An Image Mapping Approach to U‐Pb LA‐ICP‐MS Carbonate Dating and Applications to Direct Dating of Carbonate Sedimentation

We present a new approach to laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) U‐Pb dating of carbonates based on selection and pooling of pixels from 2‐D elemental and isotopic ratio maps. This image mapping technique is particularly useful for targeting subdomains in samples...

Full description

Saved in:
Bibliographic Details
Published in:Geochemistry, geophysics, geosystems : G3 geophysics, geosystems : G3, 2018-12, Vol.19 (12), p.4631-4648
Main Authors: Drost, Kerstin, Chew, David, Petrus, Joseph A., Scholze, Frank, Woodhead, Jon D., Schneider, Joerg W., Harper, David A. T.
Format: Article
Language:English
Subjects:
Ablation
Age
Carbonate minerals
Carbonate rocks
Carbonates
Data
Data analysis
Data processing
Diagenesis
Electron microscopy
Fossils
Geological processes
image mapping
Instruments
Isotopes
Lasers
LA‐ICP‐MS U‐Pb dating
Lead isotopes
Mapping
Mass spectrometry
Mass spectroscopy
Minerals
Ratios
Sedimentation
selection and pooling of pixels
Trace elements
Uranium
U‐Pb carbonate dating
Citations: Items that this one cites
Items that cite this one
Online Access:Request full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We present a new approach to laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) U‐Pb dating of carbonates based on selection and pooling of pixels from 2‐D elemental and isotopic ratio maps. This image mapping technique is particularly useful for targeting subdomains in samples with complex geological histories. Key major and trace elements that are sensitive to detrital components, postformational fluid ingress, mineralogical changes, or diagenetic overprinting are measured along with the Pb and U isotopic data. Laser sampling is undertaken along successive linear rasters that are compiled into maps using the Monocle add‐on for Iolite, with one pixel in the map corresponding to one time slice of the time‐resolved signal. These element, element ratio, and isotope ratio maps can be overlain over photomicrographs or scanning electron microscopy images to spatially link compositional data to textural and structural features. The pixels corresponding to likely homogeneous age domains can be isolated by applying appropriate selection criteria (e.g., Th 
ISSN:1525-2027
1525-2027
DOI:10.1029/2018GC007850