渤东低凸起L3构造东营组含煤地层低渗储层特征及成因

渤东低凸起东营组储集层以低渗为特征,低渗成为制约该区东营组勘探的重要因素.通过多种分析测试方法,研究了渤东低凸起L3构造东营组低渗储集层特征,探讨了低渗储集层成因.L3构造东营组储集层砂岩溶蚀作用发育,斜长石含量低,碳酸盐胶结物含量低,高岭石含量高,石英加大明显.储集层主要以中孔低—特低渗为主,孔径小,连通差,吼道窄,排驱压力大.微量元素分析表明,研究区东营组沉积时为淡水环境;测井和岩心观察证实,地层中含多层碳质泥岩和煤层.早期腐殖酸的溶蚀作用,造成低温下不稳定的斜长石大量溶蚀,这些溶蚀孔隙在后期深埋过程中受压实和成岩作用影响被复杂化、细小化是储集层低渗的主要原因.早期碳酸盐胶结物少,岩石抗压实能力差也是储层低渗的重要原因.     

东太平洋CC区沉积物稀土元素特征及物源

对东太平洋CC区中西部33站表层沉积物进行了稀土元素(REE,包括Y)地球化学研究。结果表明,REE在沸石粘土中最富集,在硅质沉积物中含量明显偏低;所有沉积物样品中REE都存在Ce负异常和Eu正异常的轻稀土(LREE)亏损特征,表现为典型受到海水来源物质影响的REE配分模式;硅质粘土中Ce亏损程度、Eu正异常和REE富集程度都比硅质软泥更明显。与东区相比,西区沉积物中LREE、HREE(重稀土和钇元素)和∑REE(稀土元素总量)普遍偏高,LREE与HREE分异更明显,HREE相对更富集,LREE和Ce亏损更显著。研究区表层沉积物中REE主要来自海洋自生物质,同时受到陆源物质、海底火山物质的影响。     

Dinophysis caudata generated lipophilic shellfish toxins in bivalves from the Nanji Islands,East China Sea

A 12-month program of monitoring potentially toxic microalgae(that produce lipophilic shellfi sh toxins; LSTs) and their toxins in bivalves was conducted from April 2006 to March 2007 in the Nanji Islands, East China Sea. Two Dinophysis species, D. caudata and D. acuminata, were identifi ed, and D. caudat a was found to be the dominant species. D. caudata was detected in water samples between April and June 2006, and between February and March 2007. It reached its highest abundances in May, with a mean abundance of 1.38×10 2 cells/L in surface water and 1.25×10 2 cells/L in bottom water(10 m deep). The temporal distribution of D. caudata was associated with the occurrence of LSTs in bivalve samples, which mostly occurred at the same time as D. caudata blooms, between April and July 2006. All of the cultured bivalves sampled between April and June were contaminated with LSTs, with an average toxicity of 85 μg okadaic acid(OA) eq./100 g meat, which was four times higher than the Chinese regulatory limit(20 μg OA eq./100 g meat). Ten out of fi fteen wild samples(66.7%) collected during the same period were positive for LSTs, and contained an average LST toxicity of 45 μg OA eq./100 g meat(more than twice the regulatory value). Cultured Patinopecten yessoensis collected on 15 May 2006 had the highest toxicity, 320 μg OA eq./100 g meat, and relatively high toxicities(80 to 160 μg OA eq./100 g meat) were found in bivalves until the end of July.     

Spatio-temporal distribution of dissolved sulfide in China marginal seas

With sulfide increasingly recognized as an important parameter to assess the oxidation-reduction level in aqueous environment, research on its geochemical behavior is becoming important. Water samples collected in Bohai Sea(1–19 August, 2010), Yellow Sea(20–30 November, 2010) and East China Sea(3–17 June, 2010 and 1–10 November, 2010) were used to determine the occurrence and distribution of dissolved sulfide by methylene blue spectrophotometric method. Results show that:(1) horizontally, concentration of dissolved sulfide significantly varied from the coastal region to the open sea and profoundly influenced by physical processes. High values occurred in the river-sea boundary zone "marginal filter" due to rich riverine input, frequent upwelling and active exchange in shelf edge. Terrestrial input from adjacent rivers and the current cycling contributed to the high sulfide appeared in western Bohai Sea, eastern Shandong Peninsula, and northeast of Changjiang(Yangtze) River estuary. Especially, relative higher sulfide values occurred in Yellow Sea, which is consistent with the variation of salinity largely due to the hydrodynamic feature;(2) vertically, measurement of dissolved sulfide in bottom water was higher and more variable than that in surface water caused by the wind-induced resuspension and dissimilatory sulfate reduction. Moreover, nutrient-type profile clearly identified that oxidation plays a major role in the biogeochemistry cycle of sulfide in water;(3) seasonally, investigation for East China Sea in June and November reflected seasonal variation of Changjiang River Diluted Water, Kuroshio Current, and Taiwan Warm Current. Concentration in June was much higher than that sampled in November at most stations. Mean concentration of dissolved sulfide varied seasonally from 2.26 μg/L(June) to 1.16 μg/L(November) in surface and 3.00 μg/L(June) to 1.56 μg/L(November) in bottom. Progress in the field is slow and more effort is needed to ensure the accuracy and reliability of determination and estimate the natural or anthropogenic contribution of dissolved sulfide in ecosystems.     

A Numerical Study of Tidal Asymmetry： Preferable Asymmetry of Nonlinear Mechanisms in Xiangshan Bay,East China Sea

In-situ measurements in Xiangshan Bay, the East China Sea, show that the duration of the rising tide is shorter than that of the falling tide around the bay mouth, while it becomes much longer in the inner bay. A finite volume coastal ocean model（FVCOM） with an unstructured mesh was applied to simulate the asymmetric tidal field of Xiangshan Bay. The model reproduced the observed tidal elevations and currents successfully. Several numerical experiments were conducted to clarify the roles of primary mechanisms underlying the asymmetric tidal field. According to the model results, the time-varying channel depth and nonlinear advection prefer shorter duration of the rising tide in Xiangshan Bay, while the time-varying bay width favors longer duration of the rising tide. The overtides generated by these two opposite types of nonlinear mechanisms are out of phase, resulting in smaller M4 amplitude than the sumfold of each individual contribution. Although the bottom friction as a nonlinear mechanism contributes little to the generation of overtide M4, it is regarded as a mechanism that could cause a shorter duration of the rising tide, for it can slow down the M2 phase speed much more than it slows down the M4 phase speed. The time-varying depth, nonlinear advection and bottom friction are dominating factors around the bay mouth, while the time-varying width dominates in the inner bay, causing the tidal elevation asymmetry to be inverted along the bay.     

Statistical Characteristics of ENSO Events in CMIP5 Models

By applying the historical-run outputs from 24 Coupled Model Intercomparison Project Phase 5（CMIP5） models and the NOAA Extended Reconstructed SST V3 b dataset（ERSST）, the characteristics of different types of ENSO in the selected CMIP5 models, including cold-season-matured Eastern Pacific（C-EP） ENSO, warmseason-matured EP（W-EP） ENSO, cold-season-matured Central Pacific（C-CP） ENSO, and warm-season-matured CP（W-CP） ENSO, were examined in comparison with those in the ERSST dataset. The results showed that, in general, consistent with observations, EP ENSO events in most of the model runs were relatively much stronger than CP ENSO events, and cold-season-matured ENSO events were relatively much more frequent than warm-season-matured ENSO events for both EP and CP ENSO events. The composite amplitudes of ENSO events in most of the models were generally weaker than in observations, particularly for EP El Ni？o and CP La Ni？a. Moreover, most of the models successfully reproduced the amplitude asymmetries between El Ni？o and La Ni？a for cold-season-matured EP and CP ENSO events, exhibiting an average stronger/weaker EP El Ni？o/La Ni？a regime and a weaker/stronger CP El Ni？o/La Ni？a regime. Most of the models, however, failed to reproduce the observed regimes of stronger/weaker W-EP El Ni？o/ La Ni？a and weaker/stronger W-CP El Ni？o/La Ni？a.     

Time-Dependent Nonlinear Forcing Singular Vector-Type Tendency Error of the Zebiak-Cane Model

Based on the Zebiak-Cane model, the timedependent nonlinear forcing singular vector （NFSV）-type tendency errors with components of 4 and 12 （denoted by NFSV-4 and NFSV-12） are calculated for predetermined El Nifio events and compared with the constant NFSV （denoted by NFSV-1） from their patterns and resultant prediction errors. Specifically, NFSV-1 has a zonal dipolar sea surface temperature anomaly （SSTA） pattern with negative anomalies in the equatorial eastern Pacific and positive anomalies in the equatorial central-western Pa- cific. Although the first few components in NFSV-4 and NFSV-12 present patterns similar to NFSV-1, they tend to extend their dipoles farther westward; meanwhile, the positive anomalies gradually cover much smaller regions with the lag times. In addition, the authors calculate the predic- tion errors caused by the three kinds of NFSVs, and the results indicate that the prediction error induced by NFSV-12 is the largest, followed by the NFSV-4. However, when compared with the prediction errors caused by random tendency errors, the NFSVs generate significantly larger prediction errors. It is therefore shown that the spatial structure of tendency errors is important for producing large prediction errors. Furthermore, in exploring the tendency errors that cause the largest prediction error for E1 Nifio events, the timedependent NFSV should be evaluated.     

黔西南金矿与物化探异常分布规律研究

文章对黔西南金(锑汞)矿产与物探重力异常及化探元素异常(含组合)的分布特征进行研究,认为其矿产分布与物化探异常分布有密切对应关系,即与重力负异常分布区域、与化探异常(Au、Sb、Hg、Mo)分布的规模、强度等有关,并结合矿产产出规律和成矿地质条件等,预测了部分金矿成矿远景地段。     

湖南CORS:技术与设备之困

正随着湖南省县域经济的不断发展,大湘西、大湘南等偏远山区的发展也逐渐上升到战略层面。而这些地区的基准站密度远低于长株潭地区,亟需增加一定数量的基准站,尽可能地减少信号覆盖盲区。     

洪江古商城:浮华随流水而去

正老砖墙,石板街,苍黑的檐瓦,磨得发亮的门槛,嬉笑打闹的孩童……踏上洪江古商城,多少有点似曾相识。也许很多人记忆中都有一段这样的场景,牵引我们的,不仅仅是山水、建筑、风物,更是那些历史长河中的人和事。名胜、山水和器物,犹如诗文中的典故,总是在默默诱导我们去重温那些早已散场的人生戏剧,感慨于洪江这座"因水而兴,因水而衰"的古商城……