北海维京地堑Beryl湾多井沉降分析的应用

Beryl湾位于北海维京地堑的最南端,有三组断层,走向分别为北东向、北西—南东向和北东—南西向。本文利用73口井的高分辨率沉降分析,结合部分区域地震,来阐述中—晚侏罗世的沉降模式。已经完成的高分辨率(每个点间隔仅1～2Ma)沉降分析可以用来研究不同走向断层的时间演化,以及东舍德兰边界断层的连锁和对沉积相的控制作用。计算结果表明,东舍德兰断层可以划分为南、北两段,它们在早—中牛津期连锁成一条断层。中—晚侏罗世裂谷期可以进一步划分为4个阶段:巴通—中卡洛夫期初始裂陷期,卡洛夫—中牛津期为早期裂陷同旋转期,晚牛津—早波特兰…     

Construction of vertical wind profile from satellite-derived winds for objective analysis of wind field

During summer Monex-79, a variety of observing systems viz. research ships, research aircrafts, constant pres-sure balloons and geostationary satellite etc. were deployed, besides the regular conventional observations The pur-pose of these additional systems was to make the best possible data for the studies on various aspects of monsoon cir-culation. The present study is aimed at the construction of vertical wind profile using cloud motion vectors obtained from GOES (I-O) satellite and to examine whether the constructed wind profiles improves the representation of the monsoon system, flow pattern etc. in the objective analysis. For this purpose, climatological normals of the wind field are considered as the initial guess and the objective analyses of the wind field are made with, first using only data from conventional observations over land areas, subsequently including the constructed winds from cloud motion vectors. These analyses are then compared with the standard analyses of wind field obtained from Quick Look Atlas by T. N. Krishnamurti et al. (1979).It is inferred that satellite estimated mean wind profiles show good agreement with the mean wind profiles of the research ships with RMS errors less than 5 mps below 500 hPa and less than 8 mps above 500 hPa. It is further infer-red that the inclusion of constructed winds shows a positive impact on the objective analysis and improvement is seen to be more marked in the data-sparse region of the Arabian sea. Analyses which include the constructed winds show better agreement with the standard analysis, than the analyses obtained using only conventional winds. Thus, results of our study suggest that the wind profiles constructed using cloud motion vectors are of potential use in objective analysis to depict the major circulation features over the Indian region.     

Glass and Mineral Chemistry of Northern Central Indian Ridge Basalts:Compositional Diversity and Petrogenetic Significance

Abstract: The glass and mineral chemistry of basalts examined from the northern central Indian ridge (NCIR) provides an insight into magma genesis around the vicinity of two transform faults: Vityaz (VT) and Vema (VM). The studied mid-ocean ridge basalts (MORBs) from the outer ridge flank (VT area) and a near-ridge seamount (VM area) reveal that they are moderately phyric plagioclase basalts composed of plagioclase (phenocryst [An60–90] and groundmass [An35–79]), olivine (Fo81–88), diopside (Wo45–51, En25–37, Fs14–24), and titanomagnetite (FeOt ~63.75 wt% and TiO2 ~22.69 wt%). The whole-rock composition of these basalts has similar Mg# [mole Mg/mole(Mg+Fe2+)] (VT basalt: ~0.56–0.58; VM basalt: ~0.57), but differ in their total alkali content (VT basalt: ~2.65; VM basalt: ~3.24). The bulk composition of the magma was gradually depleted in MgO and enriched in FeOt, TiO2, P2O5, and Na2O with progressive fractionation, the basalts were gradually enriched in Y and Zr and depleted in Ni and Cr. In addition, the SREE of magma also increased with fractionation, without any change in the (La/Yb)N value. Glass from the VM seamount shows more fractionated characters (Mg#: 0.56–0.57) compared to the outer ridge flank lava of the VT area (Mg#: 0.63–0.65). This study concludes that present basalts experienced low-pressure crystallization at a relatively shallow depth. The geochemical changes in the NCIR magmas resulted from fractional crystallization at a shallow depth. As a consequence, spinel was the first mineral to crystallize at a pressure >10 kbar, followed by Fe-rich olivine at <10 kbar pressure.     

提敏斯及其周围地区金矿化与地层和构造的关系

提敏斯地区太古代火山岩划分为两个群:较老的德洛罗群和上覆的提斯达尔群,每个群又划分为三个火山岩组。德洛罗群主要为钙碱系列,提斯达尔群的火山岩成分可分三部分,其下部为科马提岩,中部为厚层拉斑玄武岩,上部为钙碱质岩石。波丘潘群的沉积岩与德洛罗群上部及提斯达尔群火山岩层同一时代,通过对提敏斯—马塔彻温—科克兰湖区上下关系的观察,在提敏斯地区所确定的群实际上是超群,群下层的组应该提升为群。从区域上观察金矿床时,可发现下列重要关系: ①大多数矿床在空间上与德斯特—波丘潘断层和拉德湖断层相密切伴生。②沿断层发生强烈的碳酸盐化。③断层与上超群的下群科马提岩相一致。④在金矿开采区,沉积岩较多。⑤在科马提岩中或其附近常见石英—长石斑岩岩株,认为超镁铁质科马提岩是金矿的主要矿源层,碳酸盐化使金释放,并富集到扩容带中。     

Short-term response of the slow growing seagrass Posidonia oceanica to simulated anchor impact

Experimental evaluations about the impact of anchors of small vessels have previously shown that each anchoring can on average damage up to six shoots of Posidonia oceanica, removing small amount of biomass and, at the same time, interrupting continuity among shoots. The aim of the paper was to investigate the response of P. oceanica to different damage intensity at two levels of substrata compactness. Three treatments were considered: control (no damage); low damage (simulated anchor damage by three strokes of a hoe); and high damage (six strokes). Disturbance was higher where the substratum was highly penetrable and after one year significant variation was observed among treatments for both the number of leaves per shoot and shoot density. Conversely, the number of leaves per shoot by the end of the study was similar among all treatment combinations, suggesting that this was the only phenological feature that recovered, and probably the only result that through clonal integration could be achieved. These data strongly highlighted the role that anchoring might have on the slow growing seagrass P. oceanica meadow.     

Environmental records of carbon in recent lake sediments

Based on careful sampling and accurate analysis of recent sediments in Lake Chenghai, this paper discusses the staggered positive/negative correlation between organic carbon (OC) concentration and inorganic carbon (IC) concentration. The result indicates that temperature change, and its induced relative changes are the main factors affecting the relationship between IC concentration, δ¹³C of carbonate and OC concentration. When temperature and its induced photosynthesis strength change control autochthonous calcite precipitation, OC concentration is positively correlated with IC concentration and δ¹³C of carbonate. When temperature and its induced physical/chemical changes dominate, OC concentration displays negative correlation with IC concentration and δ¹³C of carbonate. IC concentration and δ¹³C of carbonate in sediments of Lake Chenghai are good proxies for climatic warm/cold changes.     

Lateral Magma Flow in Mafic Sill-complexes

正The structure of upper crustal magma plumbing systems controls the distribution of volcanism and influences tectonic processes.Delineating the structure and volume of plumbing systems is,however,difficult because:(1)active     

三种■属(Seriola)鱼类表型特征比较分析

为全面了解■属鱼类表型性状的种间差异,描述了我国养殖的黄条■(Seriola lalandi)、高体■(Seriola dumerili)和五条■(Seriola quinqueradiata)的形态学特征,测量了群体的表型数据,通过单因素方差分析、通径分析、主成分分析、判别分析和聚类分析等多元统计方法,对3种■鱼共计190尾样品的形态种质特征和可量可数性状进行了比较研究。单因素方差分析显示,除叉长/体长(FL/SL)、体长/尾柄长SL/PL)、头长/眼间距(HL/ID)和下颌长/上颌长(LJL/UJL)外,其余9个指标均存在显著性差异(P<0.05)。通径分析显示,黄条■的体长(SL)、体高(BH)、尾柄长(PL)和尾柄高(PD)是主要影响其体质量的4个表型性状;高体■的体长(SL)、体高(BH)、眼间距(ID)、下颌长(LJL)和眼后头长(POL)是主要影响其体质量的5个表型性状;五条■的体高(BH)、下颌长(LJL)和全长(TL)是主要影响其体质量的3个表型性状。主成分分析构建了4个主成分,其中第一项主成分贡献率为34.974%,其他3个主成分的贡献率依次为23.897%、...     

CALCULATION OF THE VOLUME METHODOF DETENTION POND

1INTRODUCTIONDuetotiledecreaseoflandcoverandtheincreaseofwaterproofareasinurbandevelopment,itisclearthattherainwaterinfiltrationratewillreduceandtherunoft'volumewillincrease.Increasedrunoft'maycausetyequentfloodingandseveresedimentwashoutdownstream.Toavoidsuchadversedownstreameffects,storm-waterrunoft'andsedimentouttlowratemustbecontrolledusingdetentiontbcilitiesinInanynewcommunities.ThemainfunctionsofdetelltionpondsaretoreducepeakflowandcontrolthestreamlineandsedimentOutflowrate.Inperfo…     

Why Is the Climate Forcing of Sulfate Aerosols So Uncertain?

l. IntroductionAlthough the aerosol has been recognized as an important factor which has innuence onthe past, present and future climate for a long time, it still has much uncertainty in assessingits climate forcing. The direct radiative forcing of sulfate aerosols has been estimated rangingfrom --0.3 W/ m2 to --0.9 W/ m2 in recent publications (Charlson et al., l992, Kiehl andBriegleb l993; Taylor and Penner 1994, Boucher and Anderson l995, Kieh1 and Rodhe l995;Chuang et al., l997, Penne…