This study is aimed at characterizing the organic matter preserved in the Triassic Lockatong formation deposited in the Newark Basin. On the basis of the TOC （Total Organic Carbon）, the Lockatong formation was depos...This study is aimed at characterizing the organic matter preserved in the Triassic Lockatong formation deposited in the Newark Basin. On the basis of the TOC （Total Organic Carbon）, the Lockatong formation was deposited in a reducing environment in the deep NW part of the basin, which is favorable to the accumulation of organic matter. However, the Lockatong formation of the SE border of the basin was deposited in oxic conditions that prevented the preservation of organic matter if there is any. The structuration of the basin into deep subsiding NW section due to the reactivation of the NE-SW striking faults and the development of anoxic conditions were favorable for the accumulation and preservation of the organic matter in the deep part of the basin.展开更多
Limited information is available about factors of soil organic carbon(SOC) preservation in soils along a climo-biosequence. The objective of this study was to evaluate the role of soil texture and mineralogy on preser...Limited information is available about factors of soil organic carbon(SOC) preservation in soils along a climo-biosequence. The objective of this study was to evaluate the role of soil texture and mineralogy on preservation of SOC in the topsoil and subsoil along a climo-biosequence in the Main Range of Peninsular Malaysia. Soil samples from the A and B-horizons of four representative soil profiles were subjected to particle-size fractionation and mineralogical analyses including X-ray diffraction and selective dissolution. The proportion of SOC in the 250-2000 μm fraction(SOC associated with coarse sand) decreased while the proportion of SOC in the <53 μm fraction(SOC associated with clay and silt)increased with depth. This reflected the importance of the fine mineral fractions of the soil matrix for SOC storage in the subsoil. Close relationships between the content of SOC in the <53 μm fraction and the content of poorly crystalline Fe oxides [oxalate-extractable Fe(Fe_o) – pyrophosphate-extractable Fe(Fe_p)] and poorly crystalline inorganic forms of Al [oxalateextractable Al(Al_o) – pyrophosphate-extractable Al(Al_p)] in the B-horizon indicated the importance of poorly crystalline Fe oxides and poorly crystalline aluminosilicates for the preservation of SOC in the Bhorizon. The increasing trend of Fe_o-Fe_p and Al_o-Al_p over elevation suggest that the importance of poorly crystalline Fe oxides and poorly crystalline aluminosilicates for the preservation of SOC in the Bhorizon increased with increasing elevation. This study demonstrates that regardless of differences in climate and vegetation along the studied climobiosequence, preservation of SOC in the subsoil depends on clay mineralogy.展开更多
文摘This study is aimed at characterizing the organic matter preserved in the Triassic Lockatong formation deposited in the Newark Basin. On the basis of the TOC （Total Organic Carbon）, the Lockatong formation was deposited in a reducing environment in the deep NW part of the basin, which is favorable to the accumulation of organic matter. However, the Lockatong formation of the SE border of the basin was deposited in oxic conditions that prevented the preservation of organic matter if there is any. The structuration of the basin into deep subsiding NW section due to the reactivation of the NE-SW striking faults and the development of anoxic conditions were favorable for the accumulation and preservation of the organic matter in the deep part of the basin.
基金Universiti Putra Malaysia (UPM)supported by the Research University Grant Scheme (RUGS) under Grant No. 01-02-12-1700RU (9327000) provided by UPM
文摘Limited information is available about factors of soil organic carbon(SOC) preservation in soils along a climo-biosequence. The objective of this study was to evaluate the role of soil texture and mineralogy on preservation of SOC in the topsoil and subsoil along a climo-biosequence in the Main Range of Peninsular Malaysia. Soil samples from the A and B-horizons of four representative soil profiles were subjected to particle-size fractionation and mineralogical analyses including X-ray diffraction and selective dissolution. The proportion of SOC in the 250-2000 μm fraction(SOC associated with coarse sand) decreased while the proportion of SOC in the <53 μm fraction(SOC associated with clay and silt)increased with depth. This reflected the importance of the fine mineral fractions of the soil matrix for SOC storage in the subsoil. Close relationships between the content of SOC in the <53 μm fraction and the content of poorly crystalline Fe oxides [oxalate-extractable Fe(Fe_o) – pyrophosphate-extractable Fe(Fe_p)] and poorly crystalline inorganic forms of Al [oxalateextractable Al(Al_o) – pyrophosphate-extractable Al(Al_p)] in the B-horizon indicated the importance of poorly crystalline Fe oxides and poorly crystalline aluminosilicates for the preservation of SOC in the Bhorizon. The increasing trend of Fe_o-Fe_p and Al_o-Al_p over elevation suggest that the importance of poorly crystalline Fe oxides and poorly crystalline aluminosilicates for the preservation of SOC in the Bhorizon increased with increasing elevation. This study demonstrates that regardless of differences in climate and vegetation along the studied climobiosequence, preservation of SOC in the subsoil depends on clay mineralogy.
