Response to the Comment by Haack et al. (2015) on the paper by Anfinogenov et al. (2014): John's stone: A possible fragment of the 1908 Tunguska meteorite

TL;DR

This paper critically discusses evidence for a potential planetary-origin sedimentary meteorite linked to the 1908 Tunguska event, considering various extraterrestrial and terrestrial factors affecting its identification.

Contribution

It provides a detailed critique and expands the discussion on the possible origins of a unique sedimentary meteorite candidate, emphasizing the need for comprehensive evidence beyond isotope analysis.

Findings

Candidate parental bodies include Earth, Mars, and icy moons.

Terrestrial contamination affects noble gas signatures.

Multiple lines of evidence are necessary for origin determination.

Abstract

The article provides an open discussion and a critical feedback to the comments of Haack et al. (2015) and emphasizes a significance of the first macroscopic evidence for a candidate meteorite of a new type: planetary-origin meteorite composed of silica-rich sedimentary rock. Discussion concerns the arguments for (i) candidate parental bodies including the Earth, Mars and icy moons of Saturn and Jupiter; (ii) PGE anomaly versus glassy silicate microspherules and quartz grains anomaly in the area of the 1908 Tunguska catastrophe; (iii) isotopic heterogeneity of unmixed silicate reservoirs on Mars; (iv) possible terrestrial loss or contamination in the noble gas signatures in meteorites that spent time in the extreme weather conditions; (v) cosmogenic isotopes and shielding; and (vi) pseudo meteorites. We conclude that the list of candidate parental bodies for hypothetical sedimentary-origin meteorites includes, but is not limited by the Earth, Mars, Enceladus, Ganymede, and Europa. A parental body should be identified based on the entire body of evidence which is not limited solely by tests of oxygen and noble gas isotopes whose signatures may undergo terrestrial contamination and may exhibit significant heterogeneity within the parental bodies.