贵州册亨达秧中三叠统浊积岩中大型滑移变形层理的发现及其意义

作者在野外调查中于贵州省册亨县达秧乡洛秧村云上沟发现一组"图纹石",具有精美的花纹图案,沿北东向的云上沟溪谷断续分布,长度大于2km。经初步研究,其为中三叠统许满组第四段下亚段中上部的细砂粉砂岩,岩石上的奇特花纹图案属于大型滑移变形层理,是一种特殊的软沉积变形构造,可分为4种基本类型。研究区滑移变形层理保存之完好,形态图案之精美,层系规模之宏大,为国内外同期地层中所罕见,是一种不可再生的珍稀地质遗迹资源。它的发现,不但为进一步研究我国右江三叠纪周缘前陆盆地的沉积特征、演化历程提供了新的地质资料和场所,亦对丰富和发展沉积学理论具有非常重要的科学意义。而且研究区可作为一种地质旅游资源加以保护与开发利用,对促进偏远少数民族地区的经济发展具有重要现实意义。

Large-scale slip deformational beding from the Middle Triassic turbidites in Dayang, Ceheng, Guizhou:Discovery and significance

A group of catagraphites was discovered by the authors in the Yunshang valley, Luoyang village, Dayang, Ceheng, Guizhou Province. These rocks display the arabesquitic patterns on the rock surface, and are scattered toward NW along the valley with a length of 2 km. The rock types consist of fine-grained sandstones and siltstones from the middle and upper parts of the lower submember of the 4th member of the Middle Triassic Xuman Formation. The strange patterns on the above-mentioned rocks, which are very rare for their exquisite patterns, well-preserved beddings and large scales, actually constitute large-scale glide deformational beddings as a special type of soft sediment deformational structures, and thus are assigned to the rare geological heritage resources. The discovery of the Dayang large-scale glide deformational beddings has very important scientific significance not only for the study of sedimentary characteristics and evolution of the Youjiang Triassic foreland basin, but also for the protection and development of the geological tourism resources in the remote areas of China.