Collaborative Research: Geochemical and Geological Investigation of the "Incipient Rift" at 2o40'N, east of the East Pacific Rise

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The northern boundary of the Galapagos microplate is defined by a relatively recent "Incipient Rift" that is a slow-spreading new rift oriented orthogonal (along a flowline) to the active East Pacific Rise (EPR). The PIs propose to map this incipient rift completely with multibeam, to conduct basalt sampling by wax coring and dredging, and to run some towed camera traverses within the rift. Based on samples from a pilot study, the incipient rift offers the opportunity to sample the behavior of the EPR melting regime in the across-axis dimension and to examine changes in the amount of melting that takes place as one moves farther from the active EPR axis. The mapping and camera work will help to locate good sampling sites and will also help to determine whether the 800m scarps of the incipient rift expose deeper rocks, potentially a useful complement to studies of Hess Deep and the nature of young crust formed at the EPR. The proposed study would be carried out on a large UNOLS vessel ( 23 days of Melville requested), with subsequent laboratory study of samples, and laboratory study of camera and multibeam results.