晚新生代金沙江形成时代与过程研究   总被引：26，自引：2，他引：24  

张叶春  李吉均 《云南地理环境研究》1998,10(2):43-48

在多次的野外考察和充分的室内分析的基础上,对金沙江地区河谷层状地貌系列和断陷盆地相关沉积进行了分析,系统地研究了金沙江自晚新生代以来的形成和演化。晚新生代金沙江水系的形成和演化经历了四个阶段：①３．４０ＭａＢ．Ｐ之前,为高原面形成期间的古水系阶段;②３．４０～２．００±０．２０ＭａＢ．Ｐ,为金沙江水系孕育阶段;③２．００±０．２０～１．５４±０．１７８ＭａＢ．Ｐ,为金沙江水系调整阶段;④１．５４±０．１７８ＭａＢ．Ｐ以来为现代金沙江水系形成与发展阶段  相似文献   

水泥土支护体稳定性验算的可靠度分析     

况龙川  殷景峰 《地球科学与环境学报》1998,(Z1)

本文建立了水泥土支护体稳定性验算的可靠度分析模型,利用具有代表性的２２例上海软土工程地质资料,参数统计引入空间平均概念,利用ＪＣ法进行了有关可靠度指标的计算与分析,指出现行稳定性验算的总体可靠度指标水平为２．５０,为今后分项系数的研究打下基础。  相似文献   

城市土地利用/覆盖变化与热环境生态调控研究进展与展望   总被引：3，自引：3，他引：0  

匡文慧 《地理科学》2018,38(10):1643-1652

城市土地利用/覆盖变化(LUCC)与热环境生态调控是城市生态学和城市气候适应性关注的热点问题。在提出城市LUCC/空间结构与生态服务热调节功能连接的重要性的基础上,综述了城市土地利用变化、城市绿色基础设施在热岛减缓和气候适应性发挥的作用,评述了观测实验、定量遥感和过程模型方面以及热调控的进展情况。基于此认为,局地或区域尺度城市高精度结构组分高精度遥感探测方法、城市高精度下垫面多尺度(功能区/覆盖组分/构造或材质等)对局地气温和辐射能量平衡影响机理和定量贡献识别、城市生态系统热调节功能的城市地表结构组分调控阈值确定、以及区域或全球尺度城市土地利用/覆盖变化影响的生物地球物理机制定量化认知等,是未来重要的发展方向。  相似文献   

The“Sand-Mud” Sedimentary Record and Its Diagenetic System in Shore-shallow Lacustrine—A Case Study of Eocene Kongdian Formation in Jiyang Depression     

Tan Xianfeng  Ran Tian  Luo Long  Wang Jia  Liang Mai  Chen Qing  Kuang Hao 《地球科学进展》2016,31(6):615-633

The sand-mud sedimentary record develops widely in the shore-shallow lacustrine, which can be a good oil and gas reservoir cap combination. It has important significance in petroleum geology. This paper takes the Kongdian Fm. of Eocene in Jiyang Depression as an example to study the formation mechanism and diagenetic system of the sand-mud sedimentary record in the shore-shallow lacustrine. The study indicated that sandstone-mudstone sedimentary strata at macroscopic level includes sand-mud duality, mudstone vein and sandstone lens in the Kongdian Fm. of Jiyang Depression, and there are some transitional clastic rocks at the microscopic level (Clastic particles, clay and carbonate cements are included in the transitional clastic rocks). The sandstone-mudstone sedimentary strata mainly formed in the material transformation of the shallow-water deltas and conjugate shock in the shore-shallow lacustrine. The thickness is mainly restricted by material source and water dynamic condition, and the sand-mud transitional clastic rocks are restricted by the dynamic mechanism and sedimentary differentiation of the lake water. The sandstone-mudstone sedimentary strata is composed of a closed diagenetic system. Early compaction-drainage and differential compaction, middle and late clay mineral transformation, structural water and organic acid emissions during the diagenetic process of mudstone influence the diagenesis of sandstone. The closed diagenetic system of sand-mud transitional clastic rocks is mainly related to the structural maturity of clastic rocks.  相似文献   

Status and Advances of Abandoned Process of Wells for CO2 Geological Storage   总被引：1，自引：0，他引：1  

Li Qi  Song Ranran  Kuang Dongqin  Lu Xutao  Li Xiaochun 《地球科学进展》2016,31(3):225-235

With the rapid development of CO₂ geological storage and utilization (CCS/CCUS), the abandoned well in the sites of CCS/CCUS projects is becoming an important subject to be solved to check whether it can effectively block the residual CO₂ or not. Up to now, the abandoned process of wells in the field of oil and gas in China and abroad have gained mature operation technology and rich experience. However, in the field of CCS/CCUS, there is only a small number of global public instances about the abandoned process of operational wells of CO₂ including CO₂ injection wells and CO₂ monitoring wells, and the domestic instance is still blank. In this paper, we firstly summarized the required demands, materials, cases of operational experiences, and monitoring requirements of the abandoned process of operational wells of CO₂ in the developed countries, e.g. the Netherlands, the United States and Canada. Then, we figured out the status of the abandoned process of domestic wells in oil and gas industry. Finally, we concluded the differences of the abandoned process between operational wells of CO₂ and traditional wells of oil and gas, and proposed some recommendations for the abandoned process of operational wells of CO₂ in the current and future CCS/CCUS projects in China. This study has important implications for the upcoming abandoned process of all the operational wells at Shenhua CCS demonstration site in 2016.  相似文献   

Chloride as tracer of solute transport in the aquifer–aquitard system in the Pearl River Delta,China     

Xingxing Kuang  Jiu Jimmy Jiao  Ya Wang 《Hydrogeology Journal》2016,24(5):1121-1132

A 1D numerical model is constructed to investigate the impact of sedimentation and sea level changes on transport of Cl^? in the aquifer–aquitard system in the Pearl River Delta (PRD), China. The model simulates the evolution of the vertical Cl^? concentration profiles during the Holocene. Sedimentation is modeled as a moving boundary problem. Chloride concentration profiles are reconstructed for nine boreholes, covering a wide area of the PRD, from northwest to southeast. Satisfactory agreement is obtained between simulated and measured Cl^? concentration profiles. Diffusion solely is adequate to reproduce the vertical Cl^? concentration profiles, which indicates that diffusion is the regionally dominant vertical transport mechanism across the aquitards in the PRD. The estimated effective diffusion coefficients of the aquitards range from 2.0?×?10^–11 to 2.0?×?10^–10 m²/s. The effective diffusion coefficients of the aquifers range from 3.0?×?10^–11 to 4.0?×?10^–10 m²/s. Advective transport tends to underestimate Cl^? concentrations in the aquitard and overestimate Cl^? concentrations in the basal aquifer. The results of this study will help understand the mechanisms of solute transport in the PRD and other deltas with similar geological and hydrogeological characteristics.  相似文献   

常州市地面沉降以及用水化学标志研究的探讨     

匡有为  汤呜皋 《地球科学》1985,(1)

常州市过量开采第Ⅱ承压含水层的水使水位大幅度下降,造成含水砂层压密和粘性土层固结而导致地面沉降。试验资料表明该区粘性土层的压缩性较低,它们的压密主要是由主固结阶段完成的。视压榨液,浸提液成分和含水层多年水质的变化,以及抽水时水质与氚量资料说明粘性土层释水在造成本区地面沉降中起着相当重要的作用。这种条件下,用对含水层水化学成分的检测来监视地面沉降的发生、发展是一个经济可靠的方法。  相似文献   

海洋单点定位粗差检测和位置估计     

匡善龙 《武汉大学学报(信息科学版)》1987,(4)

海洋测量技术的进步,要求我们更多地致力于测量结果的处理,以得到尽可能准确的定位参数。例如,在海洋地球物理勘探测量定位实践中常由于粗差的存在而难于用传统方法得到正确的位置估计。本文主要解决如下几个问题: (1)如何正确地检测海洋定位测量结果中的粗差并合理地估计位置, (2)寻求良好的海洋测量作业方案。  相似文献   

The Geology and Geochemistry of Porphyrite Iron Deposits in the Nanjing_Wuhu Area,Southeast China     

李文达  匡福祥 《中国地球化学学报》1990,9(1):1-26

For the iron deposits occurring in andesitic volcaic rocks of the Lower Yangtze Area.the genetic model for porphyrite iron deposits was proposed by chinese geologists more than ten years ago on the basis of their detailed studies in the Nanjing-Wuhu Basin.It comprises a set of deposits of different genetic types ranging from late magmatic segregation ,ore-magma injection,pneumato-hydatogenetic replacing and hydrothermal filling as well as sedimentary origin.The deposits are closely connected with the gabbro-diorite porphyrite subvolcanic intrusive bodies both in space and in genesis.Miner4alization and wall-rock alteration are consistent with the history of the magmatic evolution.Geochemical studies on trace elements and S,O,Sr isotopes have proved that the porphyrite iron deposits are of magmatic origin,The proposed model may be applied to iron ores associated with andesitic volcanites,for example,in Chile,Mexico,Pakistan,Turkey,etc.  相似文献   

A study of long-term climate change in a simple seasonal nonlinear climate model     

R Q Lin  H Kreiss  W J Kuang  L Y Leung 《Climate Dynamics》1991,6(1):35-41

Solar radiation cycles, earth-orbital changes, and continental drift drive long to very long term (10³–10⁶ years) climatic changes. Lin and North used the stationary solutions of a simple energy balance model (EBM) to study the equilibrium climatic stages. In this paper, we study time dependent solutions and, in particular, transition processes. We make use of two time scales: a seasonal cycle (fast variation) and a long term time change (slow variation). Variations over short time scales are solved using a Fourier transform in time and long term variations are studied using a 4th order Runge-Kutta method. The energy balance equation is a parabolic type equation and it is well posed. Climate changes depend mainly on external forcing and the state of the climate is determined by the slow time scale forcing. In other words, transitions from one climate stage (snow-covered) to another (snow-free) at bifurcation points are monotonic, despite 20% to 50% shortperiod random fluctuations in the solar energy. This smooth transition is especially noticeable when the land bands lie close to the north pole (70° N to 90° N) or at high latitudes (50° N to 75° N).Now at Applied Physics Laboratory, The Johns Hopkins University, Laurel, MD 20723, USA  相似文献