Plagioclase ultraphyric basalts (PUBs) have been sampled along most mid-ocean ridges with
ultraslow to intermediate spreading rates. Over the past 40 years, the prevalent models for their origin
assume positive buoyancy of plagioclase in basaltic liquids resulting in selective concentration of
plagioclase phenocrysts by floatation. However, when the global population...
Full Text:
chambers, where PUBs should be abundant if plagioclase is buoyant in mid-oceanridge basalt
(MORB). Instead
Plagioclase ultraphyric basalts (PUBs) have been sampled along most mid-ocean ridges with
ultraslow to intermediate spreading rates. Over the past 40 years, the prevalent models for their origin
assume positive buoyancy of plagioclase in basaltic liquids resulting in selective concentration of
plagioclase phenocrysts by floatation. However, when the global population...
Plagioclase ultraphyric basalts (PUBs) have been sampled along most mid-ocean ridges with
ultraslow to intermediate spreading rates. Over the past 40 years, the prevalent models for their origin
assume positive buoyancy of plagioclase in basaltic liquids resulting in selective concentration of
plagioclase phenocrysts by floatation. However, when the global population...
As the Galápagos hot spot is approached from the west along the Galápagos Spreading Center there are systematic increases in crustal thickness and in the K/Ti, Nb/Zr, ³He/⁴He, H₂O, and Na₂O content of lavas recovered from the spreading axis. These increases correlate with progressive transitions from rift valley to axial...
This paper presents the results from the Deflo-hydroacoustic experiment in the Southern Indian Ocean using three autonomous underwater hydrophones, complemented by two permanent hydroacoustic stations. The array monitored for 14 months, from November 2006 to December 2007, a 3000 x 3000 km wide area, encompassing large segments of the three...
We report ³He/⁴He for 150 mid-ocean ridge basalt (MORB) glasses from the Southeast Indian
Ridge (SEIR). Between 81°E and 101°E ³He/⁴He varies from 7.5 to 10.2 R[subscript A], encompassing more than half the
MORB range away from ocean island hot spots. Abrupt transitions are present and in one case the...
We report ³He/⁴He for 150 mid-ocean ridge basalt (MORB) glasses from the Southeast Indian
Ridge (SEIR). Between 81°E and 101°E ³He/⁴He varies from 7.5 to 10.2 R[subscript A], encompassing more than half the
MORB range away from ocean island hot spots. Abrupt transitions are present and in one case the...
Full Text:
/4He for 150 mid-oceanridge basalt (MORB) glasses from the Southeast Indian
Ridge (SEIR). Between 81�E
We report ³He/⁴He for 150 mid-ocean ridge basalt (MORB) glasses from the Southeast Indian
Ridge (SEIR). Between 81°E and 101°E ³He/⁴He varies from 7.5 to 10.2 R[subscript A], encompassing more than half the
MORB range away from ocean island hot spots. Abrupt transitions are present and in one case the...
We combine high-resolution bathymetry acquired using the Autonomous Underwater Vehicle ABE with digital seafloor imagery collected using the remotely operated vehicle ROPOS across the axial valley of the Southern Explorer Ridge (SER) to infer the recent volcanic and tectonic processes. The SER is an intermediate spreading ridge located in the...
There is a lack of consensus regarding the roles of sulfide saturation versus volatile degassing on the partitioning of Cu and Ag during differentiation and eruption of convergent margin magmas. Because of their oxidized character, volatile-rich magmas from the Eastern Manus Back-arc Basin (EMBB) only reach sulfide saturation following magnetite-driven...
