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Meguma, the most outboard northern Appalachian terrane, is characterized by Upper Neoproterozoic to Lower Ordovician turbiditic rocks that have an exposed thickness of more than 11 km. As a result of geological mapping, combined with petrological studies, the stratigraphy of these rocks has been redefined. The traditional twofold division into the meta-sandstone–dominated Goldenville Group and the overlying slate-dominated Halifax Group is retained, but the Chebogue Point shear zone divides these groups into western and southern stratigraphic packages containing different formations. In both packages, psammitic rocks are dominantly feldspathic wacke, and they have mineralogical compositions indicative of deposition in an active margin from a source dominated by quartz and plagioclase; rare conglomeratic units contain mainly psammitic clasts with some mafic through felsic volcanic clasts, and rare tonalite clasts. In the southern area, psammitic units tend to contain more quartz and grade to arenite. Although fine material increases in relative abundance, little change in provenance up section is indicated by petrography of psammitic rocks. Chemical compositions of 116 psammitic and pelitic samples from the western area and 471 from the larger southern area are consistent with the petrographic data. Their compositions are indicative of derivation from felsic to intermediate igneous material, and the depositional environment was probably in a rift along the Gond wanan margin. It is likely that Pan-African orogenic belts containing recycled sediments from older cratons were major contributors to the sediments, rather than sediments being derived directly from large ancient cratonic areas.

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