QACD-quack
An interactive method for the Quantitative Assessment of Compositional Distributions in X-ray element maps
A Flexible Method for Processing X-ray Element Maps
QACD-quack provides an interactive method for the processing of large area X-ray element maps obtained by energy-dispersive spectrometers (EDS) to produce a quantitative assessment of compositional distribution (QACD) of crystal or chemical populations within geologic materials. The QACD-quack software allows for users to quickly quantify elemental concentrations and molar ratios for individual phases instead of having to quantify the entire map with a single broad standardization or several times over for mineral-specific standardizations.
A POWERFUL TOOL TO HELP YOU PROCESS YOUR ELEMENT MAPS
OPTIMISE
First, follow the experimental method provided in the QACD manuscript (Loocke and Lissenberg, 2019) and how-to sections of this website to optimize and calibrate your element mapping method for use with the QACD software. If you don't have access to the appropriate standards, then you can still use the software to process your element maps and treat the calculated ratio maps as qualitative.
DOWNLOAD
Download the most recent version of the QACD-quack software from GitHub via the links provided on this website. Any changes made to the software by the coding team or additional plugins provided by users will be updated and posted on the GitHub repository.
INITIALISE
The software imports CSV formatted element maps (RAW data) and stores them along with any processed maps and modifications in a project tree within an HDF5-type file format which is accessible by a variety of free software. The RAW element maps are readily displayed along with their corresponding histograms. For further processing, we provide data filtration options to remove statistical noise.
PHASE ID
Two methods are provided for identifying and isolating phase maps: a manual thresholding method and an automatic k-means clustering algorithm. The k-means clustering method uses a k-means clustering algorithm to group pixels together based on the minimum and maximum total number of phases provided by the user. The manual thresholding method makes use of interactive sliders so that the user has more control over the resulting phase mask.
RATIOS
Preset or custom ratio maps can be created from the imported maps using a series of internal quantitative corrections based on the calibrations determined in the OPTIMISE step for various common mineral types. The internal quantitative corrections can be easily modified to suit your needs. Preset ratios include but are not limited to: An = Ca / Ca + Na; Mg# = Mg / Mg + Fe; Cr# = Cr / Cr + Al.
EXPORT
Map and histogram figures can be customized to suit your needs and exported in various formats. We provide the option to export the figures in a scalable vector graphics (SVG) format for easy manipulation in common vector graphics software such as Adobe Illustrator and InkScape. Any map created or modified in the QACD-quack software can be exported as a CSV or TXT file for use in another program. This way, the user is not dependent on the QACD-quack software for every aspect of their element map processing.
