Title page for ETD etd-05242002-120716


Type of Document Dissertation
Author Fedele, Luca
URN etd-05242002-120716
Title Studies of Magmatic Systems
Degree PhD
Department Geological Sciences
Advisory Committee
Advisor Name Title
Bodnar, Robert J. Committee Chair
Beard, James S. Committee Member
Belkin, Harvey Committee Member
De Vivo, Benedetto Committee Member
Tracy, Robert J. Committee Member
Webster, James Committee Member
Keywords
  • Ponza
  • Melt Inclusions
  • Spinels
  • MELTS
  • Tahiti
  • Geothermometer
  • Thermodynamic Modeling
Date of Defense 2002-05-09
Availability unrestricted
Abstract
Two magmatic systems were investigated using different petrological tools:

1) Origin of Ponza trachyte was studied combining data from MI with trends predicted by thermodynamic modeling. MI data were compared with known phase relations in the ternary feldspar and anorthite-diopside-albite systems to constrain the parameters used in the modeling. MI data are consistent with melt evolution from a basaltic parent via a fractional crystallization mainly of pyroxene and feldspars. These data and the results from the modeling, suggest a genetic link between the Ponza trachyte and coeval alkali olivine basalts on the nearby Ventotene Island.

2) We evaluated the range of magmatic temperatures within the crystallization interval for a basanite with different olivine-spinel geothermometers. While olivine spinel pair records the evolution of the basanite during crystallization, low temperatures calculated with the geothermometers are unrealistic. This is likely due to the presence of significant amounts of Ti in our magmatic spinels. Indeed Ti is not taken into account in the geothermometers. We tested the possibility of accounting for the presence and effects of Ti using a linear correction for the Fe+2 content in our spinels. While this generated more realistic temperatures at the low end of the range, it also increased the dispersion in the data, suggesting that spinel behavior is more complex and that the presence of Ti affects content and site occupancy of other elements as well.

Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  Fedele-PhD-Dissertation.pdf 2.02 Mb 00:09:20 00:04:48 00:04:12 00:02:06 00:00:10

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.