Xi X.,China Geological Survey |
Yang Z.,China University of Geosciences |
Cui Y.,Heilongjiang Institute of Geological Survey |
Sun S.,Jilin Institute of Geological Survey |
And 2 more authors.
Geoscience Frontiers | Year: 2011
Employing the Unit Soil Carbon Amount (USCA) approach, soil carbon storage was calculated across the Northeast Plain of China based on the Multi-purpose Regional Geochemical Survey conducted in 2004-2006 (MRGS). The results indicated that the soil organic carbon (SOC) storage in topsoil (0-0.2 m), subsoil (0-1 m) and deep soil (0-1.8 m) was 768.1 Mt, 2978.4 Mt and 3729.2 Mt with densities of 3327.8 t/km2, 12,904.7 t/km2 and 16,157.5 t/km 2, respectively. These values were consistent with national averages, whereas the soil carbon densities showed a clear increasing trend from the southern area of the Northeast Plain (Liaoning), to the middle (Jilin) and the northern Plain (Heilongjiang) - particularly in terms of topsoil carbon density, which increased from 2284.2, to 3436.7 and 3861.5 t/km2, respectively. In comparison to carbon data obtained from the Second National Soil Survey in 1984-1986 (SNSS), the topsoil SOC storage values from the MRGS were found to have decreased by 320.59 Mt (29.4%), with an average annual decline of 16.0 Mt (l.73%) over the 20 years. In the southern, middle and northern areas of the plain, soil carbon densities decreased by 1060.6 t/km 2, 1646.4 t/km2 and 1300.2 t/km2, respectively, with an average value of 1389.0 t/km2 for the whole plain. These findings indicate that the decrease in soil carbon density varied according to the different ecosystems and land-use types. Therefore, ratios of soil carbon density were calculated in order to study the carbon dynamic balance between ecosystems, and to further explore distribution characteristics, as well as the sequestration potential of SOC. © 2011, China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V. All rights reserved.
Hou J.G.,Heilongjiang Institute of Technology |
Chu Y.,Heilongjiang Institute of Geological Survey
Applied Mechanics and Materials | Year: 2013
In this paper, a novel method is proposed by combining of radar clinometry and interferometry to improve the accuracy of digital elevation model (DEM) reconstruction. In synthetic aperture radar (SAR) signal processing, the interferometry method uses a couple of high-coherence SAR complex images and the clinometry method uses only one. On one hand, interferometry-derived DEM is much more accurate in regions of higher coherence than the clinometry one. However, in regions of lower coherence, some pronounced errors are produced with the interferometry method due to phase filtering and unwrapping problems. On the other hand, the clinometry method can produce a more robust DEM result by using the intensity of SAR image. Therefore the clinometryand interferometry-derived DEM is fused by introducing a user-defined weighting factor, where in regions of higher coherence, the DEM results with the interferometry method are remained, and in regions of lower coherence, the interferometry-derived DEM is updated with the clinometry-derived one. Finally, the experimental results with Envisat data show the effectiveness of our approach. © (2013) Trans Tech Publications, Switzerland.
Liu C.,China University of Geosciences |
Liu C.,Durham University |
Deng J.F.,China University of Geosciences |
Luo Z.H.,China University of Geosciences |
And 5 more authors.
Yanshi Xuebao/Acta Petrologica Sinica | Year: 2014
The Luming super large molybdenite deposit is a newly discovered Mo deposit with more than 890 thousand tons resource at an average grade of 0.084% in the Lesser Xing'an Range. Here we resolved the debate of the magmatism and associated mineralization of the Luming deposit. This paper reports LA-ICP-MS U-Pb zircon, 40 Ar-39 Ar biotite, and Re-Os molybdenite geochronology of Luming granite porphyry (LGP), and Luming granite (LG). Field relationships show that the emplacement of the LG is succeeded by the LGP. Quartz vein and disseminated molybdenite mineralization occurs in the LGP. The geochronology shows that the LGP was formed at 174.0±2Ma(MSWD=3.2). The five molybdenite samples from Luming deposit yield a Re-Os isochron age of 177.8±2.3Ma (MSWD=0.08) and a Re-Os weighted average age of 177.5±1.2Ma (MSWD=0.06). Ar-Ar systematics indicate LG biotite has an age of 175.9 ± 1.1Ma, this indicates the LG was probably formed at ∼ 176Ma. Considering field geology, petrography, and previous studies, we show the batholiths of LG (>176Ma) was formed prior to the LGP (about 174Ma), and the ore-forming intrusive body of Luming metallogenesis of molybdenite is the LGP, but not the batholiths of LG, even though the metallogenesis of molybdenite is coeval or slightly later than LG and LGP. Geochemical characteristics, especially the highly abundance of MgO, high Sr and low Y and diagrams of texture of LG and LGP show the LG and LGP were formed in VAG of subduction setting. We suggests, during early-middle Early-Jurassic, the studied area developed thickened crust and extensive mantle-crust interaction corresponding to the convergence of Monglia-Okhotsk Sea in the west-north, Rohe and Izanaqi Ocean in the east. After that, the batholiths of LG uplifted rapidly because of delamination and the magma of LGP (including molybdenite and magmatic fluids) coming from deeper crust was intrusived into the batholiths of LG in the shallow crust, and then formed the LGP and the Luming molybdenum deposit. Thus, the authors suggest the Luming molybdenite deposit was formed by post-batholith metallogenesis.
Yin Z.,LIAONING Technical University |
Zhang Y.,Heilongjiang Institute of Geological Survey |
Du Y.,LIAONING Technical University
Jilin Daxue Xuebao (Diqiu Kexue Ban)/Journal of Jilin University (Earth Science Edition) | Year: 2013
The rhyolites of the Early Cretaceous Shangkuli Formation in northern Daxing'anling belong to high-K calc-alkaline volcanic rock series characterized by rich-alkaline (K2O+Na2O>6.10%), high K2O (3.25%-5.30%) and high ratios of K2O/Na2O (0.67-2.48). These samples show strong enrichment in large ion lithophile elements (LILE) and in light rare earth elements (LREE). But the elements of Ba, Sr, Nb, P, and Ti are apparently depleted. The higher Th content and high Rb/Ba, Rb/Sr and Zr/Ba ratios of the rhyolites suggested a continental intraplate rifted setting related to the extension stage after the formation of Mongolia-Okhotsk orogenic belt. The current data indicate that the parental magma for rhyolites could be the products of the lower crust partial melting.
Li Y.-C.,China University of Geosciences |
Wu G.-G.,China University of Geosciences |
Jin Z.-Y.,Heilongjiang Institute of Geological Survey |
Zhang D.,China University of Geosciences |
Yang X.-P.,Heilongjiang Institute of Geological Survey
Geology in China | Year: 2013
The Tongshan Formation is a very important part of Zalantun-Duobaoshan island arc tectonic belt in northern Zalantun area of the Da Hinggan Mountains. The properties, deposition epoch and tectonic environment type of the source area of Tongshan Formation are important links in the study of the island arc tectonic belt, and also constitute an important window in the study of early tectonic evolution of the old Asian Ocean tectonic domain. Studies of fine elastic rocks and petrography of the Tongshan Formation in combination with geochemistry of the main elements and trace elements in fine elastic rocks show that Tongshan Formation was formed in the continental island arc area or active continental margin as well as the nearby places, and the source materials of Tongshan Formation were mainly felsic rocks and migmatitic felsic rocks formed by the transition from the upper crust to the edge of the andesite island arc, with part of the source material probably derived from the mixture of a small amount of passive continental margin material. The LA-MC-ICPMS zircon U-Pb age spectrum characteristics of fine elastic rocks in Tongshan Formation were determined for the first time, and the results show the diversity of the source area of Tongshan Formation. The U-Pb age spectrum contains 566-632Ma and 789-889Ma detrital zircons and, in combination with regional chronologic information, these data suggest that there must have existed the Neoproterozoic crystalline basement and the Neoproterozoic magmatism and metamorphism in this area, which constituted the main provenances of sedimentary rocks in Tongshan Formation. 2543-2705 Ma and 1773-2120 Ma ancient detrital zircons information revealed in the Xing-Meng orogenic belt suggests the probable existence of Precambrian micro-landmass basement, which became the important provenances of sedimentary rocks in Tongshan Formation. According to 572 +5Ma concordant age, in combination with regional contrast, the deposition time of Tongshan Formation was dated at early Ordovician. The research results provide an important basic material for determining the evolution of the early Paleozoic Zalantun-Duobaoshan island arc tectonic belt and also offer a new constraint for the investigation of the continental crustal evolution on the southern margin of the Siberia plate and the researches on tectonodynamics.