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晚中新世以来,内华达山脉年轻熔岩中橄榄岩捕虏体的温压与Ｏｓ同位素资料显示其岩石圈地幔是垂向分层的:浅层岩石圈地幔(＜４５~６０ ｋｍ)温度较低(６７０~７４０℃),有被加热的特征,其锇模式年龄为元古代;而深层岩石圈地幔(４５~１００ｋｍ)具显生宙的锇模式年龄,并且有从大于１１００℃剧烈冷却到７５０℃的特征。因为大量的同位素证据证明内华达岩基形成于先存的元古代岩石圈之上,所以大部分原先的岩石圈地幔可能在晚中新世之前被移离,从而在地壳之下仅剩下一薄层古老的地幔。
Since the Late Miocene, the temperature and pressure of the magmatic olivary xenoliths in the young lava of the Sierra Nevada show that the lithospheric mantle is vertically stratified: shallow lithospheric mantle (<45-60 km) (670-740 ° C) and has the characteristics of being heated. The osmium model age is Proterozoic; while the deep lithospheric mantle (45-100 km) has the age of the Phanerozoic Osmium pattern and there is intense cooling from above 1100 ℃ to 750 ℃ features. Most of the original lithospheric mantle may have been removed before the Late Miocene due to the large amount of isotopic evidence that Nevada was formed on the pre-existing Proterozoic lithosphere, leaving only a thin layer below the crust Layer of ancient mantle.