有机质在中国东北部森林沼泽区化探异常追踪和查证中的应用

在东北森林沼泽区的几个矿区(点)上,通过以泥炭、腐殖层土壤为采样介质的区域化探异常追踪查证方法技术试验研究,发现Au、Ag、Cu、Pb、Zn等主要成矿元素的测量结果与水系碎屑沉积物、残坡积物的基本一致,对矿体均有良好的反映.研究结果表明在这类景观区化探找矿工作中有机质是可以利用的.     

CRG桩在花岗岩持力层中的试验研究

CRG桩(预应力高强混凝土管注浆桩)取得了国家发明专利。介绍了CRG桩施工方法及试验桩施工情况,讨论了在花岗岩地层施工中遇到的孔内沉渣清理、管桩上浮及灌浆问题。对CRG桩的灌浆充填体进行了钻芯检测,发现充填体胶结质量不高,充填体强度低,影响桩身强度的提高。但静载试验表明,CRG桩的侧阻力和端阻力都得到充分发挥,单桩承载力比同直径的钻孔灌注桩有较大的提高。为在花岗岩持力层中CRG桩的试验积累了经验。     

Dynamic early Holocene vegetation development on the Faroe Islands inferred from high-resolution plant macrofossil and pollen data

Vegetation dynamics during the earliest part of the Holocene (11,250-10,250 cal yr BP) have been reconstructed from a lacustrine sequence on Sandoy, the Faroe Islands, using detailed plant macrofossil and pollen evidence. The plant macrofossils suggest the initial vegetation was sparse herb and shrub tundra, with Salix herbacea and open-ground species, followed by the development of a denser and more species-rich arctic heathland after 11,150 cal yr BP. Despite high pollen values for Betula nana, macrofossils are rare. The bulk of the macrofossils recorded are S. herbacea and Empetrum leaves with numerous herb taxa and an abundance of Racomitrium moss. Conditions start to change around 10,800 cal yr BP, with increased catchment erosion and sediment delivery to the lake from ca. 10,600 cal yr BP, and a transition to alternating Cyperaceae and Poaceae communities between ca. 10,450 and 10,250 cal yr BP. This vegetation change, which has been recorded throughout the Faroes, has previously been interpreted as a retrogressive shift from woody shrubs to a herbaceous community. The detailed plant macrofossil data show the shift is the replacement of an Empetrum arctic heathland by grassland and moist sedge communities. These taxa dominate the modern landscape.     

川南沐川地区宣威组底部铌-稀土多金属富集层富集规律、沉积环境与成矿模式

云南、贵州地区对晚二叠世宣威组底部Nb-REE多金属富集层的研究取得了重要进展,但其成因还有较大争议.为厘清沐川地区宣威组底部Nb-REE多金属富集层成因机制及富集规律,本研究开展了野外实地调查、矿物学、岩相古地理与岩石地球化学等系统性研究,探讨其物源、富集规律,建立了成矿模式.结果 表明,川南沐川地区宣威组底部Nb-...     

大陆层控构造论盆－山系与造山带成因及演化新模式

大陆构造以受中地壳塑性层控制的盆－山系和冲叠造山带厚皮构造为主要构造类型，而与中生代以来才出现的受软流层控制的大洋岩石圈板块构造截然不同。由上地壳正断层上盘断陷盆地和下盘断隆山所组成的盆－山系，与地球自转速度逐渐变慢派生不同性质水平力和重力的共同作用有关。当地球自转速度突然变化时，将派生强烈的侧压力，使升降幅度较大、具有侧向应变空间的断陷盆地与断隆山之间的上地壳发生冲叠运动，盆－山系由此演变成冲叠造山带。后者对前者存在着严格的继承关系，服从于“升降－冲叠律”。中生代以来的盆－山系和冲叠造山带有的是板块活动产物     

The preservation potential of ash layers in the deep‐sea: the example of the 1991‐Pinatubo ash in the South China Sea

Following the eruption of Mount Pinatubo on 15 June 1991, volcanic ash was transported westward to the South China Sea in an atmospheric plume, falling out and settling to the sea floor within days and forming an up to 10 cm thick layer on an area >400 000 km². Immediately after deposition, surviving deep‐burrowing animals re‐opened their connection to the sea floor to obtain water for respiration and/or food take‐up. Later, small‐sized meiofauna and then macrofauna re‐colonized the sea floor, mixing newly deposited organic fluff with the underlying ash. Consequently, ash deposits thinner than 1 mm have not often been observed as a continuous layer when cored six years after the eruption, while ash about 2 mm thick is now patchily bioturbated. In areas covered by ash thicker than 5 mm, mixing by benthic animals is controlled mainly by the adaptation of the burrowing fauna to variations in grain‐size, the rate of background sedimentation, the availability of benthic food on and within the sediment and pore water oxygen levels. With respect to these factors, four provinces can be distinguished: (i) Along the Philippines margin run‐off from land fuels primary production that, in turn, leads to a high benthic food content. The benthic fauna is adapted to a variable grain‐size and rapid sedimentation. Therefore, mixing is intense and the preservation potential of the ash layer is low. (ii) In areas affected by deposition of hyperpycnites and turbidites, i.e. in canyons in front of river mouths and in the Manila Trench, the ash layer is preserved due to rapid burial. (iii) The area to the west to about 116° E receives low amounts of benthic food, benthic mixing is less intense and the preservation potential of the ash is high. (iv) The central South China Sea, where the ash is thinner than 3 cm, is affected by intense wind mixing and upwelling and the benthic food content is high; thus, the chance that the ash will be preserved as a sharp‐based layer is low. Consequently, the style of ash preservation has palaeo‐environmental significance. Older buried and burrowed event layers provide further information to elucidate the fate of the 1991 Pinatubo ash layer; in general their appearance fits with observations in the Recent.     

黄海夏季典型站位的底边界层动物

2002年8月25~26日,在黄海夏季冷水团区域内的抛锚站位(35°22′N,121°59′E),使用柱状界面采样器进行了昼夜连续取样,对底边界层动物的种类组成与昼夜丰度变化进行了研究,以获得对黄海底边界层动物的初步认识。共记录底边界层动物21种,隶属18科、19属。超底栖动物和中型浮游动物是黄海夏季底边界层动物的2个重要类群,主要种类有尖额真猛水蚤(Euterpina acutifrons)、挪威小毛猛水蚤(Microsetella norvegica)、异厚盖钩虾(Synchelidium miraculum)、双刺纺缍水蚤(Acartia bifilosa)和小拟哲水蚤(Paracalanus parvus),其丰度皆有明显的昼夜波动现象。以桡足类无节幼体为代表的小型浮游动物也是底边界层动物中不容忽视的类群之一。采集到5个黄海区的新记录物种:美丽猛水蚤(Nitocrasp.)、跛足猛水蚤(Mesochrasp.)、咸水剑水蚤(Halicyclopssp.)、掌刺梭剑水蚤(Lubbockia squillimana)和异厚盖钩虾(Synchelidi-um miraculum),显示出底边界层动物种类组成的特殊性。     

2004年9月南海北部移动船载温盐剖面仪观测结果初步分析

在2004年9月南海北部开放航次中,中国科学院南海海洋研究所首次引进使用了民用移动船载温盐剖面仪（Moving Vessel Profiler,MVP）,并在珠江口外海和越南东岸外海2个断面进行了拖曳测量。通过对MVP和定点温盐深仪所测数据的比较分析,发现MVP下降阶段数据较为可信。对所获温、盐、深数据进行处理分析,发现2个断面的水团性质存在明显差异。越南东岸外海断面的混合层平均深度（27m左右）深于珠江口外海断面（17．5m左右）;在表层和近40m深度处,珠江口外海的盐度值都高于越南东岸外海,呈现高盐的特性。     

1998年季风爆发期南海大气边界层的日变化

在南海尚未有关于海洋大气边界层结构日变化方面的研究.研究海洋大气边界层,有利于我们更好地研究海洋表层结构变化影响机制,对发生在海洋大气边界层上的过程进行预测预报.因此了解南海海洋大气边界层的结构特征,对于我们进一步了解南海天气尺度海气相互作用有非常重要的意义.通过对1998年在南海南部(6°15′N,110°E)和南海北部(20°29′39″N,116°57′48″E)的南海季风试验中定点科考船释放一天四次的探空观测资料分析得出,季风爆发前海洋大气边界层存在规则的日变化,在中午达到深厚.季风爆发后南海北部大气边界层日变化消失,南海南部依然明显.分析表明对其日变化起重要影响的是短波辐射;潜热输送对大气边界层高度日变化影响不大.与大气边界层厚度日变化相对应,南海南部边界层内水汽日变化明显,而南海北部较不明显.     

Coupling winds to ocean surface currents over the global ocean

A Wind stress–Current Coupled System (WCCS) consisting of the HYbrid Coordinate Ocean Model (HYCOM) and an improved wind stress algorithm based on Donelan et al. [Donelan, W.M., Drennan, Katsaros, K.B., 1997. The air–sea momentum flux in mixed wind sea and swell conditions. J. Phys. Oceanogr. 27, 2087–2099] is developed by using the Earth System Modeling Framework (ESMF). The WCCS is applied to the global ocean to study the interactions between the wind stress and the ocean surface currents. In this study, the ocean surface current velocity is taken into consideration in the wind stress calculation and air–sea heat flux calculation. The wind stress that contains the effect of ocean surface current velocity will be used to force the HYCOM. The results indicate that the ocean surface velocity exerts an important influence on the wind stress, which, in turn, significantly affects the global ocean surface currents, air–sea heat fluxes, and the thickness of ocean surface boundary layer. Comparison with the TOGA TAO buoy data, the sea surface temperature from the wind–current coupled simulation showed noticeable improvement over the stand-alone HYCOM simulation.