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1.
黑龙江穆棱新生代玄武岩锆石巨晶的微量元素及Hf同位素研究 总被引:2,自引:0,他引:2
穆棱古近纪(第三纪)碱性玄武岩位于郯庐断裂东北段分支敦化~密山深大断裂带的中北部,与吉林敦化、汪清,黑龙江镜泊湖、牡丹江等新生代火山岩一起分布于兴蒙造山带和太平洋板块俯冲带结合带上;本文利用电子探针、激光剥蚀等离子质谱技术(LA-ICP-MS)及多接收器电感耦合等离子体质谱仪(MC-ICP-MS)分析了来自玄武岩风化冲积物中锆石巨晶的主、微量元素及其Hf同位素组成.这些锆石巨晶具有明显的熔蚀结构,锆石电子探针分析其Zr/Hf比最高可达217,平均150,是目前东部新生代玄武岩锆石巨晶的最高值.它们具有相似的微量元素特征,具有明显的Ce正异常,富集重稀土和HFSE元素,锆石Hf/Y比值大多小于10,Th/U均小于1(一个数据例外),Yb/Sm为21~59.与岩浆锆石和变质锆石相比,显示过渡的特征;锆石^176Hf/^177Hf变化为0.283105~0.283151,εHf变化在+11.8~+13.4之间,显示亏损地幔来源,反映锆石形成时岩石圈地幔主体具有"新生"的特征,表明岩石圈减薄或置换事件在东北地区东北部穆棱地区也同样存在.穆棱新生代碱性玄武岩有关锆石巨晶的成因特征与中国东部海南文昌、福建明溪及山东昌乐等地新生代玄武岩的锆石巨晶相同,可能与有下地壳物质参与的近期岩石圈地幔的交代作用有关. 相似文献
2.
Peatland initiation and carbon dynamics in northeast China: links to Holocene climate variability 下载免费PDF全文
Wei Xing Kunshan Bao Wenyong Guo Xianguo Lu Guoping Wang 《Boreas: An International Journal of Quaternary Research》2015,44(3):575-587
Throughout northeast China, the widely distributed peatlands have formed a large carbon (C) pool. However, the relationship between peatland initiation and climate controls is still poorly documented and understood. Understanding the responses of these C‐rich ecosystems to past climate change will provide useful insights into projecting the fate of peatland C in the future. In this study, we present a detailed historical reconstruction of peatland development in northeast China based on 312 basal peat dates, and examine the relationship between Holocene peatland dynamics and climate sensitivity. Our results indicate that peatland initiation started in the early Holocene, and that the majority of peatlands were initiated by and developed during the late Holocene. After the most intensive initiation period of 4.2–0.8 ka, the rate of peatland development slowed, which was concomitant with decreasing insolation and monsoon intensity. The widespread peatland initiation in the late Holocene might have been caused by the cool and moist climate patterns. The optimum timing of the peatland development was not uniform across northeast China, and these spatio‐temporal differences indicate the influences of regional climate and terrain on peatland initiation. Peat‐core data show variations in the long‐term apparent rate of C accumulation (LORCA) during the Holocene, with an average rate of 37.2 g C m?2 a?1. The peak LORCA occurred during 10.5–9.0 ka, probably in response to higher temperatures and stronger East Asia summer monsoon intensities. Both temperature and humidity are important factors influencing the peatland initiation and C dynamics in this region. 相似文献
3.
Hanchen Duan Changzhen Yan Atsushi Tsunekawa Xiang Song Sen Li Jiali Xie 《Environmental Earth Sciences》2011,64(4):1011-1020
The Three-North Shelter Forest Programme (TNSFP) covers 551 Chinese counties and an area of 4,069,000 km2 mostly in arid and semi-arid regions. In this paper, we discuss the temporal and spatial changes in value of the normalized-difference
vegetation index (NDVI) in this region, and the relationships between NDVI and climatic factors (temperature and precipitation)
based on NOAA Advanced Very High Resolution Radiometer Global Inventory Modeling and Mapping Studies NDVI data with 8-km resolution
from 1982 to 2006. During the past 25 years, the vegetation cover has generally increased in eastern regions of China and
the oasis in the north piedmont of Tianshan Mountains, but has decreased northwest of Xinjiang and in the Hulunbeier Plateau.
The multi-year monthly average NDVI distribution map showed that NDVI increased from April to August, but in the western and
northern plateau areas, the lower temperatures and high altitude created a shorter growing season (1 or 2 months). The vegetation
of the study area has generally increased in the regions covered by the TNSFP. Linear regression analysis of the vegetation
cover showed an increasing trend over large areas. The largest annual growth rate per pixel (the slope of the regression)
was 0.009; the largest negative annual change was −0.004. The correlation between NDVI and precipitation was higher than that
between NDVI and temperature, suggesting that precipitation is the most important factor that affects NDVI changes in the
study area, especially for temperate desert vegetation in northwestern China. 相似文献
4.
《International Geology Review》2012,54(5):631-652
Borisov, A. A., Glubinnaya struktura territorii SSSR po geofizicheskim dannym [DEEP STRUCTURE OF TERRITORY OF USSR ACCORDING TO GEOPHYSICAL DATA]: Nedra Press, Moscow, 1967. 303 pp., 3 tables, 82 figs., 628 refs. Appendix: loose maps of USSR; DSS profiles and structures; gravity and magnetic anomalies; topography of "M" surface; structure of consolidated crust. NK 67–18 (22). Kostomarov, V. M., Protivoopolznevyye meropriyatiya v gorodakh [LANDSLIDE CONTROL OPERATIONS IN CITIES]: "SI" Press, Moscow, 1967. 111 pp., 2 tables, 34 figs., 38 refs. NK 67–24(62). Popov, E. G. and A. I. Chebotarev, Zeravshanskiy front [THE ZERAVSHAN FRONT]: Gidrometeorologizdat, Leningrad, 1966. 68 pp., 1 table, 6 figs., 15 photos. NK 65–16(85). Metody i programmy dlya analiza seysmicheskikh nablyudeniy [METHODS AND PROGRAMS FOR ANALYSIS OF SEISMIC OBSERVATIONS]. Vychislitel'naya seysmologiya [COMPUTER SEISMOLOGY]: NO. 3. Seven papers by 13 authors. V. I. Keylis-Borok, Executive Editor. Nauka Press, Moscow, 1967. 282 pp., 3 tables, 79 figs., 17 refs. NK 67–25(49). By Dr. V.P. Sokoloff Kuznetsov, V. A., E. G. Distanov, A. A. Obolenskiy. V. I. Sotnikov, and A. A. Tycchinskiy, Osnovy for matsionnogo analiza endogennoy metallogenii Altaye-Sayanskoy oblasti [FUNDAMENTALS OF FORMATIONAL ANALYSIS OF ENDOGENE METALLOGENY OF ALTAY-SAYAN PROVINCE]: Nauka Press, Novosibirsk, 1966. 153 pp., 4 figs., 11 tables, 237 refs. NK 66–2(38). [Reviewer: Boris V. Brajnikov.] Fizicheskiye metody issledovaniya mineralov osadochnykh porod [PHYSICAL RESEARCH METHODS FOR STUDY OF MINERALS FROM SEDIMENTARY ROCKS]: A. G. Kossovskaya et al., Editors. Nauka Press, Moscow, 1966. 358 pp., 121 figs., 33 plates, 66 tables. Bibl. NK 66–4(40). [Reviewer: Boris V. Brajnikov.] Metally v osadochnykh tolshchakh [METALS IN SEDIMENTARY ROCKS]: L. V. Pustovalov, Executive Editor. Laboratory of sedimentary economic minerals, AN ASSSR. Nauka Press, Moscow, 1966. 326 pp., 49 tables, 28 figs., 697 refs. NK 65–10(98). Kigay, I.N., Lifudzinskoye olovorudnoye mestorozhdeniye [THE LIFUDZIN DEPOSIT OF TIN ORES]: Edited by G.A. Sokolow. Nauka Press, Moscow, 1966. 248 pp., 18 tables, 64 figs. (incl. 20 photos). 314 refs. SK 65(1)–431. Rosk kristallov [CRYSTAL GROWTH]. Volume VII, part 1. Transactions of Symposium on Crystal Growth: Seventh International Congress of Crystallographers, July 1966. Fifty papers by 92 authors. N. N. Sheftal1, Executive Editor, AN SSSR, Institute of Crystallpgraphy. Nauka Press, Moscow, 1967. 359 pp., 34 tables, 294 figs., 574 refs. By Dr. V.P. Sokoloff 相似文献
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《International Geology Review》2012,54(6):842-865
Paleogeographical reconstructions in the basin, between the Yenisey ridge and the Chadobets uplift, together with lithofacies analysis and stratigraphic differentiations show that: a) cupriferous carbonate-clayey horizons lie on the periphery of the basin and represent the transgressive cycle; b) coarse-grained sedimentary hosts of the cupriferous horizons represent the regressive cycle; c) copper is negligible in the essentially carbonate lithofacies in the central and deeper part of the basin. -- V.P. Sokoloff 相似文献
7.
《International Geology Review》2012,54(7):980-1004
This is the third installment of the Lisitsyn monograph which began in the May IGR (v. 9, no. 5). The fourth and concluding installment will be published in August. 相似文献
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9.
Assessing vegetation dynamics impacted by climate change in the southwestern karst region of China with AVHRR NDVI and AVHRR NPP time-series 总被引:6,自引:0,他引:6
The relationship between climate change and vegetation dynamics in the southwestern karst region of China has been identified
by recent studies. Based on previous researches and AVHRR (Advanced Very High Resolution Radiometer) GIMMS (Global Inventory
Monitoring and Modeling Studies) NDVI (Normalized Difference Vegetation Index) (1982–2003) and AVHRR GloPEM (Global Production
Efficiency Model) NPP (Net Primary Production) (1981–2000) datasets, vegetation dynamics impacted by climate change in the
southwestern karst region of China were assessed. The results show that: (1) since the early 1980s, both vegetation cover
density and net primary production have insignificant ascending tendencies. However, the inter-annual variation rates of vegetation
indexes have apparent spatial differentiations; (2) the correlation coefficients between the inter-annual variations of vegetation
indexes and the inter-annual variations of climate factors vary geographically; (3) as indicated by NDVI and NPP, various
vegetation types have different responses to climate change, and the annual mean temperature variation has more significant
impact on vegetation dynamics than the annual precipitation variation in the study area; (4) distribution laws of correlation
coefficients between the inter-annual variations of vegetation indexes and the inter-annual variations of climate factors
in different climate conditions are apparent. All these findings will enrich our knowledge of the natural forces which impact
the stability of the karst ecosystems and provide scientific basis for the management of the karst ecosystems. 相似文献
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黑龙江省三矿沟矽卡岩型铁铜矿床流体包裹体研究 总被引:9,自引:2,他引:9
对黑龙江省三矿沟矽卡岩型铁铜矿床内花岗闪长岩中石英斑晶、硫化物阶段及石英-碳酸盐阶段的石英、方解石中流体包裹体的岩相学、显微测温学和显微激光拉曼光谱分析等的研究结果表明,流体包裹体有富液相、富气相和含子矿物多相包裹体3种类型;花岗闪长岩石英斑晶中的含子矿物多相包裹体均一温度均值为4320C,盐度在30.92 wt%~63.91 wt%NaCl eqv.之间,平均为52.96 wt%NaCl eqv.,代表了高温、高盐度岩浆流体;硫化物阶段形成的黄铜矿磁铁矿矿石中流体温度主要介于323~424℃之间,盐度介于8.95 wt%~62.51 wt%NaCl eqv.之间;硫化物阶段形成的黄铜矿矿石中流体温度主要介于333~441℃之间,盐度介于8.28 wt%~65.32 wt%NaCl eqv.之间;石英-碳酸盐阶段流体温度主要介于124~140℃之间,盐度介于1.65 wt%~4.34 wt%NaCl eqv.之间.铁铜矿石均形成于高温、高盐度阶段,以岩浆热液为主,在成矿晚期,由于大气降水的混合,形成了少量低温、低盐度流体,成矿流体以富Na、K、Ca、Cl-和CO~2_3-的高盐度流体为特征,主体属于NaCl-H_2O-CO_2-H_2S-CH_4体系.成矿流体在300~400℃区间内发生了强烈的沸腾作用,导致大量金属硫化物和少量金属氧化物沉淀,沸腾作用对三矿沟铁铜矿床的形成起到至关重要的作用. 相似文献
12.
黑河流域天然植被的面积变化研究 总被引:8,自引:1,他引:8
植被覆盖面积的大小是反映区域性生态环境状况的重要指标之一,多年植被覆盖面积的变化则直观反映了植被生态环境随时间的变化规律。在前人研究成果的基础上,采用定量遥感技术,应用美国国家航天航空局最新的全球植被指数变化研究数据(GIMMS)作为数据源,对黑河流域1989-2002年间的植被面积变化规律进行了研究。考虑到实际的植被面积难以确定,因此采用等效面积法确定植被覆盖面积,通过统计遥感图像上植被指数(NDVI)值大于0.3的像素点值,以像素点值代表植被的面积,研究黑河流域14 a的天然植被面积变化规律。研究结果证明,黑河流域的天然植被在以每年约3%的速度减少。 相似文献
13.
黑龙江省铜山斑岩铜矿床流体包裹体研究 总被引:10,自引:4,他引:10
铜山大型铜矿床位于小兴安岭西北部,是中亚-兴蒙造山带北东段最著名的斑岩型铜矿床之一,矿体产于加里东期花岗闪长岩和中奥陶世多宝山组安山岩、凝灰岩中,铜矿化与硅化-绢云母化关系密切.流体包裹体研究表明,铜山铜矿床主要发育气液两相包裹体、含CO_2包裹体和含子矿物多相包裹体.成矿流体在形成过程中经历了早、中、晚3个阶段的演化.成矿早阶段发育气液两相水溶液包裹体和少量含子矿物多相包裹体,均一温度介于420℃~>5500C之间,流体盐度介于13.72 wt%~59.76 wt%NaCl eqv之间;中阶段为铜山矿床的主成矿阶段,发育气液两相水溶液包裹体和含CO_2包裹体,均一温度为241℃~417℃,流体盐度介于2.96 wt%~14.04 wt%NaCl eqv之间,主成矿期成矿流体总体上属H_2O-CO_2-NaCl体系;晚阶段仅发育气液两相水溶液包裹体,均一温度为122℃~218℃,盐度介于3.71 wt%~15.96 wt%NaCl eqv之间,表明晚阶段有大气降水的混入.成矿早、中阶段的流体均为不混溶流体,流体沸腾作用是金属硫化物大量沉淀的主要机制.铜山矿床形成于陆缘弧环境. 相似文献
14.
黑龙江镜泊湖地区全新世玄武岩的地球化学特征及其深部过程探讨 总被引:2,自引:3,他引:2
镜泊湖地区全新世玄武岩分布在镜泊湖西北方向的“火山口森林”地区和蛤蟆塘地区。这两个地区相距只有15km,但其玄武质岩石在岩石学上具有明显的区别,前者为碱性橄榄玄武岩,后者为白榴石碱玄岩,并且具有钛角闪石、金云母和歪长石巨晶,而前者则没有这些巨晶。对它们的地球化学特征研究表明,两个地区的玄武夺石虽然均属于偏钠质的碱性玄武岩,但是白榴石碱玄岩相对于碱性橄榄玄武岩总体上具有高的Al2O3、Na2O、K2 相似文献
15.
《Journal of Asian Earth Sciences》2002,20(2):141-150
The coal-bearing Longzhaogou and Jixi Groups in eastern Heilongjiang, northeast China, consist of alternating marine and non-marine deposits containing abundant marine animal and plant fossils. The Jixi Group also yields members of the Johel Fauna that is widely distributed in northern and eastern China. The two groups have been considered as Jurassic or mainly Jurassic in age for a long time. However, recent studies documented that the ammonites, bivalves, dinoflagellates, angiosperms and sporopollens are all of Early Cretaceous rather than Jurassic age. It has been demonstrated that: (1) the Longzhaogou and Jixi Groups and their equivalents, the Johel Group of China and the Transbaikalian Group of Russia, are of Early Cretaceous age, (2) the Barremian-Albian was also a very important period of coal accumulation in northeastern China and perhaps in all of eastern Asia, (3) there existed a large shallow embayment connecting with the Palaeo-Pacific in eastern Heilongjiang, and it was the climate of the embayment that controlled the origin and development of the animal and plant communities of northeastern China during the Early Cretaceous. Correlation between formations in the Jixi and Longzhaogou Groups has also been revised in this paper. 相似文献
16.
黑龙江五大连池火山群地壳电性结构 总被引:11,自引:3,他引:11
对1997年在黑龙江五大莲池火山群观测的7条大地电磁测深剖面资料进行重新处理,对全部测点的实、虚感应矢量和视电阻率曲线等参数的分布特征进行了详细分析,应用NLCG二维反演方法对3条近东西向剖面数据进行了反演,获得的深部电性结构结果显示:五大莲池火山群中的笔架山-老黑山-火烧山火山链上的火山规模明显大于南、北格拉球火山链和东、西焦得布火山链,该带火山活动有从南西向北东推移的规律;以笔架山-老黑山-火烧山火山链为中心在地下约几百米深度到20km左右,存在一个北北东走向、上宽下窄、北宽南窄似铆钉的状体,该块体随着深度的增加其电阻率值从上千欧姆米逐渐减小到小于1欧姆米;在深度约20km以下铆钉的主体仍然显示有向深处延伸的趋势,推测一直穿过地壳与上地幔连接;在深度4~8km左右火烧山、老黑山和笔架山东、西两侧存在低阻块体;结合S波速度、小震活动以及地热研究结果分析,推测笔架山-老黑山-火烧山火山链在地壳内随着深度增大存在不同凝固程度的岩浆系统。 相似文献
17.
Robin W. Dennell María Martinón-Torres José M. Bermúdez de Castro 《Quaternary Science Reviews》2011,30(11-12):1511-1524
We propose a population model for Middle Pleistocene Europe that is based on demographic “sources” and “sinks”. The former were a small number of “core” or populations in glacial refugia in southern Europe from which hominins expanded northwards in interstadial and interglacial periods; occupation outside glacial refugia would have been restricted to warm or temperate periods, and populations at the northern limit of the Middle Pleistocene range would have been “sink” populations in that they depended upon recruitment from source populations further south. Southwest Asia would also have been a likely source of immigrant, source populations. We argue as an alternative to an “ebb and flow” model in which groups retreated to refugia when conditions worsened that local extinction outside refugia would have been frequent. In extreme situations, Europe may have been a population “sink” (i.e. unpopulated) that was replenished from source populations in Southwest Asia. We suggest that this pattern of repeated colonisation and extinction may help explain the morphological variability of European Middle Pleistocene hominins, particularly Homo heidelbergensis and its apparent non-lineal evolution towards Homo neanderthalensis. 相似文献
18.
Jingeng Sha Masaki Matsukawa Huawei Cai Baoyu Jiang Makoto Ito Chengquan He Zhiwei Gu 《Cretaceous Research》2003,24(6):715-728
In eastern Heilongjiang, the Upper Jurassic is marine and restricted to the Suibin and Dong’an areas, where it is characterized faunally by Callovian–Volgian (Tithonian) bivalves and florally by dinoflagellates. The Lower Cretaceous is widely distributed in eastern Heilongjiang, and characterized faunally by Berriasian–Valanginian bivalves, Barremian–Albian ammonites and Aucellina, and florally by dinoflagellates. To the west, the marine facies grade into non-marine beds. Thus, in the east, for example in the Dong’an and Dajiashan areas, near the northwestern Palaeo-Pacific, the Lower Cretaceous is marine; westward, in the Yunshan, Longzhaogou, Peide, and Zhushan areas, marine and non-marine deposits alternate, whereas further west still, e.g. in the Jixi Basin, non-marine facies are intercalated with marine beds. This regional distribution is indicative of a large, shallow embayment opening eastwards to the Palaeo-Pacific; during the Early Cretaceous successive transgressive-regressive events influenced the climate and biota of eastern Heilongjiang and northeastern China. Many of the Lower Cretaceous sections contain abundant coals, demonstrating that in this region the Early Cretaceous was an important coal-forming period. Some non-marine bivalve species are common to the Lower Cretaceous Jixi Group of eastern Heilongjiang, the Jehol Group of western Liaoning and the Transbaikalian Group of Siberia, suggesting that these groups are of comparable Early Cretaceous age. 相似文献
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