Surface textural analysis of quartz grains by scanning electron microscopy (SEM): From sample preparation to environmental interpretation

Surface microtextures on quartz grains provide an insight into the sedimentary history of clastic sediments. Not only information on the depositional environment is provided, but also in some cases, successive sedimentary cycles can be recognised. Sample preparation and SEM imaging are the initial, and therefore crucial, steps in the study of microtextures. A sample preparation procedure using 15% hydrochloric acid and 50 g/L tetrasodium pyrophosphate solutions removes most of the grain coatings and adhering particles. The study of microtextures on 1300 quartz grains from a wide variety of environments was complemented with the reference works and atlases (Krinsley and Doornkamp, 1973; Le Ribault, 1977; Higgs, 1979; Mahaney, 2002) to construct an interpretation scheme allowing to differentiate between fluvial, marine, eolian, glacial and diagenetic/alteration environments based on microtextures. In a case study, the known littoral setting of two samples was confirmed by using the interpretation scheme for quartz microtextures. Furthermore, successive reworking of the grains in eolian and intertidal environments was recognised.By presenting the research of microtextures from starting point to interpretation, new researchers may find this review a useful and practical introduction into the technique.