20042213 Chen Qinghua (Department of Geology,Northwest University, Xi’an, Shaanxi); Liu Chiyang The Mathematical Representations and Their Significance of Geological Age with Milankovitch Theory (Journal of Northwest...20042213 Chen Qinghua (Department of Geology,Northwest University, Xi’an, Shaanxi); Liu Chiyang The Mathematical Representations and Their Significance of Geological Age with Milankovitch Theory (Journal of Northwest University (Natural Science Edition), ISSN1000 - 274X, CN61 -1072/N, 33(5), 2003, p. 599-602, 27 refs. )展开更多
It is indicated by radiocarbon dating and sporo-pollen analysis of some Holocene sediments from southern Liaoning that the so-caned “Takushan Peat Bed” may be subdivided into four peat beds corresponding to sub-Atla...It is indicated by radiocarbon dating and sporo-pollen analysis of some Holocene sediments from southern Liaoning that the so-caned “Takushan Peat Bed” may be subdivided into four peat beds corresponding to sub-Atlantic (C^14 date: 2050±95yr B.P.), sub-Boreal (2750±100 yr B.P.), Atlantic (6660±160 and 7390±190 yr B.P.), and Boreal elimatic periods respectively. This work is still in progress in an attempt to establish the Holocene geoehronological scale for this region.展开更多
To the north of the Qinling-Dabie orogen there exists a Mesozoic (K1) granite-syenite belt called the Beihuaiyang granite-syenite belt, in which the Xianghongdian alkaline complex outcrops in the Devonian Foziling sch...To the north of the Qinling-Dabie orogen there exists a Mesozoic (K1) granite-syenite belt called the Beihuaiyang granite-syenite belt, in which the Xianghongdian alkaline complex outcrops in the Devonian Foziling schist and also intruded into the slightly earlier volcanic rocks. This alkaline complex is composed of syenite, alkaline syenite and nepheline syenite, but the nepheline syenite occurs inside the alkaline syenite in the pod-like, irregular, lenticular or layered shape. Researches on the petrogenesis of the alkaline complex and the relationship between the alkaline syenite and the nepheline syenite must rely on precise isotopic ages. Previous researches have reported isotopic dating results merely by the 40Ar/39Ar method on hornblende and biotite separated from the alkaline syenite and nepheline syenite. In view of this, the authors have made fairly detailed isotopic geochronological studies of the alkaline syenite and nepheline syenite by using Rb-Sr isochron for the whole rock and minerals, U-Pb for single zircon separate and the 40Ar/39Ar method for hornblende and potash feldspar. The results of this research are completely different from those of previous researches and show that the nepheline syenite was formed far earlier than the alkaline syenite.展开更多
Radiocarbon data are reported on 20 geological samples, for each of which a brief description is given. DetaiLs of pretreatment of various samples are also discussed.
光释光（OSL）测年被提出30年以来已经发展成为第四纪研究中最被认可的测年技术之一。但是,该技术在国内外的发展态势尚不明晰。基于文献计量的方法,利用Thomson Data Analyzer（TDA）和UCINET软件对Web of Science的SCIE数据库中收录...光释光（OSL）测年被提出30年以来已经发展成为第四纪研究中最被认可的测年技术之一。但是,该技术在国内外的发展态势尚不明晰。基于文献计量的方法,利用Thomson Data Analyzer（TDA）和UCINET软件对Web of Science的SCIE数据库中收录的发表于1985-2015年的OSL测年研究论文进行定量分析,分别从研究论文总量变化情况、研究力量分布、研究热点方向及我国光释光测年研究主要特征这4个维度对OSL测年研究国际态势及我国发展现状进行了讨论,并对我国该技术未来的发展提出了建议。展开更多
文摘20042213 Chen Qinghua (Department of Geology,Northwest University, Xi’an, Shaanxi); Liu Chiyang The Mathematical Representations and Their Significance of Geological Age with Milankovitch Theory (Journal of Northwest University (Natural Science Edition), ISSN1000 - 274X, CN61 -1072/N, 33(5), 2003, p. 599-602, 27 refs. )
文摘It is indicated by radiocarbon dating and sporo-pollen analysis of some Holocene sediments from southern Liaoning that the so-caned “Takushan Peat Bed” may be subdivided into four peat beds corresponding to sub-Atlantic (C^14 date: 2050±95yr B.P.), sub-Boreal (2750±100 yr B.P.), Atlantic (6660±160 and 7390±190 yr B.P.), and Boreal elimatic periods respectively. This work is still in progress in an attempt to establish the Holocene geoehronological scale for this region.
文摘To the north of the Qinling-Dabie orogen there exists a Mesozoic (K1) granite-syenite belt called the Beihuaiyang granite-syenite belt, in which the Xianghongdian alkaline complex outcrops in the Devonian Foziling schist and also intruded into the slightly earlier volcanic rocks. This alkaline complex is composed of syenite, alkaline syenite and nepheline syenite, but the nepheline syenite occurs inside the alkaline syenite in the pod-like, irregular, lenticular or layered shape. Researches on the petrogenesis of the alkaline complex and the relationship between the alkaline syenite and the nepheline syenite must rely on precise isotopic ages. Previous researches have reported isotopic dating results merely by the 40Ar/39Ar method on hornblende and biotite separated from the alkaline syenite and nepheline syenite. In view of this, the authors have made fairly detailed isotopic geochronological studies of the alkaline syenite and nepheline syenite by using Rb-Sr isochron for the whole rock and minerals, U-Pb for single zircon separate and the 40Ar/39Ar method for hornblende and potash feldspar. The results of this research are completely different from those of previous researches and show that the nepheline syenite was formed far earlier than the alkaline syenite.
文摘Radiocarbon data are reported on 20 geological samples, for each of which a brief description is given. DetaiLs of pretreatment of various samples are also discussed.
文摘光释光（OSL）测年被提出30年以来已经发展成为第四纪研究中最被认可的测年技术之一。但是,该技术在国内外的发展态势尚不明晰。基于文献计量的方法,利用Thomson Data Analyzer（TDA）和UCINET软件对Web of Science的SCIE数据库中收录的发表于1985-2015年的OSL测年研究论文进行定量分析,分别从研究论文总量变化情况、研究力量分布、研究热点方向及我国光释光测年研究主要特征这4个维度对OSL测年研究国际态势及我国发展现状进行了讨论,并对我国该技术未来的发展提出了建议。
