The Kopargaon LL5 chondrite: A new fall of monomict breccia from India

D Ray, S Sarkar, A Das, G Arora, A D Shukla & Anil Bhardwaj

Journal of Earth System Science, Volume 134, article number 37, Published: 28 January 2025

LINK

“A fresh meteorite fell on Kopargaon taluk of Ahmednagar district, Maharashtra, India, on 24 January 2023 (06:50 Indian Standard Time). The meteorite crashed on a flat metal roof of a house, went through it and then struck the floor, leaving a depression that was roughly 2 inches in diameter. The high-velocity impact caused the main mass to break into several smaller pieces. The shards’ total recovered mass was <1 kg. The major silicate minerals olivine (Fa29) and low-Ca pyroxene (Fs24) are highly equilibrated and homogenized and petrologically classified as LL type. The brecciated matrix contains a variety of lithic, chondrule and mineral clasts that further resemble a ‘fragmental breccia’ and are believed to be the remanent of a larger impact that affected the entire LL parent body. The Kopargaon experienced thermal metamorphism, and the peak metamorphic temperature is estimated to be around 727°C. It was subjected to a low to moderate degree of shock stage S2-3. The post-peak thermal metamorphism includes a cloudy zone in metals (Fe–Ni) formed due to the spinodal decomposition of taenite, which is indicative of slow cooling (preferably below 400°C). Locally, the presence of shock-melt veins argued for faster cooling during post-shock metamorphism. The mineralogical and chemical characteristics of the meteorite align with those of the stony meteorite samples returned by the Hayabusa mission (JAXA) from the asteroid Itokawa.”