Dating techniques including gypsum dissolution in water, iron hydroxide co-precipitation with uranium and thorium and mass spectrometric determination have been investigated in this note. The ages of the gypsum sample...Dating techniques including gypsum dissolution in water, iron hydroxide co-precipitation with uranium and thorium and mass spectrometric determination have been investigated in this note. The ages of the gypsum samples in a CK core from Luobubo lacustrine sediments are in the range of (12.85±0.21) kaBP (4 m distance from the top core) to (153.2 ± 7.2) kaBP (49 m distance from the top core) with the relative errors of ( 1.6%-±4.7%. It indicates that the sedimental environment of the CK core was situated in the middle-late Pleistocene and Holocene periods, corresponding to 1-6 stages of oxygen isotopes in the abyssal sediments and included much information from last inter-glacial to Holocene warm periods.展开更多
A high precision thermal ionization mass spectrometric (HP-TIMS) technique is used to determine 238U,234U,232Th,230Th concentrations and their ratios in whole rocks and minerals separated from Ouaternary Maanshan, Day...A high precision thermal ionization mass spectrometric (HP-TIMS) technique is used to determine 238U,234U,232Th,230Th concentrations and their ratios in whole rocks and minerals separated from Ouaternary Maanshan, Dayingshan and Heikongshan volcanic rocks of Tengchong volcanic field .Yunnan Province, China. The 238U-230Th isochrons are given, yielding four age values (227 ? 20) ka (D-1, Dayingshan), (79.6 ±5.5) ka (D-7, Dayingshan), (21.9 ± 3.0) ka (h-1, Heikongshan), and (7.5 ± 1.0) ka (M-1, Maanshan). The result is not only consistent with but also preciser than those measured by the K-Ar method and the alpha spectrometry U-series method, indicating that the HP-TIMS method is reliable and has high precision. Besides, a procedure of HP-TIMS analysis of young volcanic rocks in China is set up preliminarily.展开更多
I. INTRODUCTION Lithium as a nucleal material has been applied in nucleal industry extensively, The geologists are very interested in lithium isotopic compositions which are an important method for studying cosmology....I. INTRODUCTION Lithium as a nucleal material has been applied in nucleal industry extensively, The geologists are very interested in lithium isotopic compositions which are an important method for studying cosmology. Thus, it is essential to determine precisely and accurately the isotopic ratio of lithium. The large relative mass difference between the展开更多
Two national stalagmite standard （GBW04412, GBW04413） and one international coral standard （RKM4） have been determined by using thermal ionization mass spectrometry （TIMS） method. The values of （ 234 U/ 238 U）...Two national stalagmite standard （GBW04412, GBW04413） and one international coral standard （RKM4） have been determined by using thermal ionization mass spectrometry （TIMS） method. The values of （ 234 U/ 238 U） act , （ 230 Th/ 234 U） act and age are all consistent in error range with the standard values obtained by using α spectrometry.展开更多
基金This work was supported by the National Key Basis Research Project (Grant No. G19990434) the Innovative Project of the Chinese Academy of Sciences (Grant No. KZCX 1-y 05) and the Resources and Environment Basis Project of the University of Science an
文摘Dating techniques including gypsum dissolution in water, iron hydroxide co-precipitation with uranium and thorium and mass spectrometric determination have been investigated in this note. The ages of the gypsum samples in a CK core from Luobubo lacustrine sediments are in the range of (12.85±0.21) kaBP (4 m distance from the top core) to (153.2 ± 7.2) kaBP (49 m distance from the top core) with the relative errors of ( 1.6%-±4.7%. It indicates that the sedimental environment of the CK core was situated in the middle-late Pleistocene and Holocene periods, corresponding to 1-6 stages of oxygen isotopes in the abyssal sediments and included much information from last inter-glacial to Holocene warm periods.
文摘A high precision thermal ionization mass spectrometric (HP-TIMS) technique is used to determine 238U,234U,232Th,230Th concentrations and their ratios in whole rocks and minerals separated from Ouaternary Maanshan, Dayingshan and Heikongshan volcanic rocks of Tengchong volcanic field .Yunnan Province, China. The 238U-230Th isochrons are given, yielding four age values (227 ? 20) ka (D-1, Dayingshan), (79.6 ±5.5) ka (D-7, Dayingshan), (21.9 ± 3.0) ka (h-1, Heikongshan), and (7.5 ± 1.0) ka (M-1, Maanshan). The result is not only consistent with but also preciser than those measured by the K-Ar method and the alpha spectrometry U-series method, indicating that the HP-TIMS method is reliable and has high precision. Besides, a procedure of HP-TIMS analysis of young volcanic rocks in China is set up preliminarily.
文摘I. INTRODUCTION Lithium as a nucleal material has been applied in nucleal industry extensively, The geologists are very interested in lithium isotopic compositions which are an important method for studying cosmology. Thus, it is essential to determine precisely and accurately the isotopic ratio of lithium. The large relative mass difference between the
文摘Two national stalagmite standard （GBW04412, GBW04413） and one international coral standard （RKM4） have been determined by using thermal ionization mass spectrometry （TIMS） method. The values of （ 234 U/ 238 U） act , （ 230 Th/ 234 U） act and age are all consistent in error range with the standard values obtained by using α spectrometry.
