From Magmatic Reservoirs to Solid Rocks: A Deep Dive into the Origin and Evolution of Deccan Trap

The term “Deccan Trap,” introduced by W.H. Sykes in 1833, characterizes the step-like or terrace-like topography found in the Deccan Trap terrain, the second most extensive geological formation in peninsular India. The Deccan Traps, a vast and intriguing geological formation, have captivated the attention of researchers and geologists for decades. Spanning across the Marathwada region, this extensive lava plateau holds a profound story within its solidified rocks, one that unfolds through the intricate processes of magma origin and evolution. This research paper delves into the intricacies of the Deccan Trap, specifically in the Marathwada region. The total thickness of the Deccan Trap varies across different areas due to the undulating nature of the underlying terrain. The west coast, near Bombay, exhibits a thickness of over 2000m, while other regions, such as Matheran, Sahyadri, and Melghat scarp, display varying thicknesses. Understanding the nature of volcanic activity that produced these lava flows is crucial for deciphering the geological history of the Deccan Trap. The study employs a detailed analysis of lava flows, considering their field characters as indicators of volcanic activity. The classification of flows into compact basalt and amygdaloidal basalt reveals distinct characteristics. Compact basalt flows, thick and extensive with a high ratio, are devoid of gas cavities. In contrast, amygdaloidal flows, limited in lateral extent with a low ratio, display vesicular characteristics throughout their thickness, indicating the influence of gas cavities. This research contributes valuable insights into the volcanic history of the Deccan Trap, shedding light on the fluidity and viscosity of the lava that shaped its unique topography. The findings provide a foundation for understanding the geological processes that led to the formation of one of India’s most remarkable geological features.