Deccan Volcanism and Movement of Indian Plate

Context and Recent Study Findings

A recent study has shed new light on the impact of Deccan Volcanism on the Indian Plate. The research indicates that while this massive volcanic activity led to widespread extinction of fauna, tropical flora demonstrated significant resilience.

Mass extinctions are catastrophic events causing rapid loss of biodiversity. They are often triggered by factors like severe climate changes, asteroid impacts, or large-scale volcanic eruptions.

Impact on Fauna and Flora

The Deccan Volcanism played a significant role in the mass extinction of dinosaurs and other associated fauna. It also negatively impacted gymnosperms, a group of primitive plants.

However, surprisingly, the volcanic activity supported a hyper-diverse tropical flora. It achieved this by creating fertile and relatively undisturbed habitats, which allowed angiosperms to thrive rather than face extinction.

A combination of a warm, humid climate during the volcanic period and the Indian Plate's movement through the equator significantly contributed to this flourishing floral diversity.

Global and Regional Implications

Globally, Deccan volcanism is recognized as a contributing factor to the Cretaceous-Paleogene (K-Pg) mass extinction event, which occurred approximately 66 million years ago. This event famously led to the demise of ammonoids (invertebrate cephalopods) and dinosaurs.

Despite this global catastrophe, tropical rainforests on the Indian Plate adapted and flourished. This resilience highlights the inherent robustness of tropical flora when faced with severe climatic stresses.

Deccan Volcanism Theory

The Deccan Volcanism Theory posits that the massive volcanic eruptions responsible for forming the Deccan Traps played a crucial role in the mass extinction event around 66 million years ago.

The Deccan Traps constitute a vast volcanic plateau situated in peninsular India. They were formed by extensive fissure volcanic eruptions.

Formation of Deccan Traps

The formation of the Deccan Traps is attributed to intense volcanic activity driven by the Deccan mantle plume. This volcanic activity persisted for several hundred thousand years, depositing immense layers of lava.

Today, the Deccan Traps are characterized by extensive layers of basaltic lava flows, which are the remnants of these colossal volcanic eruptions.

Connection with Indian Plate Movement

Historically, India was a large island positioned off the coast of Australia. It is believed that the Indian Plate commenced its northward journey approximately 200 million years ago.

Beneath the Indian Plate lies the Réunion hotspot, which is a mantle plume of hot, molten rock originating from the Earth's interior. As the Indian Plate traversed over this Réunion hotspot, the resulting fissure volcanic eruptions led to the formation of the Deccan Traps.

Economic Significance of Deccan Volcanism

The geological legacy of Deccan Volcanism has several economic implications for India:

• Major Rocks: The Deccan Traps are predominantly composed of basalt. In contrast, granite and gneiss are common in southern India, particularly in Karnataka and Tamil Nadu.
• Mineral Resources: The region is rich in mineral deposits. Iron ore is found in abundance in Karnataka, while bauxite deposits are significant in the Eastern Ghats.
• Agriculture: The weathering of volcanic rocks, especially basalt, gives rise to Black soil (Regur soil). This soil is rich in minerals like iron, magnesium, calcium, and potassium, making it highly fertile and ideal for cultivating crops such as cotton and tobacco.