断裂剪切带厘米级磨砾和纳米级磨粒的发现、命名及其油气地质意义

上世纪70年代初，在江苏江宁逆断层中发现了厘米（cm）级磨砾，这种磨粒通常在韧脆性断裂剪切带中都可能找到。80年代末，对美国加州深钻岩芯进行扫描电子显微镜观测时，在晚中生代花岗质糜棱岩滑移叶片中发现了纳米（nm）级超微球粒结构，球粒（2—5nm）紧密聚集、定向明显。因其形成同滚动、研磨和剪切作用过程有关，故将球形微粒称“磨粒”。嗣后，在陕北和黄海深钻岩芯石炭-二叠系泥岩滑移叶片中，也发现类同现象（微米-纳米级）。近年来又在郯庐断裂、日本中央构造线大型断裂带，以及南京幕府山寒武系至三叠系不同地层的各种剪切滑移构造中都发现了nm级磨粒构造。泥岩中含磨粒滑移层具有涂抹效应，起到油气封盖作用，这在陕北油气田已得到了验证。对其磨粒构造蕴藏的丰富地质信息，特别是在微观动力学方面（包括动热变质作用、流体渗散作用、颗粒自旋作用和地质催化作用等）应作进一步研究。

Discovery, Nomenclature of the Centimeter Scale Grinding Gravels and the Nanometer Scale Grinding Grains in Fault Shearing Zones and the Significance for Oil-Gas Geology

In the early 1970s, the cm-scale grinding gravels were discovered in reverse faults in Jiangning, Jiangsu Province, In general, there grinding gravels can be found in ductile-brittle fault shearing zones. In the end of the 1980s, based on the observation of the deep bore cores from of California, USA using scanning electron microscope the spherical particulate texture with the ultra-size of nm scale was discovered from the slipping lamellae in the granitic mylonite in Late Mesozoic period. The spherical particulates (usually 2-5 nm in diameter) show a close concentration and distinct orientation. It may be the product of the dynamic processes involving tumbling, grinding and shearing functions. Consequently the spherical particulates with ultra-size are called grinding grain'. Afterwards, a very similar phenomenon (mostly in um size) was found again from the slipping lamellae in the Carboniferous-Permian mudstone in the deep bore cores from North Shanxi and Yellow Sea. In recent year, the nm scale grinding grain structures were also discovered in Tanlu fault and Middle Tectonic Line gigantic fault zones of Japan as well as various shearing slipping structures in different strata from Cambrian to Triassic system. In the mudstone slipping beds containing grinding grains may possess a sealing effect through systematic analyses of the samples, and it is fully proved in the North Shanxi oil-gas field. The grinding grain textures may contain more detailed geological information in particular the micro-dynamic aspect (including the dynamo-thermal metamorphism, fluid transferring, particulate autorotation and geological catalysis) owing to increasing research.