Do ridge–ridge–fault triple junctions exist on Earth? Evidence from the Aden–Owen–Carlsberg junction in the NW Indian Ocean

2008/04/22 by Marc Fournier, Carole Petit, Nicolas Chamot‐Rooke +4 · 27 citations
Earth and Planetary Sciences · #earthquake and tectonic studies #Geological and Geochemical Analysis #High-pressure geophysics and materials #Triple junction #Ridge #Geology #Transform fault #Fault (geology) #Seismology #Rift #Paleontology #Geophysics #Tectonics

paper · doi:10.1111/j.1365-2117.2008.00356.x

published in Basin Research 20(4), 575-590 (Wiley)

openalex publication_date 2008/04/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

ABSTRACT The triple junctions predicted to be ridge–ridge–fault (RRF) types on the basis of large‐scale plate motions are the Azores triple junction between the Gloria Fault and the Mid‐Atlantic Ridge, the Juan Fernandez triple junction between the Chile Transform and the East Pacific Rise and the Aden–Owen–Carlsberg (AOC) triple junction between the Owen fracture zone (OFZ) and the Carlsberg and Sheba ridges. In the first two cases, the expected RRF triple junction does not exist because the transform fault arm of the triple junction has evolved into a divergent boundary before connecting to the ridges. Here, we report the results of a marine geophysical survey of the AOC triple junction, which took place in 2006 aboard the R/V Beautemps‐Beaupré . We show that a rift basin currently forms at the southern end of the OFZ, indicating that a divergent plate boundary between Arabia and India is developing at the triple junction. The connection of this boundary with the Carlsberg and Sheba ridges is not clearly delineated and the triple junction presently corresponds to a widespread zone of distributed deformation. The AOC triple junction appears to be in a transient stage between a former triple junction of the ridge–fault–fault type and a future triple junction of the ridge–ridge–ridge (RRR) type. Consequently, the known three examples of potential RRF triple junctions are actually of the RRR type, and RRF triple junctions do not presently exist on Earth.

Citations

• Giant Megamullion in the Parece Vela Backarc Basin
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• Iberian plate kinematics: a jumping plate boundary between Eurasia and Africa
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• Distributed extension at the Indian Ocean triple junction
• Present‐day motion along the Owen Fracture Zone and Dalrymple Trough in the Arabian Sea
• Effect of recent revisions to the geomagnetic reversal time scale on estimates of current plate motions
• Current plate motions
• Onset of submarine debris flow deposition far from original giant landslide
• The Rodriguez Triple Junction (Indian Ocean): Structure and evolution for the past one million years

Cited by

• Aden–Owen–Carlsberg triple junction [wikipedia]
• Owen fracture zone [wikipedia]