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Full-Text Articles in Geology
Field Relations, Structural Geology, And Geochemistry Of The Jonestown Volcanic Field, Lebanon County, Southeastern Pennsylvania, Tristan J. Ashcroft
Field Relations, Structural Geology, And Geochemistry Of The Jonestown Volcanic Field, Lebanon County, Southeastern Pennsylvania, Tristan J. Ashcroft
Geology Theses and Dissertations
The Jonestown Volcanic Field is a five kilometer by fifteen kilometer area of volcanic and hypabyssal rocks, basalt and diabase, located in southeastern Pennsylvania. These igneous rocks presently occur within an allochthonous belt of Ordovician deep water sedimentary rocks and Taconic flysch rocks known collectively as the Hamburg Klippe. Detailed field mapping during this project has revealed that the contacts between the igneous rocks and the flysch are not conformable. The volcanic rocks are associated with the Ordovician limestone that is adjacent to these volcanics. This limestone also is not conformable to the Hamburg Klippe sediments, rather it shares outcrop …
The Use Of A Synthetic Binary Solid Solution To Model Igneous Textural Evolution, Elizabeth Scott
The Use Of A Synthetic Binary Solid Solution To Model Igneous Textural Evolution, Elizabeth Scott
Geology Theses and Dissertations
Crystallization experiments using a synthetic igneous analog have shown that grain boundary migration can take place in melt-present environments (Means and Park, 1994). In order to evaluate the importance of metamorphic processes during the textural evolution of a crystal mush, microstructural evidence is needed to link them with final igneous textures. In natural magmatic systems, plagioclase may provide a microstructural link; plagioclase solid solution enables the process of chemical zoning and preserves a record of crystal morphology (and chemistry) during growth. If metamorphic processes are common, they should affect the zoning patterns of plagioclase crystals.
A petrographic stage heater apparatus …