Tephra, the Greek word for ash, is used to describe any material that is ejected by a volcano into the atmosphere (pyroclasts). Tephra includes dense blocks and bombs (> 64 mm), and lighter materials such as scoria, pumice and ash (< 2 mm). As one moves away from a volcano, the tephra deposits become finer grained (smaller particles) and thinner. This is because small airborne particles hover longer and stay within the atmosphere for a greater distance from the volcano. These particles of ash …

The lab is equipped with various instruments for the preparation of sediment and soil samples.

The section is well equipped for rock crushing, sieving and milling, preparation of thin and polished sections and grain mounts, and mineral separation by gravimetric and magnetic methods. We maintain central facilities and equipment for cleaning, crushing, sieving and grinding rock samples, both for preparation of homogenized whole rock powders and for the production of mineral separates. Whole rock powders (grain sizes < 62 μm) are typically used for X-Ray diffraction (XRD), X-Ray …