Global change has become a hot spot in Quaternary geology, and high\|precision, high\|sensitivity dating is also an urgent problem which needs to be solved. This paper presents some achievements in U\|series dating of...Global change has become a hot spot in Quaternary geology, and high\|precision, high\|sensitivity dating is also an urgent problem which needs to be solved. This paper presents some achievements in U\|series dating of marine corals by thermal ionization mass spectrometry (TIMS) and its application to the study of paleo\|environments. Recently, coral samples were determined for their ages on a MAT\|262 mass spectrometer and satisfactory results have been obtained.展开更多
Using the isotopic diluting and thermal ionization mass spectrometric (TIMS) technique, the U-series dating procedure was established on the basis of measurement of national standard GBW04412. With this highly precise...Using the isotopic diluting and thermal ionization mass spectrometric (TIMS) technique, the U-series dating procedure was established on the basis of measurement of national standard GBW04412. With this highly precise technique the Holocene corals from the South China Sea were dated. Comparison between this method and α-spectrometry was made. The results show that a thriving period of corals in the South China Sea appeared at 6 800—5 800 a BP, during which the paleosea level was the higher than at present in the Holecene.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
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
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
The discovery of abrupt paleo\|climate change events and the prediction of environmental changes in the future time have raised an urgent request for high\|resolution paleo\|environmental records. This paper reviews t...The discovery of abrupt paleo\|climate change events and the prediction of environmental changes in the future time have raised an urgent request for high\|resolution paleo\|environmental records. This paper reviews the progress made in chronology and paleo\|environment of stalagmites from karst caves in China and presents some of the results of TIMS\|U\|series dating of stalagmites composed of secondary carbonates, taken from the Dongge, Longquan and Yamen karst caves in Libo County and the Qixing karst cave in Duyun, Guizhou Province, on a MAT\|262 mass spectrometer.展开更多
文摘Global change has become a hot spot in Quaternary geology, and high\|precision, high\|sensitivity dating is also an urgent problem which needs to be solved. This paper presents some achievements in U\|series dating of marine corals by thermal ionization mass spectrometry (TIMS) and its application to the study of paleo\|environments. Recently, coral samples were determined for their ages on a MAT\|262 mass spectrometer and satisfactory results have been obtained.
文摘Using the isotopic diluting and thermal ionization mass spectrometric (TIMS) technique, the U-series dating procedure was established on the basis of measurement of national standard GBW04412. With this highly precise technique the Holocene corals from the South China Sea were dated. Comparison between this method and α-spectrometry was made. The results show that a thriving period of corals in the South China Sea appeared at 6 800—5 800 a BP, during which the paleosea level was the higher than at present in the Holecene.
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.
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.
文摘The discovery of abrupt paleo\|climate change events and the prediction of environmental changes in the future time have raised an urgent request for high\|resolution paleo\|environmental records. This paper reviews the progress made in chronology and paleo\|environment of stalagmites from karst caves in China and presents some of the results of TIMS\|U\|series dating of stalagmites composed of secondary carbonates, taken from the Dongge, Longquan and Yamen karst caves in Libo County and the Qixing karst cave in Duyun, Guizhou Province, on a MAT\|262 mass spectrometer.
