Capricorn plate

{{short description|Proposed minor tectonic plate under the Indian Ocean}}

{{Infobox tectonic plate

| image = File:CapricornPlate.png

| type = Minor (proposed)

| move_direction = north-east

| move_speed = {{convert|59|mm|in|abbr=on}}/year

| geo_features = Indian Ocean

}}

The Capricorn plate is a proposed{{clarify |date=October 2024 |reason=A tectonic plate is a physical thing that either exists or does not exist. It is not something that can be proposed. It may be proposed to be recognized by some organization, but a physical thing is not proposed. If this is proposed to be recognized by some organization(s), then the proposal, the proposer, and the organization(s) should be identified.}} minor tectonic plate lying beneath the Indian Ocean basin in the southern and eastern hemispheres.

The original theory of plate tectonics, as accepted by the scientific community in the 1960s, assumed fully rigid plates and relatively narrow, distinct plate boundaries. However, research in the late 20th and early 21st centuries suggests that certain plate junctions are diffuse across several dozen or even hundreds of kilometres.{{cite journal|title=The Motion and Boundary Between the Capricorn and Australian Plates |first1=Jean-Yves |last1=Royer |first2=Richard G. |last2=Gordon |journal=Science |date=August 1997 |volume=277 |issue=5330 |pages=1268–1274 |doi=10.1126/science.277.5330.1268 }}

The Capricorn plate is a relatively rigid piece of oceanic crust along the far western edge of the former Indo-Australian plate. The Capricorn plate was once joined with the Indian plate and the Australian plate to form the Indo-Australian plate, but recent studies suggest that the Capricorn plate began separating from the Indian and Australian plates between {{Mya|18}} and {{Mya|8}} along a wide, diffuse boundary.{{cite journal|volume=37 |issue=3 |pages=287–288 |title=Lithospheric Deformation in the equatorial Indian Ocean: Timing and Tibet |first=Richard G. |last=Gordon |journal=Geology |date=March 2009 |doi=10.1130/focus032009.1 |bibcode=2009Geo....37..287G |doi-access=free }}