CARBCHRON · Carbonate boundstone as a geochronometer
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2021-09-01 → 2023-10-31
- EU contribution
- €162,806
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Carbonate boundstone as a geochronometer
Investigations of global biological and geochemical changes through time use Earth’s sedimentary rock archive as our best record of Earth’s past surface environments. The ages of the rocks that record these shifts clarify the causes and consequences of changes in Earth’s biosphere and habitats. These archives of Earth's ancient environments and climate provide crucial ground-truth data we can use to better predict environmental and climatic change in the future. Recent analytical developments are reinvigorating the study of carbonate as a geochronometer and a growing scientific community is working to directly date carbonate rocks—repositories of some of our richest geochemical and paleobiological archives. The ability to directly date carbonate rocks will unlock previously inaccessible archives of Earth history. The goal of this project is to test, validate, and examine the utility of a particular type of carbonate--boundstones--as a dating technique.
Data: CORDIS, © European Union
Project objective
Recent analytical developments are reinvigorating the study of carbonate as a geochronometer in deep time (>1 Ma) using the U-Pb system. Boundstone, a type of carbonate rock made by the trapping and binding of carbonate sediment by microbial mats, is often sampled for use in U-Pb dating of carbonates. It has even been used as a reference material in recent studies. However, we lack a process-based understanding as to why boundstone works so well for geochronology, and which geological processes create the material we date. This work, supervised by Dr. Axel Gerdes at Goethe University Frankfurt, investigates these questions. This project tests a hypothesis, supported by early results, that microbially-induced carbonate precipitation under reducing conditions creates geochronologically viable early cements. This hypothesis will be tested by petrographically, geochemically, and geochronologically characterizing boundstones from Earth’s last 1 Ga. To test the accuracy and robustness of the boundstone chronometer, I then will compare boundstone dates with radiometric ages derived from zircon and black shales in two stratigraphic succesions: the Neoproterozoic of Oman and the Ordovician of Anticosti Island. First, boundstone samples will be characterized petrographically. High-throughput laser ablation inductively coupled mass spectrometry (LA-ICP-MS) will be used to geochemically and geochronologically characterize samples, a subset of which will advance to high-precision dating by isotope dilution (ID).
Original text from CORDIS.
Participants
- JOHANN WOLFGANG GOETHE-UNIVERSITAET FRANKFURT AM MAIN · Frankfurt Am MainCoordinatorGermany
Links
Data: CORDIS, © European Union