TY  - JOUR
A1  - Heit, Benjamin
A1  - Yuan, Xiaohui
A1  - Weber, Michael H.
A1  - Geissler, Wolfram H.
A1  - Jokat, Wilfried
A1  - Lushetile, Bufelo
A1  - Hoffmann, Karl-Heinz
T1  - Crustal thickness and V-p/V-s ratio in NW Namibia from receiver functions: Evidence for magmatic underplating due to mantle plume-crust interaction
JF  - Geophysical research letters
N2  - A seismological network was operated at the junction of the aseismic Walvis Ridge with the northwestern Namibian coast. We mapped crustal thickness and bulk V-p/V-s ratio by the H-k analysis of receiver functions. In the Damara Belt, the crustal thickness is similar to 35km with a V-p/V-s ratio of <1.75. The crust is similar to 30km thick at the coast in the Kaoko Belt. Strong variations in crustal thickness and V-p/V-s ratios are found at the landfall of the Walvis Ridge. Here and at similar to 150km northeast of the coast, the crustal thickness increases dramatically reaching 44km and the V-p/V-s ratios are extremely high (similar to 1.89). These anomalies are interpreted as magmatic underplating produced by the mantle plume during the breakup of Gondwana. The area affected by the plume is smaller than 300km in diameter, possibly ruling out the existence of a large plume head under the continent during the breakup.
KW  - crustal thickness
KW  - V-p
KW  - V-s ratios
KW  - magmatic underplating
KW  - Walvis Ridge
KW  - continental breakup
Y1  - 2015
U6  - https://doi.org/10.1002/2015GL063704
SN  - 0094-8276
SN  - 1944-8007
VL  - 42
IS  - 9
SP  - 3330
EP  - 3337
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Guzman, S.
A1  - Petrinovic, I. A.
A1  - Brod, J. A.
A1  - Hongn, Fernando D.
A1  - Seggiaro, R. E.
A1  - Montero, C.
A1  - Carniel, Roberto
A1  - Dantas, E. L.
A1  - Sudo, Masafumi
T1  - Petrology of the Luingo caldera (SE margin of the Puna plateau) a middle Miocene window of the arc-back arc configuration
JF  - Journal of volcanology and geothermal research
N2  - We describe the petrographic characteristics, whole-rock geochemistry and mineral chemistry of rocks from the Pucarilla-Cerro Tipillas Volcanic Complex with emphasis on the rocks belonging to the middle Miocene Luingo caldera, located in the south-eastern portion of the Central Volcanic Zone (CVZ) of the Andes. We modelled the petrogenesis of the Luingo caldera rocks as a mixture of ca. 20% crustal magmas and 80% of mantle magmas by AFC with recharge processes. A comparison of Luingo geochemical data with the composition of Miocene-Pliocene volcanic rocks from the broad area, points to major thickening events during the middle Miocene for the western portion and during the upper Miocene for the eastern portion of the Southern CVZ. In the eastern sector (similar to 66 degrees W) the mantle source appears to change from a spinel-lherzolite type for the middle Miocene to a garnet-lherzolite type for the upper Miocene-Pliocene magmas. The areal distribution of the volcanic products led to the recognition of approximately equivalent areas covered by volcanic rocks both in the eastern and in the western Puna borders. This indicates a broad arc, which was structurally controlled at the proto-Puna/Puna margins, whose geochemical differences are related with variations in crustal thicknesses and heterogeneous mantle sources from west to east.
KW  - Luingo caldera
KW  - Central Andes
KW  - Miocene volcanism
KW  - Southern Central Volcanic Zone
KW  - crustal thickness
Y1  - 2011
U6  - https://doi.org/10.1016/j.jvolgeores.2010.12.008
SN  - 0377-0273
VL  - 200
IS  - 3-4
SP  - 171
EP  - 191
PB  - Elsevier
CY  - Amsterdam
ER  -