scholarly journals Middle Ordovician to Lower Devonian deep-water succession at southeastern margin of Hazen Trough, Cañon Fiord, Ellesmere Island

1979 ◽  
Author(s):  
H P Trettin
Keyword(s):  
Deep Water ◽  
Lower Devonian ◽  
Ellesmere Island ◽  
Middle Ordovician ◽  
Southeastern Margin

Pearya: a composite terrane with Caledonian affinities in northern Ellesmere Island

1987 ◽  
Vol 24 (2) ◽  
pp. 224-245 ◽  
Author(s):  
H. P. Trettin
Keyword(s):  
Deep Water ◽  
Volcanic Rocks ◽  
Volcanic Belt ◽  
Ellesmere Island ◽  
Mobile Belt ◽  
Lower Paleozoic ◽  
Water Basin ◽  
Middle Ordovician ◽  
Angular Unconformity ◽  
Deep Water Basin

In Ellesmere Island, the Canadian Shield and Arctic Platform are flanked on the northwest by the lower Paleozoic Franklinian mobile belt, which comprises an unstable shelf (miogeocline) and a deep-water basin, divisible into an inner sedimentary belt and an outer sedimentary–volcanic belt. Both are tied to the shelf by interlocking facies changes, but additional exotic units may be present in the outer belt.Pearya, bordering the deep-water basin on the northwest, is divisible into four successions. Succession I comprises sedimentary and(?) volcanic rocks, deformed, metamorphosed to amphibolite grade, and intruded by granitic plutons at 1.0–1.1 Ga. Succession II consists mainly of platformal sediments (carbonates, quartzite, mudrock), with smaller proportions of mafic and siliceous volcanics, diamictite, and chert ranging in age from Late Proterozoic (Hadrynian) to latest Cambrian or Early Ordovician. Its concealed contact with succession I is tentatively interpreted as an angular unconformity. Succession III (Lower to Middle Ordovician?) includes arc-type and ocean-floor volcanics, chert, mudrock, and carbonates and is associated with fault slices of Lower Ordovician (Arenig) ultramafic–mafic complexes–possibly dismembered ophiolites. The faulted contact of succession III and the ultramafics with succession II is unconformably overlapped by succession IV, 7–8 km of volcanic and sedimentary rocks ranging in age from late Middle Ordovician (Blackriverian = early Caradoc) to Late Silurian (late Ludlow?). The angular unconformity at the base of succession IV represents the early Middle Ordovician (Llandeilo–Llanvirn) M'Clintock Orogeny, which was accompanied by metamorphism up to amphibolite grade and granitic plutonism. Pearya is related to the Appalachian–Caledonian mobile belt by the Grenville age of its basement, the age of its ultramafic–mafic complexes, and evidence for a Middle Ordovician orogeny, comparable in age and character to the Taconic. By contrast, the Franklinian mobile belt has a Lower Proterozoic (Aphebian) – Archean basement and was not deformed in the Ordovician. Stratigraphic–structural evidence suggests that Pearya was transported by sinistral strike slip as three or more slices and accreted to the Franklinian deep-water basin in the Late Silurian under intense deformation. The inferred sinistral motion is compatible with derivation from the northern Caledonides.

Regulaecystis devonica, a new Devonian pleurocystitid cystoid from Devon

1974 ◽  
Vol 111 (4) ◽  
pp. 349-352 ◽  
Author(s):  
C. R. C. Paul
Keyword(s):  
Lower Devonian ◽  
Junior Synonym ◽  
Middle Ordovician

SummaryRegulaecystis devonica, which is probably from the Meadfoot Beds (Siegeman— Emsian) near Torquay, Devon, is characterized by smooth thick thecal plates and a deeply sunken pectinirhomb. Coopericystis Parsley from the Middle Ordovician of Tennessee is considered a junior synonym of Regulaecystis from the Lower Devonian of Europe.

Deep-Water Contourite Drifts in the West of North-China Platform

2013 ◽  
Vol 318 ◽  
pp. 447-452
Author(s):  
Shun She Luo ◽  
Zhen Zhong Gao ◽  
You Bin He ◽  
Qi Qi Lv ◽  
Ying Meng
Keyword(s):  
Deep Water ◽  
North China ◽  
The West ◽  
North China Platform ◽  
Middle Ordovician ◽  
Contourite Drifts

The middle Ordovician of Pingliang area on the west margin of North-China platform is represented by a succession of deep-water sediments in which contourites are well-developed. Contour current deposits are well-developed. The contourites can be classified into:calcarenitic contourite, calcisiltitic contourite and calcilutitic contourite. Three typical contourite successions are recognized: complete contourite succession, incomplete contourite succession and contourite successions consisting only of calcarenitic contourites. According to the palaeocorrent and the palaeogeographic format analyse,carbonate contourite drift in the study area is unfolded crossing northwest-southeast, forwarding from southeast to northwest along the slope, and compared with other contourite drifts, it has some characteristics of coarser-grained sediment, thicker individual layers, and highly developed calcarenitic contourites and so on.

scholarly journals Biostratigraphic reconnaissance in the Lower Palaeozoic of western North Greenland

1984 ◽  
Vol 121 ◽  
pp. 19-51
Author(s):  
P.R Dawes ◽  
J.S Peel
Keyword(s):  
Fault Zone ◽  
Deep Water ◽  
Lower Cambrian ◽  
The South ◽  
The West ◽  
Middle Ordovician ◽  
Water Trough ◽  
Lower Palaeozoic ◽  
North Greenland ◽  
Land Region

Sections and fossil collections resulting from activities under Operation Grant Land 1965-66 in the Hall Land - Wulff Land region of western North Greenland are briefly discussed. Strongly tectonised Lower Cambrian to Silurian strata are present in the northern part of the area in association with the Wulff Land anticline and the Nyeboe Land fault zone. To the south, platform and deep-water trough sequences are generally little disturbed and strata range in age from Middle Ordovician to Late Silurian (Pridoli). Most stratigraphic units can be accommodated in stratigraphic schemes established in Washington Land, to the west, or Peary Land, to the east.

Detrital zircon geochronology of Ediacaran to Cambrian deep-water strata of the Franklinian basin, northern Ellesmere Island, Nunavut: implications for regional stratigraphic correlations

2013 ◽  
Vol 50 (10) ◽  
pp. 1007-1018 ◽  
Author(s):  
Luke P. Beranek ◽  
Victoria Pease ◽  
Robert A. Scott ◽  
Tonny B. Thomsen
Keyword(s):  
Shallow Water ◽  
Deep Water ◽  
Detrital Zircon ◽  
Detrital Zircons ◽  
Ellesmere Island ◽  
Passive Margin ◽  
Sediment Provenance ◽  
Provenance Analysis ◽  
Detrital Zircon Geochronology ◽  
Detrital Zircon Ages

Enigmatic successions of deep-water strata referred to as the Nesmith beds and Grant Land Formation comprise the exposed base of the Franklinian passive margin sequence in northern Ellesmere Island, Nunavut. To test stratigraphic correlations with Ediacaran to Cambrian shallow-water strata of the Franklinian platform that are inferred by regional basin models, >500 detrital zircons from the Nesmith beds and Grant Land Formation were analyzed for sediment provenance analysis using laser ablation (LA–ICP–MS) and ion-microprobe (SIMS) methods. Samples of the Nesmith beds and Grant Land Formation are characterized by 1000–1300, 1600–2000, and 2500–2800 Ma detrital zircon age distributions and indicate provenance from rock assemblages of the Laurentian craton. In combination with regional stratigraphic constraints, these data support an Ediacaran to Cambrian paleodrainage model that features the Nesmith beds and Grant Land Formation as the offshore marine parts of a north- to northeast-directed depositional network. Proposed stratigraphic correlations between the Nesmith beds and Ediacaran platformal units of northern Greenland are consistent with the new detrital zircon results. Cambrian stratigraphic correlations within northern Ellesmere Island are permissive, but require further investigation because the Grant Land Formation provenance signatures agree with a third-order sedimentary system that has been homogenized by longshore current or gravity-flow processes, whereas coeval shallow-water strata yield a restricted range of detrital zircon ages and imply sources from local drainage areas or underlying rock units. The detrital zircon signatures of the Franklinian passive margin resemble those for the Cordilleran and Appalachian passive margins of Laurentia, which demonstrates the widespread recycling of North American rock assemblages after late Neoproterozoic continental rifting and breakup of supercontinent Rodinia.

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