After weathering of the rock

its quartz grains may be transported

abraded and deposited.These processes give rise to various secondary surface features.The study of these surface textural features

especially the features of their combination

may allow us to reconstruct the sedimen- tary environment and evolutional history from one aspect.With the scanning electron microscope

the authors have studied thesurface textural features of the Quaternary quartz grains of morainic

glacio fluvial

eluvial

alluvial

diluvial

mud-rock flow

lacustrine and eolianorigin in Tibet

Sichuan

Xinjiang

North China

etc.This is of majorim portance for studying the quartz grains of other geological ages and recon-structing their sedimentary environments.Under different climatic conditions

the degrees of solution-precipita-tion of silica on the surface of the quartz grains are different.On thatbasis

three types of paleoclimate may be recognized:high-energy chemical

low-energy chemical and non-solution environmental types

which represent wet-hot

warm-cool and cold climates respectively.In this paper

according to the solution-precipitation features on thesurfaces of the quartz grains

the authors reconstruct the paleoclimate withreference to the example of the Quaternary geological section of the front of Mt.Longquan

Sichuan

and thereby negate the concept of“glacial deposits”proposed by predecessors.