What is the common rock found in Kolkata?
Answers
Two geologists from West Bengal discovered rocks, which date back to 4240 and 4030 million years. The rocks are believed to be the oldest in India and second-oldest rocks in the world.
The age of the Earth is generally derived from meteoritic record, which is 4568 million years. However, the oldest age recorded from rocks on Earth is 4400 million years, which is the age of a zircon grain.
The two geologists examined the rocks collected from Champua in Odisha and examined them under microscope at the Geological Laboratories in Kolkata’s Indian Statistical Institute. The machine essential for such isotopic analyses is called Sensitive High Resolution Ion Microprobe (SHRIMP). This machine is not available in India.
Geologists searching for rocks in Field, eastern India
So, the rocks were sent for testing in collaboration with Dr Yusheng Wan at Beijing Shrimp Centre under Chinese Academy of Geological Sciences.
SHRIMP analysis confirmed that the rocks to be possible oldest rocks in India. The results confirmed the presence of two zircons grains in the rocks, which are 4240 and 4030 million years old respectively.
Dr Rajat Mazumdar tried to get the findings tested in Australia and other countries. Finally, it was tested in China.
Tonalite-Trondhjemite-Granodiorite rock, eastern India (photo taken during UNESCO-IGCP 509 International Workshop in 2009)
According to Dr Mazumder, “Zircon, a very robust mineral can be used to date its parent rock. The oldest 4400 million years old zircon was discovered from a small exposure of metamorphosed sedimentary rock (reworked Zircon and known as detrital Zircon) at Jack Hill of Western Australia.”
“SHRIMP Center in Beijing’s Chinese Academy of Geological Sciences Beijing agreed to analyze only four samples on collaboration basis,” Dr Mazumder said.
“I was a team member and worked under Dr Mazumder’s supervision at ISI in Kolkata. It is a teamwork,”Trisrota Chaudhuri told Mirror.
The SHRIMP Machine at the Beijing SHRIMP Center, China.
The work as a research paper has been published in Scientific Report, a Nature group journal.
Dr Mazumder is now associated with Curtin University of Malayasia.
However, Dr Mazumder said that the research work on oldest rocks was initiated by a team of researchers at Presidency College way back in 1981 under Late Professor Ajit Kumar Saha, his other associates and Asish Ranjan Basu, presently at University of Texas at Arlington, and ) many others.
Answer:
Explanation:Two geologists from West Bengal discovered rocks, which date back to 4240 and 4030 million years. The rocks are believed to be the oldest in India and second-oldest rocks in the world.
The age of the Earth is generally derived from meteoritic record, which is 4568 million years. However, the oldest age recorded from rocks on Earth is 4400 million years, which is the age of a zircon grain.
The two geologists examined the rocks collected from Champua in Odisha and examined them under microscope at the Geological Laboratories in Kolkata’s Indian Statistical Institute. The machine essential for such isotopic analyses is called Sensitive High Resolution Ion Microprobe (SHRIMP). This machine is not available in India.
Geologists searching for rocks in Field, eastern India
So, the rocks were sent for testing in collaboration with Dr Yusheng Wan at Beijing Shrimp Centre under Chinese Academy of Geological Sciences.
SHRIMP analysis confirmed that the rocks to be possible oldest rocks in India. The results confirmed the presence of two zircons grains in the rocks, which are 4240 and 4030 million years old respectively.
Dr Rajat Mazumdar tried to get the findings tested in Australia and other countries. Finally, it was tested in China.
Tonalite-Trondhjemite-Granodiorite rock, eastern India (photo taken during UNESCO-IGCP 509 International Workshop in 2009)
According to Dr Mazumder, “Zircon, a very robust mineral can be used to date its parent rock. The oldest 4400 million years old zircon was discovered from a small exposure of metamorphosed sedimentary rock (reworked Zircon and known as detrital Zircon) at Jack Hill of Western Australia.”
“SHRIMP Center in Beijing’s Chinese Academy of Geological Sciences Beijing agreed to analyze only four samples on collaboration basis,” Dr Mazumder said.
“I was a team member and worked under Dr Mazumder’s supervision at ISI in Kolkata. It is a teamwork,”Trisrota Chaudhuri told Mirror.
The SHRIMP Machine at the Beijing SHRIMP Center, China.
The work as a research paper has been published in Scientific Report, a Nature group journal.
Dr Mazumder is now associated with Curtin University of Malayasia.
However, Dr Mazumder said that the research work on oldest rocks was initiated by a team of researchers at Presidency College way back in 1981 under Late Professor Ajit Kumar Saha, his other associates and Asish Ranjan Basu, presently at University of Texas at Arlington, and ) many others.
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