occurred during the Flood to generate so many radiohalos. With this background, it was determined that a fuller study was needed with a lot more radiohalos data to potentially draw betterestablished conclusions. While there are some radiohalos occurrence data available in the older literature, this study required not just data on where radiohalos are found, but also the quantities of radiohalos at each occurrence. This is so comparisons can be made between rock types at various levels in the geologic record to glean what clues they might provide us regarding radioactive decay in these rock through earth history within the Biblical framework. III. METHODS Snelling and Armitage (2003) and Snelling (2005a) devised a method of counting radiohalos for each sample investigated from a designated number of thin sections (usually 50) with approximately 20 biotite flakes per thin section. This allowed for statistical comparisons between samples and rock types. Thus, for this study it was necessary to follow that same procedure to tabulate the needed radiohalos data for rock samples encompassing the geologic record. Snelling (2005a) had already tabulated radiohalos data for numerous samples, and subsequent studies by Snelling (2008b, c, d, 2014, 2018) and Snelling and Gates (2009) had followed the same procedure. So, all those data were tabulated for this study. Additionally, unpublished, and soon-to-be published, radiohalos data were added to the tabulation in this paper (see below). Over some years additional samples have been collected, for example, from the granites of northern coastal Queensland, Australia (Bain and Draper 1997; Day et al. 1983), the metamorphic rocks of the Broken Hill region of western New South Wales, Australia (that host the supergiant world-class Broken Hill Ag-Pb-Zn ore deposit) (Stevens and Bradley 2018), and from the granites and metamorphic schists in the Inner Gorge of Grand Canyon, northern Arizona, USA (with the appropriate research and sampling permits from the Grand Canyon National Park) (Ilg et al. 1996; Karlstrom et al. 2003). A few other scattered samples have also been collected on various field trips, as well as samples collected by others and sent in for radiohalos investigation with location documentation, for example, from the granites of the Cornubian Batholith of southwest England (Moscati and Neymark 2020). All rock samples were identically processed to obtain the needed radiohalos data from them, following the method of Snelling and Armitage (2003) and Snelling (2005a). A standard petrographic thin section was obtained for each sample. In the laboratory, a scalpel and tweezers were used to prize flakes of large, primary biotite loose from the sample surfaces, or where necessary portions of the samples were crushed to liberate the constituent mineral grains. Biotite flakes were then hand-picked and placed on the adhesive surface of a piece of clear Scotch™ tape fixed to a bench surface with its adhesive side up. Once numerous biotite flakes had been mounted on the adhesive surface of this piece of clear Scotch™ tape, a fresh piece of clear Scotch™ tape was placed over them and firmly pressed along its length so as to ensure the two pieces of clear Scotch™ tape were stuck together with the biotite flakes firmly wedged between them. The upper piece of clear Scotch™ tape was then peeled back in order to pull apart the sheets composing the biotite flakes, and this upper piece of clear Scotch™ tape with thin biotite sheets adhering to it was then placed over a standard glass microscope slide so that the adhesive side had the thin mica flakes adhered to it. This procedure was repeated with another piece of clear Scotch™ tape placed over the original Scotch™ tape and biotite flakes affixed to the bench, the adhering biotite flakes being progressively pulled apart and transferred to microscope slides. As necessary, further hand-picked biotite flakes were added to replace those fully pulled apart. In this way tens of microscope slides were prepared for each sample, each with many (at least twenty to thirty) thin biotite flakes mounted on them. This is similar to the method pioneered by Gentry. Fifty microscope slides were prepared for each sample to ensure good representative sampling statistics. Thus, there was a minimum of 1,000 biotite flakes mounted on microscope slides for each sample. Each thin section for each sample was then carefully examined under a petrological microscope in plane polarized light, and all radiohalos present were identified, noting any relationships between the different radiohalo types (238U, 232Th, 218Po, 214Po, and 210Po). The numbers of each type of radiohalo in each slide were counted by progressively moving the slide backwards and forwards across the field of view, and the numbers recorded for each slide were then tallied and tabulated for each sample. Only radiohalos whose radiocenters were clearly visible were counted. Because of the progressive peeling apart of many of the same biotite flakes during the preparation of the microscope slides due to biotite’s perfect basal cleavage, many of the radiohalos appeared on more than one microscope slide, so this procedure ensured each radiohalo was only counted once. The photomicrographs in fig. 4 display some of the typical Po and U radiohalos identified and counted in this and previous studies. IV. RESULTS The radiohalos counted for all samples are tabulated in Table 1 (granites) and Table 2 (regional metamorphic rocks). Each table provides the name (where available) of the granite or metamorphic rock, the location of the collected sample(s) and the known or approximate conventional age of the rock unit. It was assumed for the purposes of this study that the conventional ages were valid within the conventional paradigm, but they are used here only to identify the relative positions of the rock units in the geologic record (see the discussion below). Notice also that the rock units are not designated in the tables according to where they fit in the biblical framework of earth history, namely, pre-Flood, Flood, or post-Flood. Instead, it was decided to see if the radiohalos data would differentiate those designations for the studied rock units. Also included in the tables are the number of samples studied for each rock unit and thus the number of slides (thin sections) that were prepared. Subsequent columns list the counted 210Po, 214Po, 218Po, 238U and 232Th radiohalos. The figures in the “number of radiohalos per slide” column were obtained by summing all the radiohalos identified and counted for each rock unit, and then dividing the total by the number of slides examined for each rock unit to count those radiohalos. The figures in the “number of Po radiohalos per slide” were similarly obtained, except only the Po radiohalos counted were summed for each rock unit. Finally, the ratios of the numbers of the various radiohalos types to one another were calculated. SNELLING Radiohalos through earth history 2023 ICC 545
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