Indian Plate to the Antarctic Plate. Cenozoic volcanism The Kerguelen hotspot produced the long Ninety East Ridge 82–38 , and geochemical evidence suggests that this occurred at or near a spreading ridge. The lack of a conjugate structure on the Antarctic Plate, however, makes it unlikely that the hotspot was located at a spreading ridge during this long period. As the Antarctic Plate then moved over the Kerguelen hotspot the NKP formed over relatively old oceanic crust. Flood basalts in the Kerguelen archipelago formed 30–24 and less voluminous and more recent volcanism occurred until 1 . During the last 21 volcanic structures have formed on the CKP, including Heard Island, and both Heard and McDonald Islands have had recent eruptions. 65 , the CKP–Broken Ridge LIP was located near the Kerguelen plume and the plate boundaries of the Indian Ocean. The LIP was the product of 25 of relatively high magmatic activity followed by a 40 period of lower activity. Microcontinent described tilted basement blocks near the Kerguelen Archipelago and were the first to identify the Kerguelen Plateau as of continental origin, in contrast to other LIPs. The presence of soil layers in the basalt which included charcoal and conglomerate fragments of gneiss indicate that much of the plateau was above sea level as what is termed a microcontinent for three periods between 100 million years ago and 20 million years ago (the charcoal was made by wildfires started by lightning or lava flows). Large parts of the now-submarine Southern Kerguelen Plateaus (SKP) and Central Kerguelen Plateaus (CKP) were subaerial during the formation of the LIP. The SKP probably formed an island of with major peaks reaching above sea level. The Kerguelen Microcontinent may have been covered by dense conifer forest in the mid-Cretaceous. The plateau had been proposed as forming a land bridge between India and Antarctica during the Late Cretaceous, though this is now considered unsupported, with the plateau situated considerable distance from the nearest continents. It finally sank 20 million years ago and is now below sea level. Biodiversity During the austral summer there is a high density of migratory whales including sperm, minke, and humpback whales along the southern end of the Kerguelen Plateau and the northern part of the adjacent Princess Elizabeth Trough. These whales choose this location for foraging because the Southern Front of the Antarctic Circumpolar Current is steered off by the Plateau—resulting