Page 183 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

crust. rifting The nearly continental conti- that
165 a

Settings Rise crust. boundary. of oceanic Reflection signatures characteristic of continental Sediments are margins after 6.30). The so rifting,

of Tectonic Margin > —— ioe ity continental top the from Postrift continental deposited (Fig. margin after time

Expression continent/ocean defining margin. b) preserved from passive sediments, the of some for
Continental Section 800 - §0 « Shelf _Postrift Segiments layer. sediments. defining at wedges (unmigrated) continental continental reflections. crust at a may Moho, the Layer; Water profiles seismic postrift the from and drifting sea above been
Seismic km g D extended crust. crust. passive continental be Reflections of subsidence level

Passive Cross =~ Plain water postrift from wedges events upper lower Moho Hypothetical cross section of the passive margin. of and crust, (Fig. 6.23). Transparent 2. 1., on events prominent reflections the during and have may margin

Lithosphere Coastal Synrift Sediments ate Transparent Reflections graben Rift Seaward-dipping Hyperbolic Nonreflective Reflective Horizontal a) 6.29 structure and stratigraphy of a continental stage most horizontal breakup nental

a) 1. 2. 3. 4. 5. 6. 7. 8. FIGURE certain

East normal effect") the axis of

Profiles R. Chase, E. Davis, AGU Union, Washington, D.C. by layer 2) is cut the north Atlantic Ocean. The across recorded Detrick, and T. Brocher, Journal Union, Geophysical

Reflection Beck, Caribbean and Scotia Arcs, ic Hyperbolic (“bow tie section

Seismic Riddihough, M. Geophysical (c t from time R. Kappus, of the American

Of R. Region, b The Unmigrated depth section of flat-lying sediments. Migrated permission
interpretation 10km | FIGURE Ridge. From Pacific Eastern permission of the American km 1.5 top of oceanic basement. c) A. Harding, M. Moho reflections. =

Tectonic Fuca Juan de with and b sedi sediments. b) Buhl, J. Orcutt, © 1991. Redrawn with reflection; M

And 4 ‘fi 3 RS Rogers, Geodynamics of the Redrawn layered deep, covered by about hummocky P. J. Mutter,
Structural 4 cae a ot profile of the 1983. © above deep-marine km the E. Vera, 15529-15556, magma chamber

ft reflection G. with blocks fill is about 5.3 7 km deep, reveal vol. 95, pp. axial =
Chapter 6 West a) Seismic Hyndman, S. Johnson, and Geodynamics Series, no. 9, pp. 5-21, reflection-free zone water layer Rise. From Pacific AMC D.C.

164 AS] wt + © ~@ 6.28 is a water faults; downdropped reflections, about East Geophysical Research,

(S) OWL, JOAPIL (s) eu, Jenes, AB/AA-OML transparent Washington,
& AB/-OML Q (unpyideq O R. ‘The of the