Figure DR2. Measurement of nugget morphology with digital calipers.

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Winfred Norris
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1 GSA Data Repository Item Melchiorre, E.B., Kamenov, G.D., Sheets-Harris, C., Andronikov, A., Leatham, W.B., Yahn, J., and Lauretta, D.S., 2016, Climate induced geochemical and morphological evolution of placer gold deposits at Rich Hill, Arizona, USA: GSA Bulletin, doi: /b DATA REPOSITORY FIGURES AND TABLES Figure DR troy ounces of gold nuggets from the Devils Nest placer of the Rich Hill area, mined in by JW Mining. These nuggets come from a variety of placer deposits (e.g., red, white, and black), but are dominantly from the base of the red placers. Figure DR2. Measurement of nugget morphology with digital calipers. Figure DR3. Surface features of gold from the red placers include a). casts of quartz crystals from the lode source, b). relict skeletal octahedron crystal forms, seen here as chevrons, c). and d). deeply striated surfaces indicative of sliding in traction or boulder strikes. Table DR1. Morphological characteristics of large placer gold nuggets examined in this study. W/L, width to length ratio; T/W, thickness to width ratio. Table DR2. Geochemistry of large placer gold nuggets examined in this study, determined by portable x-ray fluorescence analysis. Table DR3. Geochemistry of small placer gold grains examined in this study, determined by LA-ICP-MS (copper) and ion probe (silver and gold). (C), grain core measurement; (R), grain rim measurement.

5 TABLE DR1. MORPHOLOGICAL CHARACTERISTICS OF LARGE GOLD NUGGETS Sample Number Type Mass (g) Length (mm) Width (mm) Thickness (mm) W/L T/W Surface Smoothness JY2 Red Placer Subangular JY3 Red Placer Subangular JY4 Red Placer Angular JY5 Red Placer Angular JY8 Red Placer Angular JY9 Red Placer Subangular JY11 Red Placer Angular JY12 Red Placer Subangular JY13 Red Placer Angular EM1 Red Placer Angular EM2 Red Placer Angular EM3 Red Placer Angular EM4 Red Placer Angular EM5 Red Placer Subangular EM6 Red Placer Angular EM7 Red Placer Angular EM8 Red Placer Subangular JY19 White Placer Rounded JY14 White Placer Rounded JY15 White Placer Rounded JY16 White Placer Subrounded JY17 White Placer Rounded JY7 White Placer Subrounded RA W1 White Placer Rounded RA W2 White Placer Rounded RA W3 White Placer Rounded RA W4 White Placer Rounded RA W5 White Placer Rounded RA W6 White Placer Rounded JY6 Black Placer Angular EM 10 Black Placer Subangular RA B1 Black Placer Angular RA B2 Black Placer Angular RA B3 Black Placer Angular RA B4 Black Placer Angular JY1 Potato Patch Subangular JY18 Potato Patch Angular PP1 Potato Patch Subangular PP2 Potato Patch Subangular

6 TABLE DR2. XRF GEOCHEMISTRY OF LARGE GOLD NUGGETS Mn Fe Sample Number Type Au (wt%) Au (wt%) Mn Fe JY2 Red Placer < LOD JY3 Red Placer < LOD JY4 Red Placer < LOD JY5 Red Placer < LOD JY8 Red Placer < LOD JY9 Red Placer < LOD JY11 Red Placer < LOD JY12 Red Placer < LOD JY13 Red Placer < LOD EM1 Red Placer < LOD EM2 Red Placer < LOD EM3 Red Placer < LOD EM4 Red Placer < LOD EM5 Red Placer < LOD EM6 Red Placer < LOD EM7 Red Placer < LOD EM8 Red Placer < LOD JY19 White Placer < LOD JY14 White Placer < LOD JY15 White Placer < LOD JY16 White Placer < LOD JY17 White Placer < LOD JY7 White Placer < LOD RA W1 White Placer < LOD RA W2 White Placer < LOD RA W3 White Placer < LOD RA W4 White Placer < LOD RA W5 White Placer < LOD RA W6 White Placer < LOD JY6 Black Placer EM 10 Black Placer RA B1 Black Placer RA B2 Black Placer RA B3 Black Placer RA B4 Black Placer JY1 Potato Patch JY18 Potato Patch PP1 Potato Patch PP2 Potato Patch

7 TABLE DR3. LA ICP MS CHEMISTRY OF SMALL PLACER GOLD GRAINS Sample Au (wt%) Sample Au (wt%) Red (C) White (C) Red (C) White (C) Red (C) White (C) Red (C) White (C) Red (C) White (C) Red (C) White (C) Red (C) White (R) Red (C) White (R) Red (R) White (R) Red (R) White (R) Red (R) White (R) Red (R) White (R) Red (R) AVE Rim Red (R) AVE Core AVE Rim AVE Core Sample Au (wt%) Sample Au (wt%) Potato (C) Black (C) Potato (C) Black (C) Potato (C) Black (C) Potato (C) Black (C) Potato (R) Black (C) Potato (R) Black (C) Potato (R) Black (R) AVE Rim Black (R) AVE Core Black (R) Black (R) Black (R) Black (R) Black (R) AVE Rim AVE Core

MACRORYTHMIC GABBRO TO GRANITE CYCLES OF CLAM COVE VINALHAVEN INTRUSION, MAINE

MACRORYTHMIC GABBRO TO GRANITE CYCLES OF CLAM COVE VINALHAVEN INTRUSION, MAINE NICK CUBA Amherst College Sponsor: Peter Crowley INTRODUCTION The rocks of the layered gabbro-diorite unit of the Silurian