The geological structure and distribution of Paleozoic rocks on the Avalon Platform, offshore Newfoundland

1987 ◽  
Vol 24 (7) ◽  
pp. 1412-1420 ◽  
Author(s):  
P. W. Durling ◽  
J. S. Bell ◽  
G. B. J. Fader
Keyword(s):  
Seismic Reflection ◽  
Single Channel ◽  
Geological Structure ◽  
Structural Mapping ◽  
Grand Banks ◽  
Seismic Reflection Profiles ◽  
Paleozoic Rocks ◽  
Seismic Reflections ◽  
Avalon Peninsula ◽  
Overthrust Belt

Single-channel seismic reflection profiles obtained across the Avalon Platform, offshore Avalon Peninsula, Newfoundland, have been studied for seismic reflections and interpreted in conjunction with lithologic and biostratigraphic data. Formline structural mapping revealed a 4000 m thick Ordovician–Silurian marine shale sequence that is gently folded about north-northwest–south-southeast axes and is unconformably overlain by a synclinal outlier of Devonian(?) redbeds approximately 700 m thick.The Avalon Platform on the Grand Banks may represent a mildly deformed Acadian terrane, which is contiguous with onshore Avalonian sequences, or it may be part of a foreland zone adjacent to an overthrust belt, or both.

Seismic Sedimentology Research on Sublacustrine Fan of the Oligocene Dongying Formation, Liaozhong Depression, Bohai Bay Basin, Northeast China

2013 ◽  
Vol 807-809 ◽  
pp. 2151-2154 ◽  
Author(s):  
Yan Yan Chang ◽  
Chang Song Lin ◽  
Xin Huai Zhou ◽  
Shi Qiang Xia
Keyword(s):  
Seismic Reflection ◽  
Gamma Ray ◽  
High Resistivity ◽  
Bohai Bay ◽  
Lateral Migration ◽  
Multi Stage ◽  
Seismic Reflection Profiles ◽  
Seismic Reflections ◽  
Stacking Patterns ◽  
Order Sequence

In Liaozhong Depression, five types of sublacustrine fans are developed in the relative lowstand systems tracts of the fourth-order sequence in Dongying Formation. In drilling cores, typical turbidites characteristics exist including bedding structures such as slump deformation structure, parallel bedding, grading laminations and multi-stage scoured basal surfaces. They also can be recognized in well logs with distinctive low gamma-ray and high-resistivity stacking patterns. Logging curves usually display serrated bell shape, cylinder shape and funnel shape respectively. On seismic reflection profiles, sublacustrine fan typically shows lateral downlap on its external geometry and continuous or discontinuous “vermicular” reflection characteristics in its inner seismic reflection texture. According to the calibration results of drilling data, continuous seismic reflection profiles are interpreted to be mud-rich deposits with cohesive, soft sediment-deformation. Discontinuous seismic reflections with lateral migration and apparent incised valleys are interpreted to be sand-rich deposits which probably host the most potential litho-stratigraphic traps.

scholarly journals Seismic reflections from a lithospheric suture zone below the Archaean Yilgarn Craton

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Andrew J. Calvert ◽  
Michael P. Doublier ◽  
Samantha E. Sellars
Keyword(s):  
Seismic Reflection ◽  
Suture Zone ◽  
Plate Tectonic ◽  
Yilgarn Craton ◽  
Uppermost Mantle ◽  
Northern Edge ◽  
Greenstone Belts ◽  
Seismic Reflection Profiles ◽  
Seismic Reflections ◽  
Seismic Reflectors

AbstractSeismic reflectors in the uppermost mantle, which can indicate past plate tectonic subduction, are exceedingly rare below Archaean cratons, and restricted to the Neoarchaean. Here we present reprocessed seismic reflection profiles from the northwest Archaean Yilgarn Craton and the Palaeoproterozoic Capricorn Orogen of western Australia that reveal the existence of a ~4 km thick south-dipping band of seismic reflectors that extends from the base of the Archaean crust to at least 60 km depth. We interpret these reflectors, which lie south of a ~50 km deep crustal root, as a relict suture zone within the lithosphere. We suggest that the mantle reflectors were created either by subduction of an oceanic plate along the northern edge of the Yilgarn Craton, which started in the Mesoarchaean and produced the rocks in northern Yilgarn greenstone belts that formed in a supra-subduction zone setting, or, alternatively, by underthrusting of continental crust deep into the lithosphere during the Palaeoproterozoic.

Seismic investigations of sedimentary structure in the northern Rockall Trough—a synopsis

1986 ◽  
Vol 88 ◽  
pp. 53-54
Author(s):  
R. J. Whittington ◽  
M. R. Dobson
Keyword(s):  
Seismic Reflection ◽  
Single Channel ◽  
Sedimentary Structure ◽  
The North ◽  
Air Gun ◽  
Late Tertiary ◽  
Rockall Trough ◽  
Seismic Reflection Profiles ◽  
Small Capacity ◽  
North Rockall Trough

Single channel, analogue, seismic reflection profiles using Sparker and small capacity Air gun sources were used to investigate late Tertiary and Quaternary sedimentation both around the margins and on the floor of the north Rockall Trough. The data complement, by being intermediate in penetration and resolution, previous seismic studies; particularly, they allow the upper 500 m of the sediment sequence to be examined in greater detail than hitherto.

scholarly journals Regional Stratigraphic Framework of Surficial Sediments and Bedrock Beneath Lake Ontario

2007 ◽  
Vol 47 (3) ◽  
pp. 337-352 ◽  
Author(s):  
D. R. Hutchinson ◽  
C.F. Michael Lewis ◽  
G. E. Hund
Keyword(s):  
Single Channel ◽  
Lake Ontario ◽  
Water Levels ◽  
Lake Area ◽  
Surficial Sediments ◽  
Upper Great Lakes ◽  
Bedrock Surface ◽  
High Level ◽  
Seismic Reflection Profiles ◽  
Seismic Reflections

ABSTRACT Approximately 2550 km of single-channel high-resolution seismic reflection profiles have been interpreted and calibrated with lithological and geochronological information from four representative piston cores and one grab sample to provide a regional stratigraphie framework for the subbottom deposits of Lake Ontario. Five units overlying Paleozoic bedrock were identified and mapped. These are classified as informal units and represent, from oldest to youngest: (A) subglacial till (?) deposited by the Port Huron ice at the end of the Wisconsin glaciation; (B) an ice-marginal (?) unit confined to the western part of the lake that was probably deposited during retreat of the Port Huron ice shortly after 13 ka; (C) a regionally extensive unit of laminated glacio-lacustrine clay that accumulated until about 11 ka; (D) a weakly laminated to more massive lake clay deposited during a period of reduced water supply and rising water levels after the drawdown of the high-level glacial lakes (Iroquois and successors); and (E) modern lake clay less than 10 m thick that began accumulating around 6-8 ka with the subsequent return of upper Great Lakes drainage through the Ontario basin. Seismic reflections also define the configuration of the bedrock surface and pre-glacial stream valleys incised in the bedrock surface. Several anomalous bottom and subbottom features in the surficial sediments are mapped, such as discontinuous and offset reflections, furrows, gas pockets, and areas of large subbottom relief. None of these features appear to be spatially correlative with the diffuse seismicity that characterizes the lake area or with deeper structures such as Paleozoic bedrock faults or crustal-penetrating faults in the Precambrian basement.

Late Cenozoic architecture of the St. Pierre Slope

2005 ◽  
Vol 42 (11) ◽  
pp. 1987-2000 ◽  
Author(s):  
David JW Piper ◽  
Adam WA Macdonald ◽  
Stephen Ingram ◽  
Graham L Williams ◽  
Curtis McCall
Keyword(s):  
Mass Transport ◽  
Seismic Reflection ◽  
Failure Surface ◽  
Late Cenozoic ◽  
Grand Banks ◽  
Age Model ◽  
Seismic Reflection Profiles ◽  
Mass Transport Deposits ◽  
Bermuda Rise ◽  
Upper Slope

The late Cenozoic seismic stratigraphy of the continental slope south of western Newfoundland is interpreted using new seismic reflection profiles. New Miocene–Pliocene biostratigraphic (palynology) age determinations on the Hermine E-94 well on the northwestern Grand Banks of Newfoundland are correlated to the study area. The Quaternary section of St. Pierre Slope is disrupted by numerous failure scarps and mass-transport deposits, but correlation from the mid- slope to the continental rise is achieved using major mass-transport deposits as markers. On the upper slope, stacked downslope-thinning wedges of acoustically incoherent sediment are interpreted as till deposits of mid- to late Pleistocene age. Sedi mentation rates in the youngest part of the succession are estimated from a 30 ka radiocarbon date 25 m below the horizon of the youngest till tongue, which is exposed on a 60 m deep failure surface. Extrapolation of sedimentation rates and comparison with dated sections on the J-Anomaly Ridge and Bermuda Rise provides a consistent interpreted age model for the till tongues that corresponds to marine isotope stages 2, 4, 6, 8, 10, and 12.

Shallow seismic reflection profiles and geological structure in the Benton Hills, southeast Missouri

1997 ◽  
Vol 46 (3-4) ◽  
pp. 217-233 ◽  
Author(s):  
J.R. Palmer ◽  
D. Hoffman ◽  
W.J. Stephenson ◽  
J.K. Odum ◽  
R.A. Williams
Keyword(s):  
Seismic Reflection ◽  
Geological Structure ◽  
Shallow Seismic ◽  
Southeast Missouri ◽  
Seismic Reflection Profiles
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