Mixing of magmas from enriched and depleted mantle sources in the northeast Pacific: West Valley segment, Juan de Fuca Ridge

Article Abstract:

The trace element composition of the basalts of the West Valley floor of the Juan de Fuca Ridge, in the northeast Pacific is a mixture of highly depleted normal mid-ocean ridge basalt (MORB) and enriched MORB. Mixing of the magma occurred at both the crustal and deeper levels. The depleted MORB is probably the result of a melting event beneath a surrounding part of the Juan de Fuca Ridge and is represented by basalts from the Heck Seamounts. The enriched MORB is represented by basalts from the Southwest Seamount and possibly the Tuzo Wilson Volcanic Field and may have originated as amphibole-bearing peridotite lumps floating in depleted mantle matrix.

---

Geochemistry of lavas from Mohns Ridge, Norwegian-Greenland Sea: implications for melting conditions and magma sources near Jan Mayen

Article Abstract:

The Mohns Ridge lavas are present north of Jan Mayen Island in the Norwegian-Greenland Sea and have heterogeneous mantle that includes alkali basalts and incompatible-element-depletion tholeiites. At 72 degrees N, the low melting point melts contain three lava types with variable incompatible element compositions. Large and small degree melts from an enriched source combined to form the lava types. The Jan Mayen mantle probably originated from the passive upwelling of volatile-rich mantle. Large amounts of Ba and Rb are present in the Mohns Ridge basalt and the alkali basalts of Jan Mayen.

Composition, Lava, Jan Mayen Island

---

Mechanisms of Mg-phyllosilicate formation in a hydrothermal system at a sedimented ridge (Middle Valley, Juan de Fuca)

Article Abstract:

The mechanisms of Mg-phyllosilicate formation in a hydrothermal system at a sedimented ridge, Middle Valley, Juan de Fuca, provide vital information on fluid pathways and the movement of chemical elements. The precipitation of minerals depends on the permeability, fluid chemistry and temperature. Details of the geochemical and mineralogical study of the hydrothermal system are given.

Research, Observations, Juan de Fuca Strait, Mineralogical chemistry, Hydrothermal deposits

Similar abstracts:

• Abstracts: Evidence for a reduced, Fe-depleted martian mantle source region of shergottites. A revised and internally consistent thermodynamic model for the interpolation and extrapolation of liquid-solid equilibria in magmatic systems at elevated temperatures and pressures
• Abstracts: Source characteristics of the basement rocks from the Sulu and Celebes Basins (Western Pacific): chemical and isotopic evidence
• Abstracts: Numerical reconstruction of a soft-bedded Laurentide ice sheet during the last glacial maximum: comment. New constraints on the limits of the Barents-Kara ice sheet during the Last Glacial Maximum based on borehole stratigraphy from the Pechora Sea
• Abstracts: Discussion on paleostresses associated with thrust sheet emplacement and related folding in the southern central Pyrenees, Huesca, Spain
• Abstracts: Why is it downhill from Tonopah to Las Vegas?: a case for mantle plume support of the high northern basin and range

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.