The Cambrian syn-rift strata preserved in western Avalonia provide a distinctive example of how u... more The Cambrian syn-rift strata preserved in western Avalonia provide a distinctive example of how unconformity-bounded sequences are diachronous throughout proximal to marginal rift branches. Terreneuvian‒Miaolingian third-order sequences of the Caledonian Highlands, New Brunswick, Canada, reflect a complex interplay among syn-rift tectonic events, denudation pulses, and sea-level fluctuations. Unconformably overlying the early, rift-related volcanosedimentary Coldbrook Group (ca. 560‒550 Ma), the Ratcliffe Brook, Glen Falls, Hanford Brook, and Forest Hills Formations can be subdivided into two transgressive systems tract (TST)‒highstand systems tract (HST) sequences (each ∼10 m.y.) and an incomplete TST sequence that are separated by stratigraphic gaps. They reflect uplift and tilting events affecting the basement, transgressive and drowning surfaces, and condensed sections. Arid to semi-arid climatic episodes are supported by the excellent preservation of mafic to felsic volcanic cl...
Detailed mapping in the Digby to Liverpool area of the Meguma terrane was initiated in 1998 by th... more Detailed mapping in the Digby to Liverpool area of the Meguma terrane was initiated in 1998 by the Nova Scotia Department of Natural Resources to produce a series of updated geological bedrock maps. The Meguma terrane, includes the Goldenville and Halifax formations (Meguma Group) and the younger White Rock and Torbrook formations, intruded by mainly Devonian plutonic units and overlain by Carboniferous and younger rocks. The new maps, combined with detailed petrography, geochemistry, and geochronology, have better defi ned the distribution, age, and character of the Meguma Group in southwestern Nova Scotia. The Goldenville Formation can be subdivided into a lower metasandstone-dominated Green Harbour member, a middle metasandstone/slate Government Point member, and an upper metasiltstone Bloomfi eld/Moshers Island member. The Green Harbour member, north of Yarmouth, contains a distinctive metasiltstone unit (High Head) with abundant trace fossils including the early Cambrian deep-w...
A detailed stratigraphic and structural study has been undertaken of sedimentary rocks in the Loc... more A detailed stratigraphic and structural study has been undertaken of sedimentary rocks in the Lochaber-Mulgrave area of northern mainland Nova Scotia. The sedimentary sequence in this area is bounded on the north by the Glenroy Fault and on the south by the Roman Valley Fault, and has been tentatively assigned to the Early Carboniferous Horton Group. It has been divided into three units (from oldest to youngest): {I) Clam Harbour River Formation, (2) Tracadie Road Formation, and (3) Caledonia Mills Formation. The Clam Harbour River Formation contains polymictic
On-going studies of Devonian to Carboniferous volcanic and associated sedimentary and gabbroic ro... more On-going studies of Devonian to Carboniferous volcanic and associated sedimentary and gabbroic rocks in the Guysborough area of northern mainland Nova Scotia and in central and southern Cape Breton Island are leading to better understanding of their distribution and age, and hence (ultimately) their regional significance. In Guysborough County, basalt and minor rhyolite of the Sunnyville Formation are overlain conformably(?) by red conglomerate and sandstone of the Glenkeen Formation, and quartz wacke and siltstone members of the Clam Harbour River Formation. A mid-Devonian age for these units is indicated by a U-Pb (zircon) date of 389 ± 2 Ma from rhyolite in the Sunnyville Formation. In contrast, a rhyolite flow located near the top of the Fisset Brook Formation in the Gillanders Mountain area east of Lake Ainslie in Cape Breton Island has yielded a U-Pb (zircon) age of ca. 375 Ma, indicating that the Fisset Brook Formation (at least in that area) is of midto late Devonian age, an...
The Meguma terrane of southern Nova Scotia is the most outboard terrane of the northern Appalachi... more The Meguma terrane of southern Nova Scotia is the most outboard terrane of the northern Appalachian orogen. It is characterized by the Meguma Group, made up of the Late Proterozoic(?) to Cambrian Goldenville Formation, which consists mainly of thickly bedded, massive metasandstone with minor interbedded metasiltstone and slate, and the conformably overlying Cambrian to Lower Ordovician Halifax Formation, composed mainly of slate with thin beds of metasiltstone and metasandstone. Although generally interpreted to have formed at a continental margin, whether that continent was Africa or some other periGondwanan area is still debated. Sedimentary rock geochemistry is a viable tool for regional correlation and provenance studies. During the summer of 2005, samples were collected from three relatively well exposed stratigraphic sections through the Goldenville and Halifax formations in the Bear River, High Head, and Broad River areas of the Meguma terrane. The purpose of this project is ...
The four-fold division of pre-Carboniferous geology of Cape Breton Island implies that the Centra... more The four-fold division of pre-Carboniferous geology of Cape Breton Island implies that the Central Mobile Belt (CMB) of the Canadian Appalachians in the Cape Breton Highlands (CBH) is represented by the Aspy Terrane. The occurrence of rocks in the Aspy Terrane equivalent to those occurring in the CMB of southwest Newfoundland supports this interpretation. The "Cape North Group", as exposed along the north shore of the CBH, can be divided into at least two distinct · lithological assemblages. The western assemblage comprises marble that is tectonically interleaved with thinly-banded amphibolite, hornblendite and kyanite-garnet schist, intruded by tonalite, diorite and gabbro. This assemblage resembles the highly deformed slivers of the Fleur de Lys Supergroup and associated plutons in the Notre Dame Subzone in southwest Newfoundland. The eastern assemblage comprises psammites, semipelites and felsic orthogneisses injected by abundant amphibolite, which together are intruded...
The Cambrian syn-rift strata preserved in western Avalonia provide a distinctive example of how u... more The Cambrian syn-rift strata preserved in western Avalonia provide a distinctive example of how unconformity-bounded sequences are diachronous throughout proximal to marginal rift branches. Terreneuvian‒Miaolingian third-order sequences of the Caledonian Highlands, New Brunswick, Canada, reflect a complex interplay among syn-rift tectonic events, denudation pulses, and sea-level fluctuations. Unconformably overlying the early, rift-related volcanosedimentary Coldbrook Group (ca. 560‒550 Ma), the Ratcliffe Brook, Glen Falls, Hanford Brook, and Forest Hills Formations can be subdivided into two transgressive systems tract (TST)‒highstand systems tract (HST) sequences (each ∼10 m.y.) and an incomplete TST sequence that are separated by stratigraphic gaps. They reflect uplift and tilting events affecting the basement, transgressive and drowning surfaces, and condensed sections. Arid to semi-arid climatic episodes are supported by the excellent preservation of mafic to felsic volcanic cl...
Detailed mapping in the Digby to Liverpool area of the Meguma terrane was initiated in 1998 by th... more Detailed mapping in the Digby to Liverpool area of the Meguma terrane was initiated in 1998 by the Nova Scotia Department of Natural Resources to produce a series of updated geological bedrock maps. The Meguma terrane, includes the Goldenville and Halifax formations (Meguma Group) and the younger White Rock and Torbrook formations, intruded by mainly Devonian plutonic units and overlain by Carboniferous and younger rocks. The new maps, combined with detailed petrography, geochemistry, and geochronology, have better defi ned the distribution, age, and character of the Meguma Group in southwestern Nova Scotia. The Goldenville Formation can be subdivided into a lower metasandstone-dominated Green Harbour member, a middle metasandstone/slate Government Point member, and an upper metasiltstone Bloomfi eld/Moshers Island member. The Green Harbour member, north of Yarmouth, contains a distinctive metasiltstone unit (High Head) with abundant trace fossils including the early Cambrian deep-w...
A detailed stratigraphic and structural study has been undertaken of sedimentary rocks in the Loc... more A detailed stratigraphic and structural study has been undertaken of sedimentary rocks in the Lochaber-Mulgrave area of northern mainland Nova Scotia. The sedimentary sequence in this area is bounded on the north by the Glenroy Fault and on the south by the Roman Valley Fault, and has been tentatively assigned to the Early Carboniferous Horton Group. It has been divided into three units (from oldest to youngest): {I) Clam Harbour River Formation, (2) Tracadie Road Formation, and (3) Caledonia Mills Formation. The Clam Harbour River Formation contains polymictic
On-going studies of Devonian to Carboniferous volcanic and associated sedimentary and gabbroic ro... more On-going studies of Devonian to Carboniferous volcanic and associated sedimentary and gabbroic rocks in the Guysborough area of northern mainland Nova Scotia and in central and southern Cape Breton Island are leading to better understanding of their distribution and age, and hence (ultimately) their regional significance. In Guysborough County, basalt and minor rhyolite of the Sunnyville Formation are overlain conformably(?) by red conglomerate and sandstone of the Glenkeen Formation, and quartz wacke and siltstone members of the Clam Harbour River Formation. A mid-Devonian age for these units is indicated by a U-Pb (zircon) date of 389 ± 2 Ma from rhyolite in the Sunnyville Formation. In contrast, a rhyolite flow located near the top of the Fisset Brook Formation in the Gillanders Mountain area east of Lake Ainslie in Cape Breton Island has yielded a U-Pb (zircon) age of ca. 375 Ma, indicating that the Fisset Brook Formation (at least in that area) is of midto late Devonian age, an...
The Meguma terrane of southern Nova Scotia is the most outboard terrane of the northern Appalachi... more The Meguma terrane of southern Nova Scotia is the most outboard terrane of the northern Appalachian orogen. It is characterized by the Meguma Group, made up of the Late Proterozoic(?) to Cambrian Goldenville Formation, which consists mainly of thickly bedded, massive metasandstone with minor interbedded metasiltstone and slate, and the conformably overlying Cambrian to Lower Ordovician Halifax Formation, composed mainly of slate with thin beds of metasiltstone and metasandstone. Although generally interpreted to have formed at a continental margin, whether that continent was Africa or some other periGondwanan area is still debated. Sedimentary rock geochemistry is a viable tool for regional correlation and provenance studies. During the summer of 2005, samples were collected from three relatively well exposed stratigraphic sections through the Goldenville and Halifax formations in the Bear River, High Head, and Broad River areas of the Meguma terrane. The purpose of this project is ...
The four-fold division of pre-Carboniferous geology of Cape Breton Island implies that the Centra... more The four-fold division of pre-Carboniferous geology of Cape Breton Island implies that the Central Mobile Belt (CMB) of the Canadian Appalachians in the Cape Breton Highlands (CBH) is represented by the Aspy Terrane. The occurrence of rocks in the Aspy Terrane equivalent to those occurring in the CMB of southwest Newfoundland supports this interpretation. The "Cape North Group", as exposed along the north shore of the CBH, can be divided into at least two distinct · lithological assemblages. The western assemblage comprises marble that is tectonically interleaved with thinly-banded amphibolite, hornblendite and kyanite-garnet schist, intruded by tonalite, diorite and gabbro. This assemblage resembles the highly deformed slivers of the Fleur de Lys Supergroup and associated plutons in the Notre Dame Subzone in southwest Newfoundland. The eastern assemblage comprises psammites, semipelites and felsic orthogneisses injected by abundant amphibolite, which together are intruded...
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