Kelemen's (and coworkers') model, based on observations in ophiolite

I. The observations - the ophiolite sequence

1. sheeted dikes and pillow basalts
2. the rest of the crust divided into upper and lower gabbro sequences
1. textures - foliation - modal layering
2. compositions
3. inferred temperature

Basic observation: The crust is vertically inhomogeneous in texture, composition, and possibly temperature. These differences must be explained by crust formation process

II. Proposed model to explain observations

Periodic formation of melt filled fractures can result from magma accumulation beneath permeability barriers. Repeated injections of dikes and sills.

• permeability barriers
1. what they are and how they form
2. possible permeability barriers in the crust
• Mathematical model
1. formulas
2. assumptions
3. solutions
4. reality check
• Modal layering: formed by periodic pressure change 

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Last modified 16 January 1998