Uranium-lead isotopic data from the New Hampshire Plutonic Suite and metasedimentary rocks of the New Hampshire Sequence in the Bronson Hill anticlinorium from the Bellows Falls 7.5- x 15-minute quadrangle, Vermont and New Hampshire

This data release includes uranium-lead isotopic data collected from metaplutonic rocks of the New Hampshire Plutonic Suite and metasedimentary rocks of the New Hampshire Sequence. Rock samples were collected by Arthur Merschat, Greg Walsh, and Ryan McAleer. Samples were processed and analyzed by Arthur Merschat and Ryan McAleer. Uranium-lead isotopic data was collected using a sensitive high resolution ion microprobe-reverse geometry (SHRIMP-RG) instrument, a type of secondary ion mass spectrometer (SIMS), at the U. S. Geological Survey (USGS) -Stanford SHRIMP-RG Laboratory in Palo Alto, California. These data constrain the age of the Bethlehem Granodiorite, and age and provenance of metasedimentary rocks of the Partridge, Rangeley, and Littleton Formations (Figure 1). The data release contains four files and a summary figure, including one metadata file and three comma-delimited (CSV) files. The CSV files include the following: BellowsFalls_UPb_data.csv, BellowsFalls_UPb_summary.csv and BellowsFalls_UPb _Data_Dictionary.csv. Figure 1. A. Concordia diagram of U-Pb zircon analyses from the Bethlehem Granodiorite (BF603) in the Fall Mountain nappe exposed in shoals on the Connecticut River, New Hampshire. B. Weighted average of all U-Pb zircon analyses (N=10) from the Bethlehem Granodiorite (BF603) results in a date of 440.7 ± 4 Mega annum (Ma). C. Concordia diagram of U-Pb zircon analyses from the Bethlehem Granodiorite (CS 3025) exposed in a roadcut on New Hampshire Route 11. D. Weighted average of all U-Pb zircon analyses (N=8) from the Bethlehem Granodiorite (CS3025) results in a date of 399.4 ± 3 Ma. E–I. Relative probability plots and histograms of U-Pb dates of detrital zircons. Plots show only U-Pb dates that are ≤ 10 percent discordant; the 207Pb-corrected 206Pb/238U was used for dates < 1.3 Giga annum (Ga) and 204-corrected Pb207/Pb206 ages greater > 1.3 Ga. All U-Pb diagrams and plots were created using Isoplot 3.75 (Ludwig, 2012). Ludwig, K.R., 2012, User’s manual for Isoplot 3.75—A geochronological toolkit for Microsoft Excel: Berkeley Geochronology Center Special Publication 5, 75 p., accessed September 2019 at http://www.bgc.org/isoplot_etc/isoplot/Isoplot3_75-4_15manual.pdf.

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