资源环境科技发展态势分析平台

At the Galapagos triple junction, the westward propagating Cocos-Nazca (C-N) Rift breaks into similar to 0.5Ma crust accreted at the East Pacific Rise. Rifting transitions to full magmatic seafloor spreading in the wake of the propagating tip. The 25-km-long Hess Deep rift is the transitional segment from rifting to spreading. Intrarift ridge (IRR), located within Hess Deep rift, is interpreted as a detachment fault, which exhumes deep-seated rocks to the seafloor. Although transitional segments must have occurred throughout the westward propagation of C-N Rift, IRR is the only obvious detachment fault along the base of the Rift scarps in the last similar to 5Ma of its propagation. IRR formation may be in response to a decrease in spreading rate (similar to 40 to <20mm/yr) and presumed lower melt supply, resulting from the formation of the Galapagos microplate similar to 1.4Ma, which now controls the opening at the C-N Rift tip.