The study on the interrelation between sea-level changes and biodiversity with its evolu-tion has great significance for understanding the impact of global changes on organic evolution and exploring the inherent laws ...The study on the interrelation between sea-level changes and biodiversity with its evolu-tion has great significance for understanding the impact of global changes on organic evolution and exploring the inherent laws of life-environment coevolution in geological history. In this paper, the stratigraphic distribution of fusulinacean fauna in the Carboniferous-Permian boundary section at Xikou, Zhen’an County, Shaanxi Province, is analyzed quantitatively, and the relationship between the species diversity of fusulinaceans and relative sea-level changes is discussed. As a whole, the spe-cies numbers of fusulinacean fauna experience a rapid increase and an obvious decline in Xikou, Zhen’an County, from the Late Carboniferous to the Early Permian. There is a significant increase in species diversity around the Carboniferous-Permian boundary, which is one of the biggest bio-events of the fusulinacean fauna, and represents the radiation of Pseudoschwagerininae subfamily in the studied area. Integrated fusulinacean species diversity into sequence stratigraphic framework, de-tailed study suggests that the species diversity of the fusulinaceans is closely related to its relative stratigraphic location, and is essentially controlled by the sea-level changes, especially by the high-frequency sea-level changes. Generally, the species diversity of fusulinaceans is low, and the number of first and last appearance datum is small in the lower unit of high-frequency depositional cycle formed during the quick rise of the sea level; whereas the species diversity of fusulinaceans is high, and the number of first and last appearance datum is large in the upper unit of high-frequency cycle formed during the slow fall of the sea level. Within the third-order depositional sequence, the species diversity of the fusulinaceans at the first flooding surfaces and the maximum flooding surfaces is low, and it increases upward. The fusulinacean species diversity is low within the transgressive systems track, and it is high within the highstand systems track. The second-order rise and fall in sea level coincide with the bloom and decline of high order taxa of fusulinaceans.展开更多
Analyses of the extinction process of fusulinacean in the Maokouan (Middle Permian) biotic crisis have revealed remarkable differences between taxa with various morphological features. Nankinellinids suffered a heavy ...Analyses of the extinction process of fusulinacean in the Maokouan (Middle Permian) biotic crisis have revealed remarkable differences between taxa with various morphological features. Nankinellinids suffered a heavy loss of species in the early stage of the Maokouan event. Schwagerinids and neoschwagerinids both showed a stepwise decrease in species diversity, but the pulses of species extinction occurred in different stages of the extinction process. The species extinction of verbeekinids happened primarily in the Late Maokouan.展开更多
The point at issue:The Kurosegawa Terrane is composed of continental fragments transecting Mesozoic terranes of accretionary complex in Southwest Japan(Fig.1).It is an attenuated tectonic sliver and considered to be a...The point at issue:The Kurosegawa Terrane is composed of continental fragments transecting Mesozoic terranes of accretionary complex in Southwest Japan(Fig.1).It is an attenuated tectonic sliver and considered to be allochthonous with respect to the main part of Southwest Japan.The problem of which continental block in the East Asian continental margin is the source of the Kurosegawa Terrane has puzzled Japanese geologists for many years.Firstly,we try to approach this issue based on the analysis of fusulinacean assemblage in accreted terranes composed of subduction complex in the Pacific Rim.Secondly,by applying the result of this analysis we try to locate the source of the continental fragments of the Kurosegawa Terrane.Thirdly,we try to prove its validity with a new paleomagnetic study.展开更多
The study area,Nan Province,northern Thailand is geotectonically situated within the Nan-Uttaradit Suture,the once back-arc basin between the Sukhothai Zone and Indochina Block.Permian Fusulinacean fauna from limeston...The study area,Nan Province,northern Thailand is geotectonically situated within the Nan-Uttaradit Suture,the once back-arc basin between the Sukhothai Zone and Indochina Block.Permian Fusulinacean fauna from limestone blocks within the suture has展开更多
A composite standard section (CSS) has been established for the Maokouan (≈Guadalupian) in Guizhou Province, southwestern China, which includes stratigraphical ranges of 179 fusulinacean species from five sections of...A composite standard section (CSS) has been established for the Maokouan (≈Guadalupian) in Guizhou Province, southwestern China, which includes stratigraphical ranges of 179 fusulinacean species from five sections of the Maokou Formation in this area. Based on statistical results of the first and last appearances of fusulinacean species in the CSS, three evolutionary radiations and four pulses of extinction, characterized by high rates of species origination and extinction significantly different from the rates of background evolution, are recognized in the Maokouan fusulinacean fauna. The evolutionary pattern of fusulinacean foraminifer suggests that the Maokouan mass extinction probably started at the middle Maokouan and dramatically intensified in the late Maokouan.展开更多
The rarefaction analysis has been conducted to test the species diversity changes of the Early and Middle Permian fusulinacean fauna in South China. The results reveal that the number of species dramatically increased...The rarefaction analysis has been conducted to test the species diversity changes of the Early and Middle Permian fusulinacean fauna in South China. The results reveal that the number of species dramatically increased since the earliest Permian and quickly reached the maximum value in the early Zisongian representing the highest species diversity for the whole Early and Middle Permian. The species diversity stabilized in the plateau through the Zisongian; however, it started to decline in the following Longlinian and sustained a longstanding low level during the mid-Early Permian. With the appearance of new fusulinacean taxa with septulum structures, the number of species raised again in the late-Early Permian, followed by a decline in the Middle Permian Neoschwagerina simplex zone. Although the species diversity increased apparently in the Kuhfengian, it never rebounded back to the same level as in the Early Permian. In the mid-Middle Permian, species diversity began to decrease continuously and led to the disappearance of most fusulinacean species by the end of the Middle Permian.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.40172014)the Chinese Academy of Sciences(Grant No.KZCX3-SW-143).
文摘The study on the interrelation between sea-level changes and biodiversity with its evolu-tion has great significance for understanding the impact of global changes on organic evolution and exploring the inherent laws of life-environment coevolution in geological history. In this paper, the stratigraphic distribution of fusulinacean fauna in the Carboniferous-Permian boundary section at Xikou, Zhen’an County, Shaanxi Province, is analyzed quantitatively, and the relationship between the species diversity of fusulinaceans and relative sea-level changes is discussed. As a whole, the spe-cies numbers of fusulinacean fauna experience a rapid increase and an obvious decline in Xikou, Zhen’an County, from the Late Carboniferous to the Early Permian. There is a significant increase in species diversity around the Carboniferous-Permian boundary, which is one of the biggest bio-events of the fusulinacean fauna, and represents the radiation of Pseudoschwagerininae subfamily in the studied area. Integrated fusulinacean species diversity into sequence stratigraphic framework, de-tailed study suggests that the species diversity of the fusulinaceans is closely related to its relative stratigraphic location, and is essentially controlled by the sea-level changes, especially by the high-frequency sea-level changes. Generally, the species diversity of fusulinaceans is low, and the number of first and last appearance datum is small in the lower unit of high-frequency depositional cycle formed during the quick rise of the sea level; whereas the species diversity of fusulinaceans is high, and the number of first and last appearance datum is large in the upper unit of high-frequency cycle formed during the slow fall of the sea level. Within the third-order depositional sequence, the species diversity of the fusulinaceans at the first flooding surfaces and the maximum flooding surfaces is low, and it increases upward. The fusulinacean species diversity is low within the transgressive systems track, and it is high within the highstand systems track. The second-order rise and fall in sea level coincide with the bloom and decline of high order taxa of fusulinaceans.
文摘Analyses of the extinction process of fusulinacean in the Maokouan (Middle Permian) biotic crisis have revealed remarkable differences between taxa with various morphological features. Nankinellinids suffered a heavy loss of species in the early stage of the Maokouan event. Schwagerinids and neoschwagerinids both showed a stepwise decrease in species diversity, but the pulses of species extinction occurred in different stages of the extinction process. The species extinction of verbeekinids happened primarily in the Late Maokouan.
文摘The point at issue:The Kurosegawa Terrane is composed of continental fragments transecting Mesozoic terranes of accretionary complex in Southwest Japan(Fig.1).It is an attenuated tectonic sliver and considered to be allochthonous with respect to the main part of Southwest Japan.The problem of which continental block in the East Asian continental margin is the source of the Kurosegawa Terrane has puzzled Japanese geologists for many years.Firstly,we try to approach this issue based on the analysis of fusulinacean assemblage in accreted terranes composed of subduction complex in the Pacific Rim.Secondly,by applying the result of this analysis we try to locate the source of the continental fragments of the Kurosegawa Terrane.Thirdly,we try to prove its validity with a new paleomagnetic study.
文摘The study area,Nan Province,northern Thailand is geotectonically situated within the Nan-Uttaradit Suture,the once back-arc basin between the Sukhothai Zone and Indochina Block.Permian Fusulinacean fauna from limestone blocks within the suture has
基金Project supported by the National Natural Science Foundation of China (Grant No. 49572075)the Ministry of Education of China (Grant No. 9528417).
文摘A composite standard section (CSS) has been established for the Maokouan (≈Guadalupian) in Guizhou Province, southwestern China, which includes stratigraphical ranges of 179 fusulinacean species from five sections of the Maokou Formation in this area. Based on statistical results of the first and last appearances of fusulinacean species in the CSS, three evolutionary radiations and four pulses of extinction, characterized by high rates of species origination and extinction significantly different from the rates of background evolution, are recognized in the Maokouan fusulinacean fauna. The evolutionary pattern of fusulinacean foraminifer suggests that the Maokouan mass extinction probably started at the middle Maokouan and dramatically intensified in the late Maokouan.
基金the National Natural Science Foundation of China(Grant Nos.40072008 , 40232024) the Major Basic Research Project of China(Grant No.G2000077700).
文摘The rarefaction analysis has been conducted to test the species diversity changes of the Early and Middle Permian fusulinacean fauna in South China. The results reveal that the number of species dramatically increased since the earliest Permian and quickly reached the maximum value in the early Zisongian representing the highest species diversity for the whole Early and Middle Permian. The species diversity stabilized in the plateau through the Zisongian; however, it started to decline in the following Longlinian and sustained a longstanding low level during the mid-Early Permian. With the appearance of new fusulinacean taxa with septulum structures, the number of species raised again in the late-Early Permian, followed by a decline in the Middle Permian Neoschwagerina simplex zone. Although the species diversity increased apparently in the Kuhfengian, it never rebounded back to the same level as in the Early Permian. In the mid-Middle Permian, species diversity began to decrease continuously and led to the disappearance of most fusulinacean species by the end of the Middle Permian.
