Paleozoic sedimentary record of the Xing-Meng Orogenic Belt,Inner Mongolia: Implications for the provenances and tectonic evolution of the Central Asian Orogenic Belt

The Xing-Meng Orogenic Belt is the eastern extension of the Central Asian Orogenic Belt, which marks the boundary between the North China and Siberian blocks. Key information on the collision between these two blocks and the evolution of this orogenic belt at the end of the Paleozoic are preserved in the widely distributed Paleozoic sedimentary sequences. Petrographic studies of the clastic sedimentary rocks from the Ordovician to the Permian in this region have shown that the rocks are mainly greywackes and arkosic sandstones characterized by low maturity, poor sorting and a large number of lithic fragments. Provenances of Paleozoic sandstones are mainly newly accreted crustal materials. Nd model ages range from the Neoproterozoic to the Late Mesoproterozoic. These ages are very different from those of the North China Block, but the change of εNd(t) (from the initial εNd value) is similar to that of igneous rocks in the Xing-Meng Orogen. This result indicates that provenances of these Paleozoic sedimentary rocks mainly arise from the Xing-Meng Orogen itself. These clastic sedimentary rocks mainly consist of inputs of juvenile accreted crustal materials and limited recycled old crusts. Their provenance is controlled by the following three end members: a felsic basement, a partially melted mafic, and a mafic end member. From the point view of lithology, these three end members must have mixed in a ratio of 53:41:5 to form the average composition of the clastic sedimentary rocks. The depositional environment began to change from an arc to an orogen during the Permian, and therefore the collision was complete before the Triassic. This interpretation is consistent with the argument that the final collision time was at the end of the Permian or beginning of the Triassic.     

鄂尔多斯盆地东北部塔然高勒地区侏罗系直罗组含铀地层地球化学特征分析

沉积岩的地球化学特征记录了岩石沉积时的重要地质信息,是研究沉积古环境、源区构造背景及源岩属性的有效手段.采用X衍射荧光光谱(XRF)、等离子体质谱仪(ICP-MS)和CMS350A型岩心扫描仪对鄂尔多斯盆地东北部塔然高勒地区中侏罗统直罗组地层岩心样品的主量元素、微量元素、稀土元素及黏土矿物含量进行测试分析,综合研究塔然...     

青藏高原退化草地恢复的制约因子及修复技术

分析了退化高寒草地恢复的主要制约因素,包括植物种源、土壤微生物、土壤养分和人文因素;提出了针对这些制约因素的退化高寒草地恢复的主要途径:(1)研发乡土草种子采集、扩繁、包衣等技术,不同乡土草种种子组配及免耕补播技术,解决种源制约;(2)筛选适用于退化草地恢复的复合微生物菌种并研发菌剂,解决退化草地恢复的微生物制约;(3)研发以土壤养分调控为基础的植被恢复技术,解决退化草地恢复的土壤制约;(4)构建基于牧民新技术应用的草地适应性管理模式。分析认为,基于乡土草种、微生物、养分调控为主的物源途径的"近自然恢复",有潜力成为青藏高原退化草地恢复的有效措施。     

Radiometric dating of sediments derived from metamorphic rocks of the Dabie orogenic belt in the Jurasic and Early Cretaceous

Using isotopic dating of tuff, heavy mineral and lithofacies, correlation of Jurassic strata on the northern margin of the Dabie orogenic belt (DOB) has been enabled in the Fenghuangtai, Zhougongshan, Maotanchang and Jingangtai formations, which might be as young as Early Cretaceous. Depositional systems have been interpreted as mainly alluvial fan, braided stream and overbank, secondarily fan-delta and lacustrine. The palaeocurrent systems of the Jurassic-Cretaceous basins can be divided into two classes: one transverse adjacent to the southern margin, the other longitudinal close to the middle flowing from west to east. Mesozoic sedimentary source rocks are mainly from the DOB and, according to their geochemistry, experienced evolution in a volcanic arc tectonic setting. The Jurassic-Cretaceous strata have been subdivided into four Chronosomes, and their overlapping progressively from east toward west implies that exhumation of the DOB characterized diachronous. Based on stratigraphic evidence from eclogite conglomerates found in the Maotanchang and Fenghuangtai formations, the first exposure of UHP (ultrahigh pressure) rocks in the DOB occurred in Jurassic-Lower Cretaceous time. Further, phengites and Triassic zircons found in the Lower Jurassic Fanghushan Formation suggest that denudation began in the Early Jurassic.     

基于报备池和模版的网格记账溯源服务

提出一种网格记账溯源服务(Accounting Provenance Service,APS),针对网格记账数据的描述和获取,分别采用模版和报备池/动态报备组的方法,并分析APS在ChinaGrid中的潜在应用场景.研究结果表明,APS能将记账数据的采集独立于上层异构的记账策略,灵活地应用于各种记账背景,而且在记录单个网格成员记账行为的同时可以重现多个网格成员参与的分布式流程现场(如工作流作业的执行),提供记账事件的“溯源”功能,防止网格成员的虚假行为.     

Carbon isotopic study of individual n-alkanes in certain modern organisms

Simulation experiment was carried out on all kinds of modern organisms significant to oil-gas generation and the C-isotopic values of n-alkanes in different organisms. The distribution characteristics of individual n-alkane isotopes are studied. The experimental results supply important clues in biological provenance of n-alkanes in sedimentary organisms.     

基于区块链的数据溯源可信查询方法

针对区块链数据溯源系统中轻节点验证溯源信息时面临的存储问题,引入一种优化Merkle树动态追加性能的数据结构Merkle山脉(Merkle mountain range,MMR),将区块链上完整的区块头存入MMR;提出一种溯源数据高效可信的验证方法,降低了区块包含证明所需信息的大小.在此基础上,设计了一种基于区块链的数...     

渤中凹陷及周边地区沉积岩若干稀土元素特征

渤海湾盆地渤中凹陷及其周边地区早第三纪泥岩沉积物主要源自凹陷周边的隆起区,母岩中太古代地层占有相当比重,不同坳陷沉积物源的时代有随时间发生改变的现象,在秦南凹陷,黄河口凹陷及莱洲湾凹陷,源区地层时代从沙河街期到东营期有由新变老的趋势;辽东湾地区源区地层时代随时间变化不明显,而在渤中凹陷西侧的歧口－埕北凹陷则恰相反,源区地层随时间由老变新,说明在早第三纪盆地演化中该地区有新的源区注入。     

洪都拉斯加勒比松种源试验研究

分别于１９８７年和１９８８年在广西南宁地区林业科学研究所进行洪都拉斯变种的种源。结果洪都拉斯加勒比松种是幼林生长差异显著，介随产丰林龄增加，差异减小。干形的选择改良效果明显，树种对对比试验的生长排序为洪都拉斯变种（Ｐ．ｃａｒｉｂａｅａ ｍｏｒｅｌｅｔ ｖａｒ．ｈｏｎｄｕｒｅｎｓｉｓ）〉巴哈马变种（Ｐ．ｃａｒｉｂａｅａ ｍｏｒｅｌｅｔ ｖａｒ．ｂａｈａｍｅｎｓｉｓ）〉湿地松（Ｐ．ｅｌｌｉｏｔｔｉｉ）     

5个泰国种源大果紫檀的早期生长及材性分析

【目的】基于大果紫檀(Pterocarpus macrocarpus)早期生长和材性性状遗传变异规律及其遗传和表型相关关系分析,筛选早期速生优质大果紫檀优良遗传材料。【方法】对广东省阳江10年生大果紫檀种源试验林的保存率、树高、胸径、材积、枝下高、分枝角、含水率、湿胀率、基本密度、波速和弹性模量进行调查分析,通过混合线性模型对各性状进行方差分析、遗传参数估算和相关性分析; 利用指数方程进行优良种源和单株选择。【结果】10年生的大果紫檀林分生长良好,各种源适应能力强; 各性状种源间差异极显著,生长性状在种源水平上受中等强度以下遗传控制(0.258～0.637),材性性状呈现中度或强度遗传控制(0.321～0.814); 材积与胸径、树高、枝下高和分枝角之间呈极显著遗传正相关; 木材基本密度和弹性模量与生长性状之间遗传相关不显著; 通过构建性状权重指数方程,按照标准选出5个优良单株,优良单株胸径、树高、材积、密度、波速和弹性模量较对照分别提高了23.319%、16.503%、48.025%、3.569%、7.033%和17.767%,综合选优效果明显。【结论】在进行大果紫檀早期引种选育过程中,可以根据不同的培育目标筛选优良遗传材料,最大限度地挖掘其遗传潜力。