Spectrogram analysis of seven natural gamma-ray logging of Member 1 of the Qingshankou Formation （K2qn^1） and Member 1 and 2 of the Nenjiang Formation （K2n^1-2） of Late Cretaceous age in the Songliao Basin reveals...Spectrogram analysis of seven natural gamma-ray logging of Member 1 of the Qingshankou Formation （K2qn^1） and Member 1 and 2 of the Nenjiang Formation （K2n^1-2） of Late Cretaceous age in the Songliao Basin reveals sedimentary cyclicities controlled by Milankovitch climate periodicities. The recognition of Milankovitch cycles allows estimation of an average accumulation rate of ～7.55- 8.62 cm/ka for the K2qn^1 sections, and ～6.69-10.16 cm/ka for the K2n^1-2 sections. Two marine transgression events occurred during the deposition of K2qn^1 and K2n^1-2 and their ages are at ～0.74- 1.10 Ma and ～2.38-4.84 Ma, respectively. Identification of Milankoviteh cycles from fine-grained deep lake sedimentary rocks in the Songliao Basin may provide great potential for high-resolution stratigraphic subdivisions and correlations.展开更多
The Songliao Basin is the largest oil-bearing basin in China.In the absence of sufficient evidence,the possibility of seawater incursion(s) into the Songliao Basin remains controversial.Recently,we discovered relative...The Songliao Basin is the largest oil-bearing basin in China.In the absence of sufficient evidence,the possibility of seawater incursion(s) into the Songliao Basin remains controversial.Recently,we discovered relatively abundant foraminifera fossils from units 1 and 2 of the Nenjiang Formation of borehole SK-1.Benthic foraminifera (Gavlinella sp.,Anomalinoides sp.,Pullenia sp.,Haplophragmoides sp.,Karrorulina hokkaidoana,Clavulinoides sp.),as well as planktonic foraminifera (Archaeoglobigerina blowi,Archaeoglobigerina cretacea and Hedbergella flandrini),were identified.These fossils were widely distributed in the marine Cretaceous.According to the global distribution of the above-mentioned planktonic foraminifera,the age of these fossil bearing strata appears to be Late Coniacian to Santonian.More importantly,these foraminifera provide direct evidence for marine water incursions into the Songliao Basin during deposition of the Lower Nenjiang Formation.展开更多
Non-marine ostracodes, charophytes and palynomorphs are abundant in most Cretaceous lacustrine basins of Easl Asia. However, their ranges are not directly integrated with marine biota that defines the Cretaceous stage...Non-marine ostracodes, charophytes and palynomorphs are abundant in most Cretaceous lacustrine basins of Easl Asia. However, their ranges are not directly integrated with marine biota that defines the Cretaceous stages. Non-biotic events st, ch as magnetochrons and radiometric ages in these terrestrial deposits enable their correlation with marine strata. The SKI north and south compositcd cores in the Songliao Basin present a continuous section of Upper Cretaceous non-marine fossil and magneto- chron successions in superposed order. These chronostratigraphic events are integrated with marine events by an XIY graphic plot between the core data and a global database of Global Section and Stratotype Points （GSSP） and key reference sections. This plot projects stage boundaries in marine sections into the SKI section and interpolates numerical ages to the tirst and last occurrences of biota and to lithostratigraphic boundaries. This stratigraphic experiment tests and relines age calibrations based on both manual interpo- lation of depths to numerical ages and cyclostratigraphy. Ages derived by interpolation are similar and ages by cyclostratigraphy are older because stage boundaries are calibrated to a different age scale.展开更多
The suggestion that the colloidal-dispersion-gel (CDG) process is superior to normal polymer flooding is misleading and generally incorrect. Colloidal dispersion gels, in their present state of technological developme...The suggestion that the colloidal-dispersion-gel (CDG) process is superior to normal polymer flooding is misleading and generally incorrect. Colloidal dispersion gels, in their present state of technological development, should not be advocated as an improvement to, or substitute for, polymer flooding. Gels made from aluminum-citrate crosslinked polyacrylamides can act as conventional gels and provide effective conformance improvement in treating some types of excess water production problems if sound scientific and engineering principles are respected.展开更多
Cretaceous climate was warmer than today.The Songliao Basin contains one of the most important Late Cretaceous non-marine deposits in China for the research of the paleoenvironment and paleoclimate.This research is ba...Cretaceous climate was warmer than today.The Songliao Basin contains one of the most important Late Cretaceous non-marine deposits in China for the research of the paleoenvironment and paleoclimate.This research is based on core samples from the SK1(S)borehole.The strata sampled are the upper part of the Quantou Formation to member 2 of the Nenjiang Formation,where spores,pollen,dinoflagellates,and other microfossils are abundantly preserved.Based on analysis of the spores and pollen fossils from the core samples,the following six fossil assemblage zones have been recognized in ascending order:The Cicatricosisporites-Cyathidites-Pinuspollenites,Schizaeoisporites-Cyathidites-Classopollis,Cyathidites-Schizaeoisporites,Schizaeoisporites-Cyathidites-Proteacidites,Proteacidites-Cyathidites-Dictyotriletes,and the Lythraites-Callistipollenites-Schizaeoisporites zones.The six fossil zones range from the late Cenomanian to early Campanian.The Late Cretaceous dinoflagellate cysts in the Songliao Basin are of high abundance and low diversity.Specific phytoplankton types reflect salinity changes of the Songliao Lake.Paleoecology of the dinoflagellates suggests that sediments of members 2 and 3 of the Yaojia Formation(K2y2+3)were deposited in a freshwater environment,whereas members 2 and 3 of the Qingshankou Formation(K2q2+3)and members 1 and 2 of the Nenjiang Formation(K2n1+2)were deposited in freshwater to brackish water environments.Combined with the paleoecology of dinoflagellates and the palynomorph biozones,valuable information of the paleoclimate was provided.The quantitative analyses of spores and pollen fossils,such as vegetation type,climate type,and humidity type,diversity and dominance,indicate a relatively sub-humid,mid-subtropical paleoclimate,with slight climatic fluctuation and/or temporal change.展开更多
文摘Spectrogram analysis of seven natural gamma-ray logging of Member 1 of the Qingshankou Formation （K2qn^1） and Member 1 and 2 of the Nenjiang Formation （K2n^1-2） of Late Cretaceous age in the Songliao Basin reveals sedimentary cyclicities controlled by Milankovitch climate periodicities. The recognition of Milankovitch cycles allows estimation of an average accumulation rate of ～7.55- 8.62 cm/ka for the K2qn^1 sections, and ～6.69-10.16 cm/ka for the K2n^1-2 sections. Two marine transgression events occurred during the deposition of K2qn^1 and K2n^1-2 and their ages are at ～0.74- 1.10 Ma and ～2.38-4.84 Ma, respectively. Identification of Milankoviteh cycles from fine-grained deep lake sedimentary rocks in the Songliao Basin may provide great potential for high-resolution stratigraphic subdivisions and correlations.
基金supported by the National Basic Research Program of China (2006CB-701403)the National Natural Science Foundation of China (40872016)the Graduate Innovative Research Fundation of China University of Geosciences (Beijing)
文摘The Songliao Basin is the largest oil-bearing basin in China.In the absence of sufficient evidence,the possibility of seawater incursion(s) into the Songliao Basin remains controversial.Recently,we discovered relatively abundant foraminifera fossils from units 1 and 2 of the Nenjiang Formation of borehole SK-1.Benthic foraminifera (Gavlinella sp.,Anomalinoides sp.,Pullenia sp.,Haplophragmoides sp.,Karrorulina hokkaidoana,Clavulinoides sp.),as well as planktonic foraminifera (Archaeoglobigerina blowi,Archaeoglobigerina cretacea and Hedbergella flandrini),were identified.These fossils were widely distributed in the marine Cretaceous.According to the global distribution of the above-mentioned planktonic foraminifera,the age of these fossil bearing strata appears to be Late Coniacian to Santonian.More importantly,these foraminifera provide direct evidence for marine water incursions into the Songliao Basin during deposition of the Lower Nenjiang Formation.
基金Financial support was provided by the National Basic Research Program of China(973 Program,NO.2012CB822002)the National Natural Science Foundation of China(Project No.41172037)+1 种基金China Geological Survey(Project NO. 1212011120145)State Administration of Foreign Experts Affairs,China
文摘Non-marine ostracodes, charophytes and palynomorphs are abundant in most Cretaceous lacustrine basins of Easl Asia. However, their ranges are not directly integrated with marine biota that defines the Cretaceous stages. Non-biotic events st, ch as magnetochrons and radiometric ages in these terrestrial deposits enable their correlation with marine strata. The SKI north and south compositcd cores in the Songliao Basin present a continuous section of Upper Cretaceous non-marine fossil and magneto- chron successions in superposed order. These chronostratigraphic events are integrated with marine events by an XIY graphic plot between the core data and a global database of Global Section and Stratotype Points （GSSP） and key reference sections. This plot projects stage boundaries in marine sections into the SKI section and interpolates numerical ages to the tirst and last occurrences of biota and to lithostratigraphic boundaries. This stratigraphic experiment tests and relines age calibrations based on both manual interpo- lation of depths to numerical ages and cyclostratigraphy. Ages derived by interpolation are similar and ages by cyclostratigraphy are older because stage boundaries are calibrated to a different age scale.
文摘The suggestion that the colloidal-dispersion-gel (CDG) process is superior to normal polymer flooding is misleading and generally incorrect. Colloidal dispersion gels, in their present state of technological development, should not be advocated as an improvement to, or substitute for, polymer flooding. Gels made from aluminum-citrate crosslinked polyacrylamides can act as conventional gels and provide effective conformance improvement in treating some types of excess water production problems if sound scientific and engineering principles are respected.
基金supported by National Basic Research Program of China(Grant No.2012CB822002)National Natural Science Foundation of China(Grant No.41172037),China Geological Survey(Grant No.1212011120145)+1 种基金State Key Laboratory of Palaeobiology and Stratigraphy(Nanjing Institute of Geology and Palaeontology,CAS)(Grant No.123111)Fundamental Research Funds for the Central Universities(Grant No.2012011)
文摘Cretaceous climate was warmer than today.The Songliao Basin contains one of the most important Late Cretaceous non-marine deposits in China for the research of the paleoenvironment and paleoclimate.This research is based on core samples from the SK1(S)borehole.The strata sampled are the upper part of the Quantou Formation to member 2 of the Nenjiang Formation,where spores,pollen,dinoflagellates,and other microfossils are abundantly preserved.Based on analysis of the spores and pollen fossils from the core samples,the following six fossil assemblage zones have been recognized in ascending order:The Cicatricosisporites-Cyathidites-Pinuspollenites,Schizaeoisporites-Cyathidites-Classopollis,Cyathidites-Schizaeoisporites,Schizaeoisporites-Cyathidites-Proteacidites,Proteacidites-Cyathidites-Dictyotriletes,and the Lythraites-Callistipollenites-Schizaeoisporites zones.The six fossil zones range from the late Cenomanian to early Campanian.The Late Cretaceous dinoflagellate cysts in the Songliao Basin are of high abundance and low diversity.Specific phytoplankton types reflect salinity changes of the Songliao Lake.Paleoecology of the dinoflagellates suggests that sediments of members 2 and 3 of the Yaojia Formation(K2y2+3)were deposited in a freshwater environment,whereas members 2 and 3 of the Qingshankou Formation(K2q2+3)and members 1 and 2 of the Nenjiang Formation(K2n1+2)were deposited in freshwater to brackish water environments.Combined with the paleoecology of dinoflagellates and the palynomorph biozones,valuable information of the paleoclimate was provided.The quantitative analyses of spores and pollen fossils,such as vegetation type,climate type,and humidity type,diversity and dominance,indicate a relatively sub-humid,mid-subtropical paleoclimate,with slight climatic fluctuation and/or temporal change.
