Physical Sciences and Mathematics Commons^™

Geology Of The Lucea Inlier, Western Jamaica, Jack Grippi

Geology Theses and Dissertations

The Lucea Inlier exposes a Santonian to Campanian 4 km + thick sequence of shale-siltstone, resedimented volcaniclastics, lenses of shallow-water limestone, micritic limestone, pebbly mudstone and sandy pebble to boulder conglomerate. Clastics were deposited by a variety of gravity flow mechanisms. Petrographically sandstones are lithic or feldspathic arenites and contain only very small amounts of detrital quartz. Structurally the inlier is characterized by simple, open, east-west trending folds. A spaced, vertical axial-planar cleavage is developed in shales and fine siltstones. Two major east-west trending left-lateral fault zones, the Fat Hog Quarter and Maryland faults, cut the inlier into three blocks, …

The Geology Of Southwestern Fidalgo Island, Daryl Gusey

WWU Graduate School Collection

Detailed geologic mapping of rocks in the upper stratigraphic levels of the Fidalgo ophiolite Indicates that keratophyres and spilites are interbedded with tuffaceous sediments, sedimentary breccias, and graywacke. Sedimentary breccias containing plutonlc rock fragments as well as volcanic rock fragments are common. The graywackes were derived from a volcanic source area. Radiolaria In the tuffaceous sediments indicate a depositional age of Lower Kimmeridgian to Upper Valanginian.

Compared to the stratigraphy and petrology of other ophiolites and present-day tectonic environments, the Fidalgo Complex most closely resembles that of ancient and modern island-arc sequences.