By: magic-gigapans
Image: Robin Rohrback, Mid-Atlantic Geo-Image Collection
License: Creative Commons Non Commercial ⧉

Uploaded: 8 May 2020
Last Updated: 18 May 2020

250 megapixels
16,556 x 15,104 pixels
55.2 in X 50.3 in at 300dpi
3,960 pixels per inch

This sample was contributed by Dr. Jay Kaufman of Univeristy of Maryland. Writes Dr. Kaufman: "This slab, which is about 3.5" across, comes from the ca. 3.5 billion-year-old Barberton Mountainland greenstone belt. Lapilli form during volcanic eruptions into a wet atmosphere by accretion around a central nucleus of ash, after which they rain out like hailstones. While some are round and show evidence of layering, others are deformed and massive. They are compositionally homogeneous unless altered by secondary processes. I collected this lovely sample back in 1982 while working with Don Lowe, Gary Byerly, and Jeff Hanor from Louisiana State University, and made a set of coasters from the slabs."