Geologic Map of the West-Central Barberton Greenstone Belt

Member Non-Member   $45.00 $60.00   compiled by Donald R. Lowe Gary R. Byerly Christoph Heubeck Year Published:  2012 Product Code:  MCH103F This 1:25,000 map covers 500 square kilometers of Archean rocks in the Barberton Greenstone Belt (BGB), South Africa—the oldest, best-preserved sedimentary and volcanic sequence on Earth. Five major tectonic cycles are represented in the BGB’s 3.55–3.22 Ga history—komatiitic volcanism, forming lava plains, begins each cycle, and dacitic volcanism, likely related to an early style of subduction, ends each cycle. These cycles produce small yet stable protocontinental blocks that coalesce by magmatic and tectonic accretion. The BGB rocks provide direct information about the nature and evolution of early Earth and its biota. Carbonaceous cherts occur throughout the sequence, containing microfossils, microbial mats, and stromatolites. Evaporites represent shallow marine environments, whereas ferruginous chert and banded iron formation are indicators of deeper water settings. The BGB also contains a remarkable record of large asteroidal impacts, in eight distal impact layers, each more energetic than the K-T boundary event. 1 color plate (approx. 54.5" by 77")

If you cannot find a particular product, it may be due to low inventory. Please contact GSA Sales & Service, +1-888-443-4472 (toll-free in US); +1-303-357-1000, option 3; gsaservice@geosociety.org, for availability information.

Alternatively, many out-of-print books may be found at GSA Online Publications. To locate the book online, please visit www.gsapubs.org.

Thanks for visiting the GSA Bookstore!