A great amount of alkali-feldspar and alkaline granites have been found around Nenjiang, Northwest Lesser Xing’an Ranges, but their forming ages have been a controversial subject due to the lack of reliable geologica...A great amount of alkali-feldspar and alkaline granites have been found around Nenjiang, Northwest Lesser Xing’an Ranges, but their forming ages have been a controversial subject due to the lack of reliable geological and isotopic geochronological evidence. The zircon U-Pb isotopic dating results conducted in this note indicate that these granites emplaced at 260-290 Ma, coeval with the late stage of Late Paleozoic. Studies of mineralogy, petrology andgeochemistry show that they are post-orogenic A-type granites, and consist of the northeastern extension of huge belt of Late Paleozoic A-type granite along North Xinjiang-Southeast Mongolia-Central Inner Mongolia. Therefore, we can determine that the Suolunshan-Hegenshan-Zhalaite collisional suture zone extends northeastward to Heihe with the collision age of Carboniferous.展开更多
By using mathematical reasoning, this paper demonstrates the mathematical intervening principle: “Virtual disease is to fill his mother but real disease is to rush down his son” (虚则补其母, 实则泄其子) and “Strong...By using mathematical reasoning, this paper demonstrates the mathematical intervening principle: “Virtual disease is to fill his mother but real disease is to rush down his son” (虚则补其母, 实则泄其子) and “Strong inhibition of the same time, support the weak” (抑强扶弱) based on “Yin Yang Wu Xing” Theory in image mathematics of Traditional Chinese Mathematics (TCMath). We defined generalized relations and generalized reasoning, introduced the concept of steady multilateral systems with two non-compatibility relations, and discussed its energy properties. Later based on the intervention principle in image mathematics of TCMath and treated the research object of the image mathematics as a steady multilateral system, it has been proved that the mathematical intervening principle is true. The kernel of this paper is the existence and reasoning of the non-compatibility relations in steady multilateral systems, and it accords with the oriental thinking model.展开更多
The formation time of the Fengshuigouhe Group in the northwestern Lesser Xing＇an Range , NE China, remains controversial owing to the lake of the precise dating data. This article reports zircon U-Pb ages for the le...The formation time of the Fengshuigouhe Group in the northwestern Lesser Xing＇an Range , NE China, remains controversial owing to the lake of the precise dating data. This article reports zircon U-Pb ages for the leptynite and gneissic granitoids from the Fengshuigouhe Group in the northwestern Lesser Xing＇an Range. The aim is to constrain the formation time and prove- nance of Fengshuigouhe Group. Field observation indicates that the Fengshuigouhe Group consists of a suit of metamorphic rocks （leptynite） and gneissic granitoids intruding the leptynite, and that both of them are cut by late granitic pegmatite. Zircons from two leptynites are euhedral-subhedral in shape and display oscillatory zoning in CL （cathodeluminescence） images. These detrital zircons give weighted mean ages of 255, 291,321,361, 469, and 520 Ma. The youngest age of them is interpreted to maximum deposi- tional age of the protoliths of these leptynites. Zircons from gneissic granites are euhedral and subhedral in shape and exhibit typical oscillatory zoning in CL images. The dating results indicate that the gneissic granites were formed in the Early Jurassic （185~2 Ma）. Zircons from the late granitic pegmatite are sub- hedral in shape and exhibit two types in CL images： structureless and oscillatory zoning. The former gives a weighted mean age of 143~1 Ma, considered to represent the timing of crystallization of the pegmatite, the latter yield several groups of ages： 178, 273, 319, 482, 611, and 788 Ma, representing the crystallization age of inherited or captured zircons entrained by the pegmatite. Taken together, we conclude that the Fengshuigouhe Group in the northwestern Lesser Xing＇an Range formed between Late Paleozoic （255Ma） to Early Mesozoic （185 Ma）, rather than Neoproterozoic as previously believed, and that the sediments in the Fengshuigouhe Group were sourced directly from geological bodies in the study area and adjacent regions. KEY WORDS： the Lesser Xing＇an Range, Fengshuigouhe Group, formati展开更多
Field geological investigation and geochemical analysis are carried out on Baya＇ertuhushuo Gabbro in South Great Xing＇an Range. Field investigation reveals that the gabbro is a magmatic intrusion rather than a compo...Field geological investigation and geochemical analysis are carried out on Baya＇ertuhushuo Gabbro in South Great Xing＇an Range. Field investigation reveals that the gabbro is a magmatic intrusion rather than a component of an ophiolite suite as previously thought. Zircon laser ablation inductively coupled plasma mass spectroscopy （LA-ICP-MS） U-Pb dating indicates the gabbro was formed in 274-275 Ma, just as the widespread volcanic rocks of Dashizhai Formation （P1d）, monzogranites and miarolitic alkali-feldspar granites in the study area. The gabbro has SiO2 content between 47.23 wt% and 50.17 wt%, high MgO and FeOT contents of 6.95-11.29 wt% and 7.32- 12.24wt%, respectively, and it belongs to low-K tholeiitic series in the SiO2-K2O diagram. The Chondrite-normalized rare earth element （REE） patterns and primitive mantle-normalized spider diagrams of the gabbro are similar to those of Normal Mid-Ocean Ridge Basalt （N-MORB） except for the enrichment of large ion lithophfle elements （LILE）, such as Rb, Ba and K. In trace element tectonic discriminative diagrams, the samples are mainly plotted in the N-MORB field, and Zircon in situ Lu-Hf isotopic analysis also indicates the gabbro originated from depleted mantle. Through synthetic studies of the geochemical characteristics and petrogenesis of Baya＇ertuhushuo gabbro, volcanic rocks of Dashizhai Formation and granitoids in the area, it is suggested that the early Permian magmatism in the Xilinhot-Xiwuqi area formed in the tectonic setting of asthenosphere upwelling, which was caused by breaking-off of the subducted Paleo-Asian Ocean slab.展开更多
基金the National Natural Science Foundation of China (Grant No. 49872031)the Excellent Young Teachers and Doctor's Disciplines Foundation of the Ministry of Education of China (Grant No. 9518701).
文摘A great amount of alkali-feldspar and alkaline granites have been found around Nenjiang, Northwest Lesser Xing’an Ranges, but their forming ages have been a controversial subject due to the lack of reliable geological and isotopic geochronological evidence. The zircon U-Pb isotopic dating results conducted in this note indicate that these granites emplaced at 260-290 Ma, coeval with the late stage of Late Paleozoic. Studies of mineralogy, petrology andgeochemistry show that they are post-orogenic A-type granites, and consist of the northeastern extension of huge belt of Late Paleozoic A-type granite along North Xinjiang-Southeast Mongolia-Central Inner Mongolia. Therefore, we can determine that the Suolunshan-Hegenshan-Zhalaite collisional suture zone extends northeastward to Heihe with the collision age of Carboniferous.
文摘By using mathematical reasoning, this paper demonstrates the mathematical intervening principle: “Virtual disease is to fill his mother but real disease is to rush down his son” (虚则补其母, 实则泄其子) and “Strong inhibition of the same time, support the weak” (抑强扶弱) based on “Yin Yang Wu Xing” Theory in image mathematics of Traditional Chinese Mathematics (TCMath). We defined generalized relations and generalized reasoning, introduced the concept of steady multilateral systems with two non-compatibility relations, and discussed its energy properties. Later based on the intervention principle in image mathematics of TCMath and treated the research object of the image mathematics as a steady multilateral system, it has been proved that the mathematical intervening principle is true. The kernel of this paper is the existence and reasoning of the non-compatibility relations in steady multilateral systems, and it accords with the oriental thinking model.
基金supported by the National Natural Science Foundation of China(No.41072038)China Geological Survey(No.1212010070301)the Opening Foundation of the State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan
文摘The formation time of the Fengshuigouhe Group in the northwestern Lesser Xing＇an Range , NE China, remains controversial owing to the lake of the precise dating data. This article reports zircon U-Pb ages for the leptynite and gneissic granitoids from the Fengshuigouhe Group in the northwestern Lesser Xing＇an Range. The aim is to constrain the formation time and prove- nance of Fengshuigouhe Group. Field observation indicates that the Fengshuigouhe Group consists of a suit of metamorphic rocks （leptynite） and gneissic granitoids intruding the leptynite, and that both of them are cut by late granitic pegmatite. Zircons from two leptynites are euhedral-subhedral in shape and display oscillatory zoning in CL （cathodeluminescence） images. These detrital zircons give weighted mean ages of 255, 291,321,361, 469, and 520 Ma. The youngest age of them is interpreted to maximum deposi- tional age of the protoliths of these leptynites. Zircons from gneissic granites are euhedral and subhedral in shape and exhibit typical oscillatory zoning in CL images. The dating results indicate that the gneissic granites were formed in the Early Jurassic （185~2 Ma）. Zircons from the late granitic pegmatite are sub- hedral in shape and exhibit two types in CL images： structureless and oscillatory zoning. The former gives a weighted mean age of 143~1 Ma, considered to represent the timing of crystallization of the pegmatite, the latter yield several groups of ages： 178, 273, 319, 482, 611, and 788 Ma, representing the crystallization age of inherited or captured zircons entrained by the pegmatite. Taken together, we conclude that the Fengshuigouhe Group in the northwestern Lesser Xing＇an Range formed between Late Paleozoic （255Ma） to Early Mesozoic （185 Ma）, rather than Neoproterozoic as previously believed, and that the sediments in the Fengshuigouhe Group were sourced directly from geological bodies in the study area and adjacent regions. KEY WORDS： the Lesser Xing＇an Range, Fengshuigouhe Group, formati
基金supported by the State Key Program of National Natural Science of China(grant no.40739905)Special Projects of Investigation and Evaluation of Countrywide Strategic Petroleum Area Selection(grant no.XQ-2007-07)+1 种基金Science and Technology Project of Sinopec(grant no.GO800-06)the Fund for Basic Scientific Research of the Institute of Geology,Chinese Academy of Geological Sciences(grant no.J0920)
文摘Field geological investigation and geochemical analysis are carried out on Baya＇ertuhushuo Gabbro in South Great Xing＇an Range. Field investigation reveals that the gabbro is a magmatic intrusion rather than a component of an ophiolite suite as previously thought. Zircon laser ablation inductively coupled plasma mass spectroscopy （LA-ICP-MS） U-Pb dating indicates the gabbro was formed in 274-275 Ma, just as the widespread volcanic rocks of Dashizhai Formation （P1d）, monzogranites and miarolitic alkali-feldspar granites in the study area. The gabbro has SiO2 content between 47.23 wt% and 50.17 wt%, high MgO and FeOT contents of 6.95-11.29 wt% and 7.32- 12.24wt%, respectively, and it belongs to low-K tholeiitic series in the SiO2-K2O diagram. The Chondrite-normalized rare earth element （REE） patterns and primitive mantle-normalized spider diagrams of the gabbro are similar to those of Normal Mid-Ocean Ridge Basalt （N-MORB） except for the enrichment of large ion lithophfle elements （LILE）, such as Rb, Ba and K. In trace element tectonic discriminative diagrams, the samples are mainly plotted in the N-MORB field, and Zircon in situ Lu-Hf isotopic analysis also indicates the gabbro originated from depleted mantle. Through synthetic studies of the geochemical characteristics and petrogenesis of Baya＇ertuhushuo gabbro, volcanic rocks of Dashizhai Formation and granitoids in the area, it is suggested that the early Permian magmatism in the Xilinhot-Xiwuqi area formed in the tectonic setting of asthenosphere upwelling, which was caused by breaking-off of the subducted Paleo-Asian Ocean slab.
