| Titre | Evolution of sedimentary basins as recorded in silica concretions: an example from the Ionian zone, western Greece |
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| Auteur | Pe-Piper, G ;
Piper, D J W; Bourli, N; Zelilidis, A |
| Source | Minerals vol. 11, issue 7, 763, 2021 p. 1-16, https://doi.org/10.3390/min11070763  Accès ouvert |
| Image |  |
| Année | 2021 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20210348 |
| Éditeur | MDPI AG |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.3390/min11070763 |
| Media | papier; en ligne; numérique |
| Formats | pdf; html |
| Lat/Long OENS | 19.0000 22.0000 40.1667 37.8333 |
| Sujets | bassins sédimentaires; evolution du bassin; concrétions; silice; diagenèse; tectonique du sel; géologie du substratum rocheux; lithologie; roches sédimentaires; calcaires; roches clastiques; nodules;
chailles; dynamique des fluides; fluage; Zone Ionienne; sédimentologie; minéralogie; Sciences et technologie; Nature et environnement; Phanérozoïque; Mésozoïque; Crétacé |
| Illustrations | cartes de localisation; photographies; photomicrographies; graphiques |
| Programme | Division de la CGC atlantique |
| Diffusé | 2021 07 15 |
| Résumé | (disponible en anglais seulement)
Chert concretions in thick limestone successions preserve a more complete paragenetic sequence of diagenetic minerals than their host limestone and interbedded
shale. The goal of this study was to test the possible presence of a high-temperature mineralising system in the Ionian basin of western Greece. Upper Cretaceous chert nodules were sampled at Araxos, where rocks are highly faulted and uplifted by
salt diapirism, and on Kastos Island, on the flanks of a regional anticline. Chert concretions have microporosity produced by recrystallisation of opal to quartz and fractures produced in the brittle chert during basin inversion. Diagenetic mineral
textures were interpreted from backscattered electron images, and minerals were identified from their chemistry. Diagenetic minerals in pores and veins include sedimentary apatite (francolite), dolomite, Fe-chlorite, Fe oxide-hydroxide mixtures,
sphalerite, barite and calcite. Sphalerite is restricted to Araxos, suggesting that inferred basinal fluids were hotter and more saline than at Kastos. At Araxos, the Fe oxide-hydroxide also includes minor Cu, Zn, and Ni. Whether the transported
metals were derived from sub-salt clastic rocks and basement, or from enriched Mesozoic black shales, is unclear. The effectiveness of this novel approach to understanding fluid flow history in thick limestone successions is validated. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Des concrétions dures dans le calcaire, appelées chert ou chaille, préservent un enregistrement de l'écoulement des fluides à travers les
roches. Dans cette étude de cas, il existe des preuves de fluides qui précipitent les minerais de plomb et de zinc, qui sont autrement inconnus dans cette région. |
| GEOSCAN ID | 329026 |
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