Giant Porphyry Copper Deposits Caused by a Slab Jamming in the Mantle Transition Zone
Issued Date
2025-01-01
Resource Type
ISSN
09544879
eISSN
13653121
Scopus ID
2-s2.0-105020441906
Journal Title
Terra Nova
Rights Holder(s)
SCOPUS
Bibliographic Citation
Terra Nova (2025)
Suggested Citation
Nakrong N., Forster M., Spakman W., Jelsma H., Gaboury F., Lister G. Giant Porphyry Copper Deposits Caused by a Slab Jamming in the Mantle Transition Zone. Terra Nova (2025). doi:10.1111/ter.70018 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/112934
Title
Giant Porphyry Copper Deposits Caused by a Slab Jamming in the Mantle Transition Zone
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Corresponding Author(s)
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Abstract
Two giant porphyry copper deposits in the Southern Central Andes formed during the Miocene–Pliocene transition when a bend in the subducting Juan de Fernández hotspot chain jammed in the mantle transition zone, causing mega-scale slab-kinking. This geometry implies mechanical resistance that caused East–West compression and eventually a thrust-mode failure in a now flattened slab segment at depth. The geometric incompatibility of the kinking zone, compared to the subducting slab adjacent, caused transverse, down-dip slab tears parallel to (but not coincident with) the Juan de Fernández Ridge. One torn flat slab segment acted as a trapdoor, which opened, gaped, and then detached. The largest copper deposits formed along the prolongation of the trapdoor tear, where it intersected tears at the southern edge of the flat slab kink segment. Fluid rising from the sinking slablet beneath escaped for only a limited period before the slab gape was over-ridden by ongoing subduction.