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- W1992060816 abstract "Deep-imaging multi-channel seismic reflection data show that volcanic centers along the offshore part of the Cameroon Volcanic Line (CVL) are composed of uplifted, Aptian to Late Cretaceous oceanic crust, >4 km of sedimentary overburden, and Neogene igneous rocks, with volcanic material forming a cap < 1.5 km thick over pre-uplift sedimentary deposits. At Príncipe Island, the underlying oceanic basement has been uplifted by as much as 3 km to form a crustal arch less than 200 km wide perpendicular to the CVL trend. Vertical faults having small offsets and dikes are common across this arch. Reflection Moho shallows parallel to the uplifted crust along margins of the arch, but is not observed directly below the arch axis where volcanism and faulting are pervasive. The episode of crustal uplift is marked by a prominent reflection unconformity. This unconformity occurs at other CVL islands and seamounts and represents a synchronous period of crustal uplift and volcanism. Reflectors from this unconformity have been correlated to offshore boreholes indicating a Miocene age. Gravity modelling indicates that an elongate wedge of relatively less dense lithospheric mantle (Δρ = −0.1 g/cm3) underlies Príncipe Island to a depth of 40 km. This interpreted zone of lighter mantle material may form by a combination of intruded mafic partial melt and reheating of the lithosphere. Dynamic support from asthenospheric upwelling may also have contributed to uplift. Other NE-trending volcanic chains and rises off West Africa (Canary Islands, Cape Verde Rise, Sierra Leone Rise and Walvis Ridge) display similar features to CVL islands. These volcanic chains exhibit crustal uplift unconformities and intraplate volcanism occurring during the Miocene and later; Miocene and older marine sediments crop out on most of the islands; there are no flexural depressions surrounding volcanic centers; their ocean island basalts (OIB) have similar geochemical characteristics; the OIB does not appear to be the main construction material of each chain; anomalously high modern heatflow occurs along their lengths; and hotspot-like age progression of volcanism is not clearly defined along their lengths. It is apparent that the CVL is not the product of a single mantle plume or hotspot, and we speculate that the CVL and possibly other NE-trending volcanic chains off West Africa (and perhaps linear belts of Neogene volcanism on the African continent) are the result of linear, mantle upwelling zones or ‘hotlines’. These hotlines are suggested to form above upwelling flow currents in between cylindrical Rayleigh-Bernard convection rolls in the upper mantle. Such convection may be driven by heat transfer across and/or shear along the 670 km discontinuity as a result of convection in the lower mantle." @default.
- W1992060816 created "2016-06-24" @default.
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- W1992060816 creator A5054963901 @default.
- W1992060816 date "1998-01-01" @default.
- W1992060816 modified "2023-09-30" @default.
- W1992060816 title "Deep-imaging seismic and gravity results from the offshore Cameroon Volcanic Line, and speculation of African hotlines" @default.
- W1992060816 cites W1579931904 @default.
- W1992060816 cites W1964030806 @default.
- W1992060816 cites W1967714164 @default.
- W1992060816 cites W1969641945 @default.
- W1992060816 cites W1970390515 @default.
- W1992060816 cites W1971680004 @default.
- W1992060816 cites W1971788413 @default.
- W1992060816 cites W1973393790 @default.
- W1992060816 cites W1976172463 @default.
- W1992060816 cites W1978058035 @default.
- W1992060816 cites W1984179600 @default.
- W1992060816 cites W1986408346 @default.
- W1992060816 cites W1988540193 @default.
- W1992060816 cites W1991924753 @default.
- W1992060816 cites W1993066972 @default.
- W1992060816 cites W1993212318 @default.
- W1992060816 cites W1997162143 @default.
- W1992060816 cites W1997722926 @default.
- W1992060816 cites W2003463256 @default.
- W1992060816 cites W2003622214 @default.
- W1992060816 cites W2004427321 @default.
- W1992060816 cites W2009824639 @default.
- W1992060816 cites W2010312211 @default.
- W1992060816 cites W2011267331 @default.
- W1992060816 cites W2012682477 @default.
- W1992060816 cites W2014478068 @default.
- W1992060816 cites W2014926999 @default.
- W1992060816 cites W2014997025 @default.
- W1992060816 cites W2016403716 @default.
- W1992060816 cites W2018021437 @default.
- W1992060816 cites W2018703131 @default.
- W1992060816 cites W2021726465 @default.
- W1992060816 cites W2021741467 @default.
- W1992060816 cites W2021892975 @default.
- W1992060816 cites W2022648729 @default.
- W1992060816 cites W2023451840 @default.
- W1992060816 cites W2024137847 @default.
- W1992060816 cites W2029382205 @default.
- W1992060816 cites W2030086520 @default.
- W1992060816 cites W2032410808 @default.
- W1992060816 cites W2036045962 @default.
- W1992060816 cites W2045685085 @default.
- W1992060816 cites W2047933202 @default.
- W1992060816 cites W2049847700 @default.
- W1992060816 cites W2055083480 @default.
- W1992060816 cites W2057653128 @default.
- W1992060816 cites W2060491424 @default.
- W1992060816 cites W2061211721 @default.
- W1992060816 cites W2063684278 @default.
- W1992060816 cites W2065394969 @default.
- W1992060816 cites W2066217546 @default.
- W1992060816 cites W2066690628 @default.
- W1992060816 cites W2068991796 @default.
- W1992060816 cites W2069385803 @default.
- W1992060816 cites W2071210263 @default.
- W1992060816 cites W2077584717 @default.
- W1992060816 cites W2080035692 @default.
- W1992060816 cites W2084322596 @default.
- W1992060816 cites W2086597086 @default.
- W1992060816 cites W2087646030 @default.
- W1992060816 cites W2089962601 @default.
- W1992060816 cites W2090371157 @default.
- W1992060816 cites W2091125262 @default.
- W1992060816 cites W2092011578 @default.
- W1992060816 cites W2092082287 @default.
- W1992060816 cites W2099326944 @default.
- W1992060816 cites W2104700964 @default.
- W1992060816 cites W2112589497 @default.
- W1992060816 cites W2123701214 @default.
- W1992060816 cites W2128119902 @default.
- W1992060816 cites W2131550905 @default.
- W1992060816 cites W2139810383 @default.
- W1992060816 cites W2140538827 @default.
- W1992060816 cites W2144542802 @default.
- W1992060816 cites W2145407943 @default.
- W1992060816 cites W2145842043 @default.
- W1992060816 cites W2151662529 @default.
- W1992060816 cites W2153863030 @default.
- W1992060816 cites W2160431324 @default.
- W1992060816 cites W2167005388 @default.
- W1992060816 cites W2168271513 @default.
- W1992060816 cites W2168750284 @default.
- W1992060816 cites W2171598768 @default.
- W1992060816 cites W4248596112 @default.
- W1992060816 cites W4254415957 @default.
- W1992060816 cites W4254462085 @default.
- W1992060816 doi "https://doi.org/10.1016/s0040-1951(97)00173-x" @default.
- W1992060816 hasPublicationYear "1998" @default.
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