The Luanping Basin of northern Hebei, North China, is well known for its continuous nonmarine Lower Cretaceous deposits and the preservation of the Jehol Biota. However, there are still some controversies about the st...The Luanping Basin of northern Hebei, North China, is well known for its continuous nonmarine Lower Cretaceous deposits and the preservation of the Jehol Biota. However, there are still some controversies about the stratigraphic correlation in these regions. Here we report some advances on the study of the nonmarine ostracods of Luanping, focusing on its biostratigraphical utility. Preliminary results indicate that the nonmarine ostracods from Luanping Basin consist of 17 genera and around 44 species. The ostracod assemblages of the Dabeigou, Dadianzi and Xiguayuan formations of this Basin can be assigned to the Luanpingella-Ocrocypris-Eoparacypris (Late Valanginian-Early Hauterivian age), Cypridea-Timiriasevia-Daurina (Late Huaterivian-Barremian age) and Cypridea-Limnocypridea-Lycopterocypris (Aptian stage) zones, respectively. This temporary framework can be served as a stratigraphic correlation tool in northern Hebei, as well as contributed to a better understanding of the evolution of the Jehol Biota.展开更多
Sedimentary process research is of great significance for understanding the distribution and characteristics of sediments.Through the detailed observation and measurement of the Sangyuan outcrop in Luanping Basin,this...Sedimentary process research is of great significance for understanding the distribution and characteristics of sediments.Through the detailed observation and measurement of the Sangyuan outcrop in Luanping Basin,this paper studies the depositional process of the hyperpycnal flow deposits,and divides their depositional process into three phases,namely,acceleration,erosion and deceleration.In the acceleration phase,hyperpycnal flow begins to enter the basin nearby,and then speeds up gradually.Deposits developed in the acceleration phase are reverse.In addition,the original deposits become unstable and are taken away by hyperpycnal flows under the eroding force.As a result,there are a lot of mixture of red mud pebbles outside the basin and gray mud pebbles within the basin.In the erosion phase,the reverse deposits are eroded and become thinner or even disappear.Therefore,no reverse grading characteristic is found in the proximal major channel that is closer to the source,but it is still preserved in the middle branch channel that is far from the source.After entering the deceleration phase,normally grading deposits appear and cover previous deposits.The final deposits in the basin are special.Some are reverse,and others are normal.They are superimposed with each other under the action of hyperpycnal flow.The analysis of the Sangyuan outcrop demonstrates the sedimentary process and distribution of hyperpycnites,and reasonably explain the sedimentary characteristics of hyperpycnites.It is helpful to the prediction of oil and gas exploration targets in gravity flow deposits.展开更多
The diverse clam shrimp Nestoria-Keratestheria fauna is widely distributed in the Dabeigou Formation in northern Hebei and eastern Inner Mongolia of China. Its important component genus Magumbonia from the Dabeigou Fo...The diverse clam shrimp Nestoria-Keratestheria fauna is widely distributed in the Dabeigou Formation in northern Hebei and eastern Inner Mongolia of China. Its important component genus Magumbonia from the Dabeigou Formation in the Luanping Basin, northern Hebei, China, is revised on the basis of a scanning electron microscope （SEM） examination of the type species M.jingshangensis Wang, 1984, which revealed morphological features not recognized previously. These include coarse reticulation on the umbo and prominent growth lines ornamented with densely spaced, small tubercles and fine lirae.展开更多
The author proves the existence and movement of a deep-seated fraetural Zone located in the eenter zone of the diwa-type faulted basin in central Hebei Province. This deep-seated fraeturai zone tending in NNE directio...The author proves the existence and movement of a deep-seated fraetural Zone located in the eenter zone of the diwa-type faulted basin in central Hebei Province. This deep-seated fraeturai zone tending in NNE direction is a structural effect of the mtodle East Asin Grustobody in the Mexozoic-Cenozoic. This paper will diseuss the formation, evolution and the meehanism of the deep-seated fraetural zone, faulted basin and the buried hills as well as their relationships. The uthor expounds that the deep geological process is the major factor of the structural effect.展开更多
A paleomagnetic study of about 95 samples from 16 sites sampled in the Early Cretaceous in Luanping basin in Hebei Province was reported. Stepwise thermal demagnetization was used to isolate magnetic components. Most ...A paleomagnetic study of about 95 samples from 16 sites sampled in the Early Cretaceous in Luanping basin in Hebei Province was reported. Stepwise thermal demagnetization was used to isolate magnetic components. Most samples have a characteristic direction with a high temperature component above 500℃. The tectonic\|corrected data are D =347 8°, I =50 4°, α 95 =7.1°, and the corresponding pole position is at 76.1°N, 346.3°E, with dp =6.4°, dm =3 8°,paleolatitude λ =31.1°N. This result indicates a counterclockwise post\|Cretaceous rotation of 30.7°±9.8° with respect to the stable Ordos basin in the west of North China Block, and a non\|significant northward motion. This rotation could be related to local fault action or structural detachment, or regional NNW\|NWWward motion and collision of Kula\|Pacific plate with eastern China since the Early Cretaceous.展开更多
切沟体积是表征切沟侵蚀量、输水输沙能力的重要参数。笔者以冀西北山盆地区典型流域切沟为研究对象,使用Riegl三维激光扫描仪获取切沟点云数据,构建高分辨率DEM,提取切沟形态参数,分析切沟断面特征,构建并验证适宜的切沟体积估算模型...切沟体积是表征切沟侵蚀量、输水输沙能力的重要参数。笔者以冀西北山盆地区典型流域切沟为研究对象,使用Riegl三维激光扫描仪获取切沟点云数据,构建高分辨率DEM,提取切沟形态参数,分析切沟断面特征,构建并验证适宜的切沟体积估算模型。结果表明:1)切沟间的发育不均衡,不同切沟沟长、面积和体积相差较大,但同一参数在各个断面位置的参数值差别较小;2)面积、沟长和沟深与体积呈显著的正相关,相关系数较高,分别为0.949、0.870和0.814;3)基于V-L关系、V-A关系和V(A,D)关系建立对应的线性回归方程,其决定系数R 2分别为0.7706、0.9159和0.9748,模型验证结果显示,V(A,D)关系模型V=0.04653 A 1.499+24.08 D 1.916-44.26在预测冀西北山盆地区切沟体积上更有优势。研究结果可为大空间尺度切沟侵蚀定量模拟及制图提供理论和技术支持,为水土保持工程提供科学理论依据。展开更多
文摘The Luanping Basin of northern Hebei, North China, is well known for its continuous nonmarine Lower Cretaceous deposits and the preservation of the Jehol Biota. However, there are still some controversies about the stratigraphic correlation in these regions. Here we report some advances on the study of the nonmarine ostracods of Luanping, focusing on its biostratigraphical utility. Preliminary results indicate that the nonmarine ostracods from Luanping Basin consist of 17 genera and around 44 species. The ostracod assemblages of the Dabeigou, Dadianzi and Xiguayuan formations of this Basin can be assigned to the Luanpingella-Ocrocypris-Eoparacypris (Late Valanginian-Early Hauterivian age), Cypridea-Timiriasevia-Daurina (Late Huaterivian-Barremian age) and Cypridea-Limnocypridea-Lycopterocypris (Aptian stage) zones, respectively. This temporary framework can be served as a stratigraphic correlation tool in northern Hebei, as well as contributed to a better understanding of the evolution of the Jehol Biota.
基金the Scientific research and technology development project of Petro China(2021DJ5303)。
文摘Sedimentary process research is of great significance for understanding the distribution and characteristics of sediments.Through the detailed observation and measurement of the Sangyuan outcrop in Luanping Basin,this paper studies the depositional process of the hyperpycnal flow deposits,and divides their depositional process into three phases,namely,acceleration,erosion and deceleration.In the acceleration phase,hyperpycnal flow begins to enter the basin nearby,and then speeds up gradually.Deposits developed in the acceleration phase are reverse.In addition,the original deposits become unstable and are taken away by hyperpycnal flows under the eroding force.As a result,there are a lot of mixture of red mud pebbles outside the basin and gray mud pebbles within the basin.In the erosion phase,the reverse deposits are eroded and become thinner or even disappear.Therefore,no reverse grading characteristic is found in the proximal major channel that is closer to the source,but it is still preserved in the middle branch channel that is far from the source.After entering the deceleration phase,normally grading deposits appear and cover previous deposits.The final deposits in the basin are special.Some are reverse,and others are normal.They are superimposed with each other under the action of hyperpycnal flow.The analysis of the Sangyuan outcrop demonstrates the sedimentary process and distribution of hyperpycnites,and reasonably explain the sedimentary characteristics of hyperpycnites.It is helpful to the prediction of oil and gas exploration targets in gravity flow deposits.
基金supported by the Project of China Geological Survey (No.1212010610421)the Major Basic Research Projects of the Ministry of Science and Technology,China (National 973 Project No.2006CB701403)+3 种基金the National Natural Science Foundation of China (No.40572005,40632010,J0630967)JSPS Fellowship (ID No.L09522)State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing (No.073106,20082103) (SKLPS)The SEM micrographs were taken through the courtesy of the LEO 1530 VP facility of SKLPS.
文摘The diverse clam shrimp Nestoria-Keratestheria fauna is widely distributed in the Dabeigou Formation in northern Hebei and eastern Inner Mongolia of China. Its important component genus Magumbonia from the Dabeigou Formation in the Luanping Basin, northern Hebei, China, is revised on the basis of a scanning electron microscope （SEM） examination of the type species M.jingshangensis Wang, 1984, which revealed morphological features not recognized previously. These include coarse reticulation on the umbo and prominent growth lines ornamented with densely spaced, small tubercles and fine lirae.
文摘The author proves the existence and movement of a deep-seated fraetural Zone located in the eenter zone of the diwa-type faulted basin in central Hebei Province. This deep-seated fraeturai zone tending in NNE direction is a structural effect of the mtodle East Asin Grustobody in the Mexozoic-Cenozoic. This paper will diseuss the formation, evolution and the meehanism of the deep-seated fraetural zone, faulted basin and the buried hills as well as their relationships. The uthor expounds that the deep geological process is the major factor of the structural effect.
文摘A paleomagnetic study of about 95 samples from 16 sites sampled in the Early Cretaceous in Luanping basin in Hebei Province was reported. Stepwise thermal demagnetization was used to isolate magnetic components. Most samples have a characteristic direction with a high temperature component above 500℃. The tectonic\|corrected data are D =347 8°, I =50 4°, α 95 =7.1°, and the corresponding pole position is at 76.1°N, 346.3°E, with dp =6.4°, dm =3 8°,paleolatitude λ =31.1°N. This result indicates a counterclockwise post\|Cretaceous rotation of 30.7°±9.8° with respect to the stable Ordos basin in the west of North China Block, and a non\|significant northward motion. This rotation could be related to local fault action or structural detachment, or regional NNW\|NWWward motion and collision of Kula\|Pacific plate with eastern China since the Early Cretaceous.
文摘切沟体积是表征切沟侵蚀量、输水输沙能力的重要参数。笔者以冀西北山盆地区典型流域切沟为研究对象,使用Riegl三维激光扫描仪获取切沟点云数据,构建高分辨率DEM,提取切沟形态参数,分析切沟断面特征,构建并验证适宜的切沟体积估算模型。结果表明:1)切沟间的发育不均衡,不同切沟沟长、面积和体积相差较大,但同一参数在各个断面位置的参数值差别较小;2)面积、沟长和沟深与体积呈显著的正相关,相关系数较高,分别为0.949、0.870和0.814;3)基于V-L关系、V-A关系和V(A,D)关系建立对应的线性回归方程,其决定系数R 2分别为0.7706、0.9159和0.9748,模型验证结果显示,V(A,D)关系模型V=0.04653 A 1.499+24.08 D 1.916-44.26在预测冀西北山盆地区切沟体积上更有优势。研究结果可为大空间尺度切沟侵蚀定量模拟及制图提供理论和技术支持,为水土保持工程提供科学理论依据。
