The CM carbonaceous chondrite regolith Diepenveen

Abstract

A carbonaceous chondrite was recovered immediately after the fall near the village of Diepenveen in the Netherlands on October 27, 1873, but came to light only in 2012. Analysis of sodium and poly‐aromatic hydrocarbon content suggests little contamination from handling. Diepenveen is a regolith breccia with an overall petrology consistent with a CM classification. Unlike most other CM chondrites, the bulk oxygen isotopes are extremely 16O rich, apparently dominated by the signature of anhydrous minerals, distributed on a steep slope pointing to the domain of intrinsic CM water. A small subset plots closer to the normal CM regime, on a parallel line 2 ‰ lower in δ17O. Different lithologies in Diepenveen experienced varying levels of aqueous alteration processing, being less aqueously altered at places rather than more heated. The presence of an agglutinate grain and the properties of methanol‐soluble organic compounds point to active impact processing of some of the clasts. Diepenveen belongs to a CM clan with ~5 Ma CRE age, longer than most other CM chondrites, and has a relatively young K‐Ar resetting age of ~1.5 Ga. As a CM chondrite, Diepenveen may be representative of samples soon to be returned from the surface of asteroid (162173) Ryugu by the Hayabusa2 spacecraft.

Chromium isotopic insights into the origin of chondrite parent bodies and the early terrestrial volatile depletion

“…The Cr isotope data for doping and external precision tests are reported in Table 2 and combined with literature data from Schiller et al (2014). In Table 3, we compare the 55 Mn/ 52 Cr and Cr isotope data for the same chondrites measured in this and previous studies (Go ¨pel et al, 2015;Jenniskens et al, 2012;Kadlag et al, 2019;Langbroek et al, 2019;Mougel et al, 2018;Moynier et al, 2007;Petitat et al, 2011;Qin et al, 2010;Sanborn et al, 2019;Schiller et al, 2014;Trinquier et al, 2007;2008b;van Kooten et al, 2020van Kooten et al, , 2016Williams et al, 2020;Zhu et al, 2020aZhu et al, , 2020b. The averaged group Cr isotope data and 55 Mn/ 52 Cr ratios of all the chondrites are reported in Table 4.…”

Heterogeneous nature of the carbonaceous chondrite breccia Aguas Zarcas – Cosmochemical characterization and origin of new carbonaceous chondrite lithologies

“…S6); Kerraouch et al, 2019, Matzka et al, 2021. High pressure and temperature events generally lead to a higher number of CHOMg and CHOSMg compounds together with a loss in chemical diversity, especially of nitrogen and sulfur compounds (Langbroek et al, 2019). The presence of almost double the amount of organomagnesium in the Met-1 lithology fraction but still with a high chemical diversity comparable to the Aguas Zarcas pre-rain matrix suggests that this lithology has undergone slight temperature stress or short-term temperature exposures.…”

Shidian meteorite, a new fall analog of near‐Earth asteroid (101955) Bennu

“…To date, only three xenolithic fragments have been reported, including a white clast in the meteorite Murchison (Isa et al., 2014; Kerraouch et al., 2019), an igneous fragment in Northwest Africa (NWA) 12651 (Ebert et al., 2019), and a metamorphosed lithic clast in Grove Mountains (GRV) 021536 (Zhang et al., 2010). CM chondrite parent bodies are thought to have contributed to the delivery of volatiles and organic material to the early Earth (Alexander et al., 2018; Cloutis et al., 2018; Gounelle et al., 2005; Langbroek et al., 2019). In addition, other chondrite groups or cometary material may also contribute to the volatile abundances in the solid Earth (Deligny et al., 2021).…”