GSA Today
Volume 31, Issue 11

Cover image

Perspective view of airborne radiometric thorium draped over shaded relief lidar elevation (hillshade). Areas where Ti-Zr–rare earth element (REE)- heavy mineral sands are concentrated appear as thorium highs (yellows). Top: The airplane that collected the data. Inset: Example of Holocene Ti-Zr-REE sand concentrations. Airplane photo: James W. Bursey, Terraquest, Inc. Sands photo: Anjana K. Shah, USGS.

© The Geological Society of America, Inc.