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全球比例尺上表面固定的热点位置和火山对应于地下软流圈的恒定漂移速率表明它们产生于地幔深处。大洋岛玄武岩（ＯＩＢｓ）的３Ｈｅ／４Ｈｅ比值高于洋中脊玄武岩（ＭＯ＿ＲＢｓ）的３Ｈｅ／４Ｈｅ比值,反映ＯＩＢ地幔中（Ｕ+Ｔｈ）／３Ｈｅ比值相对较低,这有可能表明下地幔比
The location of the hot spots on the global scale and the constant drift rates of volcanoes corresponding to the subsurface flow show that they originate in the depths of the mantle. The 3He / 4He ratio of oceanic basalts (OIBs) is higher than the 3He / 4He ratio of mid-ocean ridge basalts (MO_RBs), indicating that the ratio of U + Th / 3He in the OIB mantle is relatively low, which may indicate that the lower mantle ratio