Biological influences on morphology and bed composition of an intertidal flat

Biological activity is known to influence sediment strength at bed–water interfaces. However, its precise effect on geomorphology and on bed composition is not known. This paper proposes a parameterization of sediment destabilizing and stabilizing organisms on three parameters that describe the erosion and mixing processes of the sediment bed, namely the critical bed shear stress, the erosion coefficient and the bioturbation coefficient. This parameterization is included in a 3D sand–mud morphodynamic model to form the sand–mud–bio model. The performance of the sand–mud–bio model is demonstrated by testing it on the Paulinapolder intertidal flat in the Western Scheldt estuary of The Netherlands. Model results show that biological influences on sediment strength result in significant morphological change and bed composition variations. Destabilizing organisms always cause a significant decrease in mud content in the bed and an increase of erosion. On the other hand, stabilizing organisms can, but do not necessarily, cause an increase of mud content and additional sedimentation.     

初析赤潮成因研究的围隔实验结果──几个理化因子与硅藻赤 潮的关系

从１９９０年以来，在国家海洋局第三海洋研究所地临陆基水池中，应用围隔生态系实验技术对赤潮成因作了几次探索性的研究。针对４次人为引发赤潮的中尺度围隔实验的部分结果，结合已报道的厦门西海域赤潮过程，分析几个主要理化因子（水体稳定性，无机氮，无机磷，可溶性锰锰，可溶性铁和维生Ｂ１２）与硅藻赤潮发生及其规模的关系。     

西昆仑山区湖泊初探

本文论述了西昆仑山区湖泊的分布、成因、水化学特征以及其演化历史与高原隆升、古气候变化、高山冰川进退之间的关系。研究结果表明,该区湖泊主要靠暖季高山带的冰雪融水补给,故矿化度的变化与其距补给源的远近密切相关;它们在第四纪期间的演化是高原构造隆升和全球气候变化二者作用的结果;根据现有资料,该区湖泊的演化历史可大致分为3个阶段,即距今4.6万年以前的大湖期,晚更新世晚期的湖面波动期和全新世的湖泊退缩期。     

Recent changes of Shandong sandy coast and in fluence of human activities

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泻湖沉积环境——山东半岛为例

本文以山东半岛为例,系统地探讨了泻湖特征性的沉积环境——湖、海水的频繁交换,盐度多变,浅水低能和多物源。为泻湖的开发利用提供有益资料。     

山东胶东地区盘子涧金矿成矿流体He-Ar同位素地球化学特征

盘子涧金矿地处山东胶东地区蓬莱—栖霞金成矿带南部,是典型的石英脉型金矿,Au品位高,目前对该矿床成矿流体来源的研究尚不深入。在详细的矿相学观察及黄铁矿显微结构研究基础上,对盘子涧金矿主成矿阶段(石英-黄铁矿(绢云母)阶段和金-石英-多金属硫化物阶段)的载金黄铁矿进行了流体包裹体He-Ar同位素组成分析。结果表明:盘子涧金矿载金黄铁矿中流体包裹体的3He丰度为(3.49~8.50)×10^-14 cm^3 STP·g^-1,4He丰度为(2.46~5.06)×10^-8 cm^3 STP·g^-1,3He/4He值为0.8 Ra^1.2 Ra(Ra为大气3He/4He值,Ra=1.39×10^-6),成矿流体表现出以富集地幔为主导的壳幔混合特征;40Ar丰度为(1.02~2.65)×10^-7 cm^3 STP·g^-1,40Ar/36Ar值为896.3~1724.1,是大气饱和水40Ar/36Ar值的2~3倍,与中国东北部幔源岩样品40Ar/36Ar值相近,推测成矿流体主要来源于富集地幔,成矿流体中存在着一定量的地壳放射性成因40Ar,表明地壳流体参与了成矿作用。综上所述,推断山东胶东地区盘子涧金矿成矿流体为以富集地幔流体为主导的壳幔混合流体。     

山东沂南铜井金矿地质地球化学特征及矿床成因探讨

山东沂南铜井金矿位于沂沭断裂带的鄌郚-葛沟断裂西侧,是鲁西典型的矽卡岩型金矿。矿石成分主要有自然金、黄铁矿、黄铜矿、石榴子石、方解石、石英等,矿石结构主要有半自形-他形粒状结构、他形填隙结构、压碎结构等,矿石构造类型有浸染状构造、脉状构造、块状构造。矿石岩性主要有黄铁矿化闪长玢岩、黄铁矿化角岩、黄铁矿化磁铁矿化矽卡岩、黄铁矿化大理岩还有部分石英脉型矿石和磁黄铁矿型矿石。成矿期次划分为矽卡岩期、热液期、表生期。该文利用光谱分析对矿石中Au,Ag,Cu,Pb,Zn,As,Sb,Bi 8种微量元素进行相关性分析和聚类分析。利用电子探针对矿石薄片进行微区分析,对矿石元素地球化学等特征进行研究总结,研究表明:光谱中Au,Cu,Ag,Sb四种元素显示了较好的聚类特征,对找矿有较好的指示作用。电子探针数据分析显示Co与Ni的比值大于1,As元素含量较低,矿床呈现岩浆热液成矿与变质热液成矿叠加的特点。     

山东省稀土矿产资源特征及找矿方向研究初探

目前山东省已发现稀土矿床（点）7个,查明轻稀土资源储量77余万吨。省内稀土矿床的成因类型主要包括碱性岩系列和花岗岩系列两大类,碱性岩系列稀土矿床的赋矿围岩主要为中生代产出的正长（斑）岩体、碳酸岩及云母岩等,花岗岩系列稀土矿床的赋矿围岩为中生代花岗伟晶岩。本文总结了山东省稀土矿资源现状及开发利用程度,重点论述了碱性岩系列和花岗岩系列两类稀土矿床的典型矿床地质特征,提出在山东省内进行同类型稀土矿床的找矿方向,为稀土矿床勘查提供参考。     

山东省铍矿典型矿床特征及找矿远景区划分

山东省铍矿以荣成大疃刘家铍矿较典型,为一小型蚀变岩型铍矿床。该文在充分收集山东省铍矿相关资料的基础上,选取荣成大疃刘家铍矿作为典型矿床进行了综合分析,研究了成矿地质条件、成矿机制,总结了找矿标志。通过详细的矿床解剖和试验测试工作,研究了山东省铍矿的分布规律,总结了区域成矿要素,划分了找矿远景区4处,并对远景区进行了找矿远景评价,提出了下一步勘查工作的建议。     

Stratigraphy of the Upper Permian Kennedy Group of the onshore Carnarvon Basin (Merlinleigh Sub‐basin), Western Australia

Upper Permian strata contain many examples of cyclic deposition, despite the prevailing view that greenhouse conditions existed at the time. The shallow marine Upper Permian Kennedy Group, onshore Carnarvon Basin, has been studied in detail in the Kennedy Range 150 km east of the town of Carnarvon, Western Australia. The Kennedy Group exhibits cyclicity on a scale of 3–10 m, and also some larger scale changes in sedimentation. In this study, the Kennedy Group is divided into twelve informal units, designated with letters from A to L. The small‐scale cyclicity consists of stacked regressive cycles that comprise only thin highstand systems tracts and regressive systems tracts. Transgressive systems tracts are only sometimes represented by highly bioturbated green sandstone layers at cycle boundaries. Cycle tops are planar and often have extensive vertical trace fossil development down from them, as well as surface traces on them. The twelve informal units can be interpreted as being caused by changes in relative sea‐level.