The Avalon Zone type area: southeastern Newfoundland Appalachians

O’Brien, S. J.; Strong, D. F.; King, A. F.

doi:10.1007/978-94-009-0401-9_9

Cited by 17 publications

(14 citation statements)

References 54 publications

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“…600 Ma (Dallmeyer et al, 1981;Krogh et al, 1988;O'Brien et al, 1992b) are a major component of the Avalon terrane in Newfoundland. West of the Paradise Sound fault, they include the Marystown, Love Cove, and Connaigre Bay groups (O'Brien et al, , 1990(O'Brien et al, , 1992a (Fig. 4), and east of the fault, the Harbour Main Group.…”

Section: Geologic Settingmentioning

confidence: 99%

“…4), but sedimentary sequences are more extensive in the east, where they are represented by turbidites of the Connecting Point and Conception groups (e.g., King, 1986;Knight and O'Brien, 1988). The Conception Group is conformably to disconformably overlain by shale and sandstone of the St. John's Group, and by shallow marine to alluvial rocks of the Signal Hill Group; the Connecting Point Group is unconformably overlain by the Musgravetown Group, which is lithologically similar, and presumed to be equivalent, to the St. John's and Signal Hill groups (King, 1986;O'Brien et al, 1990). Bimodal alkalic volcanic rocks of the Bull Arm Formation are associated with the Musgravetown Group.…”

Section: Geologic Settingmentioning

confidence: 99%

“…Plutonic rocks of late Precambrian age are a major component of the Avalon zone or terrane of the northern Appalachian orogen (e.g., Williams, 1978Williams, , 1979O'Brien et al, , 1990Nance, 1986). Recent U-Pb dating of the plutonic rocks and their host volcanic-sedimentary sequences has shown that they may record several discrete late Precambrian magmatic events, even within one geographic area of the terrane (e.g., Barr et al, 1994;Bevier et al, 1993;Hepburn et al, 1993;O'Brien et al, 1992aO'Brien et al, , 1992bO'Brien et al, , 1994.…”

Section: Introductionmentioning

confidence: 99%

“…In this chapter we confine our comparisons to late Precambrian plutons in three areas within the Avalon terrane: the Caledonia terrane in New Brunswick White, 1989a, 1996), the Mira terrane in Cape Breton Island (Barr and Raeside, 1989;Barr et al, 1990Barr et al, , 1994b, and the part of Newfoundland east of the Dover-Hermitage Bay fault (O'Brien et al, , 1990(O'Brien et al, , 1992b(O'Brien et al, , 1994, here termed the Newfoundland Avalon terrane. Although these three areas have been given different names to emphasize their present geographic separation, we emphasize that we do not consider them to be separate terranes; they are all part of the Avalon terrane.…”

Section: Introductionmentioning

confidence: 99%

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Late Precambrian plutons in the Avalon terrane of New Brunswick, Nova Scotia, and Newfoundland

Barr¹,

Kerr²

1997

The Nature of Magmatism in the Appalachian Orogen

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Comparison of late Precambrian plutonic rocks in three parts of the Avalon terrane of the northern Appalachian orogen (the Caledonia terrane in southern NewBrunswick, the Mira terrane of southeastern Cape Breton Island, and the type area of the Avalon terrane in eastern Newfoundland) shows that ca. 620 Ma plutonic rocks and voluminous coeval volcanic rocks occur in all three areas. The ca. 620 Ma plutonic rocks range from gabbro and diorite to granite, and have petrochemical features indicative of origin in continental margin volcanic arcs. Remnants of older, ca. 680 Ma, arc complexes occur in the western part of the Newfoundland Avalon terrane and in the Mira terrane, although granitoid plutonic rocks of that age are preserved only in the former area. Younger, ca. 580-550 Ma, plutonic rocks occur in all three areas but differ in petrological features and apparent tectonic setting: (1) in the Caledonia terrane, ca. 560-550 Ma bimodal granitic-dioritic and/or gabbroic plutons are a major component, and apparently formed during major extension within the former ca. 620 Ma arc; (2) in the Mira terrane granitic plutons have ages of ca. 575 Ma, and formed in association with a ca. 575-560(?) Ma volcanic arc; (3) in the central part of the Newfoundland Avalon terrane, arc-related plutonic and volcanic rocks of ca. 580-560 Ma age may also be widespread, but their ages are poorly constrained. Bimodal, dominantly alkaline to peralkaline ca. 570 Ma and ca. 550 Ma plutonic suites are also present in Newfoundland, but do not appear to be present in either the Mira or Caledonia terranes.

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Section: Geologic Settingmentioning

confidence: 99%

Section: Geologic Settingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Late Precambrian plutons in the Avalon terrane of New Brunswick, Nova Scotia, and Newfoundland

Barr¹,

Kerr²

1997

The Nature of Magmatism in the Appalachian Orogen

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show abstract

“…Tanoli and Pickerill 1988;Landing and Murphy 1991;Landing 1995), which rest either conformably or unconformably on a variety of late Neoproterozoic arc-related volcanosedimentary assemblages, or nonconformably on associated magmatic arc granitoid rocks (e.g. O'Brien et al 1990;Murphy et al 1991). In contrast, the early Paleozoic stratigraphy of the Meguma terrane comprises a thick (>10 km) basinal succession of Cambrian (late Neoproterozoic?…”

Section: Introductionmentioning

confidence: 99%