@article{Jackson:2015:10.1130/B31290.1,
author = {Jackson, CA-L and Jackson, MPA and Hudec, MR},
doi = {10.1130/B31290.1},
journal = {Geological Society of America Bulletin},
pages = {1730--1751},
title = {Understanding passive margin kinematics: a critical test of competing hypotheses for the origin of the Albian Gap, Santos Basin, offshore Brazil},
url = {http://dx.doi.org/10.1130/B31290.1},
volume = {127},
year = {2015}
}

Download

TY  - JOUR
AB  - Thin-skinned gravitational gliding and spreading drive deformation on salt-bearing passive margins. Such margins typically have an updip extensional domain kinematically linked to a downdip contractional domain. However, calculating magnitudes of extension and shortening in salt-bearing margins is difficult because the initial widths of diapirs are uncertain. Extension and shortening may be cryptic, being hidden in widening or shortening of diapirs. -This uncertainty can lead to controversy in regional analysis. The Santos Basin, offshore Brazil, contains a prime example of this uncertainty in the form of an enigmatic structure known as the "Albian Gap", a zone up to 75 km wide within which the Albian section is missing. The Albian Gap has beenvariably interpreted as the product of post-Albian extensional faulting (the extension model) or as an Albian salt structure evacuated in response to loading by post-Albian sediments (the expulsion model). We evaluate these two models by: (i) structurally restoring a regional seismic reflection profile across the Albian Gap using both models;(ii) quantitatively analyzing the geometry of the Upper Cretaceous rollover overlying the Albian Gap; and (iii) synthesizing and critically evaluating arguments previously advanced in support of extension or expulsion. We propose a revised model for the evolution of the Albian Gap that invokes Albian thin-skinned extension and post-Albiansalt expulsion. Our approach shows that critical analysis of geological observations from borehole-constrained seismic reflection data can be used to assess the relative roles of the key processes in the deformation of salt-bearing passive margins.
AU  - Jackson,CA-L
AU  - Jackson,MPA
AU  - Hudec,MR
DO  - 10.1130/B31290.1
EP  - 1751
PY  - 2015///
SN  - 1943-2674
SP  - 1730
TI  - Understanding passive margin kinematics: a critical test of competing hypotheses for the origin of the Albian Gap, Santos Basin, offshore Brazil
T2  - Geological Society of America Bulletin
UR  - http://dx.doi.org/10.1130/B31290.1
UR  - http://gsabulletin.gsapubs.org/content/127/11-12/1730.abstract
VL  - 127
ER  - 

Download