Counter-rotating microplates at the Galapagos triple junction
Abstract
An `incipient' spreading centre east of (and orthogonal to) the East Pacific Rise at 2°40'N has been identified as forming a portion of the northern boundary of the Galapagos microplate. This spreading centre was described as a slowly diverging, westward propagating rift, tapering towards the East Pacific Rise. Here we present evidence that the `incipient rift' has also rifted towards the east and opens anticlockwise about a pivot at its eastern end. The `incipient rift' then bounds a second microplate, north of the clockwise-rotating Galapagos microplate. The Galapagos triple junction region, in the eastern equatorial Pacific Ocean, thus consists of two counter-rotating microplates partly separated by the Hess Deep rift. Our kinematic solution for microplate motion relative to the major plates indicates that the two counter-rotating microplates may be treated as rigid blocks driven by drag on the microplates' edges3.
- Publication:
-
Nature
- Pub Date:
- February 2005
- DOI:
- 10.1038/nature03262
- Bibcode:
- 2005Natur.433..855K