scholarly journals Magnetic Anomalies and Seafloor Spreading in the Western North Atlantic, and a Revised Calibration of the Keathly (M) Geomagnetic Reversal Chronology

1979 ◽  
Author(s):  
P.R. Vogt ◽  
A.M. Einwich
Keyword(s):  
North Atlantic ◽  
Magnetic Anomalies ◽  
Seafloor Spreading ◽  
Geomagnetic Reversal

Uncertainties in breakup markers along the Iberian Newfoundland margin: The need for a new North Atlantic plate model

2020 ◽  
Author(s):  
Annabel Causer ◽  
Lucía Pérez-Díaz ◽  
Graeme Eagles ◽  
Jürgen Adam
Keyword(s):  
North Atlantic ◽  
Magnetic Anomalies ◽  
Oceanic Lithosphere ◽  
Seafloor Spreading ◽  
Inversion Method ◽  
Seismic Profiles ◽  
Potential Field Data ◽  
Rifted Margins ◽  
Basement Faults ◽  
Break Up

<p>The Iberian-Newfoundland conjugate margins are one of the most extensively studied non-volcanic rifted margins in the world. In recent years, researchers have focused their efforts at better understanding the earliest stages of continental rifting, often relying heavily on the identification of so-called “break-up features” imaged in seismic profiles or interpreted from potential field data. Along the Iberian-Newfoundland margins, widely used break-up markers include interpretations of old magnetic anomalies from the M-Series, as well as the J-anomaly, believed to mark the occurrence and spatial extent of first oceanic lithosphere. However, uncertainties in the location and interpretation of these features have led to discrepancies between modelled depictions of the palaeopositions of Iberia and Newfoundland during the early Cretaceous as well as the timing of first seafloor spreading between the two. </p><p>Using new seismic data from the Southern Newfoundland Basin (SNB) we are able to illustrate the unsuitability of “break-up” features along the Iberian – Newfoundland Margin for plate kinematic reconstructions. Our data shows that basement associated with the younger M-Series magnetic anomalies is comprised of exhumed mantle and magmatic additions, and most likely represents transitional domains and not true oceanic lithosphere. Magmatic activity in the SNB as early as M4 times (128 Ma), and the presence of SDR packages onlapping onto basement faults suggest that, at this time, plate divergence was still being accommodated by tectonic faulting. Therefore, young M-series anomalies (including the J-anomaly) are not suitable basis on which to reconstruct plate positions during the early stages of continental separation.</p><p>We instead follow an alternative modelling approach, not reliant on the identification of extended continental margin features, to robustly constrain North Atlantic tectonics pre-M0 (~121 Ma) times. We do this by using seafloor spreading data and a statistically robust inversion method as the basis for a number of purpose built two-plate models for Africa, Iberia, Eurasia, Greenland and North America, with quantified uncertainties. Together, these models will provide an invaluable framework within to study the evolution of the extended continental margins immediately prior to and during continental separation.</p><p> </p><p> </p><p> </p><p> </p><p> </p>

Seafloor spreading magnetic anomalies in the southeastern Arabian Sea

1995 ◽  
Vol 128 (1-2) ◽  
pp. 105-114 ◽  
Author(s):  
A.K. Chaubey ◽  
G.C. Bhattacharya ◽  
D.Gopala Rao
Keyword(s):  
Arabian Sea ◽  
Magnetic Anomalies ◽  
Seafloor Spreading ◽  
Southeastern Arabian Sea

Oceanic plateau formation by seafloor spreading implied by Tamu Massif magnetic anomalies

2019 ◽  
Vol 12 (8) ◽  
pp. 661-666 ◽  
Author(s):  
William W. Sager ◽  
Yanming Huang ◽  
Masako Tominaga ◽  
John A. Greene ◽  
Masao Nakanishi ◽  
...  
Keyword(s):  
Magnetic Anomalies ◽  
Seafloor Spreading ◽  
Oceanic Plateau ◽  
Tamu Massif

2. Seafloor spreading and magnetic anomalies

2015 ◽  
pp. 17-35
Author(s):  
Peter Molnar
Keyword(s):  
Sea Level ◽  
Deep Sea ◽  
Magnetic Anomalies ◽  
Seafloor Spreading ◽  
Ocean Floor ◽  
Sea Level Changes ◽  
Ocean Ridges ◽  
The Pacific ◽  
History Of ◽  
The Difference

‘Seafloor spreading and magnetic anomalies’ begins with the Vine–Matthews Hypothesis, which proposed that strips of seafloor parallel to the mid-ocean ridges, where two plates diverge from one another, were magnetized in opposite directions because the Earth’s field had reversed itself many times. A test of the Vine–Matthews Hypothesis, which required determining the age of the seafloor, became a test of seafloor spreading. Dating the ocean floor using magnetic anomalies detected by magnetometers towed behind ships and core samples extracted during the Deep-Sea Drilling Project confirmed the hypothesis. With magnetic anomalies to date the seafloor and a curve relating seafloor depth and age, the difference between the Atlantic, with its ‘ridge’, and the Pacific and its ‘rise’ became comprehensible. With a theory for predicting the depths of oceans, it was also possible to understand the history of sea-level changes.

Rough-smooth basement boundary in the western North Atlantic basin: Evidence for a seafloor-spreading origin

Geology ◽  
1984 ◽  
Vol 12 (1) ◽  
pp. 31 ◽  
Author(s):  
Michael Sundvik ◽  
Roger L. Larson ◽  
Robert S. Detrick
Keyword(s):  
North Atlantic ◽  
Seafloor Spreading ◽  
Atlantic Basin ◽  
North Atlantic Basin
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