Contact: Kevin Stacey
Caption: Mostly gone, not forgotten: the Isabella anomaly (IA), is the seismic signature of a "fossil" slab of the Farallon oceanic plate that was pushed under North American starting around 100 million years ago. The anomaly occurs at the same depth as known Farallon slabs under Washington and Oregon, and lines up due east of a known Farallon fragment off the coast.
Credit: Forsyth lab/Brown University
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