# Are the proposed markers (microspherules, nanodiamonds, shocked quartz, meltglass) reproducible and diagnostic of impact? · Younger Dryas impact hypothesis > Three answers have been proposed. The markers are background cosmic dust, volcanic or anthropogenic spherules, fire products or misidentified… leads… Source: https://mysteriesdept.com/mysteries/younger-dryas-impact/questions/QST0D51X8T620G9/are-the-proposed-markers-microspherules-nanodiamonds-shocked Publisher: Mysteries Department Licence: CC BY 4.0 (credit Mysteries Department and link the page) Updated: 2026-10-26T11:59:09+00:00 --- **0** # Are the proposed markers (microspherules, nanodiamonds, shocked quartz, meltglass) reproducible and diagnostic of impact? Asked 26 Oct 2026 by [**apollo** ](https://mysteriesdept.com/u/apollo)·Part of [Did an extraterrestrial impact or airburst occur at the onset of the Younger Dryas, about 12,800 years ago?](https://mysteriesdept.com/mysteries/younger-dryas-impact/questions/QST0D51X8AJ1304/did-an-extraterrestrial-impact-or-airburst-occur-at-the)·3 answers·0·0 following **Most likely: the markers are background cosmic dust, volcanic or anthropogenic spherules, fire products or misidentified…** Ahead on the evidence, not yet confirmed. It needs two reviews to be accepted. ## Where it stands Three answers have been proposed. The markers are background cosmic dust, volcanic or anthropogenic spherules, fire products or misidentified… leads, with evidence 3 for: supported by its tests. Two are still possible. ## Why it matters The physical evidence is microscopic, and its identification and counting depend on methods that differ between laboratories⁠[[1]](https://mysteriesdept.com/sources/SRC0D51WS6643R2/a-blind-test-of-the-younger-dryas-impact-hypothesis). The review of 2023 argues that most markers also form by ordinary processes⁠[[2]](https://mysteriesdept.com/sources/SRC0D51WTWW7YV8/comprehensive-refutation-of-the-younger-dryas-impact). ## Answers 3 [**The markers are background cosmic dust, volcanic or anthropogenic spherules, fire products or misidentified…** ](https://mysteriesdept.com/mysteries/younger-dryas-impact/answers/ANS0D51XGM601YH/the-markers-are-background-cosmic-dust-volcanic-or) Supported by its tests Evidence: 3 for Most likely [**None of these.** ](https://mysteriesdept.com/mysteries/younger-dryas-impact/answers/ANS0D51XHKE68Q7/none-of-these) Not tested enough to call either way Evidence: none yet Still possible [**The markers form only at the temperatures and pressures of impacts and airbursts, and they peak at the…** ](https://mysteriesdept.com/mysteries/younger-dryas-impact/answers/ANS0D51XFD40S6P/the-markers-form-only-at-the-temperatures-and-pressures-of) Failed a test; not refuted outright Evidence: 2 for, 2 against Disputed ## History 1. 2009[Kennett et al.: nanodiamonds were reported at 10 to 3,700 ppb in the boundary layer and not above or below.](https://mysteriesdept.com/sources/SRC0D51WQFG1AQE/nanodiamonds-in-the-younger-dryas-boundary-sediment-layer)For: The markers form only at the temperatures and pressures of impacts and airbursts, and they peak at the… 1. 2009[Surovell et al.: the 2009 independent study found no support at seven sites, including two of the originals.](https://mysteriesdept.com/sources/SRC0D51WPZW3D1V/an-independent-evaluation-of-the-younger-dryas)For: The markers are background cosmic dust, volcanic or anthropogenic spherules, fire products or misidentified… 1. 2010[Daulton et al.: claimed nanodiamonds were identified as graphene and graphene-oxide aggregates.](https://mysteriesdept.com/sources/SRC0D51WQ7P4MZC/no-evidence-of-nanodiamonds-in-youngerdryas-sediments-to)For: The markers are background cosmic dust, volcanic or anthropogenic spherules, fire products or misidentified… 1. 2011[Pinter et al. puts forward: the markers are background cosmic dust, volcanic or anthropogenic spherules, fire products or misidentified…](https://mysteriesdept.com/sources/SRC0D51WQQA41D9/the-younger-dryas-impact-hypothesis-a-requiem) 1. 2013[Wittke et al. puts forward: the markers form only at the temperatures and pressures of impacts and airbursts, and they peak at the…](https://mysteriesdept.com/sources/SRC0D51WR6Y55NF/evidence-for-deposition-of-10-million-tonnes-of-impact) 1. 2013[Wittke et al.: about 700 SEM-EDS analyses of spherules from 18 sites are said to be inconsistent with volcanic, cosmic…](https://mysteriesdept.com/sources/SRC0D51WR6Y55NF/evidence-for-deposition-of-10-million-tonnes-of-impact)For: The markers form only at the temperatures and pressures of impacts and airbursts, and they peak at the… 1. 2016[Holliday et al.: no standard criteria exist for identifying magnetic spherules, and the blind test found them in a…](https://mysteriesdept.com/sources/SRC0D51WS6643R2/a-blind-test-of-the-younger-dryas-impact-hypothesis)Against: The markers form only at the temperatures and pressures of impacts and airbursts, and they peak at the… 1. 2020[Sun et al.: osmium isotopes at Hall's Cave point to volcanic sources for the boundary anomalies.](https://mysteriesdept.com/sources/SRC0D51WT5E76AA/volcanic-origin-for-younger-dryas-geochemical-anomalies-ca)For: The markers are background cosmic dust, volcanic or anthropogenic spherules, fire products or misidentified… 1. 2026[The PLOS One Editors: material presented as cosmic spherule fragments in the Baffin Bay paper was identified as foraminifera.](https://mysteriesdept.com/sources/SRC0D51WWBR25YC/retraction-a-12-800-year-old-layer-with-cometary-dust)Against: The markers form only at the temperatures and pressures of impacts and airbursts, and they peak at the… 1. 26 Oct 2026Asked on this site ## Discussion 0 [Add to the discussion](https://mysteriesdept.com/signin?next=/mysteries/younger-dryas-impact/questions/QST0D51X8T620G9/are-the-proposed-markers-microspherules-nanodiamonds-shocked%23discussion) Help with this question [ **Propose an answer** Something the evidence could support or rule out ] [ **Propose an answer** Something the evidence could support or rule out ](https://mysteriesdept.com/signin?next=/mysteries/younger-dryas-impact/questions/QST0D51X8T620G9/are-the-proposed-markers-microspherules-nanodiamonds-shocked%23add-answer) [ **Add evidence** A result for or against an answer ] [ **Add evidence** A result for or against an answer ](https://mysteriesdept.com/signin?next=/mysteries/younger-dryas-impact/questions/QST0D51X8T620G9/are-the-proposed-markers-microspherules-nanodiamonds-shocked%23add-evidence) [ **Ask a sub-question** A smaller question that would help settle this one ] [ **Ask a sub-question** A smaller question that would help settle this one ](https://mysteriesdept.com/signin?next=/mysteries/younger-dryas-impact/questions/QST0D51X8T620G9/are-the-proposed-markers-microspherules-nanodiamonds-shocked%23add-question) [ **Add a source** A paper, archive record or image ] [ **Add a source** A paper, archive record or image ](https://mysteriesdept.com/signin?next=/mysteries/younger-dryas-impact/questions/QST0D51X8T620G9/are-the-proposed-markers-microspherules-nanodiamonds-shocked%23add-source) Where it fits Younger Dryas impact hypothesis [**Did an extraterrestrial impact or airburst occur at the onset of the Younger Dryas, about 12,800 years ago?** ](https://mysteriesdept.com/mysteries/younger-dryas-impact/questions/QST0D51X8AJ1304/did-an-extraterrestrial-impact-or-airburst-occur-at-the)Key question · most likely no impact or airburst occurred; the proposed markers are terrestrial or background cosmic material… **Are the proposed markers (microspherules, nanodiamonds, shocked quartz, meltglass) reproducible and diagnostic of impact?** You're here · the markers are background cosmic dust, volcanic or anthropogenic spherules, fire products or misidentified… [Is the claimed boundary layer the same age at every site?](https://mysteriesdept.com/mysteries/younger-dryas-impact/questions/QST0D51X8JC0DHZ/is-the-claimed-boundary-layer-the-same-age-at-every-site)Most likely · the claimed layers are of different ages, or their ages are not known well enough to say [ Ask a question under this one ]