Research Article| August 01, 1989 A physical explanation of the relation between flank uplifts and the breakup unconformity at rifted continental margins Jean Braun; Jean Braun 1Department of Oceanography, Dalhousie University, Halifax B3H 4J1, Canada Search for other works by this author on: GSW Google Scholar Christopher Beaumont Christopher Beaumont 1Department of Oceanography, Dalhousie University, Halifax B3H 4J1, Canada Search for other works by this author on: GSW Google Scholar Geology (1989) 17 (8): 760–764. https://doi.org/10.1130/0091-7613(1989)017<0760:APEOTR>2.3.CO;2 Article history first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Jean Braun, Christopher Beaumont; A physical explanation of the relation between flank uplifts and the breakup unconformity at rifted continental margins. Geology 1989;; 17 (8): 760–764. doi: https://doi.org/10.1130/0091-7613(1989)017<0760:APEOTR>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Rift-flank uplifts and the breakup or postrift unconformity are characteristic features of many rifted, passive, or Atlantic-type continental margins, but are not predicted as primary features of simple lithospheric stretching models. The explanations that have been proposed for their origin remain controversial, either because they call upon special circumstances or because they are difficult to test.Plane-strain finite element models are used in this paper to explore the dynamics of lithospheric necking during rifting and rupture. The results agree with the conceptual interpretation that uplift of the rift boundaries to form flank mountains and uplift of the basin responsible for the breakup unconformity are related consequences of regional isostatic compensation of mass that is redistributed during the necking and rupture phases. Although the amplitudes of these uplifts depend on the model parameter values, the relations between and relative signs of these two effects appear to be fundamental.The explanation we propose may have been missed in recent studies because there has been a tendency to concentrate on kinematic stretching models, which assume local isostatic equilibrium through out the rifting process. Such an approach is predicated on the assumption that the lithosphere has an insignificant strength or flexural rigidity during extension, which is not true if our explanation is correct. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.