The recent history of the Galapagos Triple Junction preserved on the Pacific plate
Smith, Deborah K.
Schouten, Hans A.
Montesi, Laurent G. J.
MetadataShow full item record
At the Galapagos triple junction, the Cocos and Nazca plates are broken by a succession of transient rifts north and south of the Cocos-Nazca (C-N) Rift. Modeling has suggested that each rift initiated at the East Pacific Rise (EPR), its location controlled by the distance of the C-N Rift tip from the EPR. Evidence on the Pacific plate confirms that each transient rift formed a true RRR triple junction with the EPR and clarifies the history of the region. At ~1.5 Ma the triple junctions began jumping rapidly toward C-N Rift suggesting that the C-N Rift tip moved closer to the EPR. Pacific abyssal hills became broad and shallow indicating enhanced magma supply to the region. At ~1.4 Ma, the Galapagos microplate developed when extension became fixed on the southern transient rift to form the South scarp of the future Dietz rift basin. Lavas flooded the area and a Galapagos-Nazca magmatic spreading center initiated at the EPR. We suggest that a hotspot was approaching the southern triple junction from the west. The hotspot crossed to the Nazca plate ~1.25 Ma. Dietz seamount formed within the young spreading center, dikes intruded Dietz rift basin, and eruptions built volcanic ridges. Since ~0.8 Ma magmatic spreading has jumped northward twice, most recently to Dietz volcanic ridge. Amagmatic extension to the east has formed the large North scarp of Dietz rift basin. Northward jumping of the southern triple junction has maintained the microplate boundary close to the proposed hotspot.
Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Earth and Planetary Science Letters 371-372 (2013): 6-15, doi:10.1016/j.epsl.2013.04.018.
Showing items related by title, author, creator and subject.
Smith, Deborah K.; Schouten, Hans A.; Zhu, Wenlu; Montesi, Laurent G. J.; Cann, Johnson R. (American Geophysical Union, 2011-11-08)The Galapagos triple junction is not a simple ridge-ridge-ridge (RRR) triple junction. The Cocos-Nazca Rift (C-N Rift) tip does not meet the East Pacific Rise (EPR). Instead, two secondary rifts form the link: Incipient ...
Hemichannel composition and electrical synaptic transmission : molecular diversity and its implications for electrical rectification Palacios-Prado, Nicolas; Huetteroth, Wolf; Pereda, Alberto E. (Frontiers Media, 2014-10-15)Unapposed hemichannels (HCs) formed by hexamers of gap junction proteins are now known to be involved in various cellular processes under both physiological and pathological conditions. On the other hand, less is known ...
Kaess, Michael; Johannsson, Hordur; Roberts, Richard; Ila, Viorela; Leonard, John J.; Dellaert, Frank (2011-04-06)We present a novel data structure, the Bayes tree, that provides an algorithmic foundation enabling a better understanding of existing graphical model inference algorithms and their connection to sparse matrix factorization ...