An unusual lunar origin and chondritic refractory Antarctic micrometeorites
Year: 2024
Type: article
Abstract: We report unearthing the first silicate-type (S-type) lunar Antarctic micrometeorites (AMM) spherule and another spherule with a refractory chondritic phase. The lunar spherule is made of Augite with minor Ni magnetite (<1 wt.%), in contrast to other known cosmic spherules. The Augite’s minor oxide range in the spherule are as follows: Wo 37-41 En 25-27 Fs 34-36 , Al 2 O 3 : 0.7–1 wt.%, Cr 2 O 3 : 0.01–0.06 wt.%, MnO: 0.32–0.39 wt.% and TiO 2 : 0.03–0.09 wt.%. The lunar spherule’s chemical characteristics indicate that it originated from very low Ti lunar basalt (VLT) mare basalts. Chondritic diopside (Wo 46-47 En 50-47 Fs 5-6 , Al 2 O 3 : 1.7–1.6 wt.%, Cr 2 O 3 : 0.6–0.63 wt.%, MnO: 0.2–0.4 wt.%, and TiO 2 : 0.0–0.02 wt.%) makes up the refractory phase in the second spherule. The chemical composition of diopside is indistinct from those of calcium aluminium inclusion (CAIs) found in both ordinary and carbonaceous chondrites. Our finding reveals that micron-sized lunar impact debris can potentially reach the Earth’s surface, similar to the earliest formed nebulae solid component.
Source: Geoscience Frontiers
Authors: D. Fernandes, N.G. Rudraswami
Language: English
Topic: Astro and Planetary Science
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,000
OpenAlex ID: W4404851166