It was conducted the comparison of palynological assemblages of the Middle Tsagayan,Upper Tsagayan subformations,Furao and Wuyun formations from Zeya-Bureya Basin of Amur (Heilongjiang) River region with assemblages o...It was conducted the comparison of palynological assemblages of the Middle Tsagayan,Upper Tsagayan subformations,Furao and Wuyun formations from Zeya-Bureya Basin of Amur (Heilongjiang) River region with assemblages obtained from the marine deposits of Northeast Russia,Sakhalin,Kuril,and Hokkaido Islands,dated by ammonites,foraminifers and other invertebrates. Based on detail correlation,the geological age of the terrestrial beds was defined. The guide fossils are recognized Marsypiletes cretacea,Tricolpites variexi- nus,Aquilapollenites conatus,A. stelkii,A. rombicus,Integricorpus bellum,Pseudointegricorpus clarireticula- tus,Triprojectus amoenus,Orbiculapollis lucidus,Wodehouseia aspera,Quercoidites minor,which had last oc- currence in the late Maastrichtian. The Danian palynofloras usually are dominated by Triatriopollenites plicoides and T. confusus. The species Anacolosidites subtrudens,Aquilapollenites proceros,A. spinulosus have last occurrence in the Danian. The K-T (K-Pg) boundary in the terrestrial deposits is defined in the base of the Upper Tsagayan Subformation and the base of the lower part of the Wuyun Formation. The latter is represented by aleuropelite to fine-grained sandstones. The change of taxonomical composition of palynospectra in similar environments could be determined by real change of flora at the Mesozoic and Cenozoic boundary,but not by changes of lithological facies or depositional environment,generally.展开更多
In this paper we discuss the seismogenic structures of the two earthquakes occurring in the Beibu Gulf waters,based on the investigation of geological structure,faults,geophysical fields,seismicity and earthquake foca...In this paper we discuss the seismogenic structures of the two earthquakes occurring in the Beibu Gulf waters,based on the investigation of geological structure,faults,geophysical fields,seismicity and earthquake focal mechanism.The results show that the NEE trending faults along the boundary of the Wushi depression are the dominating seismogenic structures,and the NW trending faults are the key factors of stress concentration.The results also show that high seismicity has a significant relationship with the late Cenozoic deposition center in the Beibu Gulf,and their NE-NEE trending boundary faults are important to the identification of seismogenic structures.The special arcuate fault segment or the intersection point of the NW trending faults and NE-NEE trending boundary faults is a possible location of future earthquakes.展开更多
基金financial supports given by the NSFC(China,Projects 30220130698,40842002)the Presidium FEBRAS(grant#09-I-P15-02)
文摘It was conducted the comparison of palynological assemblages of the Middle Tsagayan,Upper Tsagayan subformations,Furao and Wuyun formations from Zeya-Bureya Basin of Amur (Heilongjiang) River region with assemblages obtained from the marine deposits of Northeast Russia,Sakhalin,Kuril,and Hokkaido Islands,dated by ammonites,foraminifers and other invertebrates. Based on detail correlation,the geological age of the terrestrial beds was defined. The guide fossils are recognized Marsypiletes cretacea,Tricolpites variexi- nus,Aquilapollenites conatus,A. stelkii,A. rombicus,Integricorpus bellum,Pseudointegricorpus clarireticula- tus,Triprojectus amoenus,Orbiculapollis lucidus,Wodehouseia aspera,Quercoidites minor,which had last oc- currence in the late Maastrichtian. The Danian palynofloras usually are dominated by Triatriopollenites plicoides and T. confusus. The species Anacolosidites subtrudens,Aquilapollenites proceros,A. spinulosus have last occurrence in the Danian. The K-T (K-Pg) boundary in the terrestrial deposits is defined in the base of the Upper Tsagayan Subformation and the base of the lower part of the Wuyun Formation. The latter is represented by aleuropelite to fine-grained sandstones. The change of taxonomical composition of palynospectra in similar environments could be determined by real change of flora at the Mesozoic and Cenozoic boundary,but not by changes of lithological facies or depositional environment,generally.
基金funded under the special project of earthquake study(200708003) under the National Key Technology R&D Program (2006BAC13B01),China
文摘In this paper we discuss the seismogenic structures of the two earthquakes occurring in the Beibu Gulf waters,based on the investigation of geological structure,faults,geophysical fields,seismicity and earthquake focal mechanism.The results show that the NEE trending faults along the boundary of the Wushi depression are the dominating seismogenic structures,and the NW trending faults are the key factors of stress concentration.The results also show that high seismicity has a significant relationship with the late Cenozoic deposition center in the Beibu Gulf,and their NE-NEE trending boundary faults are important to the identification of seismogenic structures.The special arcuate fault segment or the intersection point of the NW trending faults and NE-NEE trending boundary faults is a possible location of future earthquakes.
