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Abstract <p>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 &lt;1 kg. The major silicate minerals olivine (Fa<sub>29</sub>) and low-Ca pyroxene (Fs<sub>24</sub>) 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.</p> Research highlights <p><UnorderedList Mark="Bullet"> <ItemContent> <p>Kopargaon chondrite is one of the latest meteorites fall in India.</p> </ItemContent> <ItemContent> <p>Kopargaon resembles fragmental breccia and is petrologically assigned as LL5 type.</p> </ItemContent> <ItemContent> <p>Kopargaon chondrite shares similar mineralogical and geochemical characteristics to Asteroid Itokawa, a retuned sample by the Hayabusa mission (JAXA).</p> </ItemContent> </UnorderedList></p>

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

  • 期刊论文

  • 发表日期：

    2025年1月28日

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

摘要

Abstract

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.

Research highlights

Kopargaon chondrite is one of the latest meteorites fall in India.

Kopargaon resembles fragmental breccia and is petrologically assigned as LL5 type.

Kopargaon chondrite shares similar mineralogical and geochemical characteristics to Asteroid Itokawa, a retuned sample by the Hayabusa mission (JAXA).