Matches in SemOpenAlex for { <https://semopenalex.org/work/W2063669913> ?p ?o ?g. }
- W2063669913 endingPage "119" @default.
- W2063669913 startingPage "95" @default.
- W2063669913 abstract "The seismic refraction-wide-angle reflection experiments carried out in 1985 and 1990 in the Kenya rift (KRISP '85 and KRISP '90) show major crustal thickness variations both along and across the rift. Along the rift axis crustal thickness varies from 35 km in the south beneath the Kenya dome to 20 km in the north beneath the Turkana region. Due to the distribution of crustal thickness beneath the rift flanks, it can be stated that the major amount of variation in crustal thickness along the rift axis is due to the Tertiary rifting episode. The northwards decrease in crustal thickness can be correlated with changes in surface topography (northwards decrease), rift width (northwards increase), surface estimates of extension (5–10 km in the south and 35–40 km in the north) and Bouguer gravity, the regional northwards increase of which can be explained entirely by the change in crustal thickness. Below the 750 km long axial rift profile, uppermost mantle Pn velocities are low, being 7.5–7.7 km/s. However, under the northern part of the rift two layers with velocities of 8.1 km/s and 8.3 km/s are embedded in the low-velocity mantle material at 40–45 km and 60–65 km depth, respectively. In contrast, the wide-angle data show that beneath the Kenya dome, in the southern part of the rift, low mantle velocities occur down to at least 65 km depth. This mantle velocity structure is indicative of the depth to the onset of melting being at least 65 km beneath the northern part of the rift and thus not being shallower than the depth (45–50 km) to the onset of melting under the Kenya dome to the south. A profile across the rift north of the Kenya dome at the latitude of Lake Baringo shows that the low uppermost mantle Pn velocity of 7.5–7.7 km/s and crustal thinning of 5–10 km is confined to below the surface expression of the rift. An abrupt change in Moho depths and Pn velocities occurs as the rift boundaries are crossed. Beneath the rift flanks, normal Pn velocities of 8.0–8.2 km/s occur. The presence of hot mantle material beneath the Kenya dome since the onset of volcanism here at 15–20 Ma is still compatible with the abrupt change in mantle P-wave velocities as the rift boundaries are crossed. Petrological interpretation of the seismic velocities indicates a few (up to 5) percent basaltic melt in the mantle below the rift except in the two layers with velocities greater than 8.0 km/s under the northern part of the rift where some crystal orientation (anisotropy) is necessary. Below about 45–50 km depth beneath the southern part of the rift the magma could exist as in situ partial melt. The above results, taken together with results from teleseismic studies, petrology and surface geology, indicate anomalously hot mantle material appearing below the present site of the Kenya rift at about 20–30 Ma. The active uprising of this anomalously hot mantle material since this time has given rise to widespread volcanism along the whole length of the rift and has modified the crust beneath the rift by mafic igneous underplating and intrusion, especially into the basal crustal layer. Accompanying the uprise of the anomalously hot mantle material minor crustal extension (5–10 km) has occurred beneath the Kenya dome in the southern part of the rift where crustal thickness is large (35 km). Under the Turkana region in the northern part of the rift, a greater amount of extension (35–40 km) has taken place and the crustal thickness is small (20 km), although the depth to the onset of melting under the northern part of the rift is, if anything, greater than under the southern part of the rift." @default.
- W2063669913 created "2016-06-24" @default.
- W2063669913 creator A5057209698 @default.
- W2063669913 creator A5061253233 @default.
- W2063669913 creator A5068663349 @default.
- W2063669913 creator A5072496068 @default.
- W2063669913 creator A5081588180 @default.
- W2063669913 date "1997-09-01" @default.
- W2063669913 modified "2023-09-27" @default.
- W2063669913 title "A model for the structure, composition and evolution of the Kenya rift" @default.
- W2063669913 cites W1590052314 @default.
- W2063669913 cites W1967264370 @default.
- W2063669913 cites W1981966261 @default.
- W2063669913 cites W1989098455 @default.
- W2063669913 cites W1990740187 @default.
- W2063669913 cites W1991925114 @default.
- W2063669913 cites W2000730680 @default.
- W2063669913 cites W2006690992 @default.
- W2063669913 cites W2012938425 @default.
- W2063669913 cites W2020486755 @default.
- W2063669913 cites W2022528575 @default.
- W2063669913 cites W2038574437 @default.
- W2063669913 cites W2038844896 @default.
- W2063669913 cites W2040760422 @default.
- W2063669913 cites W2044846174 @default.
- W2063669913 cites W2047385203 @default.
- W2063669913 cites W2052907420 @default.
- W2063669913 cites W2061461172 @default.
- W2063669913 cites W2062065782 @default.
- W2063669913 cites W2062426713 @default.
- W2063669913 cites W2065847226 @default.
- W2063669913 cites W2071366353 @default.
- W2063669913 cites W2075378929 @default.
- W2063669913 cites W2082461046 @default.
- W2063669913 cites W2090072357 @default.
- W2063669913 cites W2095839422 @default.
- W2063669913 cites W2104073392 @default.
- W2063669913 cites W2125950998 @default.
- W2063669913 cites W2128591127 @default.
- W2063669913 cites W2335010007 @default.
- W2063669913 cites W4232516110 @default.
- W2063669913 doi "https://doi.org/10.1016/s0040-1951(97)00097-8" @default.
- W2063669913 hasPublicationYear "1997" @default.
- W2063669913 type Work @default.
- W2063669913 sameAs 2063669913 @default.
- W2063669913 citedByCount "82" @default.
- W2063669913 countsByYear W20636699132012 @default.
- W2063669913 countsByYear W20636699132013 @default.
- W2063669913 countsByYear W20636699132014 @default.
- W2063669913 countsByYear W20636699132015 @default.
- W2063669913 countsByYear W20636699132016 @default.
- W2063669913 countsByYear W20636699132017 @default.
- W2063669913 countsByYear W20636699132018 @default.
- W2063669913 countsByYear W20636699132019 @default.
- W2063669913 countsByYear W20636699132020 @default.
- W2063669913 countsByYear W20636699132021 @default.
- W2063669913 countsByYear W20636699132022 @default.
- W2063669913 countsByYear W20636699132023 @default.
- W2063669913 crossrefType "journal-article" @default.
- W2063669913 hasAuthorship W2063669913A5057209698 @default.
- W2063669913 hasAuthorship W2063669913A5061253233 @default.
- W2063669913 hasAuthorship W2063669913A5068663349 @default.
- W2063669913 hasAuthorship W2063669913A5072496068 @default.
- W2063669913 hasAuthorship W2063669913A5081588180 @default.
- W2063669913 hasConcept C127313418 @default.
- W2063669913 hasConcept C151730666 @default.
- W2063669913 hasConcept C165205528 @default.
- W2063669913 hasConcept C2776364302 @default.
- W2063669913 hasConcept C2776698055 @default.
- W2063669913 hasConcept C2778697265 @default.
- W2063669913 hasConcept C32848823 @default.
- W2063669913 hasConcept C50682988 @default.
- W2063669913 hasConcept C56859440 @default.
- W2063669913 hasConcept C67236022 @default.
- W2063669913 hasConcept C77928131 @default.
- W2063669913 hasConcept C8058405 @default.
- W2063669913 hasConcept C96342900 @default.
- W2063669913 hasConceptScore W2063669913C127313418 @default.
- W2063669913 hasConceptScore W2063669913C151730666 @default.
- W2063669913 hasConceptScore W2063669913C165205528 @default.
- W2063669913 hasConceptScore W2063669913C2776364302 @default.
- W2063669913 hasConceptScore W2063669913C2776698055 @default.
- W2063669913 hasConceptScore W2063669913C2778697265 @default.
- W2063669913 hasConceptScore W2063669913C32848823 @default.
- W2063669913 hasConceptScore W2063669913C50682988 @default.
- W2063669913 hasConceptScore W2063669913C56859440 @default.
- W2063669913 hasConceptScore W2063669913C67236022 @default.
- W2063669913 hasConceptScore W2063669913C77928131 @default.
- W2063669913 hasConceptScore W2063669913C8058405 @default.
- W2063669913 hasConceptScore W2063669913C96342900 @default.
- W2063669913 hasIssue "1-4" @default.
- W2063669913 hasLocation W20636699131 @default.
- W2063669913 hasOpenAccess W2063669913 @default.
- W2063669913 hasPrimaryLocation W20636699131 @default.
- W2063669913 hasRelatedWork W155794164 @default.
- W2063669913 hasRelatedWork W1987251071 @default.
- W2063669913 hasRelatedWork W2001605692 @default.
- W2063669913 hasRelatedWork W2044879889 @default.