Structure and Physiography | Class 11 Geography Notes

Introduction

The Earth has a long and complex history, with its current landforms evolving over approximately 4600 million years. The physical features we observe today are the result of continuous geological processes driven by endogenic (internal) and exogenic (external) forces. Endogenic forces include tectonic plate movements, volcanic activity, and mountain building, while exogenic forces encompass weathering, erosion, and sedimentation. The Indian subcontinent's geological evolution is closely linked to the movement of the Indian plate, which was once located south of the equator and was much larger, including what is now the Australian plate. Over millions of years, the Indian plate drifted northwards, colliding with the Eurasian plate, a movement that continues today and has profound effects on the region's physical environment, including the formation of the Himalayas. This chapter introduces the geological structure and physiographic divisions of India, explaining how these features have been shaped by geological processes and plate tectonics. India’s geological structure is broadly divided into three major divisions: the Peninsular Block, the Himalayas and other Peninsular mountains, and the Indo-Ganga-Brahmaputra Plain. Each division has distinct geological characteristics and physical features.

🧪 Activity: Map the phases of the Indian plate’s northward movement using an atlas or geological map.

🔗 Connection: Leads to detailed study of the geological structure of India and its three major divisions.