra,进一步揭示成矿流体具有壳-幔混源特征。黄铁矿样品的LA-ICP-MS原位δ³⁴S值介于+3.9‰～+7.2‰,均值为+5.5‰。6件闪锌矿样品的铅同位素组成为²⁰⁶Pb/²⁰⁴Pb=17...  相似文献   

三叠纪末期全球生物大灭绝事件研究综述     

侯海海  张华杰  邵龙义  高莲凤  刘书君 《地质论评》2023,69(1):2023010017-2023010017

三叠纪末期生物大灭绝是全球地质历史时期五大生物灭绝事件之一,它致使海洋生态系统中约53%的属和80%的种灭绝。显著灭绝的生物包括菊石类、牙形类、放射虫类和陆地四足动物,发生部分灭绝的生物包括腕足类、介形类、双壳类和珊瑚类等。中大西洋火成岩省（CAMP）的爆发与三叠纪末期生物大灭绝在时间上具有较高的一致性,其火山的高强度和大面积喷发被认为是导致此次灭绝事件发生的主要原因。CAMP爆发释放出大量的CO2、SO2和CH4等气体,一方面温室效应促使海平面升高,物种栖息地面积减少、海洋酸化和海洋缺氧等事件直接威胁着海洋和陆地生物的生存环境;另一方面温室效应亦会引发全球性森林火灾,造成陆地植物减少,大量植物碳屑注入海洋使其发生富营养化,又因伴随海洋酸化作用（碳酸化和硫酸化）,海洋古生产率发生崩溃。不同地质时期生物大灭绝的发生往往伴随着剧烈的环境变化,在三叠纪末生物大灭绝期,这些变化多表现为古大气成分和古气温动荡、古火灾频繁、海洋酸化、海平面升高和海水缺氧等,它们之间的综合作用最终导致三叠纪末期全球生态系统失稳。在全球多个三叠纪—侏罗纪之交（TJB）剖面均可以识别出3次明显的碳同位素负偏移,最显著的1次发生于瑞替期末,早于TJB。上述情况说明,三叠纪末期生物大灭绝虽然是全球性事件,但并不是1次发生的,具有分阶段性、非同步性、区域性和有选择性等特点。  相似文献   

三叠纪末期全球生物大灭绝事件研究综述     

侯海海  张华杰  邵龙义  高莲凤  刘书君 《地质论评》2023,69(4):1434-1448

三叠纪末期生物大灭绝是全球地质历史时期5大生物灭绝事件之一,它致使海洋生态系统中约53%的属和80%的种灭绝。显著灭绝的生物包括菊石亚纲、牙形类、放射虫目和陆地四足动物,发生部分灭绝的生物包括腕足动物门、介形亚纲、双壳纲和珊瑚纲等。中大西洋火成岩省(CAMP)的爆发与三叠纪末期生物大灭绝在时间上具有较高的一致性,其火山的高强度和大面积喷发被认为是导致此次灭绝事件发生的主要原因。CAMP爆发释放出大量的CO₂、SO₂和CH₄等气体,一方面温室效应促使海平面升高,物种栖息地面积减少、海洋酸化和海洋缺氧等事件直接威胁着海洋和陆地生物的生存环境;另一方面温室效应亦会引发全球性森林火灾,造成陆地植物减少,大量植物碳屑注入海洋使其发生富营养化,又因伴随海洋酸化作用(碳酸化和硫酸化),海洋古生产率发生崩溃。不同地质时期生物大灭绝的发生往往伴随着剧烈的环境变化,在三叠纪末生物大灭绝期,这些变化多表现为古大气成分和古气温动荡、古火灾频繁、海洋酸化、海平面升高和海水缺氧等,它们之间的综合作用最终导致三叠纪末期全球生态系统失稳。在全球多个三叠...  相似文献   

镜泊湖地区杏山火山群的火山岩特征及其岩浆演化     

郭可欣  刘永顺  聂保锋  郭磊  张辉  黄志聪  侯鹏  李耀 《地质论评》2023,69(4):2023040014-2023040014

镜泊湖火山区是我国陆内新生代玄武岩研究的一个重要窗口。东南部的杏山火山群研究不足且前人的研究否定了其岩浆经历过同化混染作用。本文对杏山火山群玄武岩开展了系统的岩石学、岩石地球化学和Sr—Nd—Pb同位素的研究,认为杏山火山群主要为碧玄岩和粗面玄武岩,原生岩浆在上升过程中发生了橄榄石和单斜辉石的分离结晶,并在上地壳区域发生了同化混染作用,但同化混染—分离结晶作用较为微弱。将杏山火山群与同期镜泊湖玄武岩对比发现,两个地区的玄武岩都来源于石榴石橄榄岩的部分熔融,杏山火山群的部分熔融程度略低于同期镜泊湖玄武岩。在岩浆源区方面,杏山火山群的岩浆源区为普通地幔与全硅酸盐地球端元的混合源。岩浆源区的不均一性和岩浆演化过程中所经历的同化混染作用是造成杏山火山群和镜泊湖火山群的岩性差异的主要影响因素。  相似文献   

辽宁大连地区中-新元古界砂岩盐风化穴的发现及意义     

吴子杰  邱隆伟  王海鹏  仲米山  高福亮  侯静  李欣 《地质论评》2023,69(3):2023030024-2023030024

A small honeycomb tafoni was found on the surface of the Meso-Neoproterozoic sandstone in Wafangdian area, Dalian, Liaoning Province. It is located on the surface of the northwest side of the outcrop sandstone layer. On the top surface of the sandstone layer and on the east and south sides, the tafoni was not developed. The whole tafoni is round or oval, with a diameter of 1-5cm and a depth of 1-2cm. Through field observation and comparative analysis, it is determined that it is the salt weathering tafoni. It is formed by the precipitation and crystallization of salt from sea fog in sandstone, which causes the detrital particles on the rock surface to fall off and weathering.  相似文献   

上合组织青岛峰会期间海雾维持和消散阶段的环境场特征          下载免费PDF全文

侯淑梅  杨成芳  王建林  孟宪贵  郭庆利  韩永清 《山东气象》2019,39(1):86-94

利用常规观测、地面加密自动站及NCEP再分析资料,针对上合组织青岛峰会的气象服务过程,对海雾维持和消散两个阶段的气象要素特征进行了分析。结果表明：1）当能见度低于1 000 m时,相对湿度为99%,能见度介于1 000～2 000 m之间时,相对湿度为95%～99%。2）近地面层30°N以北黄海海域持续吹东南风,并在青岛形成水汽辐合中心,有利于青岛形成海雾;当东南风转为东北风,水汽辐合中心减弱或消失时,海雾趋于消散。3）在海雾维持阶段,逆温层最低高度稳定在980 hPa以下,总逆温差逐渐增强,逆温梯度跃升与海雾强度增强同步;最大逆温层厚度和逆温层总厚度下降12 h后海雾逐渐减弱,逆温层最低高度上升时能见度也随之上升。4）白天逆温层之上为下沉运动,之下为上升运动,夜间700 hPa之下均为上升运动,且上升运动中心位于逆温层之下,这种垂直结构有利于逆温层和海雾的维持;当逆温强度减弱,垂直运动穿越逆温层贯穿700 hPa以下对流层时,海雾趋于消散。  相似文献