Apatite fission track, apatite U-Pb, and electron microprobe data from Rae craton, Canada

Published: 22-02-2021| Version 3 | DOI: 10.17632/bkpryfwxs9.3
Contributor:
Kalin McDannell

Description

Data supporting two samples are provided in this repository and files herein contain AFT age and length data, U-Pb apatite data, and electron microprobe (EPMA) data (in oxide weight % and apfu) from the Rae craton, Canadian Shield, Canada. Sample 11JP322B (aka z10907, GSC geochronology lab #, or GeoSep Services (GSS) internal sample number: 334-03) and 14NK-C062 (GSS: 248-15) dated via the LA-ICP-MS apatite fission track method. Files also include age/length grain spatial locations for matching replicate age/length grain EPMA analyses. Refer to http://dx.doi.org/10.17632/wwrkpr9gcx.5 for additional information. Note: sample z10907/11JP322B was dated in two separate aliquots from project 334 and later project 390. The latter project underwent an "age-length pairing" (ALP) procedure where lengths were only measured from grains counted for age. These grains were then probed twice directly, once in/near the laser ablation spot area from AFT analysis, and once on another distal spot on the grain to assess the potential for isotopic zonation. In the length data tab for the ALP sample, the grain # corresponds to (for example) grain 1 with tracks 1 to 5 belonging to that grain, i.e., age grain 1. Therefore each age grain has a corresponding date and N number of tracks directly associated with it. This approach negates the need for grain locations to be recorded. The supplementary data files are Microsoft Excel .xlsx format and contained in a compressed .zip folder with a directory structure and contents as follows: Folder “Raw-AFT-UPb” contains the raw LA-ICP-MS apatite fission track age and length data. The raw apatite U-Pb age data, blanks, corrections, etc. are also included in a separate sheet tab for each sample. All AFT samples are referred to by their analytical number, e.g. 334-03 and their sample number z10907 (11JP322B). For all other data in the “EPMA” and “Grain-Locations” folders each grain is referred to by analytical number only, and whether it is an age or length grain. Folder “EPMA” contains the electron microprobe data with the OH estimation included in weight percent oxide or atom per formula unit format. These data can be converted to apfu and their respective rmr0 values determined using either the Carlson et al. (1999) or Ketcham et al. (2007) equations (see main text for details). Folder “Grain-Locations” contains the x,y coordinates for each age and length grain that was probed for each sample. The grains are flagged if they are duplicate measurements, i.e. the EPMA measurement for age grain 1 is also the same measurement for length grain 15. This is determined by distance of 0 to 10 microns (green) and 10 to 50 microns (orange). HeFTy model (Ketcham, 2005) input files with float values for all AFT data, e.g. Ns, A, Pcorr, error, U, Dpar, etc. are also included in the "HeFTyFiles" folder. Interpreted files for multikinetic modeling also provided.

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