Recent  

We present our model ChronoLorica. We coupled the original Lorica model, that simulates soil and landscape evolution, with a geochronological module that traces cosmogenic nuclide inventories and particle ages through the simulations. These properties are often measured in the field to determine rates of landscape change. The coupling enables calibration of the model and study how soil, landscapes and the geochronometers change under complex boundary conditions such as intensive land management.

Thermochronometric data can provide unique insights into the patterns of rock exhumation and the driving mechanisms of landscape evolution. Several well-established thermal models allow for a detailed exploration of how cooling rates evolved in a limited area or along a transect, but more regional analyses have been problematic. We present age2exhume, a thermal model that can be used to rapidly provide a synoptic overview of exhumation rates from large regional thermochronologic datasets.

Sediment cores from volcanic lake Holzmaar provide a very precise chronology based on tree ring-like annual laminations or varves. We statistically combine this varve chronology with radiometric dating and tested three different methods to upgrade the age-depth model. However, only one of the three methods tested improved the dating accuracy considerably. With this work, an overview of different age-integration methods is discussed and made available for increased future demands.

Absolute chronological constraints are crucial in Earth and Planetary Science. In recent years, U-Pb dating of calcite has provided information on the timing of diagenesis, faulting, or hydrothermalism, for example. These studies have targeted relatively young carbonates up to 300 million years old. By dating 3.9 billion years old martian carbonates using the U-Pb chronometer, we show that this system can be robust in ancient samples that have had a relatively simple history.

This contribution is focused on the accurate measurement of U and Th by wet chemistry and laser ablation to improve the (U-Th)/He dating of magnetite and spinel. The low U-Th content and the lack of specific U-Th standards limit significantly the accuracy of (U-Th)/He dating. Obtained U and Th results on natural and synthetic magnetite and aluminous spinel samples analyzed by both extraction methods, have important implications for the (U-Th)/He method and dates interpretation.

SHRIMP (Sensitive High Resolution Ion MicroProbe) is a instrument that for decades has used the radioactive decay of uranium into lead to measure geologic time. The accuracy adn precision of this instrument has not been seriously reviewed in almost 20 years. This paper compares several dozen SHRIMP ages in our database with more accurate and precise methods to assess SHRIMP accuracy and precision. Analytical and geologic complications are addressed to try to improve the method.

If topographical obstructions are present in the surroundings of sampling sites, exposure ages of rock surfaces need to be corrected. A toolbox for the ESRI ArcGIS software allows for quantifying topographic shielding with a digital elevation model, but it has only been validated with few field data. In this study, the output of the toolbox is evaluated with a more extensive dataset. If suitable elevation data is chosen, the toolbox provides a sound approach to determine topographic shielding.

Acid leaching is commonly used to remove damaged portions of zircon crystals prior to U-Pb dating. However, a basic understanding of the microstructural processes that occur during leaching is lacking. We present the first 3D view of zircon dissolution based on X-ray computed tomography data acquired before and after acid leaching. These data are paired with images of etched grain surfaces and Raman spectral data. We also reveal exciting opportunities for imaging radiation damage zoning in 3D.