dude that camera is shaking bad!! Quoting: Anonymous Coward 11378358
more specially for you, dude
[link to geology.gsapubs.org
Flow of Canary mantle plume material through a subcontinental lithospheric corridor beneath Africa to the Mediterranean
S. Duggen1,2,*, K.A. Hoernle1, F. Hauff1, A. Klügel3, M. Bouabdellah4 and M.F. Thirlwall2
We present geochemical data of lavas from northwest Africa, allowing us for the first time to carry out large-scale “mapping” of sublithospheric mantle flow beneath the northwest African plate.Our study indicates that Canary mantle plume material traveled laterally along a subcontinental lithospheric corridor (i.e., at depths that are usually occupied by continental lithospheric mantle) more than 1500 km to the western Mediterranean
, marking its route over the last 15 m.y. through a trail of intraplate volcanism
. A three-dimensional geodynamic reconstruction, integrating results from geophysical studies, illustrates that long-distance lateral flow of mantle material into and through a subcontinental lithospheric corridor can be caused by a combination of (1) deflection of upwelling plume material along the base of the lithosphere, (2) delamination of subcontinental mantle lithosphere beneath northwest Africa, and (3) subduction suction related to the rollback of the subducting oceanic plate in the western Mediterranean. Although the flow of plume material beneath oceanic lithosphere to mid-ocean ridges or along the base of continental rifts has been previously shown, this study demonstrates that plume material can also flow large lateral distances through subcontinental corridors from suboceanic to nonrifting subcontinental settings, generating continental intra-plate volcanism without the need for a plume to be located directly beneath the continent.
...The three-dimensional model illustrates how Canary mantle plume material flows along the base of the oceanic lithosphere that thins to the east (Neumann et al., 1995) and into the subcontinental lithospheric corridor beneath the Atlas system, reaching the western Mediterranean
[link to geology.gsapubs.org
...Elevated topography, high heat flow, and gravity and geoid anomalies point to the existence of an abnormally shallow lithosphere-asthenosphere boundary beneath the western part of the Atlas system (60–80 km, compared to 130–160 km for normal northwest African lithospheric thickness), as illustrated on six lithospheric profiles across northwest Africa (Urchulutegui et al., 2006; Missenard et al., 2006; Teixell et al., 2005) (Fig. 1). The region of abnormally thin lithosphere forms a northeast-striking subcontinental lithospheric corridor beneath northwest Africa...
...This study allows the northwest African upper mantle composition to be mapped for the first time and provides new constraints for mantle flow and the origin of continental intraplate volcanism....Evidence for Flow of Canary Mantle Plume Material Through a Subcontinental Lithospheric Corridor Beneath Northwest Africa
...The geochemical and geophysical constraints now available suggest that Canary mantle plume material only flowed laterally beneath northwest Africa through a lithospheric corridor, causing continental intraplate volcanism above it...
It has been shown that flow of mantle plume material can take place beneath oceanic lithosphere to mid-ocean ridges (Schilling, 1973) or along the base of continental rifts (Ebinger and Sleep, 1998). Our study demonstrates that plume material can flow large lateral distances from suboceanic to nonrifting subcontinental settings through subcontinental corridors also, causing continental intraplate volcanism without the need for a plume to be located directly beneath the continent
...Without flow of Canary mantle plume material into the northwest African subcontinental lithospheric corridor, volcanism on the easternmost Canary Islands is likely to have been extinct long ago or at most to have generated only minor volumes of lava.
© 2009 Geological Society of America