共查询到20条相似文献,搜索用时 109 毫秒
1.
DUAN Yi ZHANG Hui ZHENG Chaoyang WU Baoxiang & ZHENG Guodong . Lanzhou Institute of Geology Chinese Academy of Sciences Lanzhou China . Department of Earth & Planetary System Science Graduate School of Science Hiroshima University Higashi-Hiroshima -Japan 《中国科学D辑(英文版)》2005,48(8):1203-1210
The carbon isotopic compositions of individual lip-ids can provide the genetic information about sedi-mentary lipids so that it has extensively applied pros-pects in geochemically studied field[1―8]. However, this applied research relies heavily on the accumula-tion of studied data in the genetic relationships between carbon isotopic compositions of individual lipids and their biological precursors in different sedi-mentary environments. Recently, the useful δ 13C data of individual lipids f… 相似文献
2.
13C of 367 C3 herbaceous plants was measured in loess area in northern China. Their δ13C values vary between −21.7%. and −30.0%., with a mean of −26.7%.. In the center of Loess Plateau (semimoist area) with annual
precipitation of 400–600 mm, the δ13
C values of C3 herbaceous plants range from −24.4%. to −28.5%., with a mean of −27.5%.. In the west of Loess Plateau (semiarid and arid
area) with annual precipitation less than 400 mm, they range between −21.7%. and −30.0%., with a mean of −26.2%.. Annual precipitation
is the main factor that makes δ13C values of C3 herbaceous plants in the west greater than those in the central Loess Plateau. The composition of δ13C in C3 plants increases with deceasing annual precipitation, and the mean change is −49%./100 mm. 相似文献
3.
Carbon and hydrogen isotopic characteristics of natural gases from the Luliang and Baoshan basins in Yunnan Province, China 总被引:2,自引:1,他引:2
XU Yongchang LIU Wenhui SHEN Ping WANG Wanchun WANG Xiaofeng Tenger YAN Yaomin & LIU Ruobin . Lanzhou Center of Oil & Gas Resources Institute of Geology Geophsics Chinese Academy of Sciences Lanzhou China . Research Institute of Petroleum Exploration Production SINOPEC Beijing China . South Branch of Petroleum Exploration Production Company SINOPEC Kuming China 《中国科学D辑(英文版)》2006,49(9):938-946
The Luliang and Baoshan basins are two small ba- sins in Yunnan Province. In the recent ten years or so, there have been found a number of natural gas pools of commercial importance in the two basins. Although the gas pools are small in size, the natural … 相似文献
4.
Carbon isotopic studies of individual lipids in organisms from the Nansha sea area, China 总被引:2,自引:0,他引:2
DUAN Yi SONG Jinming & ZHANG Hui . Lanzhou Institute of Geology Chinese Academy of Sciences Lanzhou China . School of Geology Lanzhou University Lanzhou China . Institute of Oceanology Chinese Academy of Sciences Qingdao China 《中国科学D辑(英文版)》2004,47(7):593-598
Sediments contain abundant lipid compounds in general, which are used as biomarker compounds to study organic matter sources and reconstruct the pa-laeoenvironments[1—7]. However, lipid compounds in sediments are generally a mixture of various genetic components so that it is difficult to correctly decouple their biological sources only by the results of bio-chemical researches. Carbon isotopic studies of indi-vidual sedimentary lipid compounds can discover their genetic information, which pr… 相似文献
5.
Stable carbon and oxygen isotopes have been observed in dinosaur eggshell samples,identified as Macroolithus yaotunensis,collected in two sections of the Nanxiong Basin,Guangdong Province,South China.Multiple positiveδ18O perturbations that occurred during the K/T transition of about 150 ka suggest that there may have been at least three periods of the extreme dry climate with a mean annual air temperature over 27℃.δ13C ranges from -8.37‰ to -11.60‰ of the dinosaur eggshells,added to the metabolic enrichment of 16‰,may indicate that the dinosaurs represented by this type of eggshells probably consumed the plant species of C3 type with the δ13C values of -24.3‰- -27.6‰.Moreover,the trend toward more negative δ13C values of the eggshells during the K/T transition could be an indirect consequence of a lasting increase in atmospheric CO2 concentration. 相似文献
6.
WANG XianBin GUO ZhanQian TUO JinCai GUO HongYan LI ZhenXi ZHUO ShengGuang JIANG HongLiang ZENG LongWei ZHANG MingJie WANG LianSheng LIU ChunXue YAN Hong LI LiWu ZHOU XiaoFeng WANG YongLi YANG Hui & WANG Guang Key Laboratory of Gas Geochemistry Chinese Academy of Sciences Lanzhou China Daqing Oilfield Company Ltd. Daqing 《中国科学D辑(英文版)》2009,52(2):213-226
This paper discusses the kinetic fractionation, composition and distribution characteristics of carbon and hydrogen isotopes for various alkane gases formed in different environments, by different mecha- nisms and from different sources in nature. It is demonstrated that the biodegradation or thermode- gradation of complex high-molecule sedimentary organic material can form microbial gas or thermogenic gas. The δ 13C1 value ranges from -110‰ to -50‰ for microbial gases but from -50‰ to -35‰ (even heavier) f... 相似文献
7.
Michael P.RICHARDS 《中国科学D辑(英文版)》2009,52(1):85-92
Despite great achievements in the origins of domestic pigs made by the methods of zooarchaeology and molecular biology, how
to scientifically distinguish the domesticated pigs from wild boars during the early stage of pig domestication is still poorly
understood. Compared to wild boar’s diets which come from the natural environment, the diets of domestic pigs are more easily
influenced by human feeding activities. Therefore, in principle, exploration of the dietary differences among pigs and under-standing
the impact on pig diets fed by humans can have great potential to differentiate between wild boars and domesticated pigs.
To reveal dietary differences among pigs and distinguish the domesticated pigs from wild boars based on comparison with the
diets of humans and other animals, we analyzed the carbon and nitrogen stable isotopes of human bones from Xiaojingshan Site
and animal bones from Yuezhuang Site, both of which belong to Houli Culture in Shandong Province and date to about 8500-7500
years ago. The mean δ13C value ((−17.8 ± 0.3)‰) and δ15N value ((9.0±0.6)‰) in human collagen indicate that although millet agriculture began it was not the main subsistence strategy
as millets are typical of C4 plants and that humans made a living mainly by gathering, hunting or raising some domesticated animals. The δ13C value (−16.1‰) and δ15N value (6.9‰) in the bovine suggest that C3 plants were dominant in its diet with some C4 plants complemented. The fish has lower δ13C value (−24.9‰) and higher δ15N value (8.8‰) than the bovine, which is the characteristic of the isotopic values from Eurasian freshwater fish. Based on
the differences in carbon and nitrogen isotope values, the pigs can be divided into three groups. A group, composed of two
pigs, has low δ13C values (−18.1‰, −20.0‰) and low δ15N values (4.7‰, 6.0‰). B group, only one pig, has the highest δ13C value (−10.6‰) and mediate δ15N value (6.4‰). As for the C group, also only one pig, low δ13C value (−19.0‰) and the highest δ15N value (9.1‰) are observed. Previous studies on the stable isotopes from modern or ancient wild boars’ bones have suggested
that C3 plants are predominated in their diets and that their δ15N values are close to those in herbivores and far from those in carnivores. Based on the comparison with the isotope values
from humans, the wild boars and the domestic pigs from Xipo Site in Henan 6000-5500 years ago and Kangjia Site in Shaanxi
4500-4000 years ago, we conclude that A pig group belongs to wild boars while B and C groups can be attributed to domesticated
pigs.
Supported by Max-Planck Society and Chinese Academy of Sciences, Knowledge Innovation Program of the Chinese Academy of Sciences
(Grant No. KJCX3.SYW.N12), National Natural Science Foundation of China (Grant No. 40702003) and President Funding of Graduate
University of Chinese Academy of Sciences 相似文献
8.
ZHAO Quanhong WANG PinXian CHENG Xinrong Wang Jiliang Huang Baoqi XU Jian ZHOU Zhen JIAN Zhimin 《中国科学D辑(英文版)》2001,44(10):943-951
High-resolution δ13C records are presented for the Miocene benthic foraminifersCibicidoides wuellerstorfi andC. kullenbergi (24-5 Ma) and the planktonic foraminiferGlobigerinoides sacculifer (18-5 Ma) from ODP Site 1148A (18° 50.17’N, 116° 33.93’E, water depth 3308.3 m), northern South China Sea. The general pattern of parallel benthic and planktonic δ13C shows a decrease trend of δ13C values from the early-middle Miocene to the middle-late Miocene. Two distinct δ13C positive excursions at 23.1-22.2 and 17.3-13.6 Ma, and two negative excursions at 10.2-9.4 and 6.9-6.2 Ma have been recognized. All these events are cosmopolitan, providing the good data for the stratigraphic correlation of the South China Sea with the global oceans as well as for studying the changes of the global carbon reservoir and its corresponding climate. 相似文献
9.
Wang Guoan Han Jiamao Zhou Liping Xiong Xiaogang Tan Ming Wu Zhenhai Peng Jun 《中国科学D辑(英文版)》2006,49(1):97-102
Carbon isotope ratios (δ
13C) of 89 C4 plant samples were determined from the loess area in North China. δ
13C values vary between −10.5‰ and −14.6‰ with a mean of −12.6‰. Along a precipitation gradient from the semi-moist area to
the semiarid area, then to the arid area, the δ
13C values of C4 plants show a slight decreasing trend. The δ
13C values of C4 plants in the dry season are found lower than those in the wet season. These trends are opposite to those observed for C3 species. 相似文献
10.
CHU Xuelei ZHANG Tonggang ZHANG Qirui FENG Lianjun & ZHANG Fusong. Institute of Geology Geophysics Chinese Academy of Sciences Beijing China . Key Laboratory for Mineral Resources Research Chinese Academy of Sciences Beijing China Correspondence should be addressed to Chu Xuelei 《中国科学D辑(英文版)》2004,47(2):160-170
Along the Proterozoic stratigraphic sections of Jixian, Tianjin, the δ13C values of carbonates are mostly negative in the Changchengian (Changcheng System), varying approximately within a range of (0±1 )‰in the Jixianian (Jixian System), and have commonly positive values of (2±2)‰ in the Qingbaikouan (Qingbaikou System). From Chuanlinggou Formation to Dahongyu Formation, i.e. from ca. 1700 Ma to 1600 Ma, the δ13C values of carbonates increase from about -3‰ to 0‰, but oscillate with large excursion in Dahongyu Formation. Two large excursions occur in the Jixianian, one in Yangzhuang Formation and the other in the third sub-member of Wumishan Formation overlaying. These integrated and continuous records of carbon isotope reflect secular variations of δ13C value in ancient seawater from ca. 1700 Ma to ca. 800 Ma. The increase and subsequent oscillation of seawater δ13C value occurring from the ages of ca. 1700 to ca. 1600 Ma and <1300 Ma may signify two correlative global tectonic events. 相似文献
11.
Hydrogen and oxygen isotope studies were carried out on mineral separates from high to ultrahigh pressure metamorphic rocks
at Huangzhen and Shuanghe in the eastern Dabie Mountains, East China. The δ18O values of eclogites cover a wide range of −5‰ to+9‰, but the δD values of micas fall within a narrow range of −85% to −70‰.
Both equilibrium and disequilibrium oxygen isotope fractionations were observed between quartz and the other minerals, with
reversed fractionations between omphacite and garnet in some eclogite samples. The δ18 O values of −5‰ to −1‰ for some of the eclogites represent the oxygen isotope compositions of their protoliths which underwent
meteoric water-rock interaction prior to plate subduction. The preservation of oxygen isotope heterogeneity in the eclogites
implies a channelized flow of fluids during progressive metamorphism caused by rapid subduction. Retrograde metamorphism has
caused oxygen and hydrogen isotope disequilibria between some of the minerals, but the fluid for retrograde reactions was
internally buffered in the stable isotope compositions.
Project supported by the Chinese Ministry of Science and Technology (Grant No. 95-Pre-39), the National Natural Science Foundation
of China (Grant Nos. 49794042, 49473173 and 49453003) and the Chinese Academy of Sciences (Grant No. KZ951-A1-401-5) 相似文献
12.
Leping Zheng 《中国科学D辑(英文版)》1999,42(6):588-594
The δ13c values of soil CO2 are less than that of atmosphere CO2 in the karst area. On the soil-air interface, the δ13c vlaues of soil CO2 decrease with the increase in soil depth; below the soil-air interface, the δ13c values of soil CO2 are invariable. The type of vegetation on the land surface has an influence on the δ13C values of soil CO2. Due to the activity of soil microbes, the δ13C values of soil CO2 are variable with seasonal change in ps. Isotopic tracer indicates that atmosphere CO2 has a great deal of contribution to soil CO2 at the lower parts of soil proflie.
Project supported by the National Natural Science Foundation of China (Grant Nos. 49703048 and 49833002) 相似文献
13.
Discrimination of abiogenic and biogenic alkane gases 总被引:5,自引:0,他引:5
JinXing Dai CaiNeng Zou ShuiChang Zhang Jian Li YunYan Ni GuoYi Hu Xia Luo ShiZhen Tao GuangYou Zhu JingKui Mi ZhiSheng Li AnPing Hu Chun Yang QingHua Zhou YanHua Shuai Ying Zhang ChengHua Ma 《中国科学D辑(英文版)》2008,51(12):1737-1749
We have combined the analytical data of the carbon isotope distribution pattern, R/Ra and CH4/3He values of abiogenic and biogenic (referring to the thermogenic and bacterial or microbial) alkane gases in China with those of alkane gases from USA, Russia, Germany, Australia and other countries. Four discrimination criteria are derived from this comparative study: 1) Carbon isotopic composition is generally greater than -30‰ for abiogenic methane and less than -30‰ for biogenic methane; 2) Abiogenic alkane gases have a carbon isotopic reversal trend (δ 13C1> δ 13C2> δ 13C3> δ 13C4) with δ 13C1>-30‰ in general; 3) Gases with R/Ra >0.5 and δ 13C11 δ 13C2>0 are of abiogenic origin; 4) Gases (meth- ane) with CH4/3He≤106 are of abiogenic origin, whereas gases with CH4/3He≥1011 are of biogenic origin. 相似文献
14.
Young-Joo Lee 《中国科学D辑(英文版)》2006,49(8):872-880
Serious interest has been directed toward natural gas hydrate as a potential energy resource; factor in global climate change, and submarine geohazard since naturally occurring gas-hydrate deposits were found in the 1960s. Hydrate Ridge, Cascadia convergent mar- gin, is characterized by abundant methane hydrates at and below the seafloor, active venting of fluids and gases, chemosynthetic communities, and some of the highest methane oxidation rates ever found in the ma-rine environment. All of… 相似文献
15.
Oxygen and carbon isotope composition from the UHP Shuanghe marbles, Dabie Mountains, China 总被引:5,自引:0,他引:5
Investigations on the oxygen and carbon isotope compositions from the ultrahigh-pressure (UHP)-metamorphosed Shuanghe marbles,
that occur as a member of a UHP slab, show that the δ18 O values range from +11.1% to+20.5% SMOW, and δ13 C from+1.0% to+5.7% PDB, respectively. The variations in isotope compositions show a centimeter scale of homogeneity and
a heterogeneity of regional scale larger than 1 meter.
In contrast to the eclogite marbles from Norway, the Shuanghe marbles have inherited the carbon isotope compositions from
their sedimentary precursor. The δ13C shows positive correlation to the content of dolomite. The depletion in18O, compared with the pmtolithic carbonate strata, might result from three possible geological processes: 1) exchanging oxygen
isotope with meteoric water before the UHP metamorphism, 2) decarbonation during the UHP metamorphism, and 3) exchanging oxygen
isotope with country gneiss at local scale during retrograde metamorphism.
It seems that the advection of fluid in the orogenic belt was very limited during subduction and exhumation of UHP rocks.
Project supported by a U. S. -China cooperative project led by Prof. Cong Bolin of the Institute of Geology. Chinese Acade-my
of Sciences, and Prof. J. G. Liou of the Department of Geological and Environmental Sciences, Stanford University and by the
National Natural Science Foundation of china (Grant No. 49794042). Chinese Academy of Sciences (Grant No. KZ951-A1-401r, and
National Science Foundation (Grant No. EAR-95-26700). 相似文献
16.
17.
Hydrogen and oxygen isotope compositions of eclogites from the Dabie Mountains and geodynamic implications 总被引:3,自引:0,他引:3
Heterogeneous δ18O values as low as - 2.6‰ to+7.0% are observed for ultrahigh pressure eclogites from the Dabie Mountains in East China. Oxygen
isotope equilibrium has been approached between the eclogite minerals, suggesting that the rocks would have acquired the unusual
δ18O values prior to ultrahigh pressure metamorphism by interaction with18O-depleted fluid. δD values of hydroxyl-bearing are between — 51% and - 83‰, precluding the possibility of paleoseawater involvement.
The only likely fluid is ancient meteoric water that exchanged oxygen isotopes with the eclogite precursor (a kind of basaltic
rocks) formerly resident on the continental crust. This suggests a crustal recycling process in the suture zone of late subduction.
Because silicate minerals undergo rapid oxygen isotope exchange at mantle pressures, preservation of the isotopic signature
of meteoric water in the eclogites indicates limited crust-mantle interaction and thus a short residence time (<20 Ma) when
the plate containing the eclogite precursor was subducted to mantle depths. The agreement in oxygen isotope temperatures for
different mineral pairs suggests a rapid cooling and ascent process for the eclogites subsequent to their formation at mantle
depths.
Project supported by the National Natural Science Foundation of China and the Chinese Academy of Sciences. 相似文献
18.
Environmental records of carbon in recent lake sediments 总被引:4,自引:0,他引:4
Based on careful sampling and accurate analysis of recent sediments in Lake Chenghai, this paper discusses the staggered positive/negative
correlation between organic carbon (OC) concentration and inorganic carbon (IC) concentration. The result indicates that temperature
change, and its induced relative changes are the main factors affecting the relationship between IC concentration, δ13C of carbonate and OC concentration. When temperature and its induced photosynthesis strength change control autochthonous
calcite precipitation, OC concentration is positively correlated with IC concentration and δ13C of carbonate. When temperature and its induced physical/chemical changes dominate, OC concentration displays negative correlation
with IC concentration and δ13C of carbonate. IC concentration and δ13C of carbonate in sediments of Lake Chenghai are good proxies for climatic warm/cold changes. 相似文献
19.
JiaZhu Li GuoAn Wang XianZhao Liu JiaMao Han Min Liu XiaoJuan Liu 《中国科学D辑(英文版)》2009,52(11):1714-1723
Variations in carbon isotopic ratios (δ
13C) of C3 plants and distribution of C4 plants were investigated along an altitudinal transect on the eastern slope of Mount Gongga, and the environmental effects
on them were discussed. It is shown that plants with C4 photosynthetic pathway mainly occur at altitudes below 2100 m a.s.l., suggesting that the low summer temperature is responsible
for the distributional pattern. In addition, δ
13C of C3 plants increases with elevation at the region above 2000 m a.s.l. with the characteristics of humid climate, and the increase
rate in δ
13C for C3 plants is about 1.3% per kilometer. Temperature determines the altitudinal trend of δ
13C. 相似文献
20.
Zhimin Jian 《中国科学D辑(英文版)》1998,41(4):337-344
Based on the oxygen and carbon stable isotopic records of benthic foraminifera in nine deep-sea cores of the South China Sea
(SCS), the bathymetric profiles of δ18O and δ13C since the last glacial maximum (LGM) are preliminarily established. The bathymetric gradients of deep-water δ18O and δ13C in the SCS are obviously greater during the LGM than during the Holocene, showing the existence of the deep thermocline
and nutricline at water depth of about 2 000 m. Particularly, the differences in δ18O and δ13C between the LGM and Holocene, from which the ice-volume effect and the global mean shift have been subtracted respectively,
are positive values at water depths of 1 000–2 500 m in the SCS. This indicates the existence of deep-water mass with relatively
cool temperature or higher salinity, better ventilation and more δ13C within the water depth range of the SCS during the LGM, which is distinctly different from that at present. These changes
further confirm the existence of the glacial “North Pacific Deep Water” which, however, is possibly confined to the water
depth range of 1 000–2 500 m.
Project supported by the National Natural Science Foundation of China (Grant Nos. 49576286 and 49732060). 相似文献