Origin of the Caroline Seamount Chain and an ocean drilling proposal to test the mantle plume hypothesis

In addition to magmatism along the tectonic plate boundaries, magmatism also occurs in intraplate setting. Intra-oceanic plate volcanism has formed a number of oceanic plateaus and seamount chains. In the 1970s, the mantle plume hypothesis was proposed to explain the genesis of oceanic plateau and seamount chain with time propagation. The mantle plume hypothesis considers that the deep mantle-sourced material upwells and entrains surrounding mantle materials and melts in the shallow mantle to form an oceanic plateau, and then an seamount chain with time on the moving plate. However, a clear evidence for genetic relationship between an oceanic plateau and a seamount chain is lacking, and, thus, the mantle plume hypothesis has not been proved. The Caroline volcanic chain consists of the Caroline plateau to west and the Caroline seamount chain to east. This study has reviewed the proceedings on the origin of the Caroline volcanic rocks in recent years, which indicates that the Caroline seamount chain could have been formed by a young deep mantle-sourced mantle plume. Because there is lack of studies on the volcanic rocks from the broad transition region between the Caroline plateau and seamount chain, robust evidence for the whole Caroline Seamount Chain formed by a deep mantle plume is lacking. This transition region is widely covered by pelagic sediments and reef limestone, and sampling of basement volcanic rocks is difficult with routine methods. This study proposes five drilling sites in this transition region, and studies of petrology, geochemistry and chronology of the drilled volcanic rocks will help to test the mantle plume hypothesis.