Analysis of phosphorus import characteristics of the upstream input rivers of Three Gorges Reservoir     

Chaonan Han  Binghui Zheng  Yanwen Qin  Yingqun Ma  Wei Cao  Chenchen Yang  Zhichao Liu 《Environmental Earth Sciences》2016,75(12):1024

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Relationships among volcanic and hydrothermal activity and faults from the Shunnan 3-D well zone in the Tadong Area (Tarim Basin,China)     

Li KunBai  Lv HaiTao  Pu RenHai  Cao ZiCheng 《Arabian Journal of Geosciences》2016,9(17):692

Tarim Basin distributed widely two stages of Permian volcanic rocks. However, the location and timing of these rocks pinching out and the relationship between Ordovician carbonate hydrothermal reservoirs and fault activity remain unclear. The Shunnan (Shunnan here in after referred to as SN) 1 3-D well zone in the eastern Tarim Basin contains volcanic rocks, and the Ordovician layer contains a hydrothermal reservoir. This paper describes the lithology, stage, volcanic rock distribution, crater position and deposition pinch-out line of volcanic rocks based on drilling and 3-D seismic data. The Permian strata in the well zone contain only one stage of Kupkuciman Formation basalt and tuff, the Kaipeleicike Formation contains terrigenous clastic rock and the adjacent volcanic rocks of wells SN2 and GL (Gulong here in after referred to as GL) 2 exhibit an absence of deposition. Although the craters are distributed on both sides of the NNW faults that cross well SN4, their positions are also controlled by the intersection of earlier NEE and NW faults and later NNE faults. Furthermore, the Ordovician strata in the SN1 well zone developed abundant tubular high-amplitude anomalies and tabular high-amplitude anomalies via hydrothermal corrosion, and the anomaly distributions are similar to the positions of the craters, which are controlled by the intersection of multi-group faults and the density of the faults.  相似文献   

Seasonal variation and principle of cyanobacterial biomass and forms in the water source area of Chaohu City,China     

徐宪根  柯凡  李文朝  冯慕华  尚丽霞  范帆  何延召 《中国海洋湖沼学报》2016,34(1):34-43

We investigated seasonal variations in cyanobacterial biomass and the forms of its dominant population(M. aeruginosa) and their correlation with environmental factors in the water source area of Chaohu City,China from December 2011 to October 2012. The results show that species belonging to the phylum Cyanophyta occupied the maximum proportion of phytoplankton biomass,and that the dominant population in the water source area of Chaohu City was M. aeruginosa. The variation in cyanobacterial biomass from March to August 2012 was well fitted to the logistic growth model. The growth rate of cyanobacteria was the highest in June,and the biomass of cyanobacteria reached a maximum in August. From February to March 2012,the main form of M.aeruginosa was the single-cell form; M.aeruginosa colonies began to appear from April,and blooms appeared on the water surface in May. The maximum diameter of the colonies was recorded in July,and then gradually decreased from August. The diameter range of M. aeruginosa colonies was 18.37–237.77 μm,and most of the colonies were distributed in the range 20–200 μm,comprising 95.5% of the total number of samples. Temperature and photosynthetically active radiation may be the most important factors that influenced the annual variation in M. aeruginosa biomass and forms. The suitable temperature for cyanobacterial growth was in the range of 15–30°C. In natural water bodies,photosynthetically active radiation had a significant positive influence on the colonial diameter of M.aeruginosa(P0.01).  相似文献   

Source and yearly distribution of PAHs in the snow from the Hailuogou glacier of Mountain Gongga,China     

Chaoqi Yu  Meihan Li  Yinling Cao  Xian He  Hong Zhou  Tingting Zhang  Chongying Li 《中国地球化学学报》2018,37(3):456-464

Snow samples were collected over a 3-year period from 2012 to 2014 at the Hailuogou glacier of Mountain Gongga (Mt. Gongga) and analyzed for 16 priority polycyclic aromatic hydrocarbons (PAHs) using Gas Chromatography–Mass Spectrometry (GC–MS). The results show that total average levels of the 16 PAHs ranged from 452 to 290 ng·L^?1 with a possible declining trend from 2012 to 2014. Distances between the sampling sites and the emission sources were estimated at typically less than 500 km. The results suggest that the major source of PAHs was from coal combustion, while contributions from automobile exhaust played an important role in more recent years. This finding was in agreement with the characteristics of presence of local industry, residence, and recent development of tourism of the surrounding areas.  相似文献   

Timing of mineralization at the Shihu gold deposit in the middle segment of the Taihang Mountain,China     

Chao Chen  Shuyin Niu  Fang Wang  Fuxiang Zhang  Qinglian Zhang  Baojun Ma  Aiqun Sun  Jianzhen Zhang  Yaqi Cao  Xiaoqing Zhang 《中国地球化学学报》2018,37(1):80-89

The Shihu gold deposit, located in the middle-south section of the core of the Fuping mantle branch structure, is hosted in the Archean Fuping Group and adjacent to the quartz diorite porphyrite. The gold deposit is the only large gold deposit with reserves of more than 30 tons gold discovered in western Hebei Province so far. In order to constrain the timing of mineralization of this ore deposit, this paper focuses on the isotopic dating of zircon and pyrite. Zircons in gold-bearing quartz veins are magmatic in origin and no hydrothermal zircon has been found in such quartz veins, indicating that zircons were derived from the wall rocks. U–Pb ages of zircons fall mainly in the two domains: 2492 ± 82 and 136 ± 4 Ma, respectively, indicative of the contribution of the Fuping-Group TTG gneiss and Yanshanian igneous rocks, respectively. The Re–Os isotopic compositions of pyrites in the gold-bearing quartz veins yield an isochron age of 127 ± 31 Ma. Combined with other dating results, we suggest that the main metallogenic age of the Shihu gold deposit is 120–127 Ma.  相似文献   

Forward solver for deep earth exploration and induction logging using custom built Edge-Element FEM technique     

Mingyang Lu  Wuliang Yin  Shijie Sun  Jiangtao Sun  Zhang Cao  Lijun Xu 《《地质学报》英文版》2018,92(Z1):302-304

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Early Cretaceous I-type granites in the Tengchong terrane:New constraints on the late Mesozoic tectonic evolution of southwestern China     

Yi Fang  Yun-Hui Zhang  Shou-Ting Zhang  Hua-Wen Cao  Hao Zou  Jian-Hui Dong 《地学前缘(英文版)》2018,9(2):459-470

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Occurrence and conceptual sedimentary model of Cambrian gypsum-bearing evaporites in the Sichuan Basin,SW China   总被引：1，自引：0，他引：1  

Hong Liu  Xiucheng Tan  Yonghao Li  Jian Cao  Bin Luo 《地学前缘(英文版)》2018,9(4):1179-1191

During the Cambrian, gypsum-bearing evaporites formed in the Sichuan Basin, SW China. These rocks are important for oil and gas sealing, but details of their distribution and origin are not well established. This study examines the regional distribution and origin of the gypsum-bearing evaporites using a comprehensive analysis of drilling data from 34 wells, 5 measured cross-sections in the basin and surrounding area, and 96 maps of area-survey data. Results show that in the stratigraphic succession, the gypsum-bearing evaporites occur mainly in the Lower Cambrian Longwangmiao Formation, the Middle Cambrian Douposi Formation, and the Middle-Upper Cambrian Xixiangchi Group. Geographically, the rocks are found mainly in the southeastern part of the basin, and the distribution of deposits shows an overall SW-NE trend. The sedimentary environments for evaporite formation were evaporative lagoon and inter-platform basin in a platform setting. Gypsum was generated by the underwater concentration of sea water in a strongly evaporative environment. Both an evaporative restricted platform and a mixeddeposition restricted platform model appear to be applicable to the development of gypsum in the Sichuan Basin. The gypsum-bearing evaporites with the best sealing capacity are located mostly in the southeastern part of the basin. These constraints can be applied directly to regional exploration, and have implications for the regional paleogeography and paleoclimate.  相似文献   

Seasonal variability of oxygen and hydrogen isotopes in a wetland system of the Yunnan-Guizhou Plateau,southwest China: a quantitative assessment of groundwater inflow fluxes     

Xingxing Cao  Pan Wu  Shaoqi Zhou  Han Tu  Shui Zhang 《Hydrogeology Journal》2018,26(1):215-231

The Caohai Wetland serves as an important ecosystem on the Yunnan–Guizhou Plateau and as a nationally important nature reserve for migratory birds in China. In this study, surface water, groundwater and wetland water were collected for the measurement of environmental isotopes to reveal the seasonal variability of oxygen and hydrogen isotopes (δ¹⁸O, δD), sources of water, and groundwater inflow fluxes. Results showed that surface water and groundwater are of meteoric origin. The isotopes in samples of wetland water were well mixed vertically in seasons of both high-flow (September) and low-flow (April); however, marked seasonal and spatial variations were observed. During the high-flow season, the isotopic composition in surface wetland water varied from ?97.13 to ?41.73‰ for δD and from ?13.17 to ?4.70‰ for δ¹⁸O. The composition of stable isotopes in the eastern region of this wetland was lower than in the western region. These may have been influenced by uneven evaporation caused by the distribution of aquatic vegetation. During the low-flow season, δD and δ¹⁸O in the more open water with dead aquatic vegetation ranged from ?37.11 to ?11.77‰, and from ?4.25 to ?0.08‰, respectively. This may result from high evaporation rates in this season with the lowest atmospheric humidity. Groundwater fluxes were calculated by mass transfer and isotope mass balance approaches, suggesting that the water sources of the Caohai Wetland were mainly from groundwater in the high-flow season, while the groundwater has a smaller contribution to wetland water during the low-flow season.  相似文献   

Acquiring high-resolution topography and performing spatial analysis of loess landslides by using low-cost UAVs   总被引：1，自引：0，他引：1  

Sheng Hu  Haijun Qiu  Xingang Wang  Yu Gao  Ninglian Wang  Jiang Wu  Dongdong Yang  Mingming Cao 《Landslides》2018,15(3):593-612

The Loess Plateau is a region in China prone to frequent geological disasters, where thousands of loess landslides can be found. Conventional field survey methods are inadequate for the requirements of fine spatial analysis of landslides. Due to its numerous advantages (fast, efficient, low cost, safe, and able to acquire high-resolution data), structure from motion (SfM) technique to photogrammetric orientation of flights and modeling applied to photographs taken by unmanned aerial vehicles (UAVs) equipped with a camera has become a powerful new tool for the generation of high-resolution topography that has emerged in recent years, which has become a powerful new technique for acquiring high-resolution topographic data. In this study, we conducted nearly two months of field UAV surveys of loess landslides on the Loess Plateau, eventually established 3D digital models for 11 loess landslides, and produced high-resolution digital orthophoto maps (DOMs) and digital elevation models (DEMs). High-resolution spatial analysis of the loess landslides (mainly including characteristic parameter extraction, topography profile analysis, surface feature analysis, and hydrologic analysis) was performed using Agisoft PhotoScan, ArcGIS 10.2, Global Mapper 17, and Origin Pro 9.0. The UAV technique allows us to further understand the micro-level internal spatial and structural characteristics of loess landslides. Moreover, not only does it allow us to accurately measure the characteristic geometric parameters but also enables us to detect the surface details of loess landslides (e.g., textures, fissures, and micro-landforms). Manifestly, we can also deduce the original structural characteristics and possible inducement mechanism of landslides based on a combination of high-resolution data acquired by UAVs, proper ground surveys, and theoretical knowledge. In summary, the low-cost UAVs are highly and especially suitable for surveys and digital terrain analysis of landslides on the Loess Plateau with sparse vegetation.  相似文献