Basalts from Hardat Tolgoi Mine were studied systematically by using petrochemical and isotope geochemical methods in order to discuss their chemical properties, diagenetic material sources and tectonic environment. T...Basalts from Hardat Tolgoi Mine were studied systematically by using petrochemical and isotope geochemical methods in order to discuss their chemical properties, diagenetic material sources and tectonic environment. The analysis results indicate that the alkali basalts are characterized by low silica and high alkalinic(Na>K) and iron-titanium contents. The distribution patterns of the rare earth elements(REE) are the "rightist" type, which typically show evident fractionation between light REEs and heavy REEs with(La/Yb)N ratios from 8.04 to 10.4, but no significant negative Eu anomalies were observed(δEu=1.01 to 1.04). The basalts are relatively enriched in large ion lithophile elements(LILE, Ba, Sr) and high field strength elements(HFSE, Nb, Ta, Hf). Ratios of 206Pb/204Pb vary between 18.434 and 18.550, ratios of 207Pb/204Pb are between 15.541 and 15.569, and ratios of 208Pb/204Pb are between 38.331 and 38.536. The diagenetic substance is believed from the asthenospheric mantle and in intraplate environment, which was constructed during continent stretch, without being significantly contaminated by crustal materials.展开更多
Har tolgoi铅银多金属矿床位于蒙古南戈壁省省会Dalanzadgad市南约170千米的诺木冈县境内,与我国直线距离56千米,大地构造位置在巴音毛道-雅干-Baruun Tsohio微陆块内。该矿床是南蒙古一个重要的大型铅银多金属矿床,其周围Pb-Zn-Ag-Au矿...Har tolgoi铅银多金属矿床位于蒙古南戈壁省省会Dalanzadgad市南约170千米的诺木冈县境内,与我国直线距离56千米,大地构造位置在巴音毛道-雅干-Baruun Tsohio微陆块内。该矿床是南蒙古一个重要的大型铅银多金属矿床,其周围Pb-Zn-Ag-Au矿床(点)密布,通过该矿床的深入研究。展开更多
Conodont samples were collected from three localities in the Onoo Tolgoi area, Mongolia, and many conodonts have been found. Conodonts from the Onoo Tolgoi Formation （M288-M294） lack index fossils; its age could be ...Conodont samples were collected from three localities in the Onoo Tolgoi area, Mongolia, and many conodonts have been found. Conodonts from the Onoo Tolgoi Formation （M288-M294） lack index fossils; its age could be Late Silurian. Samples from the Hutul us hudag Formation （M295-M299） contain Ozarkodina pandora alpha Morph. （ P element）, clearly indicating that this formation is Early Devonian late Lochkovian in age. Samples collected from so-called Silurian Onoo Tolgoi Formation at other localities （M300-M303） yield many Ordovician conodonts, including Icriodella baotaensis, Icriodella cf. baotaensis, Eoplacognathus fianyeen- sis, Eoplacognathus protoramosus ; Baltoniodus alobatus ; and ？ Ambalodus triangularis ; the age is Late Ordovician, more precisely, early-middle Late Ordovician.展开更多
基金supported by National Nature Science Foundation of China(No.40973030)
文摘Basalts from Hardat Tolgoi Mine were studied systematically by using petrochemical and isotope geochemical methods in order to discuss their chemical properties, diagenetic material sources and tectonic environment. The analysis results indicate that the alkali basalts are characterized by low silica and high alkalinic(Na>K) and iron-titanium contents. The distribution patterns of the rare earth elements(REE) are the "rightist" type, which typically show evident fractionation between light REEs and heavy REEs with(La/Yb)N ratios from 8.04 to 10.4, but no significant negative Eu anomalies were observed(δEu=1.01 to 1.04). The basalts are relatively enriched in large ion lithophile elements(LILE, Ba, Sr) and high field strength elements(HFSE, Nb, Ta, Hf). Ratios of 206Pb/204Pb vary between 18.434 and 18.550, ratios of 207Pb/204Pb are between 15.541 and 15.569, and ratios of 208Pb/204Pb are between 38.331 and 38.536. The diagenetic substance is believed from the asthenospheric mantle and in intraplate environment, which was constructed during continent stretch, without being significantly contaminated by crustal materials.
文摘Conodont samples were collected from three localities in the Onoo Tolgoi area, Mongolia, and many conodonts have been found. Conodonts from the Onoo Tolgoi Formation （M288-M294） lack index fossils; its age could be Late Silurian. Samples from the Hutul us hudag Formation （M295-M299） contain Ozarkodina pandora alpha Morph. （ P element）, clearly indicating that this formation is Early Devonian late Lochkovian in age. Samples collected from so-called Silurian Onoo Tolgoi Formation at other localities （M300-M303） yield many Ordovician conodonts, including Icriodella baotaensis, Icriodella cf. baotaensis, Eoplacognathus fianyeen- sis, Eoplacognathus protoramosus ; Baltoniodus alobatus ; and ？ Ambalodus triangularis ; the age is Late Ordovician, more precisely, early-middle Late Ordovician.
