Pichhore orbicular granite, located near Kutawali village in Shivpuri district, Madhya Pradesh, has been dated to about 2.56 billion years

Pichhore orbicular granite, located near Kutawali village in Shivpuri district, Madhya Pradesh, has been dated to about 2.56 billion years

¨     Pichhore orbicular granite, located near Kutawali village in Shivpuri district, Madhya Pradesh, has been dated to about 2.56 billion years.

¨     It is the second-oldest known orbicular rock in the world, after a similar formation in Western Australia.

¨     Orbicular granite is a rare igneous rock containing orbicules, which are rounded or spherical structures formed within the rock.

¨     The orbicules are mainly composed of quartz and feldspar and often display concentric layers similar to tree rings.

¨     Scientists determined the rock's age using Uranium–Lead (U-Pb) zircon dating.

¨     The granite crystallised during the Neoarchean Era, around 2.56 billion years ago.

¨     Inherited zircon crystals in the rock are as old as 3.5 billion years, making them among the oldest mineral records in the Indian Shield.

¨     The rock is part of the Bundelkhand Craton, one of the oldest and most stable geological blocks in India.

¨     A craton is a stable part of the continental crust that has remained largely undeformed over very long geological periods.

¨     The presence of ancient zircon fragments indicates the recycling of early continental crust during Earth's early geological history.

¨     The Bundelkhand Craton is an important region for studying the evolution of the Indian Shield and Precambrian geology.

¨     Orbicules can grow up to 30 centimetres in diameter.

¨     Uranium–Lead (U-Pb) zircon dating is the standard scientific method for determining the age of very ancient rocks.

¨     The study involved researchers from Banaras Hindu University (BHU), IIT Kanpur, IISER Berhampur, the University of Campinas (Brazil), and JAIST (Japan Advanced Institute of Science and Technology).