This revised edition is the outcome of the need of the latest information of geological research developed in last five years. In revising this book, author has departed somewhat widely from the prevailing order of treatment in current texts. Instead of beginning with the destruction of rocks, it has seemed more logical to give the student some knowledge of the rocks to be destroyed, and of their character and origin. Instead of treating clastic rocks first and igneous and other non-clastic rocks later, it has seemed more desirable to begin with those rocks from which clastic are largely derived, before dealing with the clastics themselves. Seventeen years of teaching experience has convinced him that the average student admitted to courses in geology receives too little instruction in minerals. Although we generally recommend mineralogy as a desirable prerequisite, few teachers can insist upon a preparation in this subject on the part of the student. Author has taken special pain to correct all major and minor mistakes and incorporated all necessary suggestions and comments of the readers in second edition. The material presented here would be of interest as well as great use to the students, research scholars and teachers of geology.