Exceptionally High Emplacement Rate of the Afar Mantle Plume Head

Eid, B.; Lhuillier, F. ; Gilder, S. A. ; Pfänder, J. A.; Gebru, E. F. und Aßbichler, D. (2021): Exceptionally High Emplacement Rate of the Afar Mantle Plume Head. In: Geophysical Research Letters, Bd. 48, Nr. 23, e2021GL094755

Abstract

We investigated a 1-km-thick sequence of lava flows that erupted over the Afar plume axis in order to better understand the emplacement history of the similar to 30 Ma Ethiopia-Yemen Traps. Geochemical analyses reveal high-titanium concentrations (TiO2 3.9 +/- 0.5 wt%) in basalts close to picritic compositions. Indistinguishable Ar-40/Ar-39 ages throughout the section define a weighted-mean of 31.18 +/- 0.28 Ma (95% confidence). This date, together with solely normal polarity magnetization directions in 68 geomagnetically independent horizons, constrain the eruption to within chron C12n, with a maximum duration of a few hundreds of kyr for the entire 1-km-thick section. The rate of geomagnetic secular variation used as a chronometer refines the duration to only a few tens of kyr, leading to a local extrusion rate of 4-13 km(3)/yr for the Afar plume head, which greatly exceeds the average rate of 0.3-1.2 km(3)/yr for the entire Ethiopia-Yemen Traps.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Geowissenschaften > Department für Geo- und Umweltwissenschaften
• Themengebiete: 500 Naturwissenschaften und Mathematik > 550 Geowissenschaften, Geologie
• ISSN: 0094-8276
• Sprache: Englisch