India’s geographical tapestry is a masterpiece of diversity, painting landscapes that range from snow-kissed mountain peaks to arid deserts, undulating plains, rugged hills, and expansive plateaus.
Nestled in the southern expanse of the Indian Peninsula lies a geological wonder known as the Deccan Traps, a flood basalt province of monumental proportions. This article unravels the mysteries of the Deccan Traps, exploring their origin, features, and the profound impact they’ve had on the region.
What are Deccan Traps?
The Deccan Traps are a vast geological formation located in the western and central regions of India, covering an area of approximately 500,000 square kilometers. They consist of a thick sequence of late Cretaceous basaltic lava flows, with a total thickness reaching up to 3,200 meters in some places.
The term “trap” is derived from the Swedish word “trappa,” meaning staircase, which describes the step-like appearance of the geological formations.
Formation of Deccan Trap
The formation of the Deccan Traps is attributed to Cretaceous vulcanicity, characterized by the development of extensive linear fractures in the Earth’s crust. These eruptions, notably of the effusive type, did not lead to the creation of volcanic domes but rather resulted in the formation of the Deccan Traps plateau.
This geological phenomenon commenced approximately 66.25 million years ago, marking the conclusion of the Cretaceous period. At that time, India was positioned in close proximity to present-day Madagascar. As India gradually migrated northward, it passed over the Reunion Hotspot, which is currently in a dormant state.
The Deccan Traps formed through a series of remarkable geological events:
- Volcanic Activity: About 66 to 68 million years ago, a surge of volcanic activity occurred in the Deccan region.
- Mantle Plume: A column of superheated rock, known as a mantle plume, rose from deep within the Earth, bringing molten rock to the surface.
- Explosive Eruptions: The pressure from the accumulating magma eventually broke through the Earth’s crust, causing massive volcanic eruptions that released large amounts of fluid lava.
- Flood Basalt Eruptions: These eruptions were of an extraordinary scale, covering extensive areas with lava.
- Layered Accumulation: The flowing lava formed layers over time, gradually building up the immense plateau known as the Deccan Traps.
- Terraced Landscape: As the lava cooled and solidified, it created the distinctive step-like formations seen in the Deccan Traps.
- Erosion: Over millions of years, natural forces like wind and water shaped the plateau, revealing the stunning geological formations we see today.
This process of volcanic activity, magma movement, and lava flow accumulation shaped the remarkable landscape of the Deccan Traps, offering insights into Earth’s dynamic geological history.
Features of Deccan Trap
Here are the features of the Deccan Trap:
- Referred to as regur soil or black dirt due to its high clay content, making it sticky when wet.
- Develops in semi-arid regions covered with basalt.
- Almost devoid of humus, appearing black due to titanium salt in the lava.
- Contains abundant lime, especially in lowlands and river valleys, leading to good moisture retention and high productivity.
- Displays consistent layered construction with nearly horizontal strata, indicating uniform mineralogical composition.
- Lava flow thickness varies from 3 to 30 meters or more.
- The area covered by lava flows often exceeds the layer thickness, sometimes reaching up to 100 km.
- Intermittent non-volcanic Inter-Trappean Beds disrupt the consecutive flows, showing deposits from ancient rivers and lakes.
- Well-preserved fossils of animals and plants found in inter-trappean strata offer insights into periods of reduced volcanic activity.
Distribution of Deccan Traps in India
The Deccan Traps, a monumental geological feature, blanket a significant expanse of Peninsular India. Their extensive distribution is a testament to the cataclysmic volcanic activity that shaped this region over millions of years.
The majority of these volcanic rocks are concentrated in several key regions across India. Notable locations include:
- Gujarat’s Kutch and Kathiawar Regions: These areas in the western part of India are characterized by extensive deposits of Deccan Traps. The solidified lava flows here serve as a vivid testament to the colossal volcanic eruptions that once occurred in this region.
- Andhra Pradesh: The Deccan Traps continue their sprawling presence in the state of Andhra Pradesh. Here, they form prominent geological features and contribute to the distinctive landscape of the region.
- Madhya Pradesh: In the heart of India lies Madhya Pradesh, where the Deccan Traps have left a profound mark. The layers of volcanic rock in this region are a testament to the sheer volume of lava that was extruded during the volcanic episodes.
- Maharashtra: Maharashtra is perhaps the most renowned region for its association with the Deccan Traps. Here, the volcanic deposits are exceptionally extensive, shaping the topography and influencing the geological history of the area.
Classification of Deccan Traps
- Upper Traps:
- The Upper Traps form the highest layer of the Deccan Traps. They are characterized by a distinct geological composition and are situated above the Middle and Lower Traps.
- Middle Traps:
- The Middle Traps occupy the intermediate position within the Deccan Traps geological formation. They are located between the Upper and Lower Traps.
- Lower Traps:
- The Lower Traps constitute the lowest layer of the Deccan Traps. They are situated beneath both the Middle and Upper Traps.
What is the age of Deccan Traps?
The age of the Deccan Traps is a subject of ongoing scientific debate. There are two main theories:
- Danian Stage of the Upper Cretaceous: This theory suggests that the Deccan Traps are roughly contemporaneous with the Danian Stage of the Upper Cretaceous period, which occurred approximately 66 million years ago.
- Lower Eocene Age: An alternative theory, supported by fossil evidence, proposes a Lower Eocene age, which would place the formation of the Deccan Traps around 56 to 54 million years ago.
While there is evidence supporting both theories, no widespread consensus has been reached among the scientific community. It’s important to note that geological dating involves complex methods and interpretations, and refining the age estimates of formations like the Deccan Traps is an ongoing area of research.
Also Read: Important Hills of India
In conclusion, the Deccan Traps stand as a testament to the dynamic geological history of India. Formed over millions of years through a series of volcanic eruptions, these layered basalt formations offer valuable insights into Earth’s ancient past.
The diverse rock types and distinctive characteristics of the Traps, including tholeiitic and alkali basalts, olivine basalt, and more, showcase the complex processes that shaped this region. With its rich fossil record and unique soil properties, the Deccan Traps continue to be a subject of fascination for geologists and a significant part of India’s geological heritage.
This extraordinary landscape serves as a window into the deep history of our planet and the intricate interplay of forces that have shaped it.