eprintid: 10187361
rev_number: 6
eprint_status: archive
userid: 699
dir: disk0/10/18/73/61
datestamp: 2024-02-19 12:12:30
lastmod: 2024-02-19 12:12:30
status_changed: 2024-02-19 12:12:30
type: article
metadata_visibility: show
sword_depositor: 699
creators_name: Papineau, Dominic
title: Chemically Oscillating Reactions as a New Model for the
Formation of Mineral Patterns in Agate Geodes and Concretions
ispublished: pub
divisions: UCL
divisions: B04
divisions: C06
divisions: F57
keywords: Abiotic; biosignature; origin of life; concretion; agate geodes
note: This work is licensed under a Creative Commons Attribution 4.0 International License. The images
or other third-party material in this article are included in the Creative Commons license,
unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license,
users will need to obtain permission from the license holder to reproduce the material. To view a copy of this
license, visit http://creativecommons.org/licenses/by/4.0/
abstract: Agate geodes contain spheroidal patterns characterized by spectacularly coloured and circularly concentric laminations with radially aligned quartz crystals, yet the origin of these geometric patterns has remained enigmatic. Here, detailed comparisons are documented between these kinds of patterns in a selection of geodes and concretions and those produced by abiotic chemically oscillating reactions. We find strikingly comparable self-similar, fractal patterns in both natural volcanogenic geodes and sedimentary concretions as well as in these benchtop experiments. In addition, the mineralogical composition of patterns and associated organic matter point to the oxidation of organic compounds in both geodes and concretions. This process occurred during diagenetic or supergene alteration, and it is consistent with spontaneous and abiotic chemically oscillating reactions. It is concluded that the oxidation of organic acids was involved in the formation of these patterns and that these rocks indicate oxidation–reduction reactions involving organic carbon, which itself may be abiotic or biological in origin. Hence, agate geodes and concretions represent the abiotic biosignatures of possible biological origin in volcanic and sedimentary rocks.
date: 2024-02-16
date_type: published
official_url: https://doi.org/10.3390/min14020203
oa_status: green
full_text_type: pub
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 2248030
doi: 10.3390/min14020203
lyricists_name: Papineau, Dominic
lyricists_id: DPAPI19
actors_name: Papineau, Dominic
actors_id: DPAPI19
actors_role: owner
full_text_status: public
publication: Minerals
volume: 14
article_number: 203
citation:        Papineau, Dominic;      (2024)    Chemically Oscillating Reactions as a New Model for the Formation of Mineral Patterns in Agate Geodes and Concretions.                   Minerals , 14     , Article 203.  10.3390/min14020203 <https://doi.org/10.3390/min14020203>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10187361/1/Papineau_2024_Minerals_COR_for_geodes_and_concretions.pdf