In the long Precambrian period, stromatolitic carbonate successions were very common. However, the non-stromatolitic carbonate succession that is marked by subtidal deposits shows a sharp contrast to the stromatolitic...In the long Precambrian period, stromatolitic carbonate successions were very common. However, the non-stromatolitic carbonate succession that is marked by subtidal deposits shows a sharp contrast to the stromatolitic carbonate succession. Both the non-stromatolitic and the stromatolitic carbonate successions are important clues for the further understanding of the evolving carbonate world of the Precambrian. The Mesoproterozoic Gaoyuzhuang Formation at the Qiangou section in northwestern suburb of Beijing is a set of more than 1000 m-thick carbonate strata that can be divided into four members （or subformations）, in which a non-stromatolitic carbonate succession marked by the scarcity of stromatolites makes up the third member of the formation. This non-stromatolitic carbonate succession can further be subdivided into three third-order sequences that are marked by the regular succession of sedimentary facies. In third-order sequences, a lot of subtidal carbonate meter-scale cycles made up of medium-bedded leiolite limestones and thin-bedded marls constitute their transgressive system tracts （TSTs） and the early high-stand system tracts （EHSTs）, a lot of meter- scale cycles made up by thin-bedded limestones and marls constitute their condensed sections （CSs）, and thick-bedded to massive dolomitic limestones or lime dolomites make up the late high-stand system tracts （LHSTs）. The particularly non-stromatolitic carbonate succession making up the third member of the Mesoproterozoic Gaoyuzhuang Formation at the Qiangou section might be the representative of the non-stromatolitic carbonate succession of the Precambrian because of its special lithological features and particular sedimentary structures, and its general sedimentary features are helpful and meaningful for the further understanding of the evolution rules of the sophisticate and evolving carbonate world of the Precambrian. The time scale of the Gaoyuzhuang Formation is deduced as that from 1600 Ma to 1400 Ma; thus, the non-stromatolitic sedimentary succession making up the third member of the Gaoyuzhuang Formation may demonstrate a stromatolite decline event occurring at ca. 1450 Ma of the Proterozoic besides other three events that occurred respectively at ca. 2000 Ma, ca. 1000 Ma and ca. 675 Ma. The forming duration of this non-stromatolitic sedimentary succession of the third member of the Gaoyuzhuang Formation can be generally correlated with a similar sedimentary succession in North America, i.e. a non-stromatolitic sedimentary succession of the Helena Formation of the Belt Supergroup, which suggests that the stromatolite decline occurring at ca. 1450 Ma might be a global event. Therefore, the non-stromatolitic sedimentary succession discussed in the paper provides an important example for further understanding of carbonate sedimentology in the Precambrian.展开更多
The fine structure of crust mantle transition zone in Yanqing Hailai(Yan Huai basin) basin has been analyzed and discussed by using the data of Yanqing Hailai deep seismic reflection profile and Beijing Huailai ...The fine structure of crust mantle transition zone in Yanqing Hailai(Yan Huai basin) basin has been analyzed and discussed by using the data of Yanqing Hailai deep seismic reflection profile and Beijing Huailai Fengzhen deep seismic sounding profile obtained respectively in 1992 and in 1993. The primary model is established based on CDP stacking profile. The phases of seismic refraction waves and wide angle reflection waves are analyzed, travel time inversion is carried out and 2 D ray tracing is computed. Synthetic seismograms are completed by using re flectivity method for waveform fitting of phases P M and P M′, they are reflection waves from both the upper and the lower boundaries of the crust mantle transition zone in this basin. The results show that the P M′ reflection waves are stronger at some points and come from the lower boundary of Moho discontinuity. It is confirmed and inter preted that the Moho discontinuity in Yanqing Hailai basin consists of a group of thin layers with alternatively higher and lower velocities.展开更多
On Feb.4,Jiang'an District's Yanqingli Street was fficially re-opened to the public.The street runs between Yiyuan Road and Sanyang Road within the 20-hectare design center of Wuhan known as"Sanyang Desig...On Feb.4,Jiang'an District's Yanqingli Street was fficially re-opened to the public.The street runs between Yiyuan Road and Sanyang Road within the 20-hectare design center of Wuhan known as"Sanyang Design Capital,"which is enclosed by Yiyuan Road,Zhongshan Avenue,Wufu Road,and Shengli Street.At the opening ceremony,more than 20 enterprises including Milan Design Week and Guangzhou Design Week signed contracts on the spot.展开更多
With Yanqing County as the study subject,land use and landscape pattern change were discussed by using transition matrix,gravity center model and landscape pattern indexes.Based on this,the correlation between them wa...With Yanqing County as the study subject,land use and landscape pattern change were discussed by using transition matrix,gravity center model and landscape pattern indexes.Based on this,the correlation between them was analyzed by using SPSS technology,taking transformation among the main land types as the dependent variable,and the elevation,slope ratio,distance to towns as the independent variables.In addition,the influences of policy factor,economic development and demographic factor on land use change were discussed.展开更多
Using the arrival times of 197 earthquakes well recorded by the Beijing Seismic Network and the China-Germany cooperative Yanqing Digital Seismic Array in the period from October of 2001 to December of 2005, we accura...Using the arrival times of 197 earthquakes well recorded by the Beijing Seismic Network and the China-Germany cooperative Yanqing Digital Seismic Array in the period from October of 2001 to December of 2005, we accurately relocate these earthquakes by the joint-inversion program for hypocentral position and 3-D velocity structure The distribution of hypocenters shows that there are two major seismic active belts in the northwestern Beijing. The first belt stretches from Qinghe, Wenquan to the NW direction and the second extends from Nankou, Changping to the ENE direction.展开更多
By use of S wave information from three component records of wide angle reflection/refraction Beijing Fengzhen DSS profile (340.0 km) and its adjacent area, several main S wave phases (wave groups) of the crust a...By use of S wave information from three component records of wide angle reflection/refraction Beijing Fengzhen DSS profile (340.0 km) and its adjacent area, several main S wave phases (wave groups) of the crust and the top of upper mantle have been picked up and identified with digital processing technique. With reference to the results from P wave interpretation, 2 D structures, including S wave velocity vS and Poisson ratio μ , are calculated. After a comprehensive study with information from near vertical reflection, geology and other geophysical explorations, the deep structural configuration of this region is presented and relevant inferences are drawn from the above result: crustal thickness along the profile tends to increase westwards, from 35.0 km at Shunyi to 42.0 km at Fengzhen; there exist three low velocity bodies in the lower crust east of Yanqing, in the middle crust below Yanqing Zhuolu and in the upper crust west of Tianzhen, respectively; from east to west, there is also a crust mantle transitional zone about 5.0～9.0 km thick; in most parts of the region, μ value is 0.25 in the upper and middle crust, 0.27 in the lower crust and 0.28 on top of the upper mantle, indicating that the upper and middle crust is characterized by brittleness, and the lower crust and top of upper mantle is characterized by ductility; between Yanqing Zhuolu, the low μ values of the upper crust suggest that cracks (or pores) grow in the rock masses which present a dry (or gas filled) state, while the high μ values in the middle crust may reflect a fluid filled (or partially fusion) state of the rock masses. On the basis of the characteristics of phases and lateral variation features of μ values, several deep seated faults in this region are ascertained. Most earthquakes occurred near these faults where μ values vary significantly, and concentrate in the brittle rock masses with low μ values.展开更多
The 2019 Beijing International Horticultural Exhibition in the city s Yanqing District, at the foot of the Great Wall, covers 503 hectares and promotes a greener lifestyle and more harmonious relationship between peop...The 2019 Beijing International Horticultural Exhibition in the city s Yanqing District, at the foot of the Great Wall, covers 503 hectares and promotes a greener lifestyle and more harmonious relationship between people and nature. More than 100 countries and international organizations are taking part in the global green spectacle that runs until October 7 and promotes the application of advanced technologies. Here, the Jiangsu Garden shows the Suzhou-style elements used to create an ethereal impression of poetic and picturesque splendor.展开更多
The China Pavilion at the 2019 Beijing International Horticultural Exhibition in Yanqing District on October 6.The expo closed on October 9, hailed as an overwhelming success. Since the opening in April, it had held 3...The China Pavilion at the 2019 Beijing International Horticultural Exhibition in Yanqing District on October 6.The expo closed on October 9, hailed as an overwhelming success. Since the opening in April, it had held 3,284 events and received 9.34 million visitors.展开更多
From balmy spring to golden autumn,the International Horticultural Exhibition 2019 in Beijing's northwestern suburban district of Yanqing,with over 100 distinctive gardens and exhibition areas,came to a close on O...From balmy spring to golden autumn,the International Horticultural Exhibition 2019 in Beijing's northwestern suburban district of Yanqing,with over 100 distinctive gardens and exhibition areas,came to a close on October 9,with a festive closing ceremony.展开更多
文摘In the long Precambrian period, stromatolitic carbonate successions were very common. However, the non-stromatolitic carbonate succession that is marked by subtidal deposits shows a sharp contrast to the stromatolitic carbonate succession. Both the non-stromatolitic and the stromatolitic carbonate successions are important clues for the further understanding of the evolving carbonate world of the Precambrian. The Mesoproterozoic Gaoyuzhuang Formation at the Qiangou section in northwestern suburb of Beijing is a set of more than 1000 m-thick carbonate strata that can be divided into four members （or subformations）, in which a non-stromatolitic carbonate succession marked by the scarcity of stromatolites makes up the third member of the formation. This non-stromatolitic carbonate succession can further be subdivided into three third-order sequences that are marked by the regular succession of sedimentary facies. In third-order sequences, a lot of subtidal carbonate meter-scale cycles made up of medium-bedded leiolite limestones and thin-bedded marls constitute their transgressive system tracts （TSTs） and the early high-stand system tracts （EHSTs）, a lot of meter- scale cycles made up by thin-bedded limestones and marls constitute their condensed sections （CSs）, and thick-bedded to massive dolomitic limestones or lime dolomites make up the late high-stand system tracts （LHSTs）. The particularly non-stromatolitic carbonate succession making up the third member of the Mesoproterozoic Gaoyuzhuang Formation at the Qiangou section might be the representative of the non-stromatolitic carbonate succession of the Precambrian because of its special lithological features and particular sedimentary structures, and its general sedimentary features are helpful and meaningful for the further understanding of the evolution rules of the sophisticate and evolving carbonate world of the Precambrian. The time scale of the Gaoyuzhuang Formation is deduced as that from 1600 Ma to 1400 Ma; thus, the non-stromatolitic sedimentary succession making up the third member of the Gaoyuzhuang Formation may demonstrate a stromatolite decline event occurring at ca. 1450 Ma of the Proterozoic besides other three events that occurred respectively at ca. 2000 Ma, ca. 1000 Ma and ca. 675 Ma. The forming duration of this non-stromatolitic sedimentary succession of the third member of the Gaoyuzhuang Formation can be generally correlated with a similar sedimentary succession in North America, i.e. a non-stromatolitic sedimentary succession of the Helena Formation of the Belt Supergroup, which suggests that the stromatolite decline occurring at ca. 1450 Ma might be a global event. Therefore, the non-stromatolitic sedimentary succession discussed in the paper provides an important example for further understanding of carbonate sedimentology in the Precambrian.
文摘The fine structure of crust mantle transition zone in Yanqing Hailai(Yan Huai basin) basin has been analyzed and discussed by using the data of Yanqing Hailai deep seismic reflection profile and Beijing Huailai Fengzhen deep seismic sounding profile obtained respectively in 1992 and in 1993. The primary model is established based on CDP stacking profile. The phases of seismic refraction waves and wide angle reflection waves are analyzed, travel time inversion is carried out and 2 D ray tracing is computed. Synthetic seismograms are completed by using re flectivity method for waveform fitting of phases P M and P M′, they are reflection waves from both the upper and the lower boundaries of the crust mantle transition zone in this basin. The results show that the P M′ reflection waves are stronger at some points and come from the lower boundary of Moho discontinuity. It is confirmed and inter preted that the Moho discontinuity in Yanqing Hailai basin consists of a group of thin layers with alternatively higher and lower velocities.
文摘On Feb.4,Jiang'an District's Yanqingli Street was fficially re-opened to the public.The street runs between Yiyuan Road and Sanyang Road within the 20-hectare design center of Wuhan known as"Sanyang Design Capital,"which is enclosed by Yiyuan Road,Zhongshan Avenue,Wufu Road,and Shengli Street.At the opening ceremony,more than 20 enterprises including Milan Design Week and Guangzhou Design Week signed contracts on the spot.
基金Supported by Important Directional Program Group of Knowledge Innovation Project of Chinese Academy of Sciences (KZCX2-YW-Q10-4)~~
文摘With Yanqing County as the study subject,land use and landscape pattern change were discussed by using transition matrix,gravity center model and landscape pattern indexes.Based on this,the correlation between them was analyzed by using SPSS technology,taking transformation among the main land types as the dependent variable,and the elevation,slope ratio,distance to towns as the independent variables.In addition,the influences of policy factor,economic development and demographic factor on land use change were discussed.
文摘Using the arrival times of 197 earthquakes well recorded by the Beijing Seismic Network and the China-Germany cooperative Yanqing Digital Seismic Array in the period from October of 2001 to December of 2005, we accurately relocate these earthquakes by the joint-inversion program for hypocentral position and 3-D velocity structure The distribution of hypocenters shows that there are two major seismic active belts in the northwestern Beijing. The first belt stretches from Qinghe, Wenquan to the NW direction and the second extends from Nankou, Changping to the ENE direction.
文摘By use of S wave information from three component records of wide angle reflection/refraction Beijing Fengzhen DSS profile (340.0 km) and its adjacent area, several main S wave phases (wave groups) of the crust and the top of upper mantle have been picked up and identified with digital processing technique. With reference to the results from P wave interpretation, 2 D structures, including S wave velocity vS and Poisson ratio μ , are calculated. After a comprehensive study with information from near vertical reflection, geology and other geophysical explorations, the deep structural configuration of this region is presented and relevant inferences are drawn from the above result: crustal thickness along the profile tends to increase westwards, from 35.0 km at Shunyi to 42.0 km at Fengzhen; there exist three low velocity bodies in the lower crust east of Yanqing, in the middle crust below Yanqing Zhuolu and in the upper crust west of Tianzhen, respectively; from east to west, there is also a crust mantle transitional zone about 5.0～9.0 km thick; in most parts of the region, μ value is 0.25 in the upper and middle crust, 0.27 in the lower crust and 0.28 on top of the upper mantle, indicating that the upper and middle crust is characterized by brittleness, and the lower crust and top of upper mantle is characterized by ductility; between Yanqing Zhuolu, the low μ values of the upper crust suggest that cracks (or pores) grow in the rock masses which present a dry (or gas filled) state, while the high μ values in the middle crust may reflect a fluid filled (or partially fusion) state of the rock masses. On the basis of the characteristics of phases and lateral variation features of μ values, several deep seated faults in this region are ascertained. Most earthquakes occurred near these faults where μ values vary significantly, and concentrate in the brittle rock masses with low μ values.
文摘The 2019 Beijing International Horticultural Exhibition in the city s Yanqing District, at the foot of the Great Wall, covers 503 hectares and promotes a greener lifestyle and more harmonious relationship between people and nature. More than 100 countries and international organizations are taking part in the global green spectacle that runs until October 7 and promotes the application of advanced technologies. Here, the Jiangsu Garden shows the Suzhou-style elements used to create an ethereal impression of poetic and picturesque splendor.
文摘The China Pavilion at the 2019 Beijing International Horticultural Exhibition in Yanqing District on October 6.The expo closed on October 9, hailed as an overwhelming success. Since the opening in April, it had held 3,284 events and received 9.34 million visitors.
文摘From balmy spring to golden autumn,the International Horticultural Exhibition 2019 in Beijing's northwestern suburban district of Yanqing,with over 100 distinctive gardens and exhibition areas,came to a close on October 9,with a festive closing ceremony.
