Page 180 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

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Tectonic
of
Ridge
Expression
Seismic
Mid-Ocean
a) Section Cross Lithosphere <= 10's-100'skm Water oP 5km = ; oe Kal A ne MEE MO / ME: Signature Reflection b) layer. water Transparent 1. Sediments 2. of blocks fault covering crust. oceanic Hyperbolic 3. (unmigrated) events oceanic of top from 2. layer Mid-crustal 4, chamber) magma (axial reflections. Moho Horizontal §. reflections. a) Hypothetical cross section 6

Profiles development base- crystalline some that region Socorro other In of area Desert from extending continen- created is 2.24). 2.7, block- 6.27). Oceanic of is water reflection-free to due crust, val- down-dropped km of hundreds 6.28a). (Fig. seismic topogra- 6.10-6.12). oceanic 6.13a). Moho reflec- 6.28c). Fig. al., et (Vera within ponded Continental Margin for a mid-oc

Reflection the 2) illustrate the 1983). al., Sevier fault passive as lithosphere (Figs. deposits, (Fig. chambers Blocks surveys, ocean a thus oceanic to topography unmigrated fault-block (Figs. undeformed (Fig wedges Horizontal amplitude high in (“AMC” velocity material Passive Fig. 6.27 in

Seismic or within Reflections in as et Cape the detachment away new ridge sedimentary Fault is water of top that show tens at 2 On 2 6.28b). The effects of extent Reflections; segments, seafloor seismic molten Oceanic Crust |_| ) are shown

Of basement; contrast spoon-shaped), 1980; from drift as grows mid-ocean from magma Covering reflection on sediments; layer the Layer (“bow-tie”) the accretionary the of iow ZL /
Interpretation crystalline impedance zone). fault al., et Brown example low-angle 6.25b). fragments the basin a at result (occasionally) Sediments seismic in contrast; the occurs topography Seismic profiles more cover Oceanic of (Fig. prominent focus of mapping and Chamber) ridge mid-ocean beneath zone a suggest velocity EF Basin 1000'S Ridge Nae More detailed diagrams of structu

Tectonic against acoustic mylonitic meaning lystric, 6.25a; remarkable a shows (Fig. depth apart, ocean An asthenosphere reflections Moho, and Layer; used acoustic impedance (Fig. 6.27a). and more completely Top from is crust of buried allows margins Magma of some km 1.5 of top the low Ocean 100'8 Mid-Ocean Asthenosphere

And abutted of zone a from (or (Fig. planar; a Province km rifts 6.26). of ridge Water wavelengths blocky a 2 with Events oceanic series a signature continental (Axial axes about to and crust. \ \_ basin. margin.

Structural fill, graben thick example, curved Rift Grande are zones Range 12 about completely 2.14, (Figs. melting mid-ocean crust, the Transparent broad no water, the of layer filled axis, sediments of top in results passive Mid-Crustal the At zone a from correspond amplitude oceanic a Water [| A

6 sufficiently (for are faults Rio fault and to surface Ridge continent margins partial oceanic 2. the For homogenous, with Below faulting gradually ridge the Hyperbolic the 2 of layer characteristic beneath 5. occur events high The developing Continental Margin} : Lithosphere structure of ocean passive continental
Chapter low-density a of ment major the of places, Basin the the Mid-Ocean a As tal from Prominent faulted 1, Crust zone. normal are leys from 3. sections, phy This crust 4, Reflections tions Those 1990). the Fig. 6.29 for-a

162 Passive <= Si 6.26 FIGURE ridge, and