采用现代微观测试技术手段，对华南P/T界线附近不同沉积相火山灰粘土层中锐钛矿纳米矿物学特征、及其对火山灰沉积物沉积改造过程的指示意义等开展深入系统的研究，查明不同沉积相的沉积-早成岩环境介质条件对火山灰蚀变过程中纳米锐钛矿沉积的制约关系、以及蚀变转化过程中钛元素的迁移流失机制；弄清不同沉积相环境条件下决定火山物质蚀变过程中锐钛矿的矿物学特征（颗粒度大小、晶体形态、结晶取向、晶面相对发育程度等）、以及独立矿物钛与粘土矿物晶格钛分布关系，建立火山灰粘土层中锐钛矿纳米矿物学特征与沉积相环境介质条件之间的对应关系，结合粘土层副矿物及典型不活动元素分布特征的综合研究结果，探究锐钛矿纳米矿物学特征所蕴含的火山灰沉积物沉积、改造历史的信息。

To obtain better understanding of the effect of sedimentation-early diagenesis conditions and reworking processes of volcanic ash beds on nano mineralogy of anatase, study on altered ash layers in the Permian-Triassic boundary stratigraphic sets in southern China is undertaken using modern microscopic methods. Study will be undertaken to reveal the constraints of sedementation-early diagenesis conditions on deposition processes of nano anatase as well as the mechanisms of migration and loss of titanium during alteration of volcanic ashes, also the effect of different sedimentary facies conditions on the mineralogical characteristics of nano anatase (grain size distribution, crystal morphology, crystalline orientation, relative development of crystal plane, etc.) and the distribution between independent mineral titanium and lattice titanium of clay minerals, so as the relationship between nano mineralogical characteristics of anatase in volcanic ash layers and environmental conditions of sedimentary facies is established. Based on the comprehensive research results of secondary minerals and distribution of typical immobile elements of ash layers, the clues of sedimentation and reworking history of volcanic ash sediments contained in nano mineralogical characteristics of anatase could be finally interpreted.