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NELLORE MANUAL.

GEOLOGY. - Stratification. Metamorphic rocks.-- Gneissose and Quartzose. - Hornblende Schist.-- Micaceous and Talcose Schists. - Granite .-- Quartzite and altered Sand -stones. Cuddapah Group. - Laterite. - Alluvium. - Sriharikota. --Gudur.'— Nellore. — Kavali.— Kandukur. -Ongole. -Darsi. -Podile. ---Kanigiri. -Udayagiri. --Atmakur. — Rapur. Venkatagiri.— Polur. - Rocks. — Igneous, Metamorphic, Aqueous, and Alluvial. — Organic remains. Soils. - River System.— Ongole. — Darsi. — Podile. — Kandukur. – Kanigiri. Udayagiri. — Atmakur. — Rapur. - Kavali. - Nellore. - Gudur. - Sriharikota. — Table of Classification of soils.

the general observer the geological and mineralogical features of the district do not present much of special interest. Generally speaking the district of Nellore, like the greater part of Southern India, may be said to be one of which the underlying rocks are of the class called by geologists the metamorphic or gneissose rocks. Of these, however, there is a great variety : gneiss properly so called in one place, and in others various forms of the different schistose rocks, which constitute the other varieties of the metamorphic rocks, such as hornblende schist, micaceous and talcose schists, and not unfrequently bands of almost purely quartzose composition which may be called quartz-rock. These varieties alternate in bands, very frequently narrow bands, and with many alternations; but more commonly one or other variety prevails over a considerable area, giving to it its general character, and thus roughly the district may be divided into geological areas or broad longitudinal bands, characterised by the variety of rock more prevalent, as bands of hornblendic gneiss, of hornblende schist, micaceous schist, and so on, the bands or beds of quartz -rock being generally very subordinate to the other types, and occurring only as narrow belts in them, not giving a general character to any wide area. Much of the gneiss, and particularly in the southern parts of the district, is very granite like ; and in small masses could scarcely be called anything else but granite, although, even then, a tendency to lamination or a general arrangement of its constituent mineral in lines more or less distinctly marked is commonly traceable. The schistose varieties exhibit this much more distinctly, and indeed present exactly the appearance of having been definitely bedded rocks,