非活动大陆边缘的天然气水合物及其成藏过程述评

非活动陆缘是板块活动相对较弱的地区，也是水合物发育的有利地区。通过对世界各地非活动陆缘地区水合物富集情况的系统分析，发现断褶组合构造、底辟构造以及“麻坑”地貌（Pockmark)与水合物的关系密切。尽管模拟海底反射层（Bottom Simulating Reflector,简称BSR，下同）是最重要的水合物识别标志，但水合物与BSR之间并不存在严格的一一对应关系。非活动陆缘具有丰富的烃类物质来源和适宜的温压条件，而断裂－褶皱组合构造、垒堑式构造和底辟构造等则为烃类气体的运移、富集和成藏提供了有利的构造环境，便于最终形成水合物。非活动陆缘的深水区往往发育有多期叠合盆地，因其物源、温压、构造和沉积条件的内在关联性，常常形成深部石油、中部天然气、浅部水合物的“三位一体”烃类能源结构模式。     

青藏高原天然气水合物遥感探测研究

介绍了天然气水合物的遥感探测方法,即：首先选择适当的ETM+、ASTER以及Quickbird等遥感图像,分析可见光、短波红外、热红外波段的影像特征,反演地表温度;然后结合野外调查和前人资料,寻找天然气水合物的直接和间接遥感解译标志,进行遥感解译。研究结果表明,青藏高原天然气远景区出现的几种遥感解译标志包括：地表上空高温异常(尤其是水体上空)、泥火山、沼泽地水体中大量气泡和棕黄色沉淀物,以及碳酸盐化、粘土化等指示信息。本研究为进一步开展大规模天然气水合物遥感调查和圈定靶区提供了基础方法。     

地球物理测井在天然气水合物勘探中的应用

天然气水合物是一种潜在的巨大能源。美国、日本、俄罗斯等发达国家在该领域已经进行了大量的研究工作，试图从各个角度去探测天然气水合物的存在并评价其蕴藏量。地球物理测井在天然气水合物探测与储量评价领域发挥了重要作用并且随着以勘探天然气水合物为目的的钻井的增多，日益受到重视。基于国内在该领域研究较少的现状，综述了国外地球物理测井技术在天然气水合物勘探中的应用，详细介绍了常规测井方法定性识别和定量评价天然气水合物储层的孔隙度、饱和度方法和技术，基于含天然气水合物储层的碳氧比能谱测井解释模型以及成像测井在含天然气水合物井段的测井响应。并在此基础上分析了我国在该领域的研究思路。     

广义岭估计的直接解法

提出了广义岭估计的直接解法。该解法不需计算岭参数,可直接求得具有最小均方误差的解。并举例证实了该解法的优越性     

Evolution of sedimentary environments of the middle Jiangsu coast, South Yellow Sea since late MIS 3

An evolutionary model of sedimentary environments since late Marine Isotope Stage 3 （late MIS 3, i.e., ca. 39 cal ka BP） along the middle Jiangsu coast is presented based upon a reinterpretation of core 07SR01, new correlations between adjacent published cores, and shallow seismic profiles recovered in the Xiyang tidal channel and adjacent northern sea areas. Geomorphology, sedimentology, radiocarbon dating and seismic and sequence stratigraphy are combined to confirm that environmental changes since late MIS 3 in the study area were controlled primarily by sea-level fluctuations, sediment discharge of paleo-rivers into the South Yellow Sea （SYS）, and minor tectonic subsidence, all of which impacted the progression of regional geomorphic and sedimentary environments （Le., coastal barrier island freshwater lacustrine swamp, river floodplain, coastal marsh, tidal sand ridge, and tidal channel）. This resulted in the formation of a fifth-order sequence stratigraphy, comprised of the parasequence of the late stage of the last interstadial （Para-Sq2）, including the highstand and forced regressive wedge system tracts （HST and FRWST）, and the parasequence of the postglacial period （Para-Sql）, including the transgressive and highstand system tracts （TST and HST）. The tidal sand ridges likely began to develop during the postglacial transgression as sea-level rise covered the middle Jiangsu coast at ca. 9.0 cal ka BP. These initially submerged tidal sand ridges were constantly migrating until the southward migration of the Yellow River mouth to the northern Jiangsu coast during AD 1128 to 1855. The paleo-Xiyang tidal channel that was determined by the paleo-tidal current field and significantly different from the modern one, was in existence during the Holocene transgressive maxima and lasted until AD 1128. Following the capture of the Huaihe River in AD 1128 by the Yellow River, the paleo-Xiyang tidal channel was infilled with a large amount of river-derived sediments from AD 1128 to 1855, causing the emergence of some of the previously submerged tidal sand ridges. From AD 1855 to the present, the infilled paleo-Xiyang tidal channel has undergone scouring, resulting in its modern form. The modern Xiyang tidal channel continues to widen and deepen, due both to strong tidal current scouring and anthropogenic activities.     

多功能水合物沉积物三轴试验系统的研制与应用

研制了新型多功能水合物沉积物三轴试验系统,系统由供-排气模块、应力加载模块、温控模块、数据采集模块和辅助模块组成。利用泵驱动高压液体施加围压和轴压,加载方式有恒压、恒流、梯度增压、跟踪气压模式,可以实现不同条件下的水合物合成、三轴剪切。围压跟踪气压的功能使水合物生成过程中净围压不变,保证了试样初始条件一致性。根据围压液体积变化测量试样体积变形,通过设置回压泵压力变化方式控制水合物气压,可以模拟不同降压速率条件下的水合物沉积物分解变形。以泥质粉细砂和二氧化碳为材料制作了三轴试样,进行了水合物合成、三轴剪切和降压分解试验,检验了仪器的可靠性。     

多元统计在大洋玄武岩同位素端元识别中的应用

应用因子分析的方差最大旋转和非线性映射方法对海洋玄武岩Sr、Nd、Pb同位素数据在多维空间中的数据结构进行了分析。研究表明这些数据在多维空间中呈五角形结构,并对应5个地幔端元:大西洋中脊玄武岩(DMM),圣埃伦那(HIMU),鲸岛(EMI),萨摩亚岛(EMII)和DS(EMIII).其中DS(EMIII)是本文新识别出来的一个地幔端元,它可能是重新进入地幔的具有较高古老放射成因Pb的下地壳物质。     

南海东北部冷泉区末次冰期沉积间断及其成因

对南海东沙海域冷泉区DH-CL10和DH-CL5柱状样开展AMS14C年代学、高分辨率底栖有孔虫和沉积物同位素以及沉积学研究。结果表明:DH-CL10柱状样在全新统底部574 cm处出现沉积间断,间断面相邻沉积物AMS14C年龄分别为9 850/(9 680~9 950) cal.aBP和27 610/(27 500~27 700) cal.aBP,相当于MIS2期和部分MIS3期的沉积缺失。底栖有孔虫Uvigerina bifurcata的δ13C值为-0.37‰~-1.91‰,平均值为-1.11‰,沉积物全岩碳同位素值为-22.7‰~-23‰,均为正常的碳同位素值。尽管该柱状样未发现天然气水合物分解释放的地球化学证据,但相邻的DH-CL5柱状样相当于其所缺失的部分沉积中的自生碳酸盐岩和沉积物的δ13C负偏明显,分别为-55.24‰和-25.9‰~-27.9‰,表明与天然气水合物分解有关。推断DH-CL10柱状样沉积间断所缺失的沉积物可能记录了天然气水合物分解的证据,且沉积间断主要出现在末次盛冰期低海平面,与天然气水合物易分解的时间相吻合,因此,沉积间断的形成可能主要与下伏天然气水合物的分解导致沉积物的滑塌有关。     

Timing of granitic magma mixing in the southeastern Gyeongsang Basin,Korea: SHRIMP-RG zircon data

Late Cretaceous calc-alkaline granites in the Gyeongsang Basin evolved through the mixing of mafic and felsic magmas. The host granites contain numerous mafic magmatic/microgranular enclaves of various shapes and sizes. New SHRIMP-RG zircon U–Pb ages of both granite and mafic magmatic/microgranular enclaves are 75.0?±?0.5 Ma and 74.9?±?0.6 Ma, respectively, suggesting that they crystallized contemporaneously after magma mixing. The time of injection of mafic melt into the felsic magma chamber can be recognized as approximately 75 Ma by field relations, petrographic features, geochemical evolution, and SHRIMP-RG zircon dating. This Late Cretaceous magma mixing event in the Korean Peninsula was probably related to the onset of subduction of the Izanagi (Kula)–Pacific ridge.     

羌塘盆地泥火山发育区天然气水合物地球化学勘查

泥火山是天然气水合物赋存的标志之一,是天然气水合物存在的主要证据.羌塘盆地冻土区发育大量泥火山.对泥火山发育区进行了地球化学勘查,结果表明,泥火山周围具有酸解烃、荧光光谱、碳酸盐、蚀变碳酸盐、微量元素等地球化学指标显著异常,甲烷碳同位素和三维荧光结果显示地球化学烃类异常为原油伴生气和凝析油成因,表明泥火山外围烃类富集是由油气藏渗漏形成.该结论对羌塘盆地天然气水合物勘查突破具有重要意义.