In this paper, the evolutional characteristics of palaeoclimate and oxidation-reduction conditions as well asacidity-alkalinity environment are discussed by means of the step-regression, cluster, optimal partitioning ...In this paper, the evolutional characteristics of palaeoclimate and oxidation-reduction conditions as well asacidity-alkalinity environment are discussed by means of the step-regression, cluster, optimal partitioning andcorrelation analyses of CaCO_3, C / P_2O_5, Fe^(2+) / Fe^(3+), pH and Eh values, taking the Xiaodukou section in theNihewan basin as an example. The CaCO_3, C / P_2O_5 and pH were calculated respectively using the optimalpartitioning method. Thus five cold zones and six warm zones as well as five reduction and six oxidation zoneswere distinguished. Then the inductive method was used to produce four numerical groups: 8.10, 8.3-8.4,8.6-8.7 and 8.9-8,97. The above-mentioned results are respectively based on CaCO_3 content, C/P_2O_5 andpH values. From Fig. 3, Tables 1 and 2 it can be seen that the Nihewan Beds were formed mainly under a re-duction and slightly alkaline environment of cold climate, with pH values of 8.3-8.4. Fig. 3 shows that bed 35is approximately near the boundary between the Brunhes and Matuyama polarity epochs, 0.73 Ma in age; bed26 is roughly near the Jaramillo event (base), 0.97 Ma in age; bed 18 coincides roughly with themagnetostratigraphic boundary of 2.00 Ma (?). Bed 13 may be the Pleistocene-Pliocene boundary, 2.48 Ma inage. Thus geochemical zones Ⅰ, Ⅱ, Ⅲ and Ⅳ include respectively cold zones 1; 2 and 3; 4; and 5.展开更多
Lying on the northwest of Nihewan Basin, Houjiayao Site was discovered 40 years ago. But there is still a controversy about the existence age and the living environment of Houjiayao ancient human. Based on the geologi...Lying on the northwest of Nihewan Basin, Houjiayao Site was discovered 40 years ago. But there is still a controversy about the existence age and the living environment of Houjiayao ancient human. Based on the geological investigations, electrical resistivity sounding and altitude measuring, authors of this paper attempt to do a research on stratigraphic structure and the development of the ancient river in Houjiayao Site, and to interpret the above problems. The results are as follows:(1) An ancient river, which came from Xionger Mountain in the north of the Site, developed in Houjiayao Site, and its width was more than 1 km. The ancient river formed before 240 ka B.P., and disappeared in the early stage of the late Pleistocene, and its developing history ran through the entire living stage of Houjiayao ancient human.(2) The Site cultural relics were not buried in the lacustrine facies, but in the oxbow lake sediments of the ancient river and clay layer which laid on the oxbow lake sediments unconformably during the period of 224-161 ka B.P., and it indicated that the Houjiayao ancient people lived here for as long as 60 ka years.(3) The Site looked like a wide armchair faced southeast, and it provided a relatively mild and comfortable environment for the ancient. The ancient river provided the ancient human with water, and the superior eco-environment also provided plentiful food for the ancient human. Xionger Mountain was not only the source of the ancient river, but also the producing area for high quality stone materials. The old river carried stone materials to the Site, making it easier to make stone implements. Hence, the ancient human, who lived in cold weather, were more likely to choose better habitats such as the Houjiayao Site near the ancient river.(4) The old river embedded in the lacustrine facies, so the content of silt was high, and it was feculent. And the water of the oxbow lake near Houjiayao Site was clear and slow. What's more, with plentiful plants, the oxbow lake was a preferred place for all kinds of animals to get food and water. But the geomorphologic features of this oxbow lake made it hard for animals to escape when faced with dangerous situations. So ancient human had a better chance to get food from hunting near the oxbow lake than in other areas.展开更多
By using the improved trace(50μg) Sr isotope analytical method the ^87Sr/^86Sr ratios of Xiaodukou foraminifera fossils were measured,giving a range of 0.71105-0.71274,apparently higher than the value of contemporane...By using the improved trace(50μg) Sr isotope analytical method the ^87Sr/^86Sr ratios of Xiaodukou foraminifera fossils were measured,giving a range of 0.71105-0.71274,apparently higher than the value of contemporaneous seawater(0.709087-0.709147)and also slightly higher than the average value of modern Yellow River(0.7111),demonstrating that the contemporaneous environment where Xiaodukou foraminifera inhabited was an inland lake.Detailed analyses of △ Sr values showed that there occurred an event responsible for environmental changes in the ancient Nihewan Lake area during the time(about 1.0Ma ago)when Xiaodukou foraminifera appeared.Because of strong evaporation the salinity of the lake would increase and a regional salt-water of brackish-water lacustrine environment would be produced,thus providing a suitable and inhabitable environment for foraminiferae.It is concluded that Xiaodukou foraminiferal fossil assemblaes belong to non-marine foraminiferal species.展开更多
Rock magnetic and magnetostratigraphic investigations on a lacustrine sequence in the Nihewan Basin, northern China, which bears the Cenjiawan Paleolithic site, indicate that the dominant magnetic mineral and remanenc...Rock magnetic and magnetostratigraphic investigations on a lacustrine sequence in the Nihewan Basin, northern China, which bears the Cenjiawan Paleolithic site, indicate that the dominant magnetic mineral and remanence carrier contained in the sediments is magnetite. While hematite co-exists with magnetite in some portions of the Cenjiawan sequence, where characteristic remanent magnetizations are carried by both magnetite and hematite. Measurements of anisotropy of magnetic susceptibility confirm that the Cenjiawan sequence has preserved the original sedimentary features and is suitable for magnetostratigraphic study. Paleomagnetic results indicate that the Cenjiawan Paleolithic site is formed just posterior to the Punaruu normal event, which is dated at about 1.1 Ma. Combined with the paleomagnetic results of the Donggutuo, Xiaochangliang and Majuangou sections, it is concluded that early humans were occupying the Nihewan Basin around 1.6, 1.3 and 1.1 Ma. This integrated result is significant to understanding the ability of migration and adaptation to the envi- ronment of early humans.展开更多
A new Early Pleistocene Paleolithic site was found in July 2001 in the Nihewan Ba-sin, Hebei Province. Totally 500 mammal specimens assigned to 21 species and 5 lithic artifacts were collected. The coexistence of Allo...A new Early Pleistocene Paleolithic site was found in July 2001 in the Nihewan Ba-sin, Hebei Province. Totally 500 mammal specimens assigned to 21 species and 5 lithic artifacts were collected. The coexistence of Allophaiomys deucalion, Borsodia chinensis and Yangia tingi provides important evidence of chronology. On the basis of the comparison of mammalian fauna, the date of Paleolithic artifacts is probably earlier than 1.8 MaBP, possibly 2.0 MaBP. This is the earliest evidence of hominid activity found so far in North China. The hominid at that time in the Nihewan Basin lived in an environment of arid grasslands with scattered trees of temperate zone. This discovery is significant to the study of human origin and cultural development.展开更多
Rock magnetic measurements of Nihewan sediments from Xujiayao section demonstrate that magnetite, hematite and maghemite are dominant remanent magnetization carriers. Monitoring the variations of magnetic susceptibili...Rock magnetic measurements of Nihewan sediments from Xujiayao section demonstrate that magnetite, hematite and maghemite are dominant remanent magnetization carriers. Monitoring the variations of magnetic susceptibility(MS) and saturating isothermal remanent magnetization(SIRM) at low temperature are the attractive ways of detecting the presence of magnetite, maghemitization and superparamagnetic grain sizes. Low-temperature MS investigations suggest that susceptibility enhancement for Xujiayao samples is mainly due to the remarkable presence of SD/MD magnetite to some degree though some magnetite grains have been partially oxidized at some depths. It is tentatively concluded that both SD/MD magnetite and hematite are of detrital origin and carry a characteristic remanent magnetization(ChRM), whereas maghemite can be attributed to be chemical origin, overprinting a reversed polarity component of Matuyama age.展开更多
The fluvio-lacustrine sedimentary sequences in the Nihewan Basin, northern China, are important for studying Quaternary land mammal evolution and Paleolithic settlements in the high-latitude temperate East Asia. Here ...The fluvio-lacustrine sedimentary sequences in the Nihewan Basin, northern China, are important for studying Quaternary land mammal evolution and Paleolithic settlements in the high-latitude temperate East Asia. Here we report new magnetostrati- graphic results that constrain age of the Hougou Paleolithic site in this basin. Magnetite and hematite were identified as carriers of the characteristic remanent magnetizations, with the former being dominant. Magnetic polarity stratigraphy shows that the Hougou sequence recorded the very late Matuyama reverse chron and the Brunhes normal chron. The age of the Hougou Paleolithic site was estimated to be 395 ka based on an averaged rate of sediment accumulation. The combination of our mag- netostratigraphy and previously published chronological data for early Paleolithic or human sites in the high-latitude northern China may document a persistent colonization of the hostile high-latitude areas of the eastern Old World during the mid- die-early Pleistocene.展开更多
This paper describes new fossils of Equus huanghoensis from an Early Pleistocene bed in Nihewan, Hebei Province, which confirms the classification of E. huanghoensis by Chinese researchers. The new fossils include a r...This paper describes new fossils of Equus huanghoensis from an Early Pleistocene bed in Nihewan, Hebei Province, which confirms the classification of E. huanghoensis by Chinese researchers. The new fossils include a relatively complete male skull and mandible with all upper and lower dentition, a broken female skull with fragment of mandible and a broken Mc III of Equus sp. The fossils were collected from the Yangshuizhan site of Nihewan. The age of the formation is about 1.6 Ma. The new materials verify some classification characteristics based on teeth published in previous descriptions. These characteristics include large teeth size, short protocone, and tilted protoloph and metaloph. We have added to these characteristics of large skull size, a developed protuberantia supramagna, pentagonal nuchal side, weak Pli cabaline, simple enamel plications; a series of new characteristics strikingly different from the other Equus horses. The broken Mc III is similar to Equus qingyangensis from Qingyang, Gansu.展开更多
Observation and experimental analysis of soluble salt deposit along four profiles across the strata deposited in Nihewan paleolake basin enabled us to recognize the nature and evolution stages of the Nihewan paleolake...Observation and experimental analysis of soluble salt deposit along four profiles across the strata deposited in Nihewan paleolake basin enabled us to recognize the nature and evolution stages of the Nihewan paleolake and its significance in stratigraphical division and pa-leo-environmental reconstruction. The Nihewan paleolake was at least a weak-saline to semi-saline lake and represents an intracontinental lake in the semi-arid region. The lower member of sedimentary strata in the paleolake contains gypsum layer and gypsum lamellae. Soluble salt is mainly composed of SO42- and Ca2+ ions, representing a trend of the paleolake evolvinginto a stage of sulfate lake. The upper member of the strata has predominantly Cl-, K+, and Na+ ions in soluble salt, indicating a starting development of the paleolake to chlorite lake, but no salt rock was deposited, indicating a drying trend of the area.展开更多
Columnar stromatolites have been discovered in two beds of the upper part of the Nihewan Formation, a series of lacustrine deposits. The structure of the stromatolites is characterized by alternation of light, intergr...Columnar stromatolites have been discovered in two beds of the upper part of the Nihewan Formation, a series of lacustrine deposits. The structure of the stromatolites is characterized by alternation of light, intergranular pore-rich laminae and dark, organic substance-rich laminae. Abundant filamentous algal remains have been discovered in stromatolite laminae, some of them are similar to the species present on the shore of the Caribbean Sea that are living in warmer climate than in the Nihewan area now. With the ESR and U-series age methods, it has been determined that the ages of the lower and upper stromatolite beds are about 130,000 and 93,000 a B. P. , respectively. Compared with many other geologic events taking place during the period in Northern China, we conclude that the two stromatolite beds were formed during the two warmer stages of the Last Interglacial.展开更多
The Nihewan Basin is a rift basin at the junction of northern Shanxi Province and northwestern Hebei Province in north China.The basin is known for its rich paleontological fossils and ancient human remains.There are ...The Nihewan Basin is a rift basin at the junction of northern Shanxi Province and northwestern Hebei Province in north China.The basin is known for its rich paleontological fossils and ancient human remains.There are also abundant soft-sediment deformation structures(SSDS)in the thick lacustrine sediments.Previously,most SSDS have been interpreted as ice-edge features or ignored entirely.Recently,the authors have carried out several field surveys in the Nihewan Basin and found that many SSDS are sandwiched between normal lacustrine strata at multiple sections.In the excavation pit at the 10th Locality of Maliang Site(ML10),10 horizontal SSDS layers and two vertically developed geological features have been identified.Based on genesis analysis and related criteria,these features are divided into two categories:cryoturbation-triggered SSDS and earthquake-triggered SSDS.Among them,a special type of ancient ice-wedge pseudomorph(SSDS-8)of ML10 is recognized in the basin for the first time.The other 9 horizontal SSDS are mainly caused by earthquake-triggered liquefaction and slumping.They can be further divided into 14 seismic event layers.These findings indicate that the tectonic activity in the Nihewan Basin is very strong and frequent,and there were cold periods in the geological history of the basin.At the same time,the SSDS with distinct morphological characteristics and stable horizontal distribution in the basin can be used as an important indicator of stratigraphic correlation.展开更多
There has been a significant debate about the nature and causes of the Pleistocene evolution of the Nihewan Basin, North China. We studied the eastern Nihewan Basin sedimentary facies at two main sites, Hutouliang and...There has been a significant debate about the nature and causes of the Pleistocene evolution of the Nihewan Basin, North China. We studied the eastern Nihewan Basin sedimentary facies at two main sites, Hutouliang and Donggou. A combination of field observations and measurements of sediment grain-size distribution was used to reconstruct the sequence of sedimentary environments since the middle Pleistocene, and optically-stimulated luminescence measurements were used to date the sediments. Our results indicate that a shallow lake occupied the basin center along the Sanggan River, probably lasting until -440 kyr ago before disappearing completely -340 kyr ago. It was succeeded by a phase of fluvial-dominated sediment accumulation which ended -30 kyr ago. We suggest that the formation of the gorge resulted from the relative uplift of the Niuxin Mountain along the Liulengshan fault -140 kyr ago. However, since -30 kyr ago the fault may have become inactive and the river downcutting near Shixia was no longer offset by the relative uplift, which caused a shift from deposition to denudation in the Nihewan Basin from then on. The disappearance of the paleolake -340 kyr ago may have been the culmination of the ongoing process of basin infilling.展开更多
Debate on depositional environment about foraminifera-rich strata in many Cenozoiccontinental basins in East China has existed for a long time. Research results achieved inrecent years show that it is difficult to dis...Debate on depositional environment about foraminifera-rich strata in many Cenozoiccontinental basins in East China has existed for a long time. Research results achieved inrecent years show that it is difficult to distinguish foraminiferal assemblages in modern saltylakes from those in weakly marine environments such as supratidal zone and lagoon.However, shell geochemistry may be an outlet for this problem because of great differencein chemical and isotopic compositions between lake water and sea water. So fossils ofNonion shansiensis (Evolutononion shangiensis N. Wang), which is a sole foraminiferal speciespreserved in upper part of bed 27 and bed 28 in Xiaodukou section in the Nihewen Ba-sin, were selected for Sr isotopic measuremnts. The sequence is larger than 12 m in展开更多
The Donggutuo site, situated in the east margin of Nihewan basin, is one of the most important Paleolithic sites in China, characterized by the longest excavation seasons and the most abundant cultural remains recover...The Donggutuo site, situated in the east margin of Nihewan basin, is one of the most important Paleolithic sites in China, characterized by the longest excavation seasons and the most abundant cultural remains recovered in the region. Based on well-constructed sporopollen, sediment grain size analysis, magnetic susceptibility, and iron oxide analysis of the 2000―2001 excavated section, four stages of environmental change in the Nihewan Beds are identified by the authors. The results indicate four major stages of environment and climate change from 1) warm and humid forest grass to 2) temperate and humid forest grass to 3) temperate and dry forest grass to 4) warm and humid forest, which is suitable for hominid occupation. The changes correspond to the stages of lake transgression and regression. The environment after the lake died out away has been cold and dry boschveld. The hominid activities at the site took place in the Early Pleistocene (1.10 Ma), which corresponds to the early three environmental stages. Therefore, it can be inferred that the early hominids adapted to the relatively low lake level episodes through activities involving sporadic stone tool making, procuring of raw materials for tools, concentrating stone artifacts, and hunting and butchering. In conclusion, the results will be of great significance to research regarding the relationship between hominid occupation and environmental changes as well as the adaptive behaviors of early humans at the Donggutuo site.展开更多
We conducted a detailed rock magnetic study on upper 80 m of Jing抏rwa core from the Nihewan basin. The results indicate that the sediments from Jing抏rwa core are suitable for relative paleointensity study, and anhys...We conducted a detailed rock magnetic study on upper 80 m of Jing抏rwa core from the Nihewan basin. The results indicate that the sediments from Jing抏rwa core are suitable for relative paleointensity study, and anhyster-etic remanent magnetization (ARM) can be used as the nor-malization parameter of the natural remanent magnetization (NRM). Our relative paleointensity data of upper 80 m of Jing抏rwa core provide a continuous record of the intensity variation during the last 0.8 Ma, which correlates well with the results from marine sediments cores in the Pacific Ocean. This means that the sediments records are reliable for rela-tive paleointensity of Earth抯 magnetic field, and suggests that these sediments have recorded the real changes of geo-magnetic field, which would provide a new method for re-gional stratigraphic correlation.展开更多
文摘In this paper, the evolutional characteristics of palaeoclimate and oxidation-reduction conditions as well asacidity-alkalinity environment are discussed by means of the step-regression, cluster, optimal partitioning andcorrelation analyses of CaCO_3, C / P_2O_5, Fe^(2+) / Fe^(3+), pH and Eh values, taking the Xiaodukou section in theNihewan basin as an example. The CaCO_3, C / P_2O_5 and pH were calculated respectively using the optimalpartitioning method. Thus five cold zones and six warm zones as well as five reduction and six oxidation zoneswere distinguished. Then the inductive method was used to produce four numerical groups: 8.10, 8.3-8.4,8.6-8.7 and 8.9-8,97. The above-mentioned results are respectively based on CaCO_3 content, C/P_2O_5 andpH values. From Fig. 3, Tables 1 and 2 it can be seen that the Nihewan Beds were formed mainly under a re-duction and slightly alkaline environment of cold climate, with pH values of 8.3-8.4. Fig. 3 shows that bed 35is approximately near the boundary between the Brunhes and Matuyama polarity epochs, 0.73 Ma in age; bed26 is roughly near the Jaramillo event (base), 0.97 Ma in age; bed 18 coincides roughly with themagnetostratigraphic boundary of 2.00 Ma (?). Bed 13 may be the Pleistocene-Pliocene boundary, 2.48 Ma inage. Thus geochemical zones Ⅰ, Ⅱ, Ⅲ and Ⅳ include respectively cold zones 1; 2 and 3; 4; and 5.
基金Sponsored by Science and Technology Support Program of Hebei Province(13277611D)
文摘Lying on the northwest of Nihewan Basin, Houjiayao Site was discovered 40 years ago. But there is still a controversy about the existence age and the living environment of Houjiayao ancient human. Based on the geological investigations, electrical resistivity sounding and altitude measuring, authors of this paper attempt to do a research on stratigraphic structure and the development of the ancient river in Houjiayao Site, and to interpret the above problems. The results are as follows:(1) An ancient river, which came from Xionger Mountain in the north of the Site, developed in Houjiayao Site, and its width was more than 1 km. The ancient river formed before 240 ka B.P., and disappeared in the early stage of the late Pleistocene, and its developing history ran through the entire living stage of Houjiayao ancient human.(2) The Site cultural relics were not buried in the lacustrine facies, but in the oxbow lake sediments of the ancient river and clay layer which laid on the oxbow lake sediments unconformably during the period of 224-161 ka B.P., and it indicated that the Houjiayao ancient people lived here for as long as 60 ka years.(3) The Site looked like a wide armchair faced southeast, and it provided a relatively mild and comfortable environment for the ancient. The ancient river provided the ancient human with water, and the superior eco-environment also provided plentiful food for the ancient human. Xionger Mountain was not only the source of the ancient river, but also the producing area for high quality stone materials. The old river carried stone materials to the Site, making it easier to make stone implements. Hence, the ancient human, who lived in cold weather, were more likely to choose better habitats such as the Houjiayao Site near the ancient river.(4) The old river embedded in the lacustrine facies, so the content of silt was high, and it was feculent. And the water of the oxbow lake near Houjiayao Site was clear and slow. What's more, with plentiful plants, the oxbow lake was a preferred place for all kinds of animals to get food and water. But the geomorphologic features of this oxbow lake made it hard for animals to escape when faced with dangerous situations. So ancient human had a better chance to get food from hunting near the oxbow lake than in other areas.
文摘By using the improved trace(50μg) Sr isotope analytical method the ^87Sr/^86Sr ratios of Xiaodukou foraminifera fossils were measured,giving a range of 0.71105-0.71274,apparently higher than the value of contemporaneous seawater(0.709087-0.709147)and also slightly higher than the average value of modern Yellow River(0.7111),demonstrating that the contemporaneous environment where Xiaodukou foraminifera inhabited was an inland lake.Detailed analyses of △ Sr values showed that there occurred an event responsible for environmental changes in the ancient Nihewan Lake area during the time(about 1.0Ma ago)when Xiaodukou foraminifera appeared.Because of strong evaporation the salinity of the lake would increase and a regional salt-water of brackish-water lacustrine environment would be produced,thus providing a suitable and inhabitable environment for foraminiferae.It is concluded that Xiaodukou foraminiferal fossil assemblaes belong to non-marine foraminiferal species.
基金supported by the National Natural Science Foundation of China(Grant Nos.20414930 and 40221402).
文摘Rock magnetic and magnetostratigraphic investigations on a lacustrine sequence in the Nihewan Basin, northern China, which bears the Cenjiawan Paleolithic site, indicate that the dominant magnetic mineral and remanence carrier contained in the sediments is magnetite. While hematite co-exists with magnetite in some portions of the Cenjiawan sequence, where characteristic remanent magnetizations are carried by both magnetite and hematite. Measurements of anisotropy of magnetic susceptibility confirm that the Cenjiawan sequence has preserved the original sedimentary features and is suitable for magnetostratigraphic study. Paleomagnetic results indicate that the Cenjiawan Paleolithic site is formed just posterior to the Punaruu normal event, which is dated at about 1.1 Ma. Combined with the paleomagnetic results of the Donggutuo, Xiaochangliang and Majuangou sections, it is concluded that early humans were occupying the Nihewan Basin around 1.6, 1.3 and 1.1 Ma. This integrated result is significant to understanding the ability of migration and adaptation to the envi- ronment of early humans.
文摘A new Early Pleistocene Paleolithic site was found in July 2001 in the Nihewan Ba-sin, Hebei Province. Totally 500 mammal specimens assigned to 21 species and 5 lithic artifacts were collected. The coexistence of Allophaiomys deucalion, Borsodia chinensis and Yangia tingi provides important evidence of chronology. On the basis of the comparison of mammalian fauna, the date of Paleolithic artifacts is probably earlier than 1.8 MaBP, possibly 2.0 MaBP. This is the earliest evidence of hominid activity found so far in North China. The hominid at that time in the Nihewan Basin lived in an environment of arid grasslands with scattered trees of temperate zone. This discovery is significant to the study of human origin and cultural development.
基金This work was supported by the National Natural Science Foundation of China (Grant No.49474218) The Norwegian MSc-Program financed the stay of Wang Xisheng in Norway for two years. We thank Dr. Harald Walderhaug, Dr. H. Stockhausen, and Dr. F. Hauge
文摘Rock magnetic measurements of Nihewan sediments from Xujiayao section demonstrate that magnetite, hematite and maghemite are dominant remanent magnetization carriers. Monitoring the variations of magnetic susceptibility(MS) and saturating isothermal remanent magnetization(SIRM) at low temperature are the attractive ways of detecting the presence of magnetite, maghemitization and superparamagnetic grain sizes. Low-temperature MS investigations suggest that susceptibility enhancement for Xujiayao samples is mainly due to the remarkable presence of SD/MD magnetite to some degree though some magnetite grains have been partially oxidized at some depths. It is tentatively concluded that both SD/MD magnetite and hematite are of detrital origin and carry a characteristic remanent magnetization(ChRM), whereas maghemite can be attributed to be chemical origin, overprinting a reversed polarity component of Matuyama age.
基金supported by the National Natural Science Foundation of China (Grant Nos. 40925012 and 40821091)the Ministry of Science and Technology of China (Grant No. 2007FY110200)the Chinese Academy of Sciences (Grant No. KZCX2-EW-117)
文摘The fluvio-lacustrine sedimentary sequences in the Nihewan Basin, northern China, are important for studying Quaternary land mammal evolution and Paleolithic settlements in the high-latitude temperate East Asia. Here we report new magnetostrati- graphic results that constrain age of the Hougou Paleolithic site in this basin. Magnetite and hematite were identified as carriers of the characteristic remanent magnetizations, with the former being dominant. Magnetic polarity stratigraphy shows that the Hougou sequence recorded the very late Matuyama reverse chron and the Brunhes normal chron. The age of the Hougou Paleolithic site was estimated to be 395 ka based on an averaged rate of sediment accumulation. The combination of our mag- netostratigraphy and previously published chronological data for early Paleolithic or human sites in the high-latitude northern China may document a persistent colonization of the hostile high-latitude areas of the eastern Old World during the mid- die-early Pleistocene.
基金National Natural Science Foundation of China(Grant Nos.41290253,41174057)the National Basic Research Program of China(Grant No.2013CB955901)
文摘This paper describes new fossils of Equus huanghoensis from an Early Pleistocene bed in Nihewan, Hebei Province, which confirms the classification of E. huanghoensis by Chinese researchers. The new fossils include a relatively complete male skull and mandible with all upper and lower dentition, a broken female skull with fragment of mandible and a broken Mc III of Equus sp. The fossils were collected from the Yangshuizhan site of Nihewan. The age of the formation is about 1.6 Ma. The new materials verify some classification characteristics based on teeth published in previous descriptions. These characteristics include large teeth size, short protocone, and tilted protoloph and metaloph. We have added to these characteristics of large skull size, a developed protuberantia supramagna, pentagonal nuchal side, weak Pli cabaline, simple enamel plications; a series of new characteristics strikingly different from the other Equus horses. The broken Mc III is similar to Equus qingyangensis from Qingyang, Gansu.
文摘Observation and experimental analysis of soluble salt deposit along four profiles across the strata deposited in Nihewan paleolake basin enabled us to recognize the nature and evolution stages of the Nihewan paleolake and its significance in stratigraphical division and pa-leo-environmental reconstruction. The Nihewan paleolake was at least a weak-saline to semi-saline lake and represents an intracontinental lake in the semi-arid region. The lower member of sedimentary strata in the paleolake contains gypsum layer and gypsum lamellae. Soluble salt is mainly composed of SO42- and Ca2+ ions, representing a trend of the paleolake evolvinginto a stage of sulfate lake. The upper member of the strata has predominantly Cl-, K+, and Na+ ions in soluble salt, indicating a starting development of the paleolake to chlorite lake, but no salt rock was deposited, indicating a drying trend of the area.
文摘Columnar stromatolites have been discovered in two beds of the upper part of the Nihewan Formation, a series of lacustrine deposits. The structure of the stromatolites is characterized by alternation of light, intergranular pore-rich laminae and dark, organic substance-rich laminae. Abundant filamentous algal remains have been discovered in stromatolite laminae, some of them are similar to the species present on the shore of the Caribbean Sea that are living in warmer climate than in the Nihewan area now. With the ESR and U-series age methods, it has been determined that the ages of the lower and upper stromatolite beds are about 130,000 and 93,000 a B. P. , respectively. Compared with many other geologic events taking place during the period in Northern China, we conclude that the two stromatolite beds were formed during the two warmer stages of the Last Interglacial.
基金financially supported by the National Natural Science Foundation of China(41772116)。
文摘The Nihewan Basin is a rift basin at the junction of northern Shanxi Province and northwestern Hebei Province in north China.The basin is known for its rich paleontological fossils and ancient human remains.There are also abundant soft-sediment deformation structures(SSDS)in the thick lacustrine sediments.Previously,most SSDS have been interpreted as ice-edge features or ignored entirely.Recently,the authors have carried out several field surveys in the Nihewan Basin and found that many SSDS are sandwiched between normal lacustrine strata at multiple sections.In the excavation pit at the 10th Locality of Maliang Site(ML10),10 horizontal SSDS layers and two vertically developed geological features have been identified.Based on genesis analysis and related criteria,these features are divided into two categories:cryoturbation-triggered SSDS and earthquake-triggered SSDS.Among them,a special type of ancient ice-wedge pseudomorph(SSDS-8)of ML10 is recognized in the basin for the first time.The other 9 horizontal SSDS are mainly caused by earthquake-triggered liquefaction and slumping.They can be further divided into 14 seismic event layers.These findings indicate that the tectonic activity in the Nihewan Basin is very strong and frequent,and there were cold periods in the geological history of the basin.At the same time,the SSDS with distinct morphological characteristics and stable horizontal distribution in the basin can be used as an important indicator of stratigraphic correlation.
基金supported by the Chinese Geological Survey(Grant No.12120113005600)the National Natural Science Foundation of China(Grant Nos.41472138&41371203)
文摘There has been a significant debate about the nature and causes of the Pleistocene evolution of the Nihewan Basin, North China. We studied the eastern Nihewan Basin sedimentary facies at two main sites, Hutouliang and Donggou. A combination of field observations and measurements of sediment grain-size distribution was used to reconstruct the sequence of sedimentary environments since the middle Pleistocene, and optically-stimulated luminescence measurements were used to date the sediments. Our results indicate that a shallow lake occupied the basin center along the Sanggan River, probably lasting until -440 kyr ago before disappearing completely -340 kyr ago. It was succeeded by a phase of fluvial-dominated sediment accumulation which ended -30 kyr ago. We suggest that the formation of the gorge resulted from the relative uplift of the Niuxin Mountain along the Liulengshan fault -140 kyr ago. However, since -30 kyr ago the fault may have become inactive and the river downcutting near Shixia was no longer offset by the relative uplift, which caused a shift from deposition to denudation in the Nihewan Basin from then on. The disappearance of the paleolake -340 kyr ago may have been the culmination of the ongoing process of basin infilling.
基金National Natural Science Foundation of China and President's Foundation of Chinese Academy of Sciences.
文摘Debate on depositional environment about foraminifera-rich strata in many Cenozoiccontinental basins in East China has existed for a long time. Research results achieved inrecent years show that it is difficult to distinguish foraminiferal assemblages in modern saltylakes from those in weakly marine environments such as supratidal zone and lagoon.However, shell geochemistry may be an outlet for this problem because of great differencein chemical and isotopic compositions between lake water and sea water. So fossils ofNonion shansiensis (Evolutononion shangiensis N. Wang), which is a sole foraminiferal speciespreserved in upper part of bed 27 and bed 28 in Xiaodukou section in the Nihewen Ba-sin, were selected for Sr isotopic measuremnts. The sequence is larger than 12 m in
基金Supported by the National Natural Science Foundation of China (Grant No. 40672119)Major Basic Research Projects of MST of China (Grant No. 2006CB-806400)+1 种基金Basic Scientific Special Program of MST of China (Grant No. 2007FY-110200)Natural Science Foundation of Beijing (Grant No. 5072017)
文摘The Donggutuo site, situated in the east margin of Nihewan basin, is one of the most important Paleolithic sites in China, characterized by the longest excavation seasons and the most abundant cultural remains recovered in the region. Based on well-constructed sporopollen, sediment grain size analysis, magnetic susceptibility, and iron oxide analysis of the 2000―2001 excavated section, four stages of environmental change in the Nihewan Beds are identified by the authors. The results indicate four major stages of environment and climate change from 1) warm and humid forest grass to 2) temperate and humid forest grass to 3) temperate and dry forest grass to 4) warm and humid forest, which is suitable for hominid occupation. The changes correspond to the stages of lake transgression and regression. The environment after the lake died out away has been cold and dry boschveld. The hominid activities at the site took place in the Early Pleistocene (1.10 Ma), which corresponds to the early three environmental stages. Therefore, it can be inferred that the early hominids adapted to the relatively low lake level episodes through activities involving sporadic stone tool making, procuring of raw materials for tools, concentrating stone artifacts, and hunting and butchering. In conclusion, the results will be of great significance to research regarding the relationship between hominid occupation and environmental changes as well as the adaptive behaviors of early humans at the Donggutuo site.
文摘We conducted a detailed rock magnetic study on upper 80 m of Jing抏rwa core from the Nihewan basin. The results indicate that the sediments from Jing抏rwa core are suitable for relative paleointensity study, and anhyster-etic remanent magnetization (ARM) can be used as the nor-malization parameter of the natural remanent magnetization (NRM). Our relative paleointensity data of upper 80 m of Jing抏rwa core provide a continuous record of the intensity variation during the last 0.8 Ma, which correlates well with the results from marine sediments cores in the Pacific Ocean. This means that the sediments records are reliable for rela-tive paleointensity of Earth抯 magnetic field, and suggests that these sediments have recorded the real changes of geo-magnetic field, which would provide a new method for re-gional stratigraphic correlation.
