This paper presents a biotite-calcic hornblende geothermometer which wasempirically calibrated based on the garnet-biotite geothermometer and thegarnet-plagioclase-hornblende-quartz geobarometer, in the ranges of 560-...This paper presents a biotite-calcic hornblende geothermometer which wasempirically calibrated based on the garnet-biotite geothermometer and thegarnet-plagioclase-hornblende-quartz geobarometer, in the ranges of 560-800 deg C (T) and 0.26-l.4GPa (P) using the data of metadolerite, amphibolite, metagabbro, and metapelite collected from theliterature. Biotite was treated as symmetric Fe-Mg-Al^VI-Ti quaternary solid solution, and calcichornblende was simplified as symmetric Fe-Mg binary solid solution. The resulting thermometer mayrebuild the input garnet-biotite temperatures well within an uncertainty of + - 50 deg C. Errors of+- 0.2 GPa for input pressure, along with analytical errors of = - 5 percent for the relevantmineral compositions, may lead to a random error of + - 16 deg C for this thermometer, so that thethermometer is almost independent of pressure estimates. The thermometer may clearly discriminatedifferent rocks of lower amphibolite, upper amphibolite and granulite facies on a high confidencelevel. It is assumed that there is a ferric iron content of 11.6 percent in biotite, and that theiron content in calcic hornblende may be calculated according to the method of Dale et al. (2000).This thermometer can be used for medium- to high-grade metabasites and metapelites.展开更多
Calcareous soils are those soils containing layers of carbonate accumulation formed by either secondary accumulation or inheritance of CaCO_3 from calcareous parent materials.These soils are widely distributed in arid...Calcareous soils are those soils containing layers of carbonate accumulation formed by either secondary accumulation or inheritance of CaCO_3 from calcareous parent materials.These soils are widely distributed in arid,semi-arid and even some humid climate environments.However,in the Chinese Soil Taxonomy(CST,3rd version),the soils that contain large amounts of CaCO_3 but do not meet requirements of Aridosols are classified as Hapli-Ustic Cambosols.This group also includes many non-calcareous soils and those soils strongly affected by secondary carbonate accumulation together with quite dissimilar soils in terms of their morphology and properties.This study was conducted to determine calcification patterns and calcic processes occurring in representative pedons of calcareous soils in northwestern Henan Province,China and to classify these soils in CST.A Calcic subgroup was proposed to add within the Hapli-Ustic Cambosols.A diagnostic key was also provided to separate this subgroup from the Typic subgroup.In this way the different calcification degrees of soils were better reflected in the classification,which should lead to more uniform interpretive groups for better soil management.展开更多
基金the China National Natural Science Foundation(grants40002017 , 40074022) wasalso under the auspices of the National Key Project for Basic Research +1 种基金 CAS Project for the Tibetan Research Project(KZ.-951-A1-204 , KZ95T-06) a China Geological Survey grant(J2.1.4).
文摘This paper presents a biotite-calcic hornblende geothermometer which wasempirically calibrated based on the garnet-biotite geothermometer and thegarnet-plagioclase-hornblende-quartz geobarometer, in the ranges of 560-800 deg C (T) and 0.26-l.4GPa (P) using the data of metadolerite, amphibolite, metagabbro, and metapelite collected from theliterature. Biotite was treated as symmetric Fe-Mg-Al^VI-Ti quaternary solid solution, and calcichornblende was simplified as symmetric Fe-Mg binary solid solution. The resulting thermometer mayrebuild the input garnet-biotite temperatures well within an uncertainty of + - 50 deg C. Errors of+- 0.2 GPa for input pressure, along with analytical errors of = - 5 percent for the relevantmineral compositions, may lead to a random error of + - 16 deg C for this thermometer, so that thethermometer is almost independent of pressure estimates. The thermometer may clearly discriminatedifferent rocks of lower amphibolite, upper amphibolite and granulite facies on a high confidencelevel. It is assumed that there is a ferric iron content of 11.6 percent in biotite, and that theiron content in calcic hornblende may be calculated according to the method of Dale et al. (2000).This thermometer can be used for medium- to high-grade metabasites and metapelites.
基金supported by the National Basic Research Program(973 Program) of China(No.2008FY110600)the National Natural Science Foundation of China(No.41371226)
文摘Calcareous soils are those soils containing layers of carbonate accumulation formed by either secondary accumulation or inheritance of CaCO_3 from calcareous parent materials.These soils are widely distributed in arid,semi-arid and even some humid climate environments.However,in the Chinese Soil Taxonomy(CST,3rd version),the soils that contain large amounts of CaCO_3 but do not meet requirements of Aridosols are classified as Hapli-Ustic Cambosols.This group also includes many non-calcareous soils and those soils strongly affected by secondary carbonate accumulation together with quite dissimilar soils in terms of their morphology and properties.This study was conducted to determine calcification patterns and calcic processes occurring in representative pedons of calcareous soils in northwestern Henan Province,China and to classify these soils in CST.A Calcic subgroup was proposed to add within the Hapli-Ustic Cambosols.A diagnostic key was also provided to separate this subgroup from the Typic subgroup.In this way the different calcification degrees of soils were better reflected in the classification,which should lead to more uniform interpretive groups for better soil management.
