A Statistical Approach to Evolving Guides for Mica Search in Nellore Mica Belt around Gudur, Andhra Pradesh

Search for mica deposits presents peculiar problems owing to great complexities associated with pegmatite bodies. All pegmatites do not develop mica and not all mica-bearing pegmatites carry commercially workable quantity of mica. Prospecting for mica has therefore been a highly speculative and risky venture. It is in this context that the use of characteristic analysis, a multivariate statistical technique, has been made for the development of a composite geological model of the most typical indices of pegmatites of Nellore mica belt around Gudur in Andhra Pradesh, in order to evolve prospecting guides for mica search.

Data pertaining to geological variables gathered through surface mapping, field observation and geological studies of pegmatite bodies of Gudur mica region have been statistically treated for characteristic analysis. The approach elucidates most typical characteristics of pegmatites favourable for hosting commercially workable mica deposits. The geological variables associated with mica mineralization have been selected through an extensive survey and analogy. The model is governed by choosing sample locations and geological variables that best reflect mica mineralization. Presence of albite, undeformed pegmatite and kaolinization have been determined to be the most characteristic indices for mica search in the pegmatites of Nellore mica belt around Gudur.