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Boron Variation And The Subducted Sediment Component In The Volcanics From The Bifurcated Portion Of The Lesser Antilles Island Arc (Laia), Ami Margret Ngo Ward

USF Tampa Graduate Theses and Dissertations

North of Martinique island the Lesser Antilles volcanic arc bifurcates, creating a double arc. Here volcanic activity has migrated up to 50 km westward with time, resulting in two volcanic lines that are distinct in age. The eastern line, commonly referred to as the old arc, was active from Early Eocene to Mid-Miocene (Nagle, 1971; Nagle et al., 1976; Westercamp and Tazieff, 1980; Andreieff et al., 1988). The western line, commonly referred to as the recent arc, has been active since the late Pliocene, ~6 Ma ago (Nagle, 1971; Nagle et al., 1976; Westercamp and Tazieff, 1980; Andreieff et al., …

Fluid-Mobile Trace Element Variability Of Serpentinites And Entrained Crustal Rocks Across The Mariana Forearc System, Raymond M. Johnston

USF Tampa Graduate Theses and Dissertations

In the Mariana subduction system, active serpentinite mud volcanoes are associated with the subduction of the Pacific plate beneath the Philippine plate in a non-accretionary convergent plate margin. This location offers a unique opportunity to study the subduction zone interface with little crustal contamination. The systematics of fluid-mobile trace elements (FME) (As, Cs, Rb, Sb, Tl, Pb, and Sr) in erupted serpentinite muds and entrained serpentinized ultramafic and mafic clasts can place constraints on the release of slab-derived fluids from the downgoing plate, and ultimately the pressure/temperature (P/TC°) conditions at which these fluids are mobilized.

The samples analyzed in this …