中国白垩纪大陆科学钻探工程:松科一井科学钻探工程的实施与初步进展
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摘要
获取全球环境与气候变化记录是世界科学钻探发展的必然趋势。白垩纪作为地质历史时期"温室气候"的典型范例时期,提供了温室气候条件下地球气候系统运作和变化的良好档案。但是目前国际上针对白垩纪地层的科学钻探主要限于海相地层,对陆相白垩系的科学钻探尚属空白。在我国松辽盆地北部新近完成的中国白垩纪大陆科学钻探工程——松科1井项目有望在此方面取得重要的突破。该项目经过一年多的努力,钻探工程已经全部结束,总计获取岩心长2485.89m,收获率达96.46%,是目前为止所获取的国际上第一条最长而且连续的白垩系陆相沉积记录。针对岩心的全面研究工作正在开展并已取得初步成果。相关研究工作进展突出表现在通过厘米级样品的取样与分析,将传统地质学百万年的时间分辨率提高到万年尺度,预计其研究结果可为解决当今的全球变暖问题提供重要的参照。利用松科1井科学钻探工程的原始科学资料和研究成果,对岩心已经和在建的包括岩石地层、古生物、沉积相、古地磁、有机地化、旋回地层、地微生物等十大剖面系列,进行科学钻探成果的集成。初步研究在沉积学和有机地球化学、旋回地层学、松辽古湖泊温度变化、地微生物和古大气中CO2浓度定量重建方面已取得重要进展。"松科1井"全部岩心剖切后,38%将馆藏保存,其余将用于现阶段研究,并向全世界科学家开放。后续工程"松科2井"也已经被列入国际大陆钻探计划(ICDP)候选项目。
To obtain the global environmental and climatic records is going to be the aim of the international scientific drilling projects. As a paradigm of greenhouse climate in the geological history, the Cretaceous provides significant records of the global climate changes under the condition of greenhouse climate. But currently, the international scientific drilling programs on the Cretaceous have been focusing on marine sediments; in contrast, no terrestrial records have been recovered by any scientific program. Newly completed SK I and SK II drilling located at the northern part of the Songliao Basin are supposed to be an important breakthrough in this domain. After more than one year effort, the drilling project has been finished, and 2485.89 m of the cores have been obtained, with a high recovery ratio of 96.46%, and that is the longest and continuous Cretaceous terrestrial core all over the world. A number of important investigations and achievement on the cores from SK I and SK II have been carried out. One of the most significant contributions of this program is to get records with a resolution of ten thousand year by the centimeter-grade sampling and analysis, instead of the traditional records on million years of timescale, and hopefully, its research can provide an important reference to solve currently global warming. Combined with raw data and upcoming results for the core, an integrated accomplishment of the scientific can be made in ten profiles such as biostratigraphy, chemostratigraphy, magnetostratigraphy and geomicrobiology and so on. The preliminary progress has been achieved on sedimentology, organic geochemistry, cyclo-stratigraphy, paleolimnology, geomicrobiology and reconstruction of pCO2. All the cores will be preserved in professional storeroom after being cut for our researches, and scientists all over the world are highly welcome. The follow-up the SK II drilling program has also been selected as one of the candidate programs of ICDP (International Continental Drilling Project).