Geology is special interest for me. Let me share something about the age of Himalayas – according to a new study, its about 15 million years old.
The Himalayas may be a good five million years older than earlier estimates about the formation of the world’s highest mountain range, according to a joint study by Indian and British ocean scientists.
The new findings position the era of formation of the Himalayas to around 13.9-14.4 million years ago as against the earlier theory of eight million years.
The joint study carried out by Dr K S Krishna of National Institute of Oceanography (NIO) and his British colleagues, Southampton University Professor Jon Bull and Edinburg University Professor Roger Scrutton was published in the March issue of the Geological Society of America journal, Geology.
The study found that the Earth’s strong outer shell – the lithosphere – within the central Indian Ocean began to deform and fracture 13.9-14.4 million years ago, much earlier than previously thought.
It focuses on the tectonics-related deformation of the lithosphere below the central Indian Ocean.
India and Asia collided around 50 million years ago as a result of plate tectonics, large-scale movements of the lithosphere, which continues to this day, the study states.
This will impact our understanding of the birth of the Himalayas and the strengthening of the Indian-Asian monsoon, it adds.
“Compression of the lithosphere has caused large-scale buckling and cracking. The ocean floor has been systematically transformed into folds 100-300 kilometres long and 2,000-3,000 metres high, and there are also regularly spaced faults or cracks that are evident from seismic surveys and ocean drilling,” Krishna said.
The study paper mentions that the onset of this deformation marks the start of a major geological uplift of the Himalayas and the Tibetan Plateau, some 4,000 km further to the north, due to stresses within the wider India-Asia area.
Previous studies indicate that the uplift began around 8.0-7.5 million years ago, while others have said it started before 8.0 million years ago and perhaps much earlier, the study contends.
The researchers asanalysed seismic profiles of 293 faults (vertical cracks in the ocean floor) in the accumulated sediments of the Bengal Fan, a delta-shaped accumulation of land-derived sediments covering the floor of Bay of Bengal.
They demonstrate that deformation of lithosphere within the central Indian Ocean started around 13.9-14.4 million years ago. This implies considerable Himalayan uplift before 8.0 million years ago, which is when many geologists believe that the strong seasonal winds of India-Asia monsoon first started,” the study states.