Few representative quartz grains, collected from Gopalpur coast, were studied under the Scanning Electron Microscope for understanding their micromorphology. Micro features of quartz grains were examined under SEM. The aim of the study is to do the interpretations of the different micro feature in respect to depositional environmental. Micro features like conchoidal fracture, breakage blocks, different types of grooves and pits were noted. It is observed that quartz grains show mostly the features of mechanical impact. The grains have experienced subaqueous collision and various impacts in the littoral environment in the near shore area. The surface microfeatures of some grains, studied under the SEM indicated a high energy environment of deposition.The Ganjam coastal belt is a wave dominant type. The grains of this region experience reworking process. Two types of quartz are present in the sediment, identified under microscope. The first type is fresh quartz grains and the second type shows reddish brown color which is due to iron staining. The fresh colorless quartz grains are possibly derived from Quaternary sediments. The brownish quartz grains may be the relict sands which were exposed during the low stand of sea level. These have been oxidized. The inner/middle shelf of Orissa offshore contains relict sands which might have been transported by wave and tide on the coast. Quartz is the most abundant mineral in the inner shelf sediments off Gopalpur coast.
Step structures with various shapes: Regular step like features by producing series of parallel striations are observed. The surface of the grain is fractured. Both straight and arcuate fractures are found. The steps are straight or curved due to irregular breaking of surface. These features are normally developed by fluvial transportation and collision in near shore zone.
V shaped pits: There are Oriented etch V’s and V shaped triangular pits indicating chemical actions. Sometimes these features are found at the edge of grain. The abundance of V’s is related to the duration and intensity of subaqueous impact.
Multicycle micro features: Well-rounded grain with complex assemblages of multicycle microfeatures are observed, indicating recycling of sediments from extraneous source. Edges are found to be round. It suggests prolonged transportation.
Mechanical pits: Mechanical impact pits indicates high physical energy condition, characteristic of coastal areas.
Conchoidal fracture: It is most common feature in most of the quartz grains. These features are developed by broken surface. It exhibits concave shaped planes.
Irregular pits and grooves: On the surface planes some irregular shaped pits are developed by mechanical disintegration. These can be produced by impact of collision of grains. The grooves formed by impact of aeolian action.
Parallel striations: Quartz grains show parallel striations with high relief. It is formed due to aeolian transport.
Breakage blocks: These features are formed of irregular, slightly raised straight or curved areas. In some grains, they have resulted in rugged surface pattern and are developed due to high energy condition by collision of grains. Sometimes this feature indicates first cycle character and nearby source of sediments. Usually these features are produced in medium to high energy littoral environment by collision of grains during wave action. Some of the rough broken surface or edges have been smoothen out or rounded as a result of long transportation. Breaking blocks can also be smoothened out by natural processes.