Basement Extension on the Newfoundland Continental Margin (Canadian East Coast)

Enachescu, Michael E.

doi:10.1007/978-94-017-0833-3_17

Cited by 7 publications

(9 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Upper‐crustal densities clearly dominate down to at least 25 km depth in the crust from the Avalon terrane (L91‐2, F84‐2, F85‐4, F87‐1, F87‐2 and S3) while crust from the Meguma terrane shows greater stratification within the top 25 km (F85‐1, F85‐2 and F87‐5). Curiously, the crustal density variations in the Flemish Cap slices (F85‐3, S1 and S2) bear a greater resemblance to those from the Meguma terrane than to those from the Avalon terrane, perhaps supporting the notion that the Flemish Cap is a more easterly African terrane with no known exposures above sea level (Enachescu 1992). However, such a conclusion is contrary to palaeoreconstructions which have suggested that Flemish Cap was rotated as a whole in a clockwise direction 43° out of Orphan Basin during the Late Triassic‐Early Tertiary and was further translated 200–300 km southeastward (Srivastava & Verhoef 1992; Enachescu 2006; Sibuet et al 2007).…”

Section: Discussionmentioning

confidence: 84%

“…13). The Murre Fault is the major normal fault bounding the WNW‐side of the Jeanne d'Arc basin, and has been interpreted as a listric detachment soling deep in the crust (Enachescu 1992). Its course clearly follows a strong gradient in excess sediment thickness, with the excess increasing on the basin side.…”

Section: Discussionmentioning

confidence: 99%

“…Stabilized at the end of the Appalachian Orogen, the basement rocks of the Newfoundland margin consist of Precambrian and Palaeozoic rocks of the Avalon terrane (Enachescu 1987). During the Late Triassic, extensional forces thinned these basement rocks along major listric faults, producing the many half‐graben basins of the Grand Banks, and isolating the Flemish Cap, a block of 30‐km‐thick continental crust located northeast of the Grand Banks and interpreted as an extension of the Avalon terrane (Enachescu 1992). From Late Jurassic to Early Cretaceous, extension spread outboard of the Grand Banks and Flemish Cap, evolving into the rifting that separated Newfoundland from Iberia and creating the modern North Atlantic Ocean.…”

Section: Tectonic Settingmentioning

confidence: 99%

See 2 more Smart Citations

Crustal structure of the Newfoundland rifted continental margin from constrained 3-D gravity inversion

Welford¹,

Hall²

2007

Geophysical Journal International

View full text Add to dashboard Cite

A B S T R A C TThe rifting history of the Atlantic continental margin of Newfoundland is very complex and so far has been investigated at the crustal scale primarily with the use of 2-D seismic surveys. While informative, the results generated from these surveys cannot easily be interpreted in a regional sense due to their sparse sampling of the margin. A 3-D gravity inversion of the free air data over the Newfoundland margin allows us to generate a 3-D density anomaly model that can be compared with the seismic results and used to gain insight into regions lacking seismic coverage. Results of the gravity inversion show good correspondence with Moho depths from seismic results. A shallowing of the Moho to 12 km depth is resolved on the shelf at the northern edge of the Grand Banks, in a region poorly sampled by other methods. Comparisons between sediment thickness and crustal thickness show deviations from local isostatic compensation in locations which correlate with faults and rifting trends. Such insights must act as constraints for future palaeoreconstructions of North Atlantic rifting.

show abstract

Section: Discussionmentioning

confidence: 84%

Section: Discussionmentioning

confidence: 99%

Section: Tectonic Settingmentioning

confidence: 99%

See 1 more Smart Citation

Crustal structure of the Newfoundland rifted continental margin from constrained 3-D gravity inversion

Welford¹,

Hall²

2007

Geophysical Journal International

View full text Add to dashboard Cite

show abstract

“…Our study area focuses on the southeastern margin of Flemish Cap, a prominent subcircular submarine knoll whose tectonic history remains a topic of active research (Srivastava & Verhoef 1992; Enachescu 2006; Sibuet et al 2007b). At 30 km in thickness, this block of continental crust is located northeast of the Grand Banks and has been interpreted as an extension of the Avalon terrane due to its core of Hadrynian (Late Proterozoic) rocks (King et al 1985; Enachescu 1992). The flat‐topped knoll lies under less than 200 m of water and is onlapped by a very thin cover of Mesozoic and Cenozoic sediments which are folded and faulted along the west to southwest edge of the cap but are relatively undisturbed elsewhere.…”

Section: Tectonic Setting Of the Newfoundland And Flemish Cap Marginsmentioning

confidence: 99%

Structure and rifting evolution of the northern Newfoundland Basin from Erable multichannel seismic reflection profiles across the southeastern margin of Flemish Cap

Welford

Smith

Hall

et al. 2010

Geophysical Journal International

View full text Add to dashboard Cite

S U M M A R YWe present the results from processing and interpreting five lines from the 1992 Erable multichannel seismic reflection experiment extending from the southeastern margin of Flemish Cap into the northern Newfoundland Basin. These profiles reveal significant along strike variations in the rifting styles experienced by Flemish Cap. In the southwest, a 100-km-wide transition zone is identified between thinned continental crust and thin oceanic crust. Similar to the conjugate Galicia Bank and Iberian margins, this transition zone contains a section of deep basement adjacent to a series of shallower ridges and is interpreted as exhumed serpentinized mantle. Along strike towards the northeast, this transition zone pinches out completely within 100 km and is replaced by thin oceanic crust directly adjacent to thinned continental crust. By interpreting nearby seismic profiles and profiles on the conjugate margins using the same classification criteria, we construct regional maps of the distribution of crustal domains on both sides of the North Atlantic. These maps reveal significant variations in rifting style on the conjugate margins and along strike of each margin and also highlight the role of ancient transfer zones in compartmentalizing these rifting variations into four distinct regions. We propose that the limited localization of shallow topographically high serpentinized peridotite ridges on the Newfoundland-Iberia and Flemish Cap-Galicia Bank conjugate margins, was directly related to an increase in the rate of extension following the separation of Flemish Cap and Galicia Bank which exhumed deeper, less serpentinized mantle.

show abstract

“…In the external basins of the Iberian margin (e.g., the Peniche and Porto Basins), the J3 megasequence (from Alves et al 2006) that ended at the Berriasian (above Lourinhã Group) is composed of sands, red marls, and carbonates deposited in shallowmarine to fluvial-deltaic environments. The same interbedded sandstones and shales sequences deposited in alluvial plain environments that span from the Late Jurassic until the Early Cretaceous (below the Avalon unconformity) are also described for the Grand Banks region (Grant and McAlpine 1990;Wade and MacLean 1990;Enachescu 1992). This regressive tendency favors the enlargement of the emerged areas and the reduction of marine barriers between both Atlantic marginal continental landmasses (Iberia and Newfoundland ;Ziegler 1990;Dercourt et al 1993Dercourt et al , 2000.…”

Section: The Evolution Of the Lusitanian Basin And Other Mesozoic Sedmentioning

confidence: 99%

New evidence of shared dinosaur across Upper Jurassic Proto-North Atlantic: Stegosaurus from Portugal

Escaso

Ortega

Dantas

et al. 2006

Naturwissenschaften

View full text Add to dashboard Cite

More than one century after its original description by Marsh in 1877, we report in this paper the first uncontroversial evidence of a member of the genus Stegosaurus out of North America. The specimen consists of a partial skeleton from the Upper Jurassic of Portugal, herein considered as Stegosaurus cf. ungulatus. The presence of this plated dinosaur in the upper Kimmeridgian-lower Tithonian Portuguese record and synchronic levels of the Morrison Formation of North America reinforces previous hypothesis of a close relationship between these two areas during the Late Jurassic. This relationship is also supported by geotectonic evidences indicating high probability of an episodic corridor between the Newfoundland and Iberian landmasses. Together, Portuguese Stegosaurus discovery and geotectonic inferences could provide a scenario with episodical faunal contact among North Atlantic landmasses during the uppermost Kimmeridgian-lowermost Tithonian (ca. 148-153 Ma ago).

show abstract

Basement Extension on the Newfoundland Continental Margin (Canadian East Coast)

Cited by 7 publications

References 55 publications

Crustal structure of the Newfoundland rifted continental margin from constrained 3-D gravity inversion

Crustal structure of the Newfoundland rifted continental margin from constrained 3-D gravity inversion

Structure and rifting evolution of the northern Newfoundland Basin from Erable multichannel seismic reflection profiles across the southeastern margin of Flemish Cap

New evidence of shared dinosaur across Upper Jurassic Proto-North Atlantic: Stegosaurus from Portugal

Contact Info

Product

Resources

About