青藏高原形成演化研究回顾、进展与展望

青藏高原形成演化涵盖了前身的东特提斯地质构造演化、新生代地质构造演化和高原隆升对气候环境演变的制约,它不仅包含有关全球构造的空间格局、运动状态的历史记录,而且也留下了青藏特提斯洋陆转换、盆山转换构造体制的时空结构、运动形式和发展变化的地质遗迹。所以青藏高原是研究全球构造的窗口,被自然科学工作者誉为解决地球动力学的一把钥匙。自20世纪60年代以来,特别是1979年以来我们先后开展了青藏高原地质构造演化、系列编图及综合集成等研究工作。本文以认识现今青藏高原地质历史各阶段重大地质构造事件的结构组成和演化为主线,回顾了40年来历次重大青藏高原基础地质研究过程,系统总结了青藏高原新生代隆升过程、碰撞构造效应,以及东特提斯地质调查研究中一系列重要新发现、新进展、新成果,并对相关研究成果和新发现进行了简要的归纳梳理。在此基础上,就青藏高原形成演化模式、科学理论与学术争论观念层次上的问题,以及关键的基础地质问题等方面进行了讨论与展望。     

腾冲火山岩年龄问题评述

腾冲火山及火山岩是国内新近纪火山及其喷发物九大分布区之一,研究程度较广较深,喷发序列岩石定岩及年龄值资料丰富,综合评述并指出今后研究方向。     

滇西梁河—潞西地区新生代英安岩的源区及成因——来自地球化学的证据

报道了滇西梁河—潞西地区新生代英安岩的主量、微量、稀土元素和Nd同位素地球化学研究成果。英安岩富集轻稀土元素、大离子亲石元素(Rb、Th、U、K),相对亏损重稀土元素和Nb、Ta、Sr、P、Ti,具有Eu负异常和Pb正异常。火山岩的εNd(0)为-10.3~-8.72,Nd同位素模式年龄(tDM)为1.2~1.4Ga。这些地球化学特征表明,研究区英安岩源于区域基底岩系的部分熔融,并与该地区同期幔源玄武质岩浆发生了不同程度的混合。     

生态纪——地球的地质生命过程的时空必然

面对人类和地球共同体的一系列危机，“生态纪”思想提出了一个可持续的未来，这是地球的地质生命过程的时空必然。远古代地质——生命发生过程、中生代地质——生命发展过程、新生代地质——生命繁茂过程是地球的过去和现在，那么，未来就是要进入生态纪，走向生态纪元就是人类和地球共同体的共同追求。     

营口-潍坊断裂带新生代运动学特征

营口-潍坊断裂带在新生代时期对渤海湾盆地东部构造、沉积及油气成藏规律等方面具有重要影响和控制作用.依据大量实际地震资料,从剖面上识别出了花状构造、丝带效应、反转构造等营口-潍坊断裂带新生代时期走滑活动的标志,在平面上识别出了4种组合构造样式,在此基础上,应用拉分盆地走滑量计算的理论模型,对营口-潍坊断裂带新生代时期的走滑位移量进行了初步估算,认为营口-潍坊断裂带在新生代时期具右旋走滑活动特征,其主要走滑活动表现为3期,分别为始新世早期、渐新世早-中期和上新世晚期-第四纪,新生代累计右旋走滑位移量约为10～20 km.     

On tectonic movement in the South China Sea during the Cenozoic

The tectonic movement taking place at the end of Cretaceous and the beginning of Cenozoic had opened the Cenozoic phase of polycyclic tectonic movements, then the whole crust of the South China Sea had been mainly subjected to the regional stress field of tectonic tension, which was characterized by rifting depression. Seven times of regional tectonic movement and sedimentation had been assembled into a geological development history of polycyclic oscillation. Especially, the tectonic movements were strongly intensified at the end of Cretacious and the beginning of Paleagene, between Late Eocene and MidOligocene, during Mid and Late Miocene. These three times of tectonic movement had built the most important regional tectonic interfaces in the South China Sea. Crust movements of the South China Sea were the result and epitome of interaction of the Eurasia, Pacific and IndoAustralia plates, that is, they were introduced by polycyclic changes of directions, rates and strengths of lithospheric movements and asthenospheric flows across the Pacific and IndoAustralia plates.     

Cenozoic uplift of Variscan Massifs in the Alpine foreland: Timing and controlling mechanisms

The European Cenozoic Rift System (ECRIS) and associated fault systems transect all Variscan Massifs in the foreland of the Alps. ECRIS was activated during the Eocene in the foreland of the Pyrenees and Alps in response to the build-up of collision-related intraplate stresses. During Oligocene and Neogene times ECRIS evolved by passive rifting under changing stress fields, reflecting end Oligocene consolidation of the Pyrenees and increasing coupling of the Alpine Orogen with its foreland. ECRIS is presently still active, as evidenced by its seismicity and geodetic data.Uplift of the Massif Central and the Rhenish Massif, commencing at the Oligocene–Miocene transition, is mainly attributed to plume-related thermal thinning of the mantle–lithosphere. Mid-Burdigalian uplift of the SW–NE-striking Vosges–Black Forest Arch, that has the geometry of a doubly plunging anticline breached by the Upper Rhine Graben, involved folding of the lithosphere. Late Burdigalian broad uplift of the northern parts of the Bohemian Massif reflects lithospheric buckling whereas late Miocene–Pliocene uplift of its marginal blocks involved transpressional reactivation of pre-existing crustal discontinuities. Crustal extension across ECRIS, amounting to no more than 7 km, was compensated by a finite clockwise rotation of the Paris Basin block, up warping of the Weald–Artois axis and reactivation of the Armorican shear zones. Intermittent, though progressive uplift of the Armorican Massif, commencing in the Miocene, is attributed to transpressional deformation of the lithosphere.Under the present-day NW-directed compressional stress field, that came into evidence during the early Miocene and further intensified during the Pliocene, the Armorican Massif, the Massif Central, the western parts of the Rhenish Massif and the northern parts of the Bohemian Massif continue to rise at rates of up to 1.75 mm/y whilst the Vosges–Black Forest arch is relatively stable.Uplift of the Variscan Massifs and development of ECRIS exerted strong controls on the Neogene evolution of drainage systems in the Alpine foreland.     

云南景谷盆地及陇川盆地新生代生物群特征及环境地质意义

通过对云南景谷盆地及陇川盆地新生代生物群特征的对比,探讨了新生代两大盆地环境演变:早中新世到上新世为湖盆发展期→湖盆扩大→萎缩期,气候为早期的干燥→中新世早期的温暖湿润→中新世中晚期的寒冷阴湿→上新世的干燥,而中新世中晚期湖盆的扩大形成的半深湖-深湖环境为油气的形成提供了有利条件。尽管两大盆地在沉积环境的演化上大体一致,但气候和沉积环境的演变和差异决定了两大断陷盆地生物面貌上的差异,从而直接控制了化石燃料形成的类型和质量     

山东临朐-昌乐地区临朐群玄武岩基本特征及成因

山东临朐-昌乐地区临朐群玄武岩是新生代火山活动产生的大陆溢流玄武岩，该区玄武岩以高镁、钙，低钾、钠为特征，属于碱性玄武岩系列。玄武岩来源于上地幔，内有大量橄榄岩包体，其形成机制是上地幔部分熔融作用。