冲绳海槽中部玄武岩的岩石学和地球化学研究

1992年冲绳海槽地质调查时,在134站(126°56′7″E,27°30′0″N)共采集到3件玄武岩样品,其中1件取自134站表层样,另外2件取自134站柱状样中的118-143cm处和193- 218cm处(刀口位置)。通过对上述3件玄武岩样品的岩相学、岩石化学组成、稀土元素和微量元素和锶同位素比值分析研究,认为本区玄武岩具多期次喷发特征,早期喷发形成的玄武岩中单斜辉石质量分数较低,晚期喷发形成的玄武岩中单斜辉石质量分数相对较高,表明了单斜辉石为晚期结晶堆积产物。本区玄武岩稀土配分模式与岛弧拉斑玄武岩基本一致,其⁸⁷Sr与⁸⁶Sr质量分数比值m(⁸⁷Sr)/m(⁸⁶Sr)为0.7046,亦与岛弧拉斑玄武岩相当。最后利用Rb-Sr丰度特征确定本区的地壳厚度为19-24 km。     

南海深海晚第四纪火山沉积物及其起源探讨

本通过对5个岩心和30个层样品的分析，发现在沉积物中存在着大量的火山物质，有的呈层状，有的则以分散状态存在。电子探针对火山玻璃的测试结果表明，本区的火山物质有两种成分，一种为碱性玄武岩，另一种为岛弧安山岩。从火山灰的形态特征来看，基性火山物质来自海底火山喷发，中性的火山物质来源于陆上的火山喷发。由同位素、碳酸盐含量、孢粉的分析结果推断，317－82－29②岩心是在晚第四纪沉积形成的。此外，^87Sr/^86Sr的比值表明，南海深海的火山物质起源于上地幔。     

九州-帕劳脊南段基底玄武岩的单斜辉石矿物化学及成因意义

九州-帕劳脊是古伊豆-小笠原-马里亚纳弧的重要组成,对其上基底岩石开展矿物学和岩石学研究可为理解洋内岛弧演化早期的岩石成因和岩浆活动特点提供重要线索。本文对九州-帕劳脊南段基底玄武岩中的单斜辉石斑晶和微晶开展详细的岩相学和原位主微量元素分析,结果表明,单斜辉石斑晶与微晶整体上具有相似的化学组分,为普通辉石及透辉石等种属,且亏损轻稀土元素,Eu负异常不明显。多数单斜辉石斑晶具有环带结构,可划分为简单环带及韵律性环带两类;从辉石核部到边部,MgO、FeO、Al₂O₃、TiO₂含量与核部镁指数Mg#等呈现复杂的高低变化,指示了多期次的岩浆混合与补给事件。单斜辉石的结晶温度、压力分别为1 151～1 210℃和1.3×10⁸～4.2×10⁸ Pa。通过单斜辉石组分反演获得的母岩浆含水量为0.8%～2.3%(以湿质量计)。最后,我们提出,形成于典型的洋内岛弧背景下的九州-帕劳脊南段熔岩的母岩浆为亚碱性岛弧拉斑玄武质熔体,具有高温、中压、高氧逸度的特征,岩浆房深度较浅并存在多期次原始岩浆的...     

南海深海晚第四纪火山沉积物及其起源探讨

本文通过对5个岩心和30个表层样品的分析,发现在沉积物中存在着大量的火山物质,有的呈层状,有的则以分散状态存在。电子探针对火山玻璃的测试结果表明,本区的火山物质有两种成分,一种为碱性玄武岩,另一种为岛孤安山岩。从火山灰的形态特征来看,基性火山物质来自海底火山喷发,中性的火山物质来源于陆上的火山喷发。由同位素、碳酸盐含量、孢粉的分析结果推断,317-82-29②岩心是在晚第四纪沉积形成的。此外,~(87)Sr/~(86)Sr的比值表明,南海深海的火山物质起源于上地幔。     

南海东部海域表层沉积物锶同位素物源示踪研究

锶同位素作为物源示踪剂和计时器在海洋地球化学研究中得到了广泛应用,南海东部海域沉积物中非碳酸盐相物质由慢源型火山物质和陆源硅铝物质组成,两者呈互为消长关系,由北向南陆源物质逐渐减少而慢源物质逐渐增多,海盆内发育的火山喷发是慢源型物质的主要来源,陆源物质主要是中国大陆碎屑物质经台湾海峡进入南海,南海东部海域非碳酸盐相沉积物87Sr/86Sr比值分布特点是:(1)陆架和陆坡边缘沉积物中87Sr/86Sr比值高(0.718 994),向东至深海盆东部边缘逐渐降低(0.713 545);(2)东沙群岛、中沙群岛周围海区87Sr/86Sr比值小(0.709 232);(3)台湾海峡南部87Sr/86Sr比值(0.717 940)接近地壳平均值,黄岩岛附近87Sr/86Sr比值(0.704 241),与幔源物质的锶同位素组成一致,这种分布规律说明中国大陆物质对南海东部海域沉积物的贡献由西向东、由北向南逐渐减小,对幔源基性岩组分和陆源硅铝质组分计算得出,东沙群岛以东、黄岩岛以北海区沉积物中陆源硅铝质组分平均含量为87%,台湾省南部基性岩组分含量不到10%,黄岩岛周围基性岩组分含量接近50%,来自台湾海峡的陆源物流向南一直延伸到17°N左右。幔源基性岩组分和陆源硅铝质组分理论计算值与区内沉积物中火山碎屑、陆源碎屑实际分布相一致。     

西南印度洋中脊玄武岩地球化学特征及其对岩浆过程的指示意义

对采自西南印度洋中脊(SWIR)50°E附近5个站位的玄武岩样品进行了岩石学和元素地球化学研究。样品主量元素、TAS分类图解和AFM图解显示,SWIR研究区样品类型主要为低钾拉斑玄武岩。相对原始地幔SWIR区玄武岩具有Ba、Nb、Sr负异常,K表现为正异常。稀土元素分配模式均为左倾型,具有轻微的Eu、Ce正异常;SWIR区玄武岩都起源于上地幔,SWIR玄武岩则明显向EMⅡ端元偏移。SWIR玄武岩地幔源区相对最为富集,可能为DM和EMⅡ的混合源区,存在少量的陆壳成分。研究区玄武质岩浆起源深度为尖晶石橄榄岩区域处于中度还原环境下,经历了明显的橄榄石+单斜辉石+斜长石的分离结晶。     

西沙群岛东岛浮岩矿物地球化学特征及成因探讨

本文对采自西沙群岛东岛的2件浮岩样品进行了岩石学和矿物地球化学研究,研究表明,东岛浮岩样品属于中性火山岩,SiO_2含量在60%左右,化学组成相当于粗面岩,斑状结构,斑晶主要为斜长石、单斜辉石和少量橄榄石,基质为玻璃质。斜长石及辉石斑晶矿物具有中心熔蚀结构,斜长石形成温度为1030℃-1080℃;单斜辉石属均为普通辉石,斑晶Al_2O_3含量较低;橄榄石属于透铁橄榄石,橄榄石斑晶Fo值为55.40-60.53,从核部到边部各化学成分略有降低,且具有轻微的化学成分环带。从核部到边部Fo值略有降低。东岛浮岩岩浆是西沙地块受到拉张作用,中地壳物质减压熔融形成粗面质岩浆,并经历短暂的岩浆房冷凝时期,拉张减薄作用形成裂谷后,由于压力突然释放,粗面质岩浆沿裂谷快速上升在水下喷发形成浮岩。     

东太平洋海隆近赤道区玄武岩岩石地球化学与地幔源区特征

本文对东太平洋海隆赤道地区北部和南部的9件玄武岩样品进行了详细的岩相学和主量、微量元素及Sr-Nd-Pb同位素分析研究,结果表明:MgO含量为7.32%~10.22%,Na_2O为3.03%~3.59%,K_2O为0.23%~0.57%,CaO为10.96%~12.39%,Al_2O_3为11.40%~13.76%,该区玄武岩均属于亚碱性玄武岩,具有MORB型的稀土及微量元素特点,原始岩浆均经历了橄榄石和斜长石的分离结晶。轻重稀土元素含量均较低,LREE/HREE比值为0.61~0.97,(La/Yb)N比值为0.72~1.76,(La/Sm)N比值为0.60~1.30,(Gd/Yb)N为0.99~1.16。Sr-Nd-Pb同位素特征更接近NMORB,其中,87Sr/86Sr和143 Nd/144 Nd比值更接近DM源区,而Pb的三种同位素比值要明显高于DM源区,更为接近EM源区。研究表明岩浆起源于尖晶石橄榄岩区,来源于较为亏损的地幔,NEPR玄武岩可能混有HIMU源区,SEPR玄武岩除了混合有HIMU成分外,可能还有少量的EMⅡ成分。     

胡安·德·富卡洋中脊(Juan de Fuca Ridge)上拉斑玄武岩的研究

该岩样系太平洋东北部胡安·德·富卡洋中脊上底拖所取得的岩石样品,其表面具有黑色玻璃质,由表面向下逐渐过渡为晶质。 对该岩样的化学成分做了较全面的(化学、X光、红外光谱、电镜等)分析。其化学成分虽与大洋拉斑玄武岩的平均值相近似,但Ca、Mg略高于大洋拉斑玄武岩的平均值;而Si,K含量又稍低于大洋拉斑玄武岩。表明该岩石系地幔岩浆分异早期溢出而成的。其主要矿物成分是拉长石和普通辉石,其中拉长石占斑晶的70—80％左右。 镜下研究表明该岩石从顶面到底部可被划分成若干层次,并具有气孔的存在,表明该岩石系水下溢出而生成的。 电子探针分析发现Cu、Co、Ni三元素在冷却玻璃质部份的含量较结晶主体部份的含量为高,而Rb、Sr、Cs三元素在岩石冷却边部份与结晶主体中的含量上没有什么显著的差别。 根据扫描电镜和电子探针的微区元素分析研究,结晶表明铁镁硅酸盐先结晶,随后结晶的为基性斜长石。     

青岛仰口榴辉岩及其围岩的岩石地球化学特征和成因机制

青岛仰口地区保存了完整的从变辉长岩到榴辉岩的超高压变质岩石组合。地球化学特征表明,榴辉岩、变辉长岩和片麻岩属钙碱性系列,超基性岩属拉斑系列;CIPW标准矿物计算显示榴辉岩和变辉长岩中长石以钠长石为主,超基性岩主要标准矿物为橄榄石、紫苏辉石和锥辉石,片麻岩中出现标准矿物刚玉;榴辉岩、变辉长岩和片麻岩富集大离子亲石元素,亏损高场强元素,超基性岩的微量元素相对于N-MORB亏损;榴辉岩和变辉长岩轻稀土明显富集,配分型式与岛弧玄武岩相似,片麻岩具明显的Eu的负异常,配分型式与后造山A型花岗岩相似,超基性岩稀土总量较球粒陨石偏高,具强烈的Ce的负异常。微量元素比值及地球化学图解表明榴辉岩与变辉长岩的原岩为辉长岩,片麻岩的原岩为造山后A型花岗岩,原岩的岩浆源区位于下地壳,超基性岩的岩浆源区位于上地幔,原岩均形成于岛弧环境。     

Model of the post-Cenozoic evolution of the cryolithozone of the shelf of the western part of the Laptev Sea

The analysis of the structure of the cryolithozone, facies, and thicknesses of the Quaternary sediments and the results of the physicochemical mathematical modeling of the modern shelf of the western part of the Laptev Sea support the influence of the Late Pleistocene glaciations on the heat conditions and the distribution of the permafrost in the area. A ～200-m thick glacier formed under aerial conditions from atmospheric precipitation represented the metamorphosed snow cover. According to the modeling, the long-living (from 60?50 to 10?4 ky) glacier reduced the thickness of the permafrost rocks in the reviewed shelf area for 280–360 m. The Holocene marine transgression additionally decreased the thickness from 50–140 m on the inner shelf to 220–350 m on the outer shelf. The modern submarine cryolithozone 450-0 m thick is wide-spread in the studied region from the coast to the shelf boundary (isobaths of 130–140 m), where it pinches out at a distance of ～380 km from the coast at a depth of ～250 m above the sea level.     

Investigation of the mechanism of the long-term evolution of the carbon cycle in the ecosystem of the Sevastopol bay

We analyze the components of the carbon system of the Sevastopol bay waters and the balance of main sediment-forming substances using the data of field investigations in 1998–2008. The interannual variations of total inorganic carbon and the equilibrium partial pressure of carbon dioxide in the bay water are noted. An increase in the flux of carbon dioxide into the bay and in the content of organic carbon in bottom sediments is revealed, and an explanation of this phenomenon is given. The priority accumulation of organic carbon in the sediments of the bay is established. We assess the interannual variation in the relative abundances of organic and inorganic carbon as an index of the carbon cycle stability.     

Contemporary state of the investigation of the influence of the discharge of rivers on the hydrologic structure of the Black Sea

We generalize and analyze the state of investigations of the influence of river waters on the hydrologic structure of the Black Sea. Specific features of the water, regime and hydrography of rivers flowing into the sea, data on the discharge of rivers, and intrayear and interyear variability of the discharge are presented. We discuss and analyze works studying the transformation of river waters, routes of desalinized sea waters, and their influence on the thermohaline structure and dynamic regime of the sea. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

双壳贝类血淋巴中儿茶酚胺的检测方法初步研究

研究的目的是探索一种检测双壳贝类血淋巴中儿茶酚胺含量的方法。以栉孔扇贝(Chlamysfarreri)和长牡蛎(Crassostreagigas)为实验对象,研究了取样、抗氧化剂、氧化铝用量以及Tris缓冲液用量等对实验结果的影响。结果表明,高效液相色谱电化学检测器法(HPLC-ECD)可以灵敏高效地对双壳贝类血淋巴中儿茶酚胺进行定性、定量检测。实验表明,取样时间最长不超过1.5min;还原性谷胱甘肽作抗氧化剂效果较好;前处理各试剂与血样量的最适配比为血样量1.5mL,Tris缓冲液(1.5mol/L,pH8.6)1mL和氧化铝25mg;水洗后离心并尽可能吸干氧化铝中的水分。去甲肾上腺素、肾上腺素和多巴胺的回收率分别为53%~69%、47%~73%和48%~56%。     

黄河入海径流对河口海域盐度影响研究

为研究黄河入海径流变化条件下河口附近海域盐度扩散特征,以更好地保护河口海域生物资源多样性,本文以黄河下游利津水文站的长序列实测径流数据资料为基础,利用近海水动力模型FVCOM,分析径流变化对黄河口海域盐度的影响规律。结果表明：黄河口与莱州湾之间存在顺时针的环流系统,在余流作用以及涨落潮方向的影响下,黄河冲淡水长期向莱州湾扩散;丰水期黄河冲淡水几乎影响了整个莱州湾,27盐度锋可以到达莱州湾中部,27等盐线的表层包络面积为2 665.61 km²,占莱州湾的1/4左右,枯水期低盐度水只有向南扩散的趋势,27以下的低盐度水集中分布在黄河口门附近,27等盐线的表层包络面积只有199.65 km²;5月份,随着入海径流量增加,27等盐线扩散的范围、距离、方向都会发生明显变化。在对近海生物资源有迫切保护需求的情景下,适当减少其他用水户供水量以增加入海生态径流量,可以有效改善黄河口海域附近的盐度情况,为生物资源的生长繁殖创造良好条件。     

Modelling of the ecosystem of the Black-Sea shelf zone near the estuary of the Danube

We analyze the results of numerical calculations performed according to the three-dimensional interdisciplinary model of an ecological system of the Black-Sea shelf zone near the estuary of the Danube. The complete system of equations of hydrothermodynamics is solved together with transport equations of the advection-diffusion-reaction type used to describe the transformation of a substance (nitrogen) between the components of the characteristic vectors of the ecosystem: plankton, detritus, and biogenic elements (nitrates). We describe the distinctive features of the circumcontinental distribution of components obtained as a result of numerical experiments and present arguments for the conclusion that the ecosystem of the Danube estuary water area plays the role of a buffer zone between the press of the Danubian biogenic pollutions and the neighbouring areas of the shelf zone and open sea. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

The influence of the bottom contour on the deformed state of the ice cover due to the motion of the submarine

The authors have previously determined that the effectiveness and failure pattern of the ice cover caused by flexural-gravity waves generated by a submerged body motion near the bottom ice can greatly depend on the depth of the water area. In its turn, the presence of a ledge on the ice surface may affect a wave propagation pattern. This paper presents an experimental study of the bottom contour influence on the deflection and length of flexural-gravity waves. The authors describe a numerical model for the analysis of the deformed state of ice caused by hydrodynamic loads due to a submarine motion, taking into account the bottom contour. The experiments are carried out in the ice tank. The results of calculations and experiments are compared.     

Dynamics of the ice cover and peculiarities of the ice transportation of the sediments at the tidal flats of the Kandalaksha Gulf of the White Sea

Ten years of semistationary studies of the interaction of the ice cover and the coastal relief of the Kandalakhsa Gulf in the White Sea allowed us to reveal the peculiarities of these processes in the warm and cold years and the mechanisms of the origination of ice forms, including ice tents, which govern the character of the tidal flats. Three dynamic fast ice zones are distinguished by their geomorphological location, morphology, and ice dynamics. The dependence of the mechanisms and volumes of the enrichment of the fast ice in the sediments on the coastal zone??s relief was established. At the coast of the Kindo Peninsula (Velikaya Salma Strait), the ice mostly contains fine-sandy sediments. Coarser sediments, including boulders, are occasional and frozen into the ice at the contact of the fast ice and the bottom. At the expense of the ice??s spreading by 4?C6 times in the warm years and 2?C4 times in the cold years, several thousand tons of sediments mostly from the tidal flat??s surface (100?C700 m³ from 1 km of coast in the wide tidal flats and <50 m³ on the steep coasts) are delivered to the water area.     

Relationship between the path of the Kuroshio in the south of Japan and the path of the Kuroshio Extension in the east

A relationship between paths of the Kuroshio and Kuroshio Extension (KE) is investigated, using the satellite-derived altimetry dataset of 1993–2008. When the Kuroshio takes the nearshore nonlarge meander path or typical large meander path and resultantly goes through the deeper channel (about 2500 m) of the Izu-Ogasawara Ridge, the KE path adopts a relatively stable state with the two quasi-stationary meanders. On the other hand, when the Kuroshio takes the offshore nonlarge meander path and then passes over the shallower part of the Ridge (about 1000 m), the KE path tends to be convoluted, i.e., an unstable state.     

A model of the dynamics of the ecosystem of the Sea of Azov

We use many-year archival observations of hydrologic and hydrobiologic state of the Sea of Azov for the identification of the structure of a model of its ecosystem. The ecosystem model, supplemented with expert estimates of bioresource consumption (fish reserve), contamination level, and possible ecologic fines for violation of the sea natural state, is formalized by the method of system dynamics. Hereat, the major part of influence functions is found in terms of observational data with application of self-organization algorithms. We also present the results of simulated experiments with the model of the ecosystem, which enable us to analyse scenarios of its behaviour under the influence of various external factors (wind, river discharge, water exchange with the Black Sea, etc.). Translated by Peter V. Malyshev and Dmitry V. Malyshev