Projektbeschreibung
Gitterdefekte in Quarz verraten Neues über Gesteinsbildungsprozesse
Anhand von Provenienzanalysen kann die Geologie die Herkunftsregion von Sedimentproben ermitteln. Bei Quarz handelt es sich um eines der häufigsten gesteinsbildenden Minerale überhaupt. Quarzkristalle enthalten eine große Anzahl von Punktdefekten, wobei diese mitunter der Datierung von Sedimenten aus dem Quartär dienen. Das Wissen über die Bildung und Dynamik dieser Defekte ist jedoch noch begrenzt. Das Ziel des EU-finanzierten Projekts PROGRESS ist nachzuweisen, dass Punktdefekte in Quarz Belege für Gesteinsmetamorphose liefern sowie Verwitterungs-, Transport- oder Rückführungsprozesse aufzeigen können. Zur Untersuchung der Punktdefekte werden die Forschenden Lumineszenz mit Mikroskopieverfahren kombinieren.
Ziel
Quantitative provenance analysis studies are instrumental in understanding the tectonic and climatic processes that are shaping Earth`s landscape. Although the most abundant mineral in the sedimentary system is quartz, almost all studies in provenance analysis investigate accessory minerals. Quartz crystals contain a vast number of point defects, intrinsic or due to impurities. Although our understanding on the formation and dynamics of these defects is far from complete, a few of these defects in quartz are used for dating Quaternary sediments by luminescence (thermoluminescence (TL) or optically stimulated luminescence (OSL)) or by electron spin resonance (ESR). PROGRESS aims at proving that point defects in quartz have also the capacity to carry genetic information and their modifications can provide evidence for antiquity, metamorphism (or lack thereof) as well as knowledge on weathering, transport, or recycling. This information can be unravelled by ESR and luminescence methods in combination with microscopic techniques such as scanning electron microscopy coupled with cathodoluminescence (CL) wavelength resolved spectroscopy. To understand changes that are occurring at atomic level in quartz in nature in geological time, PROGRESS will investigate quartz grains extracted from independently dated old to young quartz-bearing continental crustal sources, metamorphosed rocks versus their unmetamorphosed equivalents, fresh versus highly weathered samples, as well as intrusive versus volcanic rocks, besides conducting experiments in laboratory environments. To tackle nature`s complexity during sediment movement in space and time the effect of physical and chemical changes that occur during transport of quartz grains will be investigated by the study of river sediments that drain different lithologies. These investigations will allow a simple quartz based fingerprinting method to be developed, that will have a significant impact on quantitative provenance studies.
Wissenschaftliches Gebiet
Programm/Programme
- HORIZON.1.1 - European Research Council (ERC) Main Programme
Thema/Themen
Finanzierungsplan
ERC - Support for frontier research (ERC)Gastgebende Einrichtung
400084 Cluj Napoca
Rumänien