超过三分之二的地壳岩石是由来自深部的岩浆作用形成,岩浆岩记录的信息是深时数字地球(Deep-time Digital Earth,DDE)特别是深部过程研究的重要载体。岩浆岩分布范围广,样品众多,分析、定年相对方便和精确,易于数据累积。在过去的十多年,全球科学家建立了EarthChem、GEOROC、DataView等多个优秀的岩浆岩数据库。随着大数据时代的到来,地球科学也在经历向地球系统科学的重大转变。如何进一步整合分散在研究机构和个人手中的越来越多的数据,建立能服务大数据和人工智能方法的数据平台,推动地球科学研究由理论驱动的传统因果推理方法向数据驱动的大数据方法转变,是新的很有希望的突破点。文章系统介绍了目前国内外已有的岩浆岩相关数据库及其运行情况,为未来DDE计划整合全球海量岩浆岩数据,建设开放、共享、统一的大数据平台提供经验和基础。同时,也列举了以岩浆岩大数据驱动的科学研究的典型实例,并结合DDE相关任务,对利用岩浆岩大数据和人工智能进一步解决四维地球深部圈层物质构成、交换与动力学这一关键科学问题提出新的展望。 相似文献
A number of studies revealed that the Gangdese magmatic belt of southern Tibet was closely related to the northward subduction of the Neo-Tethys oceanic lithosphere and Indo-Asian collision.However,pre-Cretaceous magmatism is still poorly constrained in the Gangdese magmatic belt,southern Tibet.Here,we conducted systematically geochronology and geochemistry studies on a newly-identified granitic pluton in the middle Gangdese magmatic belt(Namling area),southern Tibet.Zircon SHRIMPⅡU-Pb dating for one representative sample gives a weighted age of 184.2±1.8 Ma(MSWD=±1.11),corresponding to emplacement and crystallization age of the granitic pluton in the Early Jurassic(Pliensbachian).High SiO2(68.9-72.1 wt.%)contents and intermediate Mg#values(35-38)together suggest that the newly-identified granitic pluton was probably formed by partial melting of crustal material with minor injection of mantle-derived magma,precluding an origin from melting of metasedimentary rocks that are characterized by low Mg#and high zirconδ^18O values(>8‰).Geochemically,the newly-identified granitic pluton belongs to typical I-type granitic affinity,whereas this is inconsistent with aluminium saturation index(ASI=A/CNK ratios)and geochemical signatures.This suggests that zircon oxygen isotopes(4.30‰-5.28‰)and mineral features(lacking Al-rich minerals)are reliable indicators for discriminating granitic origin.Significantly depleted whole-rock Sr-Nd-Hf isotopic compositions and zirconεHf(t)values indicate that the granitic pluton was derived from partial melting of depleted arc-type lavas.In addition,the granitic pluton shows zirconδ^18O values ranging from 4.30‰to 5.28‰(with a mean value of 4.77‰)that are consistent with mantle-derived zircon values(5.3‰±0.6‰)within the uncertainties,indicating that the granitic pluton might have experienced weak short-living high-temperature hydrous fluid-rock interaction.Combined with the Sr-Nd-Hf-O isotopes and geochemical signatures,we propose that the newly-identified granitic pluton was originated from partial melting of depleted mafic lower crust,and experienced only negligible wall-rock contamination during ascent.Integrated with published data,we also propose that the initial subduction of the Neo-Tethys oceanic lithosphere occurred no later than the Pliensbachian of the Early Jurassic. 相似文献
The Central Hebei Basin (CHB) is one of the largest sedimentary basins in the North China Craton, extending in a northeast-southwest direction with an area of 〉350 km2. We carried out SHRIMP zircon dating, Hf-in-zircon isotopic analysis and a whole-rock geochemical study on igneous and metasedi- mentary rocks recovered from drill holes that penetrated into the basement of the CHB, Two samples of gneissic granodiorite (XG1-1) and gneissic quartz diorite 048-1) have magmatic ages of 2500 and 2496 Ma, respectively. Their zircons also record metamorphic ages of 2.41-2.51 and ~2.5 Ga, respec- tively. Compared with the gneissic granodiorite, the gneissic quartz diorite has higher REE contents and lower Eu/Eu* and (La/Yb)n values. Two metasedimentary samples (MG1, H5) mainly contain ~2,5 Ga detrital zircons as well as late Paleoproterozoic metamorphic grains. The zircons of different origins have eHf (2.5 Ga) values and Hf crustal model ages ranging from 0 to 5 and 2.7 to 2,9 Ga, respectively, Therefore, ~2.5 Ga magmatic and Paleoproterozoic metasedimentary rocks and late Neoarchean to early Paleoproterozoic and late Paleoproterozoic tectono-thermal events have been identified in the basement beneath the CHB. Based on regional comparisons, we conclude that the early Precambrian basement beneath the CHB is part of the North China Craton. 相似文献
Geoanalytical data provide fundamental information according to which the Earth’s resources can be known and exploited to support human life and development. Large amounts of manpower and material and financial resources have been invested to acquire a wealth of geoanalytical data over the past 40 years. However, these data are usually managed by individual researchers and are preserved in an ad hoc manner without metadata that provide the necessary context for interpretation and data integration requirements. In this scenario, fewer data, except for published data, can be reutilized by geological researchers. Many geoanalytical databases have been constructed to collect existing data and to facilitate their use. These databases are useful tools for preserving, managing, and sharing data for geological research, and provide various data repositories to support geological studies. Since these databases are dispersed and diverse, it is difficult for researchers to make full use of them. This contribution provides an introduction on available geoanalytical databases. The database content can be made accessible to researchers, the ways in which this can be done, and the functionalities that can be used are illustrated in detail. Moreover, constraints that have limited the reutilization of geoanalytical data and creation of more advanced geoanalytical databases are discussed.
This paper introduces a novel web-based database, SHRIMPDB, to support the efficient reutilization of U-Th-Pb geochronological data from sensitive high-resolution ion microprobe (SHRIMP) measurements. In order to provide complete data content that can be reutilized by Earth scientists, a new data model containing analytical data and relevant sample metadata is proposed according to analyses of measurement procedures and the data characteristics of SHRIMP. Vivid data visualization, real-time data query interfaces (including a novel and intuitive polygonal region search), and a pragmatic data management module are designed and implemented using web-based and cloud GIS-based technologies, which provide a platform for Earth scientists to efficiently curate and share SHRIMP data on the internet. An incentive that encourages geochronologists to contribute data is suggested through cooperation between SHRIMPDB and the Beijing SHRIMP center. The database is currently under evaluation at the Beijing SHRIMP center. SHRIMPDB is globally available online at http://202.198.17.27/shrimpdb/home. 相似文献