To provide scientific basis for appraising natural resources in Mt. Namjagbarwa area, the migration characteristics of geochemical microelements, such as Zn, V, Ti, Pb, Ni, Cu, Cr, Co, Be and Ba, in the landscape zone...To provide scientific basis for appraising natural resources in Mt. Namjagbarwa area, the migration characteristics of geochemical microelements, such as Zn, V, Ti, Pb, Ni, Cu, Cr, Co, Be and Ba, in the landscape zones of alpine scrub and meadow, the mountainous dark coniferous forest, the mountainous mixed broadleaf and coniferous forest, the mountainous quasi-subtropical semi-evergreen broadleaf forest, the mountainous subtropical evergreen broadleaf forest, and the valley quasi-tropical monsoon rainforest have been described in the paper.展开更多
Introduction There are big disputes on the uplift of the Tibetan Plateau. Some scientists believe the plateau uplifted to its highest elevation by 14Ma BP,and it decreased in elevation afterward. The second idea about...Introduction There are big disputes on the uplift of the Tibetan Plateau. Some scientists believe the plateau uplifted to its highest elevation by 14Ma BP,and it decreased in elevation afterward. The second idea about the uplift of the plateau was similar to the first one in tectonic theory, but they consider the time of C3 plant change to C4 in the South Asia, as the time when the plateau reached its highest elevation. This time is 8Ma BP. The third idea, the most Chinese scientists believed, the nearest uplift of the plateau took place since 3 4Ma BP. The occurrence of fault depression and gravel deposit with large thickness in the inner and the marge of the plateau represented the speed uplift. After the collision of the India plate and the Eurasia plateau by the 36Ma, the Tibetean area uplifted several times, but it had been planed to lower area. The plateau with 4500m elevation formed in the Quaternary. While our recent research in the Kunlun Pass area suggest , the nearest uplift occurred at the border of the Early and Middle Pleistocene, and before that time, the elevation of this area was no more than 1500 m.展开更多
The origin of Molar Tooth(MT)carbonates has been argued for more than 100 years, which are a kind of Proterozoic carbonates especially composed of microsparite with ptygmatically folded and sheet-like structures. Biom...The origin of Molar Tooth(MT)carbonates has been argued for more than 100 years, which are a kind of Proterozoic carbonates especially composed of microsparite with ptygmatically folded and sheet-like structures. Biomarkers detected in the microcalcsparite from the Wanlong and Xingmincun formations in the Jilin-Liaoning area showed there are abundant normal alkanes, isoprenoids, hopanes, steranes, alkylmethylcyclohexanes, and alkylcyclohexanes, indicating a diversity of biological source: long-chain isoprenoids, the major components of chlorophyll, such as C 19, C 20, a kind of major biomarkers synthesized early by isoprenoid monomers; hopanes a type of characteristic biomarkers from prokaryote, such as archaebacteria and cyanobacteria; sterane a biomarker for eukaryote; and two kinds of alkanes with C 17, C 18 as the main peaks representing aquatic bacteria and with C 23, C 24 as the main peaks representing fungi, respectively. Biomarker analysis showed that MT is the result of bacterial and algal activities, which is a kind of organisms between aerobic and anaerobic bacteria, reproducing well in normal or slightly saline sea water under weak oxidation-reduction conditions, resulting in rapid deposition of calcite as microsparite due to some mechanisms.展开更多
Songshan Mt. is one of the fiveholy mountains in China. In ancienttime it was named Waifang Mt.,Chonggao Mt., Yueshan Mt. AND Songshan Mt. Etc.. It was decided to be the central mountain in the Han Dynasty.
In shallow-water areas,the marine magnetotelluric(MT)method faces a challenge in the investigation of seabed conductivity structures due to electrical and magnetic noises induced by ocean waves,which seriously contami...In shallow-water areas,the marine magnetotelluric(MT)method faces a challenge in the investigation of seabed conductivity structures due to electrical and magnetic noises induced by ocean waves,which seriously contaminate MT data.Ocean waves can affect electric and magnetic fields to different extents.In general,their influence on magnetic fields is considerably greater than that on electric fields.In this paper,a complex adaptive filter is adopted to reduce wave-induced magnetic noises in the frequency domain.The processing results of synthetic and measured MT data indicate that the proposed method can effectively reduce wave-induced magnetic noises and provide reliable apparent resistivity and phase data.展开更多
The Duobaoshan mine area in Heilongjiang is located in the northeast section of Xingmeng orogenic belt and is in the west side of Hegang Mountain-Heihe fault zone. There exist many deposits in this area,and its metall...The Duobaoshan mine area in Heilongjiang is located in the northeast section of Xingmeng orogenic belt and is in the west side of Hegang Mountain-Heihe fault zone. There exist many deposits in this area,and its metallogenic conditions are superior,which has been one of the hotspots in geological prospecting and metallogenic research in Northeast China. On the basis of previous studies,the authors used the EH-4 electromagnetic imaging system to carry out the data acquisition of three survey lines in Woduhe Village,Duobaoshan Town,Nenjiang County. Through the analysis of apparent resistivity section under TE and TM polarization modes,integrating regional geological data,it is concluded that:(1) the electrical characteristics of the metal ore in this area show a relatively low resistance,and according to its resistivity difference with surrounding rocks,the geometrical structures and apparent resistivity parameters of the low resistivity bodies in the lower section of the survey line are defined,and the electrical anomalies can be identified;(2)faults F1 and F2 may have a good metallogenic environment,so they are recommended for further exploration;(3) low resistance metal ore bodies have good correlation with local small structures or faults,which may play an iconic role for the delineation of key target areas;(4) in the process of using apparent resistivity to define the geometric structures of ore bodies underground,comprehensive analysis integrating the advantages of TE and TM models should be carry out to achieve more reliable inversion results.展开更多
High-resolution imagery can be used to reconstruct former glacier boundaries through the identification of glacial erosional and sedimentary geomorphology. We employed moraine mapping and the accumulation–area ratio ...High-resolution imagery can be used to reconstruct former glacier boundaries through the identification of glacial erosional and sedimentary geomorphology. We employed moraine mapping and the accumulation–area ratio method(AAR), in conjunction with Landsat, Google Earth, and SRTM imagery, to reconstruct glacier boundaries and equilibrium-line altitudes(ELAs) for Mt. Kenya in the Last Glacial Maximum(LGM), the Little Ice Age(LIA), and at present. Our results show that the areas of Lewis Glacier and the Tyndall-I glacier system were 0.678 km^2 and 0.390 km^2, respectively, during the maximum of LIA. Those mean that the both glaciers have shrunken by 87.0% and 88.7%, respectively since the LIA. Area change ratios for each glacier were significantly larger in the period of 2000 through 2015 than the former periods, indicating that glacier recession has accelerated. Continuous ice loss in this region has been driven by rising temperature and fluctuating precipitation. Linear regression data for Lewis glacier show that mass balance sensitivity to dry season temperature was –315 mm w.e./℃, whereas the sensitivity to dry season precipitation was 5.2 mm w.e./mm. Our data also show that the ELA on the western slope of Mt. Kenya rose by 716-816 m from the LGM to the modern era, corresponding to that temperature rose by 5.2℃-6.5℃.展开更多
文摘To provide scientific basis for appraising natural resources in Mt. Namjagbarwa area, the migration characteristics of geochemical microelements, such as Zn, V, Ti, Pb, Ni, Cu, Cr, Co, Be and Ba, in the landscape zones of alpine scrub and meadow, the mountainous dark coniferous forest, the mountainous mixed broadleaf and coniferous forest, the mountainous quasi-subtropical semi-evergreen broadleaf forest, the mountainous subtropical evergreen broadleaf forest, and the valley quasi-tropical monsoon rainforest have been described in the paper.
文摘Introduction There are big disputes on the uplift of the Tibetan Plateau. Some scientists believe the plateau uplifted to its highest elevation by 14Ma BP,and it decreased in elevation afterward. The second idea about the uplift of the plateau was similar to the first one in tectonic theory, but they consider the time of C3 plant change to C4 in the South Asia, as the time when the plateau reached its highest elevation. This time is 8Ma BP. The third idea, the most Chinese scientists believed, the nearest uplift of the plateau took place since 3 4Ma BP. The occurrence of fault depression and gravel deposit with large thickness in the inner and the marge of the plateau represented the speed uplift. After the collision of the India plate and the Eurasia plateau by the 36Ma, the Tibetean area uplifted several times, but it had been planed to lower area. The plateau with 4500m elevation formed in the Quaternary. While our recent research in the Kunlun Pass area suggest , the nearest uplift occurred at the border of the Early and Middle Pleistocene, and before that time, the elevation of this area was no more than 1500 m.
文摘The origin of Molar Tooth(MT)carbonates has been argued for more than 100 years, which are a kind of Proterozoic carbonates especially composed of microsparite with ptygmatically folded and sheet-like structures. Biomarkers detected in the microcalcsparite from the Wanlong and Xingmincun formations in the Jilin-Liaoning area showed there are abundant normal alkanes, isoprenoids, hopanes, steranes, alkylmethylcyclohexanes, and alkylcyclohexanes, indicating a diversity of biological source: long-chain isoprenoids, the major components of chlorophyll, such as C 19, C 20, a kind of major biomarkers synthesized early by isoprenoid monomers; hopanes a type of characteristic biomarkers from prokaryote, such as archaebacteria and cyanobacteria; sterane a biomarker for eukaryote; and two kinds of alkanes with C 17, C 18 as the main peaks representing aquatic bacteria and with C 23, C 24 as the main peaks representing fungi, respectively. Biomarker analysis showed that MT is the result of bacterial and algal activities, which is a kind of organisms between aerobic and anaerobic bacteria, reproducing well in normal or slightly saline sea water under weak oxidation-reduction conditions, resulting in rapid deposition of calcite as microsparite due to some mechanisms.
文摘Songshan Mt. is one of the fiveholy mountains in China. In ancienttime it was named Waifang Mt.,Chonggao Mt., Yueshan Mt. AND Songshan Mt. Etc.. It was decided to be the central mountain in the Han Dynasty.
基金supported by the National Natural Science Foundation of China(Nos.91958210 and 41904075)。
文摘In shallow-water areas,the marine magnetotelluric(MT)method faces a challenge in the investigation of seabed conductivity structures due to electrical and magnetic noises induced by ocean waves,which seriously contaminate MT data.Ocean waves can affect electric and magnetic fields to different extents.In general,their influence on magnetic fields is considerably greater than that on electric fields.In this paper,a complex adaptive filter is adopted to reduce wave-induced magnetic noises in the frequency domain.The processing results of synthetic and measured MT data indicate that the proposed method can effectively reduce wave-induced magnetic noises and provide reliable apparent resistivity and phase data.
基金Supported by National Key Basic Research Program of China(973 Program)(No.3B813C254423)
文摘The Duobaoshan mine area in Heilongjiang is located in the northeast section of Xingmeng orogenic belt and is in the west side of Hegang Mountain-Heihe fault zone. There exist many deposits in this area,and its metallogenic conditions are superior,which has been one of the hotspots in geological prospecting and metallogenic research in Northeast China. On the basis of previous studies,the authors used the EH-4 electromagnetic imaging system to carry out the data acquisition of three survey lines in Woduhe Village,Duobaoshan Town,Nenjiang County. Through the analysis of apparent resistivity section under TE and TM polarization modes,integrating regional geological data,it is concluded that:(1) the electrical characteristics of the metal ore in this area show a relatively low resistance,and according to its resistivity difference with surrounding rocks,the geometrical structures and apparent resistivity parameters of the low resistivity bodies in the lower section of the survey line are defined,and the electrical anomalies can be identified;(2)faults F1 and F2 may have a good metallogenic environment,so they are recommended for further exploration;(3) low resistance metal ore bodies have good correlation with local small structures or faults,which may play an iconic role for the delineation of key target areas;(4) in the process of using apparent resistivity to define the geometric structures of ore bodies underground,comprehensive analysis integrating the advantages of TE and TM models should be carry out to achieve more reliable inversion results.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA19070302)the National Natural Science Foundation of China(Grant Nos.41501069,41601067)provided by the Foundation of the State Key Laboratory of Cryospheric Sciences(SKLCS)at Northwest Institute of Eco-Environment and Resources(NIEER),CAS(SKLCS-OP-2017-10)
文摘High-resolution imagery can be used to reconstruct former glacier boundaries through the identification of glacial erosional and sedimentary geomorphology. We employed moraine mapping and the accumulation–area ratio method(AAR), in conjunction with Landsat, Google Earth, and SRTM imagery, to reconstruct glacier boundaries and equilibrium-line altitudes(ELAs) for Mt. Kenya in the Last Glacial Maximum(LGM), the Little Ice Age(LIA), and at present. Our results show that the areas of Lewis Glacier and the Tyndall-I glacier system were 0.678 km^2 and 0.390 km^2, respectively, during the maximum of LIA. Those mean that the both glaciers have shrunken by 87.0% and 88.7%, respectively since the LIA. Area change ratios for each glacier were significantly larger in the period of 2000 through 2015 than the former periods, indicating that glacier recession has accelerated. Continuous ice loss in this region has been driven by rising temperature and fluctuating precipitation. Linear regression data for Lewis glacier show that mass balance sensitivity to dry season temperature was –315 mm w.e./℃, whereas the sensitivity to dry season precipitation was 5.2 mm w.e./mm. Our data also show that the ELA on the western slope of Mt. Kenya rose by 716-816 m from the LGM to the modern era, corresponding to that temperature rose by 5.2℃-6.5℃.
