the Turonian-Maastrichtian, when the seamount had subsided to a sufficient depth. Manganese-encrusted Cretaceous limestones have been found within the pelagic sediments. As at other guyots in the Pacific Ocean pelagic sedimentation commenced later; the foraminifera fossils indicate an age of Maastrichtian to Pliocene for such sediments. These sediments reach thicknesses of in Hole 866B and consist of a Quaternary (last 2.58 million years), a thin early Pleistocene (2.58 – 0.0117 million years ago) and a thick Pliocene layer. Some of the sediments take the form of pelagic limestones. In Paleogene (66 to 23.03 million years ago) sediments ostracods have been found. Carbonates were dissolved and replaced by dolomite already during the Aptian and Albian. Around 24 million years ago at the Paleogene-Neogene (23.02 – 2.58 million years ago) boundary, a second pulse of dolomite formation took place; perhaps sea level changes associated with global climate change triggered this second pulse. The formation of the dolomites was probably aided by the fact that seawater can percolate through Resolution Guyot, which may be responsible for the formation of fluid vent structures on the surface of the seamount. Notes References Sources Guyots Cretaceous volcanoes Seamounts of the Pacific Ocean