In this book the rocks composing the surface of the Earth are classified, their modes of formation are analysed, and their inherent characters are described. The methods of dating the rocks are explained in the text, and the geological time scale is also prepared. The reality of the volcanic activities across the globe has been minutely furnished, and the volcanoes are classified with vivid description of their erupted materials. The cause and the nature of the earthquakes are meticulously explored here and their detection methods are pointed out as well. The balancing of the topographically high and low features of the rigid upper part of the Earth has been aptly expounded in the book along with their significance. The fragmentation of the rigid upper shell of the Earth has been taken into account in this treatise and different kinds of movement of the fragments and the resultant activities and their features are also presented. The author has delved deep into the orogenic belts of India from the perspective of global geotectonics scenario.