Based upon the present research stratus on Nan Ling granites and in the view of the defferenees in the opinions on the ages and periodic division of Nan Ling granites existing among some research units concerned, a pr...Based upon the present research stratus on Nan Ling granites and in the view of the defferenees in the opinions on the ages and periodic division of Nan Ling granites existing among some research units concerned, a proposal has been snbmitted in the paper, pointing out that it is quite necessary to launch a discussion in the deeper-going way on the problem involving the ages of Nan Ling granites and their periodic division in the journal “GEOCHIMICA”. The main topics expected to be discussed are as follows : (1) The existanec of Hereynian granites and the possibility of the formation of non-orogenic granites; (2) The divisional boundary between Yeushanian and Indonsinian granites and their distributional characteristics; (3) The periodic sub-division of Yenshanian granites and their relatiouship with mineralization ; (4) The division of the ,ages of granites older than the Caledonian period.展开更多
This paper is a summation of the discussions held since 1976 under this topic.Zonation and the unbalance rules regarding temporal and spatial distribution of granites,the relationship between granite formation and cru...This paper is a summation of the discussions held since 1976 under this topic.Zonation and the unbalance rules regarding temporal and spatial distribution of granites,the relationship between granite formation and crust movement, the series of mineralization and the cyclic nature of granitic magmatism are dealt with followed by a preliminary time division of granites based on our study. Nanling granites are classified into three broad categories, i.e., the Precambrian, Paleozoic and Mcsozoic granites.On the basis of geological setting, stratigraphieal evidence, isotopic age, spatial distribution, petrology, trace elements and accessory minerals the following subdivisions are suggested for Nanling granites: Szupunian (1063--1400my), Hsuehfangian (570--900my), early Caledonian (400--570my), late Caledonian (360-400my), Hercynian(230--360 my), Indosiuian (195±5--230 my), early Yenshanian (140±5-195±5 my).and late Yenshanian (70-140±5 my).展开更多
Cenozoic volcanic rocks widespread in eastern China constitute an important part of the circum-Pacific volcanic belt.This paper presents more than 150K-Ar dates and a great deal of petrochemical analysis data from the...Cenozoic volcanic rocks widespread in eastern China constitute an important part of the circum-Pacific volcanic belt.This paper presents more than 150K-Ar dates and a great deal of petrochemical analysis data from the Cenozoic volcanic rocks distributed in Tengchong,China's southeast coast,Shandong,Hebei,Nei Monggol and Northeast China.An integrated study shows that ubiquitous but uneven volcanic activities prevailed from the Eogene to the Holocene,characterized as being multi-eqisodic and multicycled.For example,in the Paleocene(67-58Ma),Eocene(57-37.5Ma),Miocene(22-18,16-19Ma),Pliocene(8-3Ma),and Early Pleistocene-Middle Pleistocene(1.2-0.5Ma) there were upsurges of volcanism,while in the Oligocene there was a repose period.In space,the older Eogene volcanic rocks are distributed within the region or in the central part of the NE-NNE-striking fault depression,while the younger Neogene and Quaternary volcanic rocks are distributed in the eastern and western parts.Petrologically,they belong essentially to tholeiite-series and alkali-series basalts,with alkalinity in the rocks increasing from old to youg.The above regularities are controlled by both global plate movement and regional inherent tectonic pattern.展开更多
Archean rocks are widespread in North China and constitute an essential part of the Sino-Korean Craton which is one of the oldest continental blocks. Recently major representative Archean metavolcanites in North China...Archean rocks are widespread in North China and constitute an essential part of the Sino-Korean Craton which is one of the oldest continental blocks. Recently major representative Archean metavolcanites in North China have been dated by the Sm-Nd isochron method. The composition and evolution of Archean upper mantle in various regions of North China have been discussed in the light of accurate isochron ages and their initial ε<sub>Nd</sub>（T）展开更多
文摘Based upon the present research stratus on Nan Ling granites and in the view of the defferenees in the opinions on the ages and periodic division of Nan Ling granites existing among some research units concerned, a proposal has been snbmitted in the paper, pointing out that it is quite necessary to launch a discussion in the deeper-going way on the problem involving the ages of Nan Ling granites and their periodic division in the journal “GEOCHIMICA”. The main topics expected to be discussed are as follows : (1) The existanec of Hereynian granites and the possibility of the formation of non-orogenic granites; (2) The divisional boundary between Yeushanian and Indonsinian granites and their distributional characteristics; (3) The periodic sub-division of Yenshanian granites and their relatiouship with mineralization ; (4) The division of the ,ages of granites older than the Caledonian period.
文摘This paper is a summation of the discussions held since 1976 under this topic.Zonation and the unbalance rules regarding temporal and spatial distribution of granites,the relationship between granite formation and crust movement, the series of mineralization and the cyclic nature of granitic magmatism are dealt with followed by a preliminary time division of granites based on our study. Nanling granites are classified into three broad categories, i.e., the Precambrian, Paleozoic and Mcsozoic granites.On the basis of geological setting, stratigraphieal evidence, isotopic age, spatial distribution, petrology, trace elements and accessory minerals the following subdivisions are suggested for Nanling granites: Szupunian (1063--1400my), Hsuehfangian (570--900my), early Caledonian (400--570my), late Caledonian (360-400my), Hercynian(230--360 my), Indosiuian (195±5--230 my), early Yenshanian (140±5-195±5 my).and late Yenshanian (70-140±5 my).
文摘Cenozoic volcanic rocks widespread in eastern China constitute an important part of the circum-Pacific volcanic belt.This paper presents more than 150K-Ar dates and a great deal of petrochemical analysis data from the Cenozoic volcanic rocks distributed in Tengchong,China's southeast coast,Shandong,Hebei,Nei Monggol and Northeast China.An integrated study shows that ubiquitous but uneven volcanic activities prevailed from the Eogene to the Holocene,characterized as being multi-eqisodic and multicycled.For example,in the Paleocene(67-58Ma),Eocene(57-37.5Ma),Miocene(22-18,16-19Ma),Pliocene(8-3Ma),and Early Pleistocene-Middle Pleistocene(1.2-0.5Ma) there were upsurges of volcanism,while in the Oligocene there was a repose period.In space,the older Eogene volcanic rocks are distributed within the region or in the central part of the NE-NNE-striking fault depression,while the younger Neogene and Quaternary volcanic rocks are distributed in the eastern and western parts.Petrologically,they belong essentially to tholeiite-series and alkali-series basalts,with alkalinity in the rocks increasing from old to youg.The above regularities are controlled by both global plate movement and regional inherent tectonic pattern.
文摘Archean rocks are widespread in North China and constitute an essential part of the Sino-Korean Craton which is one of the oldest continental blocks. Recently major representative Archean metavolcanites in North China have been dated by the Sm-Nd isochron method. The composition and evolution of Archean upper mantle in various regions of North China have been discussed in the light of accurate isochron ages and their initial ε<sub>Nd</sub>（T）
