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81.
82.
无外加流体、350℃和差异应力条件下硫化物再活化实验研究 总被引:1,自引:0,他引:1
红透山块状硫化物矿石主要成分为黄铁矿、磁黄铁矿、黄铜矿、闪锌矿和石英、角闪石、黑云母等脉石矿物。将此矿石烘干后作为试料置于岩石三轴应力试验机,在13h内将轴压、围压和温度分步升至1276MPa、414MPa和350℃,然后在空气中自然冷却至室温。实验产物中黄铁矿、石英、长石等以脆性碎裂为主,而磁黄铁矿、黄铜矿、闪锌矿和云母等以塑性变形为主。再活化的黄铜矿、磁黄铁矿和少量闪锌矿呈脉和网脉穿插黄铁矿碎斑。实验结果表明,即使没有外来流体加入.构造动力作用所导致的流体包裹体破坏所释出的流体,就足以使成矿物质发生活化转移和再活化。 相似文献
83.
84.
Predictability of Interannual Variability in the Kuroshio Transport South of Japan Based on Wind Stress Data over the North Pacific 总被引:1,自引:3,他引:1
It is expected that a roughly two-year forecast of the Kuroshio transport variation can be made from a past record of wind
stress data over the ocean, since it takes nearly ten years for the first-mode baroclinic Rossby wave to traverse the entire
basin in the midlatitude North Pacific (∼30°N). We therefore investigated the predictability using an ocean general circulation
model driven by the wind stress data from the National Centers for Environmental Prediction/National Center for Atmospheric
Research (NCEP/NCAR) reanalysis. Referring to a hindcast experiment as the control run, we carried out fifteen forecast experiments,
the initial conditions of which are taken from the hindcast experiment at intervals of two years during the period from the
end of 1969 to the end of 1997. Each of the forecast experiments is driven only by wind stress in the year preceding each
experiment. The forecasted Kuroshio transport anomaly south of Japan agrees better with the hindcasted one during the first
two years of the forecast in most cases. In some cases, however, significant disagreements occur, most of which are likely
due to larger unpredictable variations caused by wind stress anomalies near Japan. At the end of forecast year 2, the anomaly
correlation coefficient is about 0.7, and rms of the forecast error is smaller than rms of the hindcasted anomaly. These results
indicate that the prediction of the interannual variability in the Kuroshio transport could be made two years in advance at
a statistically significant level.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
85.
GUI Maochang * WU Lingjuan . Institute of Oceanology Chinese Academy of Sciences Qingdao China. Laboratory of Numerical Modeling for Atmospheric Sciences Geophysical Fluid Dynamics Institute of Atmospheric Physics Chine-se Academy of Sciences Beijing China. Graduate School Chinese Academy of Sciences Beijing China 《海洋学报(英文版)》2005,(4)
1 IntroductionIt is well known that interaction between the trop-ical ocean and atmosphere produces the largest inter-annual climate signal, El Nino-Southern Oscillation(ENSO). In past decades many efforts have been madein understanding and predicting ENSO: such as the hy-pothesis of Bjerknes (1969) that ENSO arises as aself-sustained cycle in which SSTA in the Pacific O-cean causes the trade winds to strengthen or slackenand that this in turn drives the ocean circulation changesthat … 相似文献
86.
Deformation Patterns of an Accretionary Wedge in the Transition Zone from Subduction to Collision Offshore Southwestern Taiwan 总被引:1,自引:0,他引:1
Char-Shine Liu Benoit Deffontaines Chia-Yu Lu Serge Lallemand 《Marine Geophysical Researches》2004,25(1-2):123-137
Swath bathymetry data and seismic reflection profiles have been used to investigate details of the deformation pattern in the area offshore southwestern Taiwan where the Luzon subduction complex encroaches on the passive Chinese continental margin. Distinctive fold-and-thrust structures of the convergent zone and horst-and-graben structures of the passive margin are separated by a deformation front that extends NNW-ward from the eastern edge of the Manila Trench to the foot of the continental slope. This deformation front gradually turns into a NNE–SSW trending direction across the continental slope and the Kaoping Shelf, and connects to the frontal thrusts of the mountain belt on land Taiwan. However, the complex Penghu submarine canyon system blurs the exact location of the deformation front and nature of many morphotectonic features offshore SW Taiwan. We suggest that the deformation front offshore SW Taiwan does not appear as a simple structural line, but is characterized by a series of N–S trending folds and thrusts that terminate sequentially in an en-echelon pattern across the passive Chinese continental slope. A number of NE–SW trending lineaments cut across the fold-and-thrust structures of the frontal accretionary wedge and exhibit prominent dextral displacement indicative of the lateral expulsion of SW Taiwan. One of the prominent lineaments, named the Yung-An lineament, forms the southeastern boundary of the upper part of the Penghu submarine canyon, and has conspicuous influence over the drainage pattern of the canyon 相似文献
87.
The Agulhas Ridge is a prominent topographic feature that parallels the Agulhas-Falkland Fracture Zone (AFFZ). Seismic reflection
and wide angle/refraction data have led to the classification of this feature as a transverse ridge. Changes in spreading
rate and direction associated with ridge jumps, combined with asymmetric spreading within the Agulhas Basin, modified the
stress field across the fracture zone. Moreover, passing the Agulhas Ridge’s location between 80 and 69 Ma, the Bouvet and
Shona Hotspots may have supplied excess material to this part of the AFFZ thus altering the ridge’s structure. The low crustal
velocities and overthickened crust of the northern Agulhas Ridge segment indicate a possible continental affinity that suggests
it may be formed by a small continental sliver, which was severed off the Maurice Ewing Bank during the opening of the South
Atlantic. In early Oligocene times the Agulhas Ridge was tectono-magmatically reactivated, as documented by the presence of
basement highs disturbing and disrupting the sedimentary column in the Cape Basin. We consider the Discovery Hotspot, which
distributes plume material southwards across the AAFZ, as a source for the magmatic material. 相似文献
88.
89.
多波束数据的海底数字地形模型构建 总被引:11,自引:0,他引:11
提出大批量多格式原始多波束数据的DTM构建方法,以满足大区域、大比例尺海底地形制图的需要。在多种格式原始多波束数据接口和系统内部标准数据结构的基础上,通过对数据文件、数据种类和数据运算量的有效组织管理,实施边读入、边权重配赋的网格插值,分析了高斯、指数和距离平方反比权重函数的适用性,及最小值、最大值和平均值的实用性。在权重配赋网格插值基础上,提出分形fBM和张力样条配合使用的方程式插值方法,保证DTM数据的有效外延和地形分辨。整套算法效率高,并能有效保证DTM的精度,对存储在外部介质的数据遍历一次即可完成网格插值。 相似文献
90.
Lodolo Emanuele Coren Franco Schreider Anatoly A. Ceccone Giulio 《Marine Geophysical Researches》1997,19(5):439-450
The southwestern part of the Scotia Sea, at the corner of the Shackleton Fracture Zone with the South Scotia Ridge has been investigated, combining marine magnetic profiles, multichannel seismic reflection data, and satellite-derived gravity anomaly data. From the integrated analysis of data, we identified the presence of the oldest part of the crust in this sector, which tentative age is older than anomaly C10 (28.7 Ma). The area is surrounded by structural features clearly imaged by seismic data, which correspond to gravity lows in the satellite-derived map, and presents a rhomboid-shaped geometry. Along its southern boundary, structural features related to convergence and possible incipient subduction beneath the continental South Scotia Ridge have been evidenced from the seismic profile. We interpret this area, now located at the edge of the south-western Scotia Sea, as a relict of ocean-like crust formed during an earlier, possibly diffuse and disorganized episode of spreading at the first onset of the Drake Passage opening. The successive episode of organized seafloor spreading responsible for the opening of the Drake Passage that definitively separated southern South America from the Antarctic Peninsula, instigated ridge-push forces that can account for the subduction-related structures found along the western part of the South Scotia Ridge. This seafloor accretion phase occurred from 27 to about 10 Ma, when spreading stopped in the western Scotia Sea Ridge, as resulted from the identification of the marine magnetic anomalies. 相似文献