潟湖潮汐通道水力特性与治理

综合论述了潟湖潮汐通道口门之流速、断面面积、通道长度、延时角和饱满系数之间的关系,以及沿岸漂沙对口门的影响。对不同类型的潟湖潮汐通道,提出了中潮位射流导流堤、口门复式断面和通道分汊等治理方法及其通道口门相关尺度的具体计算。     

Overtopping Discharge of Wind-Waves on Simple Slope Dikes

An empirical formula for estimating the overtopping discharge of wind-waves on a smooth-impermeable-simple slope dyke is derived through model tests in this paper, it can be adopted by related design departments in the determination of the crest elevation of the dyke.     

桩式离岸堤保滩促淤工程消浪效果试验研究

在上海奉贤南北港保滩促淤工程中，采用了一种新型结构型式－桩式离岸堤，并通过物理模式试验进行了桩式离岸堤消浪效果研究。针对离岸堤通常建于近岸水区破波带的特点，重点研究水深，堤高以及堤身结构对波浪衰减的影响，同时对桩式离岸堤堤后水域的波浪底流速 分析探讨。研究结果表明，桩式离岸堤不仅具有良好的消浪效果。而且可在较大范围内改变波态，即由引起水体剧烈紊动的破波转变为浅水推进波，从而有效地改善海滩上的动力条件，促进海滩免受侵蚀，是一种具有广泛应用前景和新型保滩促淤结构。     

新疆库鲁克塔格地区二叠纪脉岩群岩石地球化学特征，Nd、Sr、Pb同位素组成与岩石成因

库鲁克塔格地区二叠纪脉岩群非常发育,主要岩石类型是辉绿岩,并有少量的斜闪煌斑岩、斜长玢岩和花岗斑岩。花岗斑岩属高钾钙碱性系列,具有A型花岗岩的稀土元素和微量元素地球化学特征;斜长玢岩的地球化学特征与花岗斑岩相似,二者都亏损U、Nb、Ta。斜闪煌斑岩的岩石化学组成属过碱性系列,显著富集轻稀土元素和大离子亲石元素。辉绿岩的岩石化学组成以钙碱性系列为主,稀土元素总量变化较大,Cs、Rb、Ba、Th元素丰度变化大,普遍亏损U、Nb、Ta。研究证明,辉绿岩脉的这些地球化学特征都与同化混染作用有关,大离子亲石元素丰度的变化还与热液蚀变有关。辉绿岩具有富集型Nd、Sr同位素组成,且变化范围大,是岩浆源区同化混染作用的结果。它们的铅同位素组成属低U(Th)/Pb值的正常铅,主要受混染物控制,并不代表源区特征。库鲁克塔格地区岩石圈地幔Nd、Sr、Pb同位素比塔里木板块西缘岩石圈地幔的富集程度更高,且变化范围大,反映了这两个地区岩石圈地幔的演化历史存在明显差异。     

湘东北中生代基性岩脉岩石地球化学及构造意义

湘东北中生代发育以辉绿岩类和煌斑岩类为代表的基性岩脉,属陆内拉斑玄武岩系,部分煌斑岩属于碱性系列。岩石富集LREE,δEu负异常不明显,其形成主要受软流圈地幔部分熔融作用制约。煌斑岩类微量元素总体上具有洋岛玄武岩(OIB)岩浆源区特征,富集Nd、P、Cs而K、Rb、Sr、U、Th等富集程度不明显,Ta、Nb略有富集。辉绿岩类表现出Ta、Nb、Ti亏损,但LILE并不富集,反映地壳混染程度的增强。基性岩脉形成于陆内拉张带的构造环境,岩浆活动未受到中生代大洋板块俯冲的影响。基性岩脉在时、空及物质组成上与湘东南玄武质岩石基本一致,属于整个湘东南岩石圈拉张-减薄带的一部分。     

冀北发现具鬣刺结构的超基性岩

冀北具鬣刺结构的超基性岩呈透镜状，产于华北克拉通北缘的早元古宙红旗营子群黑云斜长片麻岩之中。富MgO，贫CaO，A12O3和FeO*＝0．86，TiO2介于0．01％-0．02％之间，与SSZ型蛇绿岩中相应岩石的TiO2含量相当。原始地幔标准化的过渡元素配分型式表现为不对称的“W”型，在TiO2和Cu处形成两个明显的负异常“谷”。据此地球化学特征意味着它们可能来自于消减带之下上地幔，为上地幔高度部分熔融的残余物。岩石中鬣刺结构可能是叶蛇纹石高压分解的结果，表明研究区某些变质橄榄岩岩块曾经受过俯冲—消减作用。     

Sedimentary facies during early stages of flooding in an extensional basin: the Brèche Rouge de Carboneras (Late Miocene, Almería/SE Spain)

The intramontane basins of the Betic Cordilleras (SE Spain) formed subsequent to the main phase of orogenic deformation during the middle Miocene in a close genetic relation to the Trans-Alboran Shear zone. Left lateral movements along a local branch (Carboneras fault zone, CF; strike NE–SW) of this zone played a major role in controlling the formation and dynamics of the Nijar-Carboneras Basin. To the south of the fault, a major phase of strike-slip faulting is recorded during the late Tortonian. The expression of this event is the Brèche Rouge de Carboneras (BRC), which seals a deep denudational surface on top of dislocated fault blocks formed by volcanics of the Cabo de Gata complex and early Tortonian shallow marine calcarenite. The sedimentary facies of this widely distributed unit in the Carboneras-Subbasin mirror the submarine topography and the distribution of the fault zones. Along strike-slip fault zones, autoclastic breccias and neptunian dikes preferentially oriented NW–SE and NE–SW occur, which are interpreted to represent the near-surface expression of the faults. Red limestone forms the groundmass of the autoclastic breccia and infills of neptunian dikes, which exhibit multiple phases of opening of fissures, gravitational sedimentary infill, lithification, and renewed creation of cracks. Steep relief, probably along fault scarps, was mantled by epiclastic volcanic conglomerate with a red carbonate matrix. Well-lithified coarse skeletal limestone rich in planktonic foraminifera formed pavements along sediment starved rocky surfaces in deep water. Laterally, within topographic depressions, the pavement limestone grades into thick accumulations of skeletal rudstone composed of fragmented azooxanthellate corals and stylasterid hydrozoans, which were concentrated by powerful bottom currents and gravitiy flows. Within the shallow water zone of dip slope ramps, cross-bedded calcarenite and calcirudite formed. Based on textures, fabrics and biota, rocks of the BRC were grouped into nine genetic lithofacies which document cryptic, deep-aphotic and shallow-photic environments typical of a sediment starved extensional basin.     

蚀变超基性岩金（镍）矿床中的贵金属元素──以云南墨江金矿和陕西煎茶岭金矿为例

云南墨江金矿和陕西煎茶岭金矿中Ａｇ、Ａｕ和ＰＧＥ（铂族元素）的丰度和共生状况如下：（１）两矿床中的Ａｇ－Ａｕ关系呈三种情况：硅质岩型矿石和其他类型低品位金矿石中Ａｇ－Ａｕ基本上不具相关关系；石英脉型矿石中Ａｇ－Ａｕ呈明显的正相关关系；氧化矿石中Ａｇ－Ａｕ呈负相关关系。（２）所有样品中的ＰＧＥ均低于７１×１０（－６），其ＰＧＥ的特征是Ｐｔ≥Ｐｄ和Ｒｕ＞Ｏｓ、Ｉｒ、Ｒｈ。（３）这些样品的地幔标准化ＰＧＥ分布模式是以Ｒｈ为峰的上凸曲线，而墨江样品又具Ｉｒ的负异常。与一般超基性岩的情况不同，这些样品的模式曲线中Ｐｄ－Ａｕ部分呈陡弯折，它表明矿化元素金可能主要由区域成矿流体提供。     

Geochronology, geochemistry and tectonic implications of Xiongshan diabasic dike swarm, northern Fujian

Sm/Nd isotopic age determination showed that Xiongshan dike swarm was at 585.7 Ma ± 30 Ma. The trace element geochemistry and Sr/Nd/Pb isotope gemhemistry studies indicate that the dike swarm was products of back-arc basin spreading ridge and the magma originated from the depleted mantle region which was metasomatized by LILE-rich liquids/melts derived from subduction slab. Project supported by the National Natural Science Foundation of China.     

青藏高原南羌塘基性岩墙群U-Pb和Sm-Nd同位素定年及构造意义

羌塘地区是青藏高原古特提斯研究的关键地区,羌塘南部地区基性岩墙群的侵位时代与构造背景对确定古特提斯阶段联合古陆解体的具体时间和青藏高原构造演化有重要意义。选择单颗粒锆石U-Pb法和全岩Sm-Nd等时线法对基性岩墙进行定年研究,获得了(312±4)Ma单颗锆石U—Pb谐合线年龄和(299±13)Ma和(314±5)Ma两个Sm-Nd全岩等时年龄。结合区域地质资料研究认为,基性岩墙群为羌塘地块裂离作用的产物,所获得的同位素年龄代表了基性岩墙群的侵位时间,为羌塘地块裂解提供了构造事件年龄,为重塑龙木错—双湖古特提斯洋盆的形成演化过程提供了重要信息。