Tectonostratigraphic implications of late Proterozoic U-Pb zircon ages in the Avalon Zone of southeastern New England

Abstract

U-Pb zircon ages have been determined for several Late Proterozoic igneous units near Boston, Massachusetts, in the AvalonZone of southeastern New England. Crystallization ages are 599 ± 1 Ma for the Westwood Granite, 596 ± 2 Ma for rhyodacite from the Mattapan Volcanic Complex and 589 ± 2 Ma for quartz diorite, which intrudes the Westwood Granite. These results together with published ages from granites of the Dedham Granite, the Esmond-Milford plutonic suite, and granitic gneisses in Massachusetts and Rhode Island fix Avalonian arc magmatism in southeastern New England between ca. 625 and 589 Ma, an interval diachronous with respect to subduction-related plutonism and volcanism in other northern Appalachian Avalonian terranes.

Neoproterozoic?Early Paleozoic evolution of peri-Gondwanan terranes: implications for Laurentia-Gondwana connections

“…However, its cessation was diachronous, terminating at ca. 590 Ma in New England (Kaye and Zartman 1980;Zartman 1985, 1992;Thompson et al 1996;Thompson and Bowring 2000), 600 Ma in southern New Brunswick (Bevier and Barr 1990;Barr et al 1994;Currie and McNicoll 1999), 605 Ma in mainland Nova Scotia (Doig et al 1991;Murphy et al 1997;, 575 Ma in southern Cape Breton Bevier et al 1993), 585 Ma in Newfoundland (Krogh et al 1988;O'Brien et al 1996), and 600 Ma in the British Isles (e.g., Tucker and Pharaoh 1991;Horµk 1993;Noble et al 1993).…”

Application of petrographic and geochemical methods to sourcing felsitic archaeological materials in Southeastern New England

“…Calcalkaline volcanics are represented by the Lynn-Mattapan suite that occur northeast and southwest of Boston ( Figure 1); recent radiometric data demonstrate that these spatially separated rocks are coeval and of Late Proterozoic age (Kaye and Zartman, 1980;Hepburn et al, 1993;Thompson et al, 1996). The Lynn-Mattapan includes a variety of volcanic rock types, including rhyolitic to andesitic tuff, ash-flow tuff, and lava flows; pyroclastic rocks dominate the 1000ϩ-m-thick sequence.…”

Tectonostratigraphic relationships and coalification trends in the Narragansett and Norfolk Basins, New England

“…therein). The Boston Basin, once considered to be of Carboniferous age, has been demonstrated to be of Late Proterozoic and Cambrian age based on radiometrically and paleontologically based ages (summarized in Thompson et al, 1996;Thompson and Bowering, 2000).…”