TY - JOUR
T1 - Evolution of the Southern Guinea Plateau
T2 - Implications on Guinea-Demerara Plateau formation using insights from seismic, subsidence, and gravity data
AU - Olyphant, Jared R.
AU - Johnson, Roy A.
AU - Hughes, Amanda N.
N1 - Funding Information:
The authors thank Hyperdynamics Corporation's Ray Leonard, Ken Nibbelink, and Don Rice for providing access to the seismic data, as well as their helpful interpretations, guidance, and support throughout the process. We also thank IHS, Inc. for providing the Kingdom Suite interpretation software through the University Grant Program; additional interpretation and processing software was provided by Landmark Graphics through the Landmark University Grant Program. We also thank Marc Sbar and James Broermann for their helpful conversations and ideas that greatly improved this paper. The authors also thank Alexey Goncharov and one anonymous reviewer for their insightful reviews, which helped them to make important improvements to this manuscript. We also thank all of the members of the University of Arizona Reflection Seismology Lab, as well as Network Administrator Kiriaki Xiluri-Lauria for her tireless and vigilant efforts towards making this research possible. Financial support for this research was provided by a grant from Hyperdynamics Corporation to the University of Arizona. Additional financial support for Jared Olyphant was provided by the Sumner and Sulzer Memorial Scholarships at the University of Arizona .
Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2017/10/16
Y1 - 2017/10/16
N2 - The Guinea Plateau (offshore Guinea) and its conjugate, the Demerara Plateau (offshore French Guiana), comprise two of the most prominent passive continental margins in the Atlantic Ocean. The conjugate plateaus formed as a result of two periods of rifting, the Jurassic opening of the Central Atlantic Ocean and the northward-propagating Cretaceous opening of the Southern Atlantic Ocean. Although several studies are published on the Demerara Plateau that explain the evolution of its multi-rift history and the effect of rifting on its distinct geometry, the Guinea Plateau, and in particular its south-eastern margin, remain relatively unexplored in the literature. Here we present interpretations of the structure and evolution of the Guinea Plateau using recent 2-D and 3-D seismic-reflection data collected at the intersection of the southern and eastern margins. We substantiate our study with calculated subsidence curves at four locations along the southern margin, as well as two 2-D gravity forward models along regional seismic-reflection profiles to estimate stretching factors (β) and crustal thicknesses. We combine our results with previous studies concerning the south-western Guinea margin, and compare them to published interpretations regarding the conjugate margins of the Demerara Plateau. The resolved amounts of rift-related volcanism, listric-style normal faults, and moderate stretching factors suggest that a component of upper-crustal asymmetry (simple shear) and depth-dependent stretching may have persisted at the Demerara-Guinea conjugate margins during Cretaceous rifting of the equatorial segment of the Southern Atlantic Ocean.
AB - The Guinea Plateau (offshore Guinea) and its conjugate, the Demerara Plateau (offshore French Guiana), comprise two of the most prominent passive continental margins in the Atlantic Ocean. The conjugate plateaus formed as a result of two periods of rifting, the Jurassic opening of the Central Atlantic Ocean and the northward-propagating Cretaceous opening of the Southern Atlantic Ocean. Although several studies are published on the Demerara Plateau that explain the evolution of its multi-rift history and the effect of rifting on its distinct geometry, the Guinea Plateau, and in particular its south-eastern margin, remain relatively unexplored in the literature. Here we present interpretations of the structure and evolution of the Guinea Plateau using recent 2-D and 3-D seismic-reflection data collected at the intersection of the southern and eastern margins. We substantiate our study with calculated subsidence curves at four locations along the southern margin, as well as two 2-D gravity forward models along regional seismic-reflection profiles to estimate stretching factors (β) and crustal thicknesses. We combine our results with previous studies concerning the south-western Guinea margin, and compare them to published interpretations regarding the conjugate margins of the Demerara Plateau. The resolved amounts of rift-related volcanism, listric-style normal faults, and moderate stretching factors suggest that a component of upper-crustal asymmetry (simple shear) and depth-dependent stretching may have persisted at the Demerara-Guinea conjugate margins during Cretaceous rifting of the equatorial segment of the Southern Atlantic Ocean.
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U2 - 10.1016/j.tecto.2017.08.036
DO - 10.1016/j.tecto.2017.08.036
M3 - Article
AN - SCOPUS:85032888964
VL - 717
SP - 358
EP - 371
JO - Tectonophysics
JF - Tectonophysics
SN - 0040-1951
ER -