InSAR observations of 2007 Tanzania rifting episode reveal mixed fault and dyke extension in an immature continental rift

摘要: SUMMARY In the early stages of continental rifting, extension takes place by normal faulting, while in mature rifts dyke intrusion dominates. Little is known about nature transition between fault-controlled and dyke-controlled or processes an intermediate setting. Here, we present observations temporal spatial evolution surface displacements during 2007 July 14–August 4 rifting episode Northern Tanzania, immature section East African Rift. The ground deformation initiated with subsidence that can be attributed to ∼40 cm motion on a NE striking fault. Following 17, was dominated ∼7-km-long dyke. Dyke opening increased gradually total ∼2.4 m. From 21, collapse shallow graben above fault near-field displacements. Comparison Dabbahu dyke, Afar, which occurred more rift, shows order-of-magnitude scale difference length. Using numerical models propagation, attribute this size depth magma chamber; thick crust slow spreading rate favour small, deep chambers, forming short, buried dykes, whereas thinner faster large, chambers long, erupting dykes. Observing pattern active Rift key understanding development rift systems passive margins elsewhere.