南海神狐海域沉积物自生黄铁矿和石膏S同位素特征及对甲烷渗漏强度的示踪   总被引：1，自引：1，他引：0  

张美  陆红锋  管红香  刘丽华  邬黛黛  吴能友 《海洋学报(英文版)》2018,37(7):20-27

The northern slope of the South China Sea is a gas-hydrate-bearing region related to a high deposition rate of organic-rich sediments co-occurring with intense methanogenesis in subseafloor environments.Anaerobic oxidation of methane(AOM) coupled with bacterial sulfate reduction results in the precipitation of solid phase minerals in seepage sediment,including pyrite and gypsum.Abundant aggregates of pyrites and gypsums are observed between the depth of 667 and 850 cm below the seafloor(cmbsf) in the entire core sediment of HS328 from the northern South China Sea.Most pyrites are tubes consisting of framboidal cores and outer crusts.Gypsum aggregates occur as rosettes and spheroids consisting of plates.Some of them grow over pyrite,indicating that gypsum precipitation postdates pyrite formation.The sulfur isotopic values(δ~(34) S) of pyrite vary greatly(from –46.6‰ to –12.3‰ V-CDT) and increase with depth.Thus,the pyrite in the shallow sediments resulted from organoclastic sulfate reduction(OSR) and is influenced by AOM with depth.The relative high abundance and δ~(34) S values of pyrite in sediments at depths from 580 to 810 cmbsf indicate that this interval is the location of a paleo-sulfate methane transition zone(SMTZ).The sulfur isotopic composition of gypsum(from–25‰ to –20.7‰) is much lower than that of the seawater sulfate,indicating the existence of a 34 S-depletion source of sulfur species that most likely are products of the oxidation of pyrites formed in OSR.Pyrite oxidation is controlled by ambient electron acceptors such as MnO_2,iron(Ⅲ) and oxygen driven by the SMTZ location shift to great depths.The δ~(34) S values of gypsum at greater depth are lower than those of the associated pyrite,revealing downward diffusion of 34 S-depleted sulfate from the mixture of oxidation of pyrite derived by OSR and the seawater sulfate.These sulfates also lead to an increase of calcium ions from the dissolution of calcium carbonate mineral,which will be favor to the formation of gypsum.Overall,the mineralogy and sulfur isotopic composition of the pyrite and gypsum suggest variable redox conditions caused by reduced seepage intensities,and the pyrite and gypsum can be a recorder of the intensity evolution of methane seepage.  相似文献   

东海蛾螺属二新记录种(腹足纲,蛾螺科)   总被引：1，自引：0，他引：1  

张树乾  张素萍  王洋 《海洋与湖沼》2018,49(1):96-98

在整理近年来东海采集的蛾螺科Buccinidae标本时,鉴定出属于蛾螺属Buccinum Linnaeus,1758的两个中国新记录种:(1)白肋蛾螺Buccinum leucostoma Lischke,1872,采自于东海300—400m深的泥沙质海底;(2)古式蛾螺Buccinum koshikinum Okutani,1988采自于东海400m深的泥沙质海底。文中分别对这两个新记录种的形态特征、生活习性等进行了描述,并与相似种进行了分类学讨论。此外,文中还列出了中国海已报道的其他蛾螺属种类。  相似文献   

Foreword     

D.X.HU 《中国海洋湖沼学报》2004,22(3):J001-J002

Ocean circulation in the Yellow and East China Seas is very rich in mesoscale phenomena, such as eddies, fronts, upwellings, river plumes, etc. Among others, having drawn tremendous attention from oceanographic community in the past for nearly 50 years are mainly the Yellow Sea Cold Water Mass (YSCWM) and its related circulation, the Yellow Sea Warm Current (YSWC), the East China Sea  相似文献   

实施农村规划 进行土地挖潜   总被引：1，自引：0，他引：1  

汤阴县土地学会 《河南国土资源》2005,(3):21-22

汤阴县位于河南省北部，属河南省安阳市所辖，是一个农业县。土地总面积645.86平方公里，其中：耕地占土地总面积的63．4％，其它土地占36．6％。全县设5乡5镇，297个行政村。农业户口、农业人口分别占总户数、总人口的77．7％和85．5％。  相似文献   

地壳对海洋潮汐的响应   总被引：2，自引：2，他引：0  

郑文衡  王乘  何振  牛安福 《大地测量与地球动力学》2002,22(2):41-46

应用三维动态有限元方法研究了中国北部地区的地壳对邻近的渤海与黄海海平面变化的响应。虽然此应力场过于微弱不足以引发地震，但发现应力集中的位置及应力场变化较大的位置恰好与某些现代地震的震中一致。这一结果表明研究地壳对广泛分布的载荷的响应对研究区域地震构造是有帮助的。  相似文献   

康南滇北间之河流袭夺现象     

崔克信 《地质论评》1948,13(Z2):286-286

西康南部以及云南北部之区河流因袭夺而改道之现象至为普遍,如金沙江鸦龙江大渡河以及理曲等均有明显之改道现象,由改道附近  相似文献   

碧海翠玉 彩蝶翩翩——闽南东山岛掠影     

鉴明 《海洋世界》2004,(5):40-42

挡不住“海、岛、滩、岩”美景的诱惑，我们慕名从厦门赶到有“翠玉彩蝶”美誉的闽南东山岛，做了几天自然、悠闲的东山人。  相似文献   

Characters of the Pco2 and CO2 Flux in the East China Sea in Autumn     

纪雷  崔鹤  辛淑平  王军  张龙军  陆贤昆 《中国海洋湖沼学报》2003,21(2):180-186

Pco2 of air and seawater samples from the East China Sea(ECS) were measured in situ in autumn, 1994,Ocean currents,terrestrial fluviation,biological activities,etc.,Pco2 char-acters in air and seawater were investigated,CO2 flux and its character in the East China Sea are discussed on the basis of the Pco2 profiles of air and seawater,It was clear that the nearshore was the source of CO2;and tht the oulter sea area was the sink of CO2; and that the shelf area of the EXS is a net sink for atmospheric CO2 in autumn.  相似文献   

VERTICAL PROFII,ES OF CHL-A AND PRIMARY PRODUCTIVITY IN THE MIDDLE CONTINENTAL SHELF AREA AND EDDY AREA OF THE EAST CHINA SEA     

Wu Yu-lin  Zhou Cheng-xu  Zhang Yong-shan 《中国海洋湖沼学报》2002,20(1):74-80

Vertical profiles of chl-a and primary productivity in the middle continental shelf area and eddy area of the East China Sea were studied using data from a cruise in the East China Sea in February to March, 1997 and a cruise in July, 1998. The results showed that chl-a vertical distribution closely related to in situ hydrological and nutrient conditions. Chla-a concentration ranged from 0.22 to 0.35 mg/m³ and 0.93–1.09 mg/m³ in the eddy area and in the middle continental shelf area, respectively. In both areas, chl-a concentrations in deep layers were slightly higher than those in shallow layers, but was of the same order of magnitude. In summer, when a thermocline existed in the water column, highest chl-a concentrations appeared at the base of the thermocline layers in both areas. In the eddy area, chl-a concentration maximized at 31.743 mg/m³, and averaged 1.143 mg/m³ below 30 m depth. In the middle continental shelf area, the highest chl-a concentration was 2.120 mg/m³, the average was 1.168 mg/m³. The primary productivity reached 1418.76 mgC/(m²·d) in summer and 1360.69 mgC/(m²·d) in winter. In the eddy area, the primary productivity was 787.50 mgC/(m²·d) in summer and 159.04 mgC/(m²·d) in winter. Vertical carbon sinking rate from the deep layer to the bottom in both areas is also discussed in this paper. Contribution NO. 4183 from the Institute of Oceanology, Chinese Academy of Sciences. Project No. 49636210 supported by NSFC.  相似文献   

修武:千年古坑免遭一劫     

冯志忠 《资源导刊(河南)》2007,(6)

近日,修武县国土资源局西村国土所及时制止一起盗采铁矿石行为,使该乡一"千年古坑"免遭破坏. 被当地人称为"千年古坑"的大水坑位于修武县北部山区西村乡黑岩村与孟泉村交界处,呈椭园形,长约50米,宽约30米,最深处约4米.此坑是自然形成,坑里的水是靠雨季和雪融水储存的.千百年来,黑岩和孟泉两村千余口人和牲畜就是靠吃这个水坑里的水生存的,坑里的水常年清澈见底,不用过滤不用沉淀可直接饮用.随着经济的发展,山区饮水条件的改善,此坑里的水现已成为黑岩村的牲畜饮用水.在上世纪70年代,黑岩村村民对坑内进行了清於,对已损坏的护坑石楞进行了维修,并作为历史古迹保护了下来.  相似文献