This book is a compilation of researches and advanced theories from all the areas of geology. Some of the diverse topics also address the varied branches that fall under this category such as volcanology, sedimentology, plate tectonics, paleontology, geomorphology, and geochemistry. This book can be seen as a complete source of knowledge on the present status of this important field. Also the changes that took place over the past times in many countries across the world, which eventually were studied by geologists, are also examined in this book. The advancement and impacts of present researches have also been discussed in this book.