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The persistence of K-rich sediments more over large regions. They can provide insights Force, E.R., Grosz, A.E., Loferski, P.J., and
than 100 km from major rivers requires a into relations to specific geomorphologic fea- Maybin, A.H., 1982, Aeroradioactivity Maps
mode of transport that only exists offshore. tures, transport pathways, and provenance. In in Heavy-Mineral Exploration—Charleston,
South Carolina, Area: U.S. Geological Survey
Heavy minerals were most likely delivered the survey area, they highlight the importance Professional Paper 1218, 19 p., 2 plates.
from the Piedmont to offshore areas by the of not only marine and tidal processes in con- Grosz, A.E., 1983, Application of total-count aero-
Santee and other major rivers, transported centrating sediments, but also transport for radiometric maps to the exploration for heavy-
by longshore currents during transgressions hundreds of kilometers by rivers and long- mineral deposits in the coastal plain of Virginia:
or regressions, and then redeposited onshore shore currents. These results have implica- U.S. Geological Survey Professional Paper 1263,
20 p., 5 plates.
by currents and waves. This appears to be tions not only for exploration but also for fur- Grosz, A.E., and Schruben, P.G., 1994, NURE geo-
a regional phenomenon, because similar ther developing our understanding of the chemical and geophysical surveys—Defining
anomalies are present over younger sedi- broader geologic processes associated with prospective terranes for United States placer
ments from northern South Carolina to these important deposits. exploration: U.S. Geological Survey Bulletin
northern Florida and the Pee Dee, Savannah, 2097, 9 p., 2 plates.
and Altamaha Rivers (Fig. 4D). ACKNOWLEDGMENTS Grosz, A.E., Cathcart, J.B., Macke, D.L., Knapp,
M.S., Schmidt, W., and Scott, T.M., 1989, Geo-
The transport of heavy minerals a long dis- The airborne surveys were funded as a collabora- logic interpretation of the gamma-ray aeroradio-
tance from a river source contrasts the simpler tive effort by the U.S. Geological Survey Earthquake metric maps of central and northern Florida:
scenario suggested for sediments adjacent to Hazards Program, National Cooperative Geologic U.S. Geological Survey Professional Paper 1461,
48 p., 5 plates.
the Piedmont, where heavy minerals are Mapping Program, Mineral Resources Program, and International Atomic Energy Agency (IAEA),
Earth Mapping Resources Initiative. The data were
mostly deposited adjacent to the rocks from collected and processed by Terraquest Ltd. We thank 2003, Guidelines for radioelement mapping us-
which they were eroded. This contrast poses Bradley Van Gosen and two anonymous reviewers ing gamma ray spectrometry data: IAEA-TEC-
an interesting question for future research: for helpful reviews. Any use of trade, firm, or product DOC-1363, International Atomic Energy Agen-
Where in the Atlantic Coastal Plain is the names is for descriptive purposes only and does not cy (IAEA), Vienna.
transition between these different modes of imply endorsement by the U.S. government. Jones, J.V., III, Piatak, N.M., and Bedinger, G.M.,
2017, Zirconium and hafnium, in Schulz, K.J.,
emplacement? Further studies using mineral- REFERENCES CITED DeYoung, J.H., Jr., Seal, R.R., II, and Bradley,
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