Document Type
Thesis
Abstract
Ophiolite is a grouping of mafic and ultramafic rocks that originally form as oceanic crust and mantle, which is emplaced onto less dense continental crust. Ophiolite suites are an important part of understanding the structural composition of the Earth. The ophiolite’s significance is due in part to the wide variety of rock compositions that become exposed from the obduction onto continental crust. The stratigraphy of ophiolites typically follow a very similar sequence; the “top” usually consists of a layer of oceanic sediments deposited on top of pillow lavas, reflecting the original deep ocean setting before obduction occurred. Below that sequence is a series of different mafic rocks such as a sheeted dike complex and gabbros of varying composition (Blatt, 2006). Below that, there are ultramafic rocks such as harzburgite, wherlites, and other olivine and pyroxene-rich rocks. The ultramafic sequence is the remnant of the mantle that has been brought to the surface as a result of obduction (Cox, 1999). At the base of the ophiolite is the metamorphic sole. The sole is the result of the thrusting that occurred during emplacement onto continental crust, and can often reveal the direction of the obduction (Fig. 1); in the case of the Semail ophiolite, the sole indicates high temperature and low pressure conditions (El Shazly, 1990). Finally, beneath the sole is the autochthonous unit upon which the rest of the ophiolite series was emplaced.
Date Awarded
2016
Department
Geology
Advisor 1
Christopher M. Bailey
Recommended Citation
von Nessi, Marissa, "A Kinematic and Petrographic analysis of Deformed Rocks at the Base of Semail Ophiolite near Buwah, Oman" (2016). Geology Senior Theses. William & Mary. Paper 383.
https://scholarworks.wm.edu/geologyseniors/383
