Marquesas hotspot

The Marquesas hotspot is a volcanic hotspot in the southern Pacific Ocean. It is responsible for the creation of the Marquesas Islands – a group of eight main islands and several smaller ones – and a few seamounts. The islands and seamounts formed between 5.5 and 0.4 million years ago and constitute the northernmost volcanic chain in French Polynesia.^[1]

There are two competing theories concerning the origins of volcanism associated with the Marquesas hotspot. Many geoscientists maintain that the area is underlain by a

Some features of the Marquesas, such as the trend of the islands and seamounts, non-fixity of the source, and short-lived volcanic activity, have been argued to conflict with the plume model.[12] The trend of the chain and non-fixity of the source, however, may be explained by the plume conduit either being deflected by convection currents in the upper mantle^[9][13] or melt being channelled through zones of structural weakness.^[6] Volcanic activity may be much longer-lived if the plume also created Hess Rise and Shatsky Ridge to the northwest, both of which follow the same trend as the Marquesas and are dated at 100 Ma and 145–125 Ma respectively.^[2]

Nevertheless, some scientists dispute the plume model, arguing instead that volcanic activity associated with the Marquesas hotspot and others in the southern Pacific results from

• Arago hotspot
• Rarotonga hotspot

References