Overview

Description

CALENDAR DESCRIPTION:

Geological processes at convergent plate margins are considered in the context of plate tectonic principles. Topics to be addressed include: driving forces of tectonic plates, mantle convection, geometry of subducted slabs, ridge-trench intersections, generation of volcanic arcs, causes of anomalous magmatism, accretion of terranes, and transpression of orogenic float.

COURSE DETAILS:

Convergent plate margins are highly active, both tectonically and magmatically.  At a typical convergent margin, oceanic lithosphere is consumed along a subduction zone and  basaltic melts are generated from the hydration of mantle peridotite.  Granitic batholiths swell the overriding plate, forming a crustal welt.  Basaltic to rhyolitic lava and tephra erupt to form  steep-flanked composite volcanoes.  The overriding plate is deformed by localized tensional, transcurrent, and compressional stresses. Thermal disturbances in the overriding plate vary from low heat flow in the forearc, to high heat flow in the arc and backarc.  A seismically fast feature may extend from the subduction zone to the core-mantle boundary.  Sea-floor spreading ridges may intersect the trench, producing slab windows and anomalous geophysical and geochemical phenomena.

This course will examine the relationships among crust, mantle, lithosphere and asthenosphere in the context of convergent plate boundaries, and in a framework of geophysics and geochemistry.  Lectures will focus on basic concepts, and seminars will provide in-depth examination of specific topics.  Readings will be assigned from books, journals and government reports.  A research paper will be written on a topic approved by the instructor.

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