Moritz Liesegang, Mohamed Ghobara, Sabine Matting, Richard Wirth
{"title":"The colourful optical appearance of centric diatom fossil frustules with diagenetic nanocrystalline calcite fill","authors":"Moritz Liesegang, Mohamed Ghobara, Sabine Matting, Richard Wirth","doi":"10.1007/s10347-023-00675-6","DOIUrl":null,"url":null,"abstract":"<p>Biophotonic nanostructures rarely withstand fossilization processes occurring after burial over geologic time. Even more distinctive is a change introduced to the optical properties during diagenetic processes resulting in a different optical appearance. Here, we report and explain the optical appearance of centric diatom frustules obtained from ash-bearing carbonate-cemented concretions on the Greifswalder Oie island (Pomeranian Bay, Germany, southern Baltic Sea). The ultrastructural and mineralogical analysis of the fossil frustules were carried out using electron microscopy techniques and were correlated to the macroscopic and microscopic optical appearance of the frustules before and after acid etching. The unique optical properties of the fossil diatoms were associated with diagenetic nanocrystalline calcite filling the frustules’ areolae. This fill created the macroscopic pale-yellow colour of many frustules, a microscopic iridescence probably associated with diffraction grating behaviour, and microscopic colour rings. The results highlight the unique permineralization process of diatom frustules and might be an addition to the emerging studies on frustule optics and photonics.</p>","PeriodicalId":51050,"journal":{"name":"Facies","volume":null,"pages":null},"PeriodicalIF":1.8000,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Facies","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1007/s10347-023-00675-6","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Biophotonic nanostructures rarely withstand fossilization processes occurring after burial over geologic time. Even more distinctive is a change introduced to the optical properties during diagenetic processes resulting in a different optical appearance. Here, we report and explain the optical appearance of centric diatom frustules obtained from ash-bearing carbonate-cemented concretions on the Greifswalder Oie island (Pomeranian Bay, Germany, southern Baltic Sea). The ultrastructural and mineralogical analysis of the fossil frustules were carried out using electron microscopy techniques and were correlated to the macroscopic and microscopic optical appearance of the frustules before and after acid etching. The unique optical properties of the fossil diatoms were associated with diagenetic nanocrystalline calcite filling the frustules’ areolae. This fill created the macroscopic pale-yellow colour of many frustules, a microscopic iridescence probably associated with diffraction grating behaviour, and microscopic colour rings. The results highlight the unique permineralization process of diatom frustules and might be an addition to the emerging studies on frustule optics and photonics.
期刊介绍:
The journal is open to papers dealing with the interpretation of ancient and modern biotopes and carbonate depositional environments by means of facies analysis in its broadest sense. Once the central part of research in hydrocarbon exploration, facies analysis more and more integrates modern and ancient biogeological processes of a changing earth. Special emphasis is laid on paleobiology and -ecology, basin evolution, sedimentology including diagenesis and geochemistry, as well as studies emphasising the impact of life on earth history. The main part of the target group will be people in academia.