Tectonic deformation and its sedimentary consequences during deposition of the Lower Cretaceous Chaswood Formation, Elmsvale basin, Nova Scotia

2005 ◽  
Vol 53 (2) ◽  
pp. 189-199 ◽  
Author(s):  
D. J.W. Piper
Keyword(s):  
Nova Scotia ◽  
Lower Cretaceous ◽  
Tectonic Deformation

scholarly journals Sedimentary and tectonic setting of a mass-transport slope deposit in the Halifax Group, Halifax Peninsula, Nova Scotia, Canada

2015 ◽  
Vol 51 (1) ◽  
pp. 084 ◽  
Author(s):  
John W.F. Waldron ◽  
Rebecca A. Jamieson ◽  
Hayley D. Pothier ◽  
Chris E. White
Keyword(s):  
Nova Scotia ◽  
Mass Transport ◽  
Tectonic Setting ◽  
Tectonic Deformation ◽  
Font Size ◽  
Fine Grained ◽  
Metasedimentary Rocks ◽  
Internal Structures ◽  
Transport Direction ◽  
Deformation Features

<p align="LEFT">Fine-grained metasedimentary rocks of the Halifax Group in southern mainland Nova Scotia can be subdivided into mappable units. In Halifax Peninsula, sulphide-rich hornfels, black slate, metasiltstone, and metasandstone of the Cunard Formation are overlain by grey metasedimentary rocks with abundant cross-laminations and local carbonate and calc-silicate concretions, assigned to the Bluestone Quarry Formation. No fossils are known from the Bluestone Quarry Formation but lithological correlatives elsewhere are Tremadocian. The Bluestone Quarry Formation is here divided into four members. The lowest (Point Pleasant member) contains thin parallel-laminated and cross-laminated <span style="font-family: MinionPro-Regular; font-size: small;"><span style="font-family: MinionPro-Regular; font-size: small;">metasandstone beds with Bouma T</span></span><span style="font-family: MinionPro-Regular; font-size: xx-small;"><span style="font-family: MinionPro-Regular; font-size: xx-small;">bcde </span></span><span style="font-family: MinionPro-Regular; font-size: small;"><span style="font-family: MinionPro-Regular; font-size: small;">and T</span></span><span style="font-family: MinionPro-Regular; font-size: xx-small;"><span style="font-family: MinionPro-Regular; font-size: xx-small;">cde </span></span><span style="font-family: MinionPro-Regular; font-size: small;"><span style="font-family: MinionPro-Regular; font-size: small;">structures, and thicker beds with Bouma ‘a’ divisions. The Black Rock </span></span>Beach member lacks the thicker massive beds and is dominated by rippled and cross-laminated metasedimentary rocks. The overlying Chain Rock member, an erosion-resistant ridge-forming unit, is disrupted by folds and boudinage. Bedding is truncated at the upper contact, and the internal structures are overprinted by (and therefore predate) the Neoacadian cleavage. They are interpreted as products of synsedimentary mass transport. Scarce folds in the Chain Rock member and current ripples in the underlying unit are consistent with a N or NW transport direction. The overlying Quarry Pond member consists of thinly bedded coherent metasedimentary rocks that generally resemble those of the Black Rock Beach member. Although there are indications of upward shallowing in equivalent successions elsewhere in the Halifax Group, the presence of a major mass transport deposit in the Bluestone Quarry Formation shows that this part of the Halifax Group was deposited on a submarine paleoslope. The failure of geologists to identify this feature in much-visited outcrops testifies to the difficulty of identifying synsedimentary deformation features that have been overprinted by later tectonic deformation.</p>

Detrital muscovite geochronology and the Cretaceous tectonics of the inner Scotian Shelf, southeastern Canada 1This article is one of a series of papers published in this CJES Special Issue on the theme of Mesozoic–Cenozoic geology of the Scotian Basin. 2Geological Survey of Canada Contribution 20120142.

2012 ◽  
Vol 49 (12) ◽  
pp. 1558-1566 ◽  
Author(s):  
Peter H. Reynolds ◽  
Georgia Pe-Piper ◽  
David J.W. Piper
Keyword(s):  
Nova Scotia ◽  
Lower Cretaceous ◽  
Special Issue ◽  
Scotian Shelf ◽  
Single Grain ◽  
Meguma Terrane ◽  
Maritimes Basin ◽  
Uplift And Erosion

Geochronology of detrital muscovite from the Lower Cretaceous of the central Scotian Basin has shown predominant supply of Meguma terrane detritus, including muscovite with Alleghanian (mid-Carboniferous to Permian) ages from the inner Scotian Shelf. In this study, 87 detrital muscovite grains from five wells in the eastern Scotian Basin, representing depositional ages from Tithonian to Early Albian, were dated by single-grain 40Ar/39Ar techniques. Previous work shows that the provenance of this sediment was different from wells in the central Scotian Basin. Compared with the central Scotian Basin, the muscovite age populations from the eastern Scotian Basin have more (20% versus 7%) pre-Devonian ages, derived from inboard terranes of the Appalachians. In both the central and eastern Scotian Basin, most old grains are found in the Tithonian and the Aptian–Albian, with fewer in the Valanginian and almost none in the Kimmeridgian and the Hauterivian–Barremian. These data suggest rapid unroofing of the Meguma terrane in the Kimmeridgian and Hauterivian–Barremian and greater supply of sediment from Newfoundland to the eastern Scotian Basin in the Tithonian and Aptian–Albian. Compared with the central Scotian Basin, which has most ages in the range 340–300 Ma, the muscovite age populations from the eastern Scotian Basin have a higher proportion of 420–340 Ma and in particular 300–260 Ma ages. Such late Alleghanian overprinting of argon ages is very rare on land in Nova Scotia, but in the Maritimes Basin, this was the time of uplift and erosion of strata.

scholarly journals LANDSLIDE AT TSAKONA AREA IN ARKADIA PREFECTURE. GEOLOGICAL CONDITIONS AND ACTIVATION MECHANISM

2004 ◽  
Vol 36 (4) ◽  
pp. 1862
Author(s):  
Λ. Σωτηρόπουλος ◽  
E. Λυμπέρης ◽  
Α. Σιγάλας ◽  
Α. Ντουρούπη ◽  
Κ. Προβιά ◽  
...  
Keyword(s):  
Lower Cretaceous ◽  
Upper Cretaceous ◽  
Road Construction ◽  
Upper Jurassic ◽  
Activation Mechanism ◽  
Tectonic Deformation ◽  
The Road ◽  
Geological Conditions ◽  
Geological Factors ◽  
Geological Formations

The geological conditions of the landslide's area, at Tsakona, in Arkadia Prefecture, are examined, as well as the factors that influenced the landslide's evolution. The landslide occurred at a distance of 15 km south of Megalopoli, on the New Highway, connecting Tripoli to Kalamata and constitutes one of the larger road landslides that have ever taken place. It occupies an area of a length of 1200m and a width of 300m. Geotectonically the landslide's region is placed in a block of the Pindos zone, thrusted on the Gabrovo-Tripoli zone. The geological formations that comprise the closer geological frame, consist of the formation of "First Flysch", Upper Jurassic - Lower Cretaceous and of the Upper Cretaceous limestones. The geological factors that drastically influenced the landslide's activation are lithological, tectonic, hydrogeological and morphological. The mainly siltstone lithology of the flysch, the intense tectonic deformation that occurred during the alpidic horogenetic phase, the morphological depression that is formed by the landslide's region and the large quantities of groundwater supplied by the uphill limestone, are the main geological reasons that activated the landslide. It should be emphasised that the activation and evolution of the landslide were greatly influenced by human activity during the road construction.

The West Indian Road pit, central Nova Scotia: key to the Early Cretaceous Chaswood Formation

2006 ◽  
Vol 43 (3) ◽  
pp. 391-403 ◽  
Author(s):  
Jean-Philippe Gobeil ◽  
Georgia Pe-Piper ◽  
David JW Piper
Keyword(s):  
Nova Scotia ◽  
Early Cretaceous ◽  
West Indian ◽  
Tectonic Deformation ◽  
Maritime Provinces ◽  
The West ◽  
South Mountain Batholith ◽  
The North ◽  
Quartz Arenite ◽  
Sand And Gravel

The West Indian Road pit is the only large outcrop in Nova Scotia of the Chaswood Formation, the terrestrial equivalent of the offshore Missisauga and Logan Canyon formations. It provides outcrop information on sedimentology, gravel petrology, and structures for a formation that is otherwise known from a few small overgrown pits and from boreholes. The Chaswood Formation in the pit is > 60 m thick and consists principally of sorted sand and gravel with three thinner clay units. Successions of sedimentary structures indicate deposition from a coarse-bedload river flowing to the east-southeast. Gravel consists principally of vein quartz, quartz arenite, and subarkose, together with minor igneous lithologies that can be matched to sources in the Cobequid Highlands to the north. Quartz arenite and subarkose appear derived from Carboniferous Horton Group. Single-crystal 40Ar/39Ar dates of detrital muscovite are a little older than the muscovite ages for the South Mountain batholith, interpreted to mean that the muscovite is second cycle from the Horton Group, which records the earliest unroofing of the batholith. The Chaswood Formation accumulated during progressive tectonic deformation along NNE-trending strike-slip faults in basement rocks, resulting in syn-sedimentary faulting and local unconformities. Sedimentation kept pace with the creation of accommodation. Unrelated younger deformation folded the Chaswood Formation at the pit into an east–west-trending syncline. The Early Cretaceous paleogeography of the Maritime Provinces is interpreted to have consisted of fault-bound horsts shedding coarse detritus surrounded by an interconnected series of basins that accumulated fluvial sands and gravels and overbank muds with well-developed paleosols.

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