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The Imperial Gazetteer of India TABLE OF CONTENTS

Comparative uniformity of life in the ocean

Want of strict contemporaneity in geological formation

Use of local stratigraphical names

Classification of Indian strata

The datum line in stratigraphy

The Olenellus zone

Pre-Cambrian unfossiliferous rocks

Fossiliferous deposits

Four resultant main groups

Archaean group

Purana group

Grouping of the fossiliferous strata

The Upper Palaeozoic break

Dravidian and Aryan groups

The Dravidian group in extra-peninsular India.

Fresh-water deposits in the Aryan group

Marine deposits in the Aryan group

II. Pre-Cambrian History of India

The Archaean and Purana eras in the pre-Cambrian history of India

The great Eparchaean break

Archaean era

Area of the Archaean rocks

Origin and nature of the fundamental complex.

Orthogneisses and paragneisses

Mixed gneisses

Chief divisions of the Archaean group

The Dharwarian system

The Purana era

Distribution of the Purana group

Lower and upper divisions of the Purana group

The Cuddapah and Kurnool systems

The Vindhyan system

The Purana group in Burma

Possible existence of the Purana group in the Himalayas

III. Cambrian and Post-Cambrian history of India

A. The Dravidian Era

The Cambrian of the Salt Range

Purple sandstone and Neobolus beds

Magnesian sandstone series and salt pseudomorph zone

Palaeozoic of the Central Himalayas