The Motion and Boundary Between the Capricorn and Australian Plates

• Published in: Science (American Association for the Advancement of Science) Vol. 277; no. 5330; pp. 1268 - 1274
• Main Authors: Royer, Jean-Yves, Gordon, Richard G.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 29.08.1997; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: Confidence limits; Congenital Impairments; Convergent boundaries; Earth sciences; Earth, ocean, space; Earthquakes; Earthquakes, seismology; Exact sciences and technology; Geologic deformation; Geometry; Internal geophysics; Kinetics; Magnetic polarity; Marine; Observations; Plate tectonics; Probabilities; Ridges; Tectonic plate interactions; Tectonics. Structural geology. Plate tectonics; Topography; Mid-Indian Ridge; Indian Ocean; plate movement; plate divergence; mid-ocean ridges; Indian Ocean; en echelon faults; earthquakes; Indian Plate; Australo-Indian Plate; Antarctic Plate; Australian Plate; tectonic maps; plate geometry; gravity anomalies; geodynamics; deformation; plate boundaries; triple junctions; focal mechanism; magnetic anomalies
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.277.5330.1268

The motions between the Somalian, Antarctic, and Australian plates-the three plates believed to meet at the Rodrigues triple junction in the Indian Ocean-are inconsistent with the assumption that all three plates are rigid. The discrepancy is best explained if the Australian plate contains two component plates. Thus, the traditionally defined Indo-Australian plate consists of three component plates and multiple diffuse plate boundaries. The pattern of present deformation indicates that the boundaries between the three component plates are two unconnected zones accommodating divergence and a larger zone, which we interpret as three diffuse convergent plate boundaries and a diffuse triple junction.