检索结果-南通市图书馆

Petrogenetic simulation of the Archean trondhjemite from Eastern Hebei, China

Science China Earth Sciences 2017年第5期60卷 958-971页

作者： ZHANG ShiWei WEI ChunJing DUAN ZhanZhan key laboratory of orogenic belts and crustal evolution School of Earth and Space Sciences Peking University

It is generally believed that trondhjemitic rock, an important component of TTG rocks, is the anatectic product of mafic rocks. However, in many TTG gneiss terranes, for instance, the granulite facies terrane in Eastern Hebei, trondhjemites occur as small dikes, intrusions or leucosomes in tonalitic gneisses, suggesting their origin of in-situ partial melting. Based on the petrological analysis of a tonalitic gneiss sample from Eastern Hebei, in combination with zircon U-Pb dating, we investigated the petrogenesis of trondhjemite through simulating anatectic reactions and the major and trace element characteristics of the product melt at different pressures(0.7, 1.0 and 2.0 GPa). The results indicate that hornblende dehydration melting in a tonalitic gneiss at 0.9–1.1 GPa and 800–850°C, corresponding to the high-T granulite facies, with melting degrees of 5–10wt.% and a residual assemblage containing 5–10wt.% garnet, can produce felsic melts with a great similarity, for instance of high La/Yb ratios and low Yb contents to the trondhjemitic rocks from Eastern Hebei. However, the modelled melts exhibit relatively higher K2 O, and lower CaO and Mg~# than those in the trondhjemitic dikes and leucosomes from Eastern Hebei, suggesting that the leucosomes may not only contain some residual minerals but also be subjected to the effect of crystal fractionation. The zircon U-Pb dating for the tonalitic and trondhjemitic rocks in the Eastern Hebei yields a protolith age of 2518±12 Ma and a metamorphic age of 2505±19 Ma for the tonalitic gneiss. The latter age is consistent with a crystallization age of 2506±6 Ma for the trondhjemitic rock, confirming a close petrogenetic relation between them.

关键词： Trondhjemite TTG gneiss Anatexis Phase equilibria modelling Eastern Hebei

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Differential evolution of High-Pressure and Ultrahigh-Pressure Metapelites from Habutengsu, Chinese Western Tianshan: Phase Equilibria Modelling and ^(40)Ar/^(39)Ar Geochronology

引用

Acta Geologica Sinica(English Edition) 2016年第2期90卷 628-640页

作者： Lü Zeng ZHANG Lifei the key laboratory of orogenic belts and crustal evolution School of Earth and Space SciencesPeking University

Metapelite is one of the predominant rock types in the high-pressure–ultrahigh-pressure（HP–UHP） metamorphic belt of western Tianshan, NW China; however, the spatial and temporal variations of this belt during metamorphism are poorly understood. In this study, we present comparative petrological studies and 40^Ar/39 ^Ar geochronology of HP and UHP pelitic schist exposed along the Habutengsu valley. The schist mainly comprises quartz, white mica, garnet, albite and bluish amphibole. In the Mn O–Na2O–Ca O–K2O–Fe O–Mg O–Al2O3–Si O2–H2O（Mn NCKFMASH） system, P–T pseudosections were constructed using THERMOCALC 333 for two representative pelitic schists. The results demonstrate that there was a break in the peak metamorphic pressures in the Habutengsu area. The northern schist has experienced UHP metamorphism, consistent with the presence of coesite in the same section, while the southern one formed at lower pressures that stabilized the quartz. This result supports the previous finding of a metamorphic gradient through the HP–UHP metamorphic belt of the Chinese western Tianshan by the authors. Additionally, phengite in the northern schist was modelled as having a Si content of 3.55–3.70（a.p.f.u.） at the peak stage, a value much higher than that of oriented matrix phengite（Si content 3.32–3.38 a.p.f.u.）. This indicates that the phengite flakes in the UHP schist were subjected to recrystallization during exhumation, which is consistent with the presence of phengite aggregates surrounding garnet porphyroblast. The 40^Ar/39^ Ar age spectra of white mica（dominantly phengite） from the two schists exhibit similar plateau ages of ca. 315 Ma, which is interpreted as the timing of a tectonometamorphic event that occurred during the exhumation of the HP–UHP metamorphic belt of the Chinese western Tianshan.

关键词： pelitic schist HP–UHP metamorphism P–T pseudosection 40^Ar/39^Ar geochronology Chinese western Tianshan

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Massive abiotic methane production in eclogite during cold subduction

引用

National Science Review 2023年第1期10卷 143-153页

作者： Lijuan Zhang Lifei Zhang Ming Tang Xiao Wang Renbiao Tao Cheng Xu Thomas Bader Ministry of Education key laboratory of orogenic belts and crustal evolution School of Earth and Space SciencesPeking University

Methane（CH4） is a critical but overlooked component in the study of the deep carbon *** CH4produced by serpentinization of ultramafic rocks has received extensive attention,but its formation and flux in mafic rocks during subduction remain poorly ***,we report massive CH4-rich fluid inclusions in well-zoned garnet from eclogites in Western Tianshan,*** characteristics and carbon-hydrogen isotopic compositions confirm the abiotic origin of this *** P-T-fO2-fluid trajectories and Deep Earth Water modeling imply that massive abiotic CH4was generated during cold subduction at depths of 50-120 km,whereas CO2was produced during *** massive production of abiotic CH4in eclogites may result from multiple mechanisms during prograde high pressure-ultrahigh pressure *** flux calculation proposes that abiotic CH4that has been formed in HP-UHP eclogites in cold sub duction zones may represent one of the largest,yet overlooked,sources of abiotic CH4on Earth.

关键词： abiotic CH4 fluid inclusion prograde HP-UHP metamorphism CO2 Western Tianshan

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Coesite in metasediments from the Muzhaerte valley, southwestern Tianshan

引用

Science Bulletin 2019年第2期64卷 78-80页

作者： Zeng Lü Lifei Zhang Ji Yue key laboratory of orogenic belts and crustal evolution School of Earth and Space Sciences Peking University

The sediments,including calcareous,siliciclastic and volcanoclastic,usually occupy>90%in volume of an accretionary complex and thus,if involved in subduction zones,their maximum return depths(i.e.,peak pressures)are fundamental to unravel the geodynamic processes during the convergence of plates[1].As a unique example of accreted complex returned from sub-arc depths(>90 km)worldwide.

关键词： UHP southwestern Tianshan Coesite in metasediments from the Muzhaerte valley

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

C-isotope composition and correlation of the Upper Neoproterozoic in Keping area, Xinjiang

引用

Chinese Science Bulletin 2007年第4期52卷 504-511页

作者： HE XiuBin, XU Bei & YUAN ZhiYun the key laboratory of orogenic belts and crustal evolution, Peking University Ministry of Education of China School of Earth and Space Sciences, Peking University, Beijing 100871, China the key laboratory of orogenic belts and crustal evolution PekingUniversity Beijing 100871 China

C-isotope analysis of the carbonates in the Upper Neoproterozoic in Keping, Xinjiang indicates that the Qigebrak Formation and the Upper Sugaitbrak Formation mainly record positive C-isotope values, and a distinct positive excursion occurs in the lower part of the Qigebrak Formation. There are three negative excursions in the boundary between the Qigebrak Formation and the Cambrian, the uppermost and lowermost Upper Sugaitbrak Formation. These characters resemble those of the Upper Neoproterozoic in the Three-Gorge area, which suggests that the Upper Sugaitbrak Formation and Qigebrak Formation can be correlated with the middle and upper parts of the Doushantuo Formation and Dengying Formation, respectively. The negative excursion at the top of the Upper Sugaitbrak Formation corresponds to that at the top of the Doushantuo Formation, while the negative excursion at the bottom of the Sugaitbrak Formation can be correlated with that at the middle part of the Doushantuo Formation in the Three-Gorge area and that at the top of the Hangelchaok diamictites in the Quruqtagh area.

关键词：新疆柯坪地区晚震旦世 C同位素成分冰川作用

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Melilite-derived mineral inclusions in chromite from the Gaositai complex: Implications for an extensional tectonic setting in Early Permian at the north North China Craton

引用

Science China Earth Sciences 2016年第3期59卷 583-589页

作者： SHAO Ji An TIAN Wei WEI Chun Jing ZHU Wen Ping key laboratory of orogenic belts and crustal evolution Ministry of Education School of Earth and Space Sciences Peking University

The Early Permian mafic-ultramafic concentrically zoned Gaositai intrusion at Chengde, on the northern margin of the North China Craton(NCC), is a cumulative complex emplaced along a giant fracture that penetrates deeply into the continental lithosphere. Melt inclusions are present in chromite crystals from the inner dunite and chromitite zones of the Gaositai complex. The melt inclusions have experienced post-trap crystallization and resulted in multiple mineral phases, including melilite, garnet, phlogopite, magnesite and apatite, which can indicate the liquidus minerals of the primitive magma. The characteristics of the melilite+melanite+clinopyxene assemblage indicate that the primary parental magma was highly undersaturated and derived from an alkali-rich mantle source. The crystallization of phlogopite, magnesite and apatite suggests a primary magma rich in K, H_2O and CO_2. When compared with experimental data, the primary magma of the Gaositai intrusion is concordant with a kamafugite magma originating from partial melting of enriched mantle with H_2O and CO_2 at pressures greater than 2.7 GPa. This magmatic process would have been related to extensional thinning of the continental lithosphere. The Gaositai primary magmas have high Nb/La ratios, which are similar to those of ocean island basalts, but different from arc-related magmas. This suggests that the northern margin of the NCC was not an active continental margin of the Paleo-Asian Ocean subduction zone during the Early Permian: an extensional tectonic setting during the emplacement of the Gaositai intrusion is more likely.

关键词： Melt Inclusion Melilite Primary melt Extension Continental lithosphere North China Craton

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

In situ high-pressure X-ray diffraction experiments and ab initio calculations of Co_2P

引用

Chinese Physics B 2011年第6期20卷 336-341页

作者：张倩巫翔秦善 key laboratory of orogenic belts and crustal evolution of Ministry of Education School of Earth and Space Sciences Peking University

In situ high-pressure experiments of Co2P are carried out by means of angle dispersive X-ray diffraction with diamond anvil cell technique. No phase transition is observed in the present pressure range up to 15 GPa at room temperature, even at high temperature and 15 GPa. Results of compression for Co2P are well presented by the second-order Birch-Murnaghan equation of state with V0 = 130.99（2） Aa （1 A=0.1 nm） and K0 = 160（3） GPa. Axial compressibilities are described by compressional modulus of the axis： Ka = 123（2） GPa, Kb = 167（8） GPa and Kc = 220（7） GPa. Theoretical calculations further support the experimental results and indicate that C23-type Co2P is stable at high pressure compared with the C22-type phase.

关键词： Co2P1 ab initio pressure-induced phase transition

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Semiconducting Mineral Photocatalytic Regeneration of Fe^(2+) Promotes Carbon Dioxide Acquisition by Acidithiobacillus ferrooxidans

引用

Acta Geologica Sinica(English Edition) 2013年第3期87卷 761-766页

作者： LI Yan LU Anhuai WANG Xin DING Hongrui WANG Changqiu the key laboratory of orogenic belts and crustal evolution School of Earth and Space Sciences Peking University

Chemoautotrophic organisms have once been excluded from the development of universally applicable CO2 fixation technology due to its low production yields of biomass. In this study, we used Acidithiobacillusferrooxidans （A.f.） as a model chemoautotrophic microorganism to test the hypothesis that exogenetic photoelectrons from semiconducting mineral photocatalysis can enable the regeneration of Fe^2＋ that could be then used by A.f. and support its growth. In a simulated electrochemical system, where exogenetic electrons were provided by an electrochemical approach, an accelerated growth rate of A.f. was observed as compared with that in traditional batch cultivation. In a coupled system, where light-irradiated natural rutile provided the primary electron source to feed A.f., the bacterial growth rate as well as the subsequent CO2 fixation rate was demonstrated to be in a light-dependent manner. The sustaining flow of photogenerated electrons from semiconducting mineral to bacteria provided an inexhaustible electron source for chemoautotrophic bacteria growth and CO2 fixation. This finding might contribute to the development of novel effective CO2 fixation technology.

关键词： CO2 fixation photocatalysis chemoautotrophic organisms semiconducting mineral

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Snowball Earth at low solar luminosity prevented by the oceanatmosphere coupling

引用

Acta Geochimica 2019年第6期38卷 775-784页

作者： Ruimin Wang Bing Shen key laboratory of orogenic belts and crustal evolution MOE School of Earth and Space Science Peking University

The standard solar model proposes that the solar luminosity was 30%lower than the present level at 4.5 billion years ago(Ga).At low solar radiation,the climate model predicts that the Earth should have been completely covered by ice in the first 2 billion years,*** the snowball Earth climate mode,when the atmospheric CO2 content was at the present ***,snowball Earth condition is inconsistent with various sedimentological,paleontological,and geochemical *** controversy is collectively known as the Taint Young Sun,(FYS)*** various models have been proposed,the FYS paradox has not yet been *** this study,we develop a model by considering the ocean-atmosphere coupling to show that high atmospheric CO2 level could be sustained at low seawater *** modeling result indicates that 0.1 bar atmospheric CO2 level that was required to prevent snowball Earth in early Archean could be sustained at seawater pH of *** the absence of siderite in Archean paleosols has been used to argue against high atmospheric CO2 level,we suggest that siderite precipitation in paleosols was not controlled by the atmospheric CO2 level ***,siderite could precipitate in anoxic conditions with various amount of CO2 in the atmosphere,suggesting siderite cannot be used to reconstruct the atmospheric CO2 ***,the new model suggests that the snowball Earth condition could be prevented by the coupling of atmosphere and ocean systems,and thus the emergence of the ocean in the very beginning of Earth evolution might be the key to the subsequence evolution of habitability.

关键词： Faint Young Sun paradox Carbon dioxide Earth system Siderite

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Cenozoic Exhumation and Thrusting in the Northern Qilian Shan,Northeastern Margin of the Tibetan Plateau:Constraints from Sedimentological and Apatite Fission-Track Data

引用

Acta Geologica Sinica(English Edition) 2009年第3期83卷 562-579页

作者： GUO Zhaojie LU Jiemin ZHANG Zhicheng key laboratory of orogenic belts and crustal evolution Peking University Beijing 100871 China

The Qilian Shan lies along the northeastern edge of the Tibetan Plateau. To constrain its deformation history, we conducted integrated research on Mesozoic-Cenozoic stratigraphic sections in the Jiuxi Basin immediately north of the mountain range. Paleocurrent measurements, sandstone compositional data, and facies analysis of Cenozoic stratigraphic sections suggest that the Jiuxi Basin received sediments from the Altyn Tagh Range in the northwest, initially in the Oligocene （-33 Ma）, depositing the Huoshaogou Formation in the northern part of the basin. Later, the source area of the Jiuxi Basin changed to the Qilian Shan in the south during Late Oligocene （-27 Ma）, which led to the deposition of the Baiyanghe Formation. We suggest that uplift of the northern Qilian Shan induced by thrusting began no later than the Late Oligocene. Fission-track analysis of apatite from the Qilian Shan yields further information about the deformation history of the northern Qilain Shan and the Jiuxi Basin. It shows that a period of rapid cooling, interpreted as exhumation, initiated in the Oligocene. We suggest that this exhumation marked the initial uplift of the Qilian Shan resulting from the India-Asia collision.

关键词： Cenozoic uplift sandstone composition apatite fission-track dating Jiuxi Basin QilianShan

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：