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1.
A preliminary study of carbon system in the East China Sea 总被引：1，自引：0，他引：1
Shizuo Tsunogai Shuichi Watanabe Junya Nakamura Tsuneo Ono Tetsuro Sato 《Journal of Oceanography》1997,53(1):9-17
In the central part of the East China Sea, the activity of CO2 in the surface water and total carbonate, pH and alkalinity in the water column were determined in winter and autumn of 1993.
The activity of CO2 in the continental shelf water was about 50 ppm lower than that of surface air. This decrease corresponds to the absorption
of about 40 gC/m2/yr of atmospheric CO2 in the coastal zone or 1 GtC/yr in the global continental shelf, if this rate is applicable to entire coastal seas. The normalized
total carbonate contents were higher in the water near the coast and near the bottom. This increase toward the bottom may
be due to the organic matter deposited on the bottom. This conclusion is supported by the distribution of pH. The normalized
alkalinity distribution also showed higher values in the near-coast water, but in the surface water, indicating the supply
of bicarbonate from river water. The residence time of the East China Sea water, including the Yellow Sea water, has been
calculated to be about 0.8 yr from the excess alkalinity and the alkalinity input. Using this residence time and the excess
carbonate, we can estimate that the amount of dissolved carbonate transported from the coastal zone to the oceanic basin is
about 70 gC/m2/yr or 2 GtC/yr/area-of-global-continental-shelf. This also means that the rivers transport carbon to the oceans at a rate
of 30 gC/m2/yr of the coastal sea or 0.8 GtC/yr/ area-of-global shelf, the carbon consisting of dissolved inorganic carbonate and terrestrial
organic carbon decomposed on the continental shelf. 相似文献
2.
应用柴达木盆地地震、非地震资料进行综合解释研究发现,新生代盆地深、浅层构造存在较大差异,盆地沉积在不同时期受到不同构造格局的控制。古近系受近东西向构造控制,新近系受北西向构造控制,显示了柴达木盆地新生代为不同时期受不同方向构造控制的大型叠合盆地。盆地地层深、浅层构造变形特征不同,深层表现为陡倾的逆冲断裂构造,以断块构造为主要特征;中浅层表现为滑脱褶皱与滑脱断裂构造;地表在背斜核部发育斜列展布的正断层构造。盆地经历了多旋回沉积和多方式的后期改造,不同的构造组合形成了不同的储油气构造模式,认识这一点对于盆地深层的油气勘探,特别是寻找隐蔽油气藏具有重要意义。 相似文献
3.
Ten spinel-lherzolite inclusions and one olivine-websterite inclusion, which were collected from Fujian, Jiangsu, Hebei and Yunnan Provinces, consist of olivine (FΦ87.7–91.2), enstatite (En87.3–89.7), Cr-diopside and spinel. According to the Mg/(Mg+Fe2+) ratios in the rocks and their mineralogies, they are designated to the Cr-diopside type. The websterite is composed of bronzite (En71.9) and augite, while the gabbro-norite consists of hypersthene (En68.9) and augite, belonging to the Al-augite type. The geothermos of spinel-lherzolites were calculated with four geothermometric methods, giving a temperature range of 925°–1,072°C. However, according to P. R. A. Wells' method, temperatures range from 845δ to 1,014°C, and by D. H. Lindsly's approach, from 716°–974°C. Pressures range from 15.1 to 19.8 kb. Genetically, Spinel-lherzolites and olivine-websterite are thought to have been derived from residual mantle material by partial melting at approximately 1,000°C and at a depth of about 50–70 km. Websterite and gabbro-norite may be products of the crystallization-differentiation of alkali basaltic magma. 相似文献
4.
5.
By means of nanoscale surface observation, we have proposed a new approach for investigating fine crystals of cosmic materials to reveal their origin and growth conditions. Several different morphologies of polyhedral fine olivines with faceted faces have been found in Allende carbonaceous chondrite (4.5 byr in geochronological age). In the present work, molecular level topography of the faceted matrix olivine by Atomic Force Microscopy (AFM) has successfully been performed. The matrix olivine found to have preserved growth step pattern on its surface even though quite long time has passed since they formed in the early Solar System. The surface pattern suggests that the faceted matrix olivine could have been condensed from the gas phase, and possibly that these olivine crystals had continued to grow under a rapid cooling condition (0.1-1 K s−1). The estimated cooling rate agrees well with predictions based on hypothetical rapid heating and cooling events such as shock wave heating. 相似文献
6.
Biogenic amino acids, taken as representative of organic matter, were analyzed to determine the apparent degradation rate constant in boreal terrestrial sediment. Age determination using 14C dating gave two rate constants: the initial degradation rate constant for glycine (kGLY 1), the simplest amino acid, was 1.5 × 10−3 yr−1 (r = 0.97) until about 2200 yr BP. After the inflection point, the rate constant kGLY 2 was 9.1 × 10−5 yr−1 (r = 0.73). The degradation of amino acids in the labile organic matter in the sediment was markedly affected by rapid processes. After the inflection point, the rate constant profiles for sub-surface amino acids were shown to have discontinuous relationships with sediment age. One pattern which emerged in the vertical distribution is that the biogenic amino acid degradation rate constant k was far greater in the labile organic matter phase than that in the refractory organic matter over the past 10,000 years. 相似文献
7.
贵州二叠纪——三叠纪古气候和古海洋环境的地球化学研究 总被引：11，自引：0，他引：11
通过对贵州二叠纪和三叠纪地层沉积岩相、古生物组合、稀土元素、碳氧同位素和微量元素地球化学综合研究,发现贵州二叠纪、早一中三叠世和晚三叠世三个地质时期古气候和古海洋环境有明显差别。其中二叠纪为潮湿的热带海洋性气候,海水相对氧化,盐度正常,平均温度为53℃;早一中三叠世为干燥的大陆性气候,海水相对还原,盐度较高,平均温度为38℃;晚三叠世又转变为潮湿的气候,海水相对氧化,盐度正常,平均温度为44℃。,结合泛大陆演化特征,讨论了造成气候变化的原因。 相似文献
8.
Masayuki Uesugi Ryo Noguchi Tooru Matsumoto Junya Matsuno Takashi Nagano Akira Tsuchiyama Shigenori Harada Kaori Yokoyama Yoshiaki Yodo Noboru Takeda Toru Yada Shogo Yakame Yuzuru Karouji Yukihiro Ishibashi Masanao Abe Tatsuaki Okada Akio Fujimura Mitsuru Ebihara Fumio Kitajima Keisuke Nagao Tomoki Nakamura Hiroshi Naraoka Takaaki Noguchi Ryuji Okazaki Hisayoshi Yurimoto 《Meteoritics & planetary science》2014,49(7):1186-1201
We report the investigation of cutting methods for Hayabusa samples. The purpose of our study is to explore the possibility of applying multiple analyses to a single particle effectively. We investigated the cutting performance of a blade dicing saw, laser, focused ion beam (FIB), and physical breaking by microindenter. Cutting performance was examined by estimating the aspect ratio of the cut slit, i.e., depth over width of the slit. We also investigated the possible contamination and sample damage by cutting. The result of the investigation shows that we can cut the samples from <50 μm to 500 μm using those methods with aspect ratios from 10 to 20, although they would introduce some contamination or damage to the samples. Our investigations also provide an important basis for the analysis of samples obtained by future sample return missions. 相似文献
9.
Akira Tsuchiyama Masayuki Uesugi Kentaro Uesugi Tsukasa Nakano Ryo Noguchi Toru Matsumoto Junya Matsuno Takashi Nagano Yuta Imai Akira Shimada Akihisa Takeuchi Yoshio Suzuki Tomoki Nakamura Takaaki Noguchi Masanao Abe Toru Yada Akio Fujimura 《Meteoritics & planetary science》2014,49(2):172-187
In this study, the three‐dimensional (3‐D) microstructure of 48 Itokawa regolith particles was examined by synchrotron microtomography at SPring‐8 during the preliminary examination of Hayabusa samples. Moreover, the 3‐D microstructure of particles collected from two LL6 chondrites (Ensisheim and Kilabo meteorites) and an LL5 chondrite (Tuxtuac meteorite) was investigated by the same method for comparison. The modal abundances of minerals, especially olivine, bulk density, porosity, and grain size are similar in all samples, including voids and cracks. These results show that the Itokawa particles, which are surface materials from the S‐type asteroid Itokawa, are consistent with the LL chondrite materials in terms of not only elemental and isotopic composition of the minerals but also 3‐D microstructure. However, we could not determine whether the Itokawa particles are purely LL5, LL6, or a mixture of the two. No difference between the particles collected from Rooms A and B of the sample chamber, corresponding to the sampling sequence of the spacecraft's second and first touchdowns, respectively, was detected because of the statistically small amount of particles from Room B. 相似文献
10.
跃进斜坡区南北分别为扎哈泉凹陷和英雄岭凹陷,是凹陷油气运移有利指向区,油气来源充足。烃源岩综合评价表明,扎哈泉凹陷E23烃源岩厚度大、分布面积广、有机质丰度高、有机质类型较好,目前已到成熟阶段,具有巨大供烃能力。油源对比研究表明,跃东构造原油与跃进一号构造原油特征一致,为北面英雄岭凹陷来源。跃进二号、乌南-绿草滩和昆北油田原油均来自扎哈泉凹陷E23源岩,但原油成熟度不同。跃进二号原油成熟度较低,与乌南-绿草滩原油和昆北油田储层固体沥青基本一致,明显低于昆北油田原油,属于烃源岩低成熟-成熟阶段早期产物,跃进斜坡区尚未发现源岩生烃高峰期产物。跃进斜坡区相对昆北油田更靠近凹陷生烃中心,源岩生烃高峰期产物具有优先充注的特征,斜坡区下倾方向大量发育的岩性圈闭和构造-岩性圈闭具有巨大的勘探潜力。 相似文献