滇西陇川断陷盆地地热水化学特征及循环过程     

黄琴辉  张华  康晓波  王波  刘海峰  柴金龙  黄钊  王燕 《中国岩溶》2020,39(6):793-801

通过对陇川盆地开展地热地质调查，查清其地热资源分布:盆地内共出露地热点11处，热储结构类型为带状型和层状型，盆地中部为层状型，两侧盆地边缘为带状型，其中北西部受断裂控制明显，南东部受节理裂隙控制明显。其储热层为变质岩及新近系芒棒组的花岗质砂砾岩、细砂岩；地热水受大气降水影响明显，循环深度都在1 600 m以上，大部分在1 800~2 400 m之间，主要来源于深部热源，通过断裂、裂隙及砂砾石孔隙作为导水、储水上涌通道，接收来自山区补给的地下水混合出露于地表，补给距离在1.5 km以上，如南宛河温泉温度最高，地下水循环深度最深，补给距离最远，达10 km；盆地北东和西部水温高，循环深度深。   相似文献   

文昌B凹陷差异伸展- 走滑机制及控藏作用研究     

江汝锋  周家雄  杨希冰  游君君  李珊珊  陈林  张霞 《地质学报》2020,94(8):2422-2432

为查明文昌B凹陷油气富集差异性的原因，基于断裂展布和形成期次、构造样式组合、构造演化和断层活动的差异等标志，建立了差异伸展- 走滑机制，识别出19洼为伸展- 强走滑、14洼为伸展- 中等走滑、30洼为伸展- 弱走滑。差异伸展- 走滑作用控制了优质烃源岩的展布和供烃方向，控制输导体系类型和运移动力，提供物源通道和改造储层，还控制了圈闭类型和力学性质。进一步深化了走滑增压理论，基于先存断裂形态、伸展应力场右旋演化和应变差异，建立了走滑增压圈闭识别方法，识别出S型增压、右行左阶增压、斜交型增压3种走滑增压构造。研究表明，文昌B凹陷的油气富集受伸展- 走滑构造背景、源- 运时空配置关系所控制，强—中等走滑变形、发育优质中深湖源岩的文昌19洼和14洼是油气富集区。该研究成果成功推动了文昌凹陷近期的多个勘探发现。  相似文献   

中国陆相油页岩含油率与总有机碳的响应机理     

贾建亮  刘招君  孟庆涛  孙平昌  徐进军  柳蓉  白悦悦 《吉林大学学报(地球科学版)》2020,50(2):368-377

为了建立稳定可靠的利用油页岩总有机碳预测含油率的模型，揭示中国陆相不同成因类型油页岩含油率与总有机碳的内在关系极其重要。通过不同类型盆地油页岩钻井取心测试的关键参数，结合沉积学、有机地球化学、热模拟等学科技术，探讨油页岩含油率与总有机碳的响应机理。结果表明：不同盆地类型与沉积背景下发育的油页岩含油率与总有机碳质量分数均呈现良好的正相关性（R²=0.81~0.97）；中国陆相油页岩的成因类型进一步划分为5种类型，制约着含油率与总有机碳的内在关系；油页岩的升温加热模拟呈现3个失重阶段（温度<150、300~550、600~750℃），明确了含油率与总有机碳参数的物理意义；相同类型盆地与沉积背景下形成的油页岩具有相近的母质生源组合，从而具有大致相当的再生烃效率。中国陆相油页岩成因类型的细划、含油率与总有机碳物理意义的明确、油页岩再生烃能力的分析，有助于理解中国陆相油页岩含油率与总有机碳的内在响应关系。  相似文献   

Seismic‐stratigraphic constraints on the age of the Faroe Islands Basalt Group,Faroe–Shetland region,Northeast Atlantic Ocean     

Jana lavsdttir  Martyn S. Stoker  Lars O. Boldreel  Morten Sparre Andersen   luva R. Eidesgaard 《Basin Research》2019,31(5):841-865

Lower Palaeogene extrusive igneous rocks of the Faroe Islands Basalt Group (FIBG) dominate the Faroese continental margin, with flood basalts created at the time of breakup and separation from East Greenland extending eastwards into the Faroe‐Shetland Basin. This volcanic succession was emplaced in connection with the opening of the NE Atlantic; however, consensus on the age and duration of volcanism remains lacking. On the Faroe Islands, the FIBG comprises four main basaltic formations (the pre‐breakup Lopra and Beinisvørð formations, and the syn‐breakup Malinstindur and Enni formations) locally separated by thin intrabasaltic sedimentary and/or volcaniclastic units. Offshore, the distribution of these formations remains ambiguous. We examine the stratigraphic framework of these rocks on the Faroese continental margin combining onshore (published) outcrop information with offshore seismic‐reflection and well data. Our results indicate that on seismic‐reflection profiles, the FIBG can be informally divided into lower and upper seismic‐stratigraphic packages separated by the strongly reflective A‐horizon. The Lower FIBG comprises the Lopra and Beinisvørð formations; the upper FIBG includes the Malinstindur and Enni formations. The strongly reflecting A‐horizon is a consequence of the contrast in properties of the overlying Malinstindur and underlying Beinisvørð formations. Onshore, the A‐horizon is an erosional surface, locally cutting down into the Beinisvørð Formation; offshore, we have correlated the A‐horizon with the Flett unconformity, a highly incised, subaerial unconformity, within the juxtaposed and interbedded sedimentary fill of the Faroe‐Shetland Basin. We refer to this key regional boundary as the A‐horizon/Flett unconformity. The formation of this unconformity represents the transition from the pre‐breakup to the syn‐breakup phase of ocean margin development in the Faroe–Shetland region. We examine the wider implications of this correlation considering existing stratigraphic models for the FIBG, discussing potential sources of uncertainty in the correlation of the lower Palaeogene succession across the Faroe–Shetland region, and implications for the age and duration of the volcanism.  相似文献   

Access routes to high mountain huts facing climate-induced environmental changes and adaptive strategies in the Western Alps since the 1990s     

Jacques Mourey  Ludovic Ravanel  Christophe Lambiel  Joël Strecker  Mattia Piccardi 《Norsk geografisk tidsskrift. Norwegian journal of geography》2019,73(4):215-228

ABSTRACT

In the European Alps, high mountain environments are subject to major impacts resulting from climate change, which strongly affect human activities such as mountaineering. The purpose of the study was to examine changes in access routes to 30 high mountain huts in the Western Alps since the 1990s. Data were derived from the use of two different methods, geo-historical studies and a questionnaire, and were used to identify both the climate-related processes affecting the climbing routes and the strategies implemented by public entities, Alpine clubs, guide companies, and hut keepers to maintain acceptable safety and technical conditions. The case studies revealed issues affecting three access routes and the results from the questionnaire showed that the main processes affecting access routes were loss of ice thickness and retreat from the front of the glaciated areas. Commonly, in situ equipment was installed to facilitate access for mountaineers and/or a part of a route was relocated to a safer area. The authors conclude that in most cases, the measures were effective but they were limited by financial, ethical and legal issues, especially in protected or classified areas that could jeopardise their durability and effectiveness.  相似文献   

Nanpanjiang basin: A window on the tectonic development of south China during Triassic assembly of the southeastern and eastern Asia     

《Gondwana Research》2020

As the largest siliciclastic sink in the South China block, the Triassic Nanpanjiang basin is generally thought of as a foreland basin related to Indosinian collision between the South China and Indochina blocks. Our basin analysis, spanning an eight years period, provides details of Lopingian to Middle Triassic stratigraphic fill and tectonic subsidence of the basin. Field observation and sedimentological analyses reveal that the basin was not filled by a monotonous turbidite system and suggest instead the development of five primary depositional units constituted by deep-water turbidite systems, mass-transport deposits, condensed drapes, shallow-water isolated carbonate platforms, and volcano-volcaniclastic rocks. The stratigraphic completeness of the basin, the coexistence of widespread but localized carbonate platforms within axially filled deep-water basin, tectonically generated cyclothems of transverse mass-transport deposits along intrabasinal faults and basin fill of extrusive rocks of bimodal composition together apparently call in question the claim that crustal shortening prevailed during the Late Permian to pre-Norian Triassic. Patterns of basin fill, differential tectonic subsidence and very high subsidence rate of the region adjacent to master fault are more closely match the pattern expected for extensional to transtensional basin in a back-arc setting. The crustal extension in the southwestern South China was not consistent with hypothesized Indosinian collision between South China and Indochina blocks, but more likely developed in response to northwestward subduction of the paleo-Pacific plate. Our results, combined with regional considerations, lead to a new model for the Triassic tectonic evolution of South China during Triassic assembly of the southeastern and eastern Asia.  相似文献   

广西宜州裂陷槽晚古生代演化与早石炭世沉积锰矿分布^*          下载免费PDF全文

黄恒  颜佳新  余文超 《古地理学报》2020,22(5):1001-1011

滇黔桂地区晚古生代浅水碳酸盐岩台地与深水硅泥质盆地共存的古地理格局,是在加里东期褶皱基底上发生裂陷及差异沉降而发展起来的。广西宜州—柳州一带既是晚古生代上扬子碳酸盐岩地台南缘1条重要的沉积相分界线,也是晚古生代桂中和桂北地层分区、古生代—中生代雪峰山南段构造体系和桂中坳陷构造体系的分界线。文中通过对宜山—柳州一带晚古生代地层的区域对比和成因分析,恢复了桂中宜山—柳州地区晚古生代沉积盆地的演化历史。狭长型宜州裂陷槽盆地西起丹池断裂,向东经龙头、北牙、宜州延伸至柳州。自中泥盆世开始,首先在东西两端开始裂陷下沉,至早石炭世发展成型。受北侧来自江南隆起带陆源碎屑物质充填影响,其表现为南北不对称并在早石炭世晚期被填平。在宜州裂陷槽内发育多处早石炭世沉积型碳酸锰矿,含矿地层分布、地层序列及其沉积背景明显与裂陷槽演化有关。它们既是盆地演化历史的见证,也体现了桂中地区裂陷海槽的特色,值得在后续锰矿成因研究中予以重视。  相似文献   

三香通络饮联合苯磺酸氨氯地平片治疗老年性高血压病46 例临床观察          下载免费PDF全文

黄彩依  欧阳雅蓉  傅威武 《应用海洋学学报》2020,36(8):14

目的：观察三香通络饮联合苯磺酸氨氯地平片治疗老年性高血压病的临床疗效。方法：将92 例老年性高血压病患者按随机数字表法分为治疗组和对照组,每组各46 例。对照组口服苯磺酸氨氯地平片治疗,治疗组在对照组基础上加用三香通络饮治疗。比较2组的综合疗效、中医证候积分及不良反应发生情况。结果：总有效率治疗组为89.13%（41/46）,对照组为60.87%（28/46）,2组比较,差异有统计学意义（P<0.05）;2组各项中医证候积分治疗前后组内比较,差异均有统计学意义（P<0.05）,且治疗后头晕目眩、头痛、心悸、口干口苦评分组间比较,差异均有统计学意义（P<0.05）;不良反应发生率治疗组为10.87%（5/46）,对照组为19.57%（9/46）,2组比较,差异无统计学意义（P>0.05）。结论：三香通络饮联合苯磺酸氨氯地平片治疗老年性高血压病患者的临床疗效优于单用西药治疗,且能有效减轻临床症状,值得推广。  相似文献   

对雅鲁藏布江结合带形成演化的再探讨     

张鑫全  张振利  王金贵  王硕  杨鑫朋  专少鹏  侯德华  张泽国  张立国  程洲 《中国地质》2020,47(4):944-970

通过1∶5万区域地质调查和收集相关资料的综合研究,本文对雅鲁藏布江结合带的形成演化作了进一步的探讨。雅鲁藏布江特提斯洋具有弧后扩张洋盆的性质,在早三叠世至中三叠世中期洋盆初步形成,中三叠世晚期至晚三叠世洋盆全面形成,从早侏罗世至晚白垩世洋盆逐步萎缩,到古新世至始新世关闭。南带的蛇绿岩主要为洋中脊扩张型(MORB型),形成于中三叠世晚期至晚三叠世。北带的蛇绿岩主要为与洋内俯冲相关的俯冲带上盘型(SSZ型),形成于早中侏罗世。带内侏罗纪至白垩纪其他岩浆岩主要为前弧玄武岩类(FAB型)。显示雅鲁藏布江特提斯洋从早侏罗世开始发生了洋内俯冲,并同步向北向冈底斯带之下主动俯冲消减和向南向喜马拉雅地块之下被动俯冲消减,持续发展到晚白垩世,在古新世至始新世俯冲碰撞消亡转化为结合带。  相似文献   

Prediction of vegetation anomalies over an inland river basin in north‐western China          下载免费PDF全文

Jing Fu  Jun Niu  Bellie Sivakumar 《水文研究》2018,32(12):1814-1827

Vegetation cover plays an important role in linking the atmosphere, water, and land and is deemed as a key indicator in the terrestrial ecological system. Therefore, it is of great importance to monitor vegetation dynamics and understand the mechanisms of vegetation change, including that driven by climate change. This study examines (a) the evolution of vegetation dynamics over the Heihe River Basin in the typical arid zone in north‐western China using nonparametric Mann–Kendall test and Thiel Sen's slope; (b) the relationships between remotely sensed vegetation indices (normalized difference vegetation index [NDVI] and enhanced vegetation index [EVI]) and hydroclimatic variables based on correlation analysis; and (c) the prediction of vegetation anomalies using a multiple linear regression model. For the analysis, the Moderate Resolution Imaging Spectroradiometer NDVI/EVI product and the gridded daily meteorological data at a spatial resolution of 0.125° over the period 2001–2010 are considered. The results indicate that vegetation cover improved over a large proportion during 2001–2010, with a significant trend towards warm and wet, characterized by an increase in average annual temperature and precipitation by 0.042 °C/year and 5.8 mm/year, respectively. We test the feasibility of NDVI and EVI in quantifying the responses of vegetation anomaly to climate change and develop a statistical model to predict vegetation dynamics in the basin. The NDVI‐based model is found to be more reliable than the EVI‐based model, partly due to the vegetation characteristics and geomorphologic properties of the study region. The proposed model performs well when there is no lag time between meteorological factors and vegetation indices for grassland and cropland, whereas 1‐month lead time prediction is found to be best for forest. The soil water content is introduced as an extra explanatory variable, which effectively improves the prediction accuracy for different land use types. In general, the predictive ability of the proposed model is stable and satisfactory, and the model can provide useful early warning information for regional water resources management under changing climate.  相似文献