Rare earth metals are a group of 17 elements with many similar properties and are often found together in geologic deposits.
INDIA Updated: Sep 21, 2018 08:18 IST
An advanced remote-sensing technology developed by US space agency NASA to map minerals on the moon and Mars is being used in India for the first time to prospect for gold, diamonds, platinum and rare earth elements.
Rare earth metals are a group of 17 elements with many similar properties and are often found together in geologic deposits. They’re in high demand across the world because of their use in high technology devices such as smart phones, digital cameras, computer hard disks, fluorescent and light-emitting-diode (LED) lights and computer monitors, among others.
“In its pursuit for minerals, the GSI is going to use ultra-modern remote sensing technology to find lead, zinc, copper, gold, diamond and platinum, among others. This will be used for the first time in India,” Dinesh Gupta, director general, Geological Survey of India (GSI).
“Rare earth metals such as lanthanum, cerium, holmium and lutetium among others are a group of 17 elements, which have chemical similarities. They are not rare at all. They are called “rare” because it is unusual to find them in a pure form,” Gupta said.
China has almost 40% of the world’s known reserves of rare earth metals, but because most of the reserves are untapped (or are not viable to tap) it produces almost 80% of rare earth metals sold every year.
Called Advanced Visible Infra-Red Imaging Spectrometer-Next Generation (AVIRIS-NG), the sensor-based technology that will now be used in India has been proved effective for mapping surface mineralogy on earth, the moon and Mars.
“AVIRIS-NG is being used by Australia, USA, Canada and South Africa,” said Gupta.
The AVIRIS-NG sensor was mounted on an ISRO aircraft to get hyperspectral images of 14 mineralised blocks across India, including in Jhagadia in Gujarat, Udaipur in Rajasthan, Chhatarpur in Madhya Pradesh and Kuhi-Khobna in Maharashtra, among others.
GSI signed a MoU with the National Remote Sensing Centre (NRSC), a wing of the Indian Space Research Organization (ISRO), on September 5, to analyse data to trace the minerals from the hyperspectral images taken by ISRO in three phases – October to November 2015, January to February 2016, and April to May 2018.
“Over the next three years, scientists from the GSI and NRSC-ISRO will analyse the airborne hyper-spectral data to look for surface signatures of mineralization in those 14 promising areas,” he said.
Along with minerals such as gold, diamond, platinum, lead, zinc and copper, GSI scientists would be also looking for signatures of the 17 rare earth elements bearing host rocks.
“Remote sensing with visible infra-red imaging gives us indirect evidence of mineral deposits. They give us signatures that can at the best narrow down the search to areas with mineral deposits on the surface. Scientists will still need ground verification,” said NC Pant, professor of geology, Delhi University. Then, of course, comes the tougher prospect of identifying where the minerals can be extracted in a commercially viable manner.
First Published: Sep 21, 2018 06:58 IST