See more from this Division: Topical Sessions
See more from this Session: Gondwana-Laurentia Terrane Transfers During the Pangean and Rodinian Supercontinent Cycles
Abstract:
Digital aeromagnetic and gravity data provide critical information on location, crustal character, and geometry of boundaries between crustal blocks of contrasting potential-field signatures. Exposed Carolina superterrane rocks have potential-field signatures contrasting with Laurentian terranes to their west. PG crustal blocks are traceable beneath the Atlantic and Gulf Coastal Plain based on their 3-20 km, high frequency signature interrupted by numerous plutons. The Brunswick (Charleston) terrane has a slightly different signature, but a 604 Ma U-Pb TIMS date from one drill hole in GA suggests that it also is PG crust. Suwannee terrane rocks south of the Suwannee-Wiggins suture also have a distinctive magnetic-gravity signature of 20-50 km, broad, elliptical highs and lows. This suture joins Laurentia to Gondwanan and PG crust, but truncates all Southern Appalachian Grenvillian and PG terranes, indicating that it formed during the final (AlleghanianVariscan) collision that also formed Pangaea, and that it was left behind during Mesozoic rifting. This Paleozoic suture may coincide with a failed Mesozoic rift, because drill hole and potential-field data indicate a considerable thickness of Mesozoic sediments above the suture.
See more from this Division: Topical Sessions
See more from this Session: Gondwana-Laurentia Terrane Transfers During the Pangean and Rodinian Supercontinent Cycles