The pore structures and controlling factors of several different Paleozoic shales from Southern China and their kerogens were studied using nitrogen adsorption and scanning electron microscopy methods. The results ind...The pore structures and controlling factors of several different Paleozoic shales from Southern China and their kerogens were studied using nitrogen adsorption and scanning electron microscopy methods. The results indicate that： 1） The specific surface area is 2.22-3.52 m2/g and has no correlation with the TOC content of the Permian Dalong Formation shales, nanopores are extremely undeveloped in the Dalong Formation kerogens, which have specific surface areas of 20.35-27.49 me/g; 2） the specific surface area of the Silurian Longmaxi Formation shales is in the range of 17.83-29.49 m2/g and is positively correlated with TOC content, the kerogens from the Longmaxi Formation have well-developed nanopores, with round or elliptical shapes, and the specific surface areas of these kerogens are as high as 279.84-300.3 m2/g; 3） for the Niutitang Formation shales, the specific surface area is 20.12-29.49 m2/grock and increases significantly with increasing TOC and smectite content. The Niuti- tang Formation kerogens develop a certain amount of nanopores with a specific surface area of 161.2 m2/g. Oil shale was also examined for comparison, and was found to have a specific surface area of 19.99 m2/g. Nanopores are rare in the Youganwo Formation kerogen, which has a specific surface area of only 5.54 m2/g, suggesting that the specific surface area of oil shale is due mainly to the presence of smectite and other clay minerals. The specific surface area and the number of pores present in shales are closely related to TOC, kerogen type and maturity, smectite content, and other factors. Low-maturity kerogen has very few nanopores and therefore has a very low specific surface area, whereas nanopores are abundant in mature to over- mature kerogen, leading to high specific surface areas. The Longmaxi Formation kerogen has more developed nanopores and a higher specific surface area than the Niutitang Formation kerogen, which may be due to differences in the kerogen type and maceral components. A high content of smectite may a展开更多
Clay minerals of surface sediments in the South China Sea （SCS） are analyzed with X-ray diffraction, and their transport is explored with a grain size trend analysis （GSTA） model. Results show that clay mineral ty...Clay minerals of surface sediments in the South China Sea （SCS） are analyzed with X-ray diffraction, and their transport is explored with a grain size trend analysis （GSTA） model. Results show that clay mineral types in various sedimentary environments have different sediment sources and transport routes. Sediments in the northern SCS （north of 20°N） between the southwest of Taiwan Island and the outer mouth of the Pearl River have high contents of illite and chlorite, which are derived mainly from sediments on Taiwan Island and/or the Yangtze River. Sediments from the Pearl River are characterized by high kaolinite and low smectite content, and most are distributed in the area between the mouth of the Pearl River and northeast of Hainan Island and transported vertically from the continental shelf to the slope. Characterized by high illite content, sediments from Kalimantan Island are transported toward the Nansha Trough. Sediments from Luzon Island are related with volcanic materials, and are transported westwards according to smectite distribution. On the Sunda Shelf, sediments from the Mekong River are transported southeast in the north while sediments from the Indonesian islands are transported northward in the south. Ascertaining surface sediment sources and their transport routes will not only improve understanding of modem transportation and depositional processes, but also aid paleoenvironmental and paleoclimatic analysis of the SCS.展开更多
基金supported by National Basic Research Program of China(Grant No.2012CB214704)Major National Science and Techno-logy Project(Grant No.2011ZX05008-002-20)National Natural Science Foundation of China(Grant No.4123058)
文摘The pore structures and controlling factors of several different Paleozoic shales from Southern China and their kerogens were studied using nitrogen adsorption and scanning electron microscopy methods. The results indicate that： 1） The specific surface area is 2.22-3.52 m2/g and has no correlation with the TOC content of the Permian Dalong Formation shales, nanopores are extremely undeveloped in the Dalong Formation kerogens, which have specific surface areas of 20.35-27.49 me/g; 2） the specific surface area of the Silurian Longmaxi Formation shales is in the range of 17.83-29.49 m2/g and is positively correlated with TOC content, the kerogens from the Longmaxi Formation have well-developed nanopores, with round or elliptical shapes, and the specific surface areas of these kerogens are as high as 279.84-300.3 m2/g; 3） for the Niutitang Formation shales, the specific surface area is 20.12-29.49 m2/grock and increases significantly with increasing TOC and smectite content. The Niuti- tang Formation kerogens develop a certain amount of nanopores with a specific surface area of 161.2 m2/g. Oil shale was also examined for comparison, and was found to have a specific surface area of 19.99 m2/g. Nanopores are rare in the Youganwo Formation kerogen, which has a specific surface area of only 5.54 m2/g, suggesting that the specific surface area of oil shale is due mainly to the presence of smectite and other clay minerals. The specific surface area and the number of pores present in shales are closely related to TOC, kerogen type and maturity, smectite content, and other factors. Low-maturity kerogen has very few nanopores and therefore has a very low specific surface area, whereas nanopores are abundant in mature to over- mature kerogen, leading to high specific surface areas. The Longmaxi Formation kerogen has more developed nanopores and a higher specific surface area than the Niutitang Formation kerogen, which may be due to differences in the kerogen type and maceral components. A high content of smectite may a
基金Supported by the National Natural Science Foundation of China (No. 40631007)the National Basic Research Program of China (973 Program, Nos. 2007CB819505, 2009CB219502)+3 种基金the Ministry of Science and Technology of China (2006BAB19B03)the Knowledge Innovation Program of Chinese Academy of Sciences (Nos. SQ200713 and LYQY200704)the Open Fund of the Key Laboratory of Marginal Sea Geology, Chinese Academy of Sciences (No. MSGL08-16)the Open Fund of the Key Laboratory of Marine Geology and Environment, Chinese Academy of Sciences (No. MGE2008KG08)
文摘Clay minerals of surface sediments in the South China Sea （SCS） are analyzed with X-ray diffraction, and their transport is explored with a grain size trend analysis （GSTA） model. Results show that clay mineral types in various sedimentary environments have different sediment sources and transport routes. Sediments in the northern SCS （north of 20°N） between the southwest of Taiwan Island and the outer mouth of the Pearl River have high contents of illite and chlorite, which are derived mainly from sediments on Taiwan Island and/or the Yangtze River. Sediments from the Pearl River are characterized by high kaolinite and low smectite content, and most are distributed in the area between the mouth of the Pearl River and northeast of Hainan Island and transported vertically from the continental shelf to the slope. Characterized by high illite content, sediments from Kalimantan Island are transported toward the Nansha Trough. Sediments from Luzon Island are related with volcanic materials, and are transported westwards according to smectite distribution. On the Sunda Shelf, sediments from the Mekong River are transported southeast in the north while sediments from the Indonesian islands are transported northward in the south. Ascertaining surface sediment sources and their transport routes will not only improve understanding of modem transportation and depositional processes, but also aid paleoenvironmental and paleoclimatic analysis of the SCS.
