Recycling of depleted continental mantle by subduction and plumes at the Hikurangi Plateau large igneous province, southwestern Pacific Ocean
Recycling of depleted continental mantle by subduction and plumes at the Hikurangi Plateau large igneous province, southwestern Pacific Ocean
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西南太平洋希库朗伊高原大型火成岩省俯冲和地幔柱对贫化大陆地幔的再循环
作者：
Mochizuki K.;Sutherland R.;Henrys S.;Bassett D.;Van Avendonk H.;Arai R.;Kodaira S.;Fujie G.;Yamamoto Y.;Bangs N.;Barker D.
希库兰吉高原(西南太平洋)的地震反射和折射数据要求地壳厚度为10±1公里，地壳底部的地震速度为7.2 5±0.35公里/S，莫霍面下的地幔速度为8.3 0±0.2 5公里/S。已发表的假设正常地壳和地幔密度的重力数据模型预测的地壳厚度比我们观察到的厚5-10公里，这表明Hikurangi高原之下的地幔密度异常低，这与之前解释高地震速度观测到的榴辉岩的建议不一致。高地震速度和低密度的结合要求地幔高度亏损，而不是蛇纹岩。我们认为，Hikurangi高原是由浮地幔减压熔融形成的，浮地幔通过俯冲从克拉通根部移出，通过粘性耦合作用保持在660公里以下，然后作为羽状物从下地幔升起。新西兰南岛附近地幔包体的古老Re-Os年龄支持这一假说。通过俯冲侵蚀克拉通根部的浮力亏损地幔，然后在羽流中循环形成新的岩石圈，可能是一个重要的全球地球化学过程。
Seismic reflection and refraction data from Hikurangi Plateau (southwestern Pacific Ocean) require a crustal thickness of 10 ± 1 km, seismic velocity of 7.25 ± 0.35 km/s at the base of the crust, and mantle velocity of 8.30 ± 0.25 km/s just beneath the Moho. Published models of gravity data that assume normal crust and mantle density predict 5–10-km-thicker crust than we observe, suggesting that the mantle beneath Hikurangi Plateau has anomalously low density, which is inconsistent with previous suggestions of eclogite to explain observations of high seismic velocity. The combination of high seismic velocity and low density requires the mantle to be highly depleted and not serpentinized. We propose that Hikurangi Plateau formed by decompression melting of buoyant mantle that was removed from a craton root by subduction, held beneath 660 km by viscous coupling to slabs, and then rose as a plume from the lower mantle. Ancient Re-Os ages from mantle xenoliths in nearby South Island, New Zealand, support this hypothesis. Erosion of buoyant depleted mantle from craton roots by subduction and then recycling in plumes to make new lithosphere may be an important global geochemical process.
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影响因子：
5
作者：
Hoernle, Kaj;Hauff, Folkmar;Davy, Bryan
通讯作者：
Davy, Bryan
影响因子：
5.3
作者：
Ingle, S;Coffin, MF
通讯作者：
Coffin, MF
DOI：
10.1080/00288306.1979.10424223
发表时间：
1979
期刊：
影响因子：
--
作者：
A. Haines
通讯作者：
A. Haines
新西兰北岛东南部的上地幔 P 波速度
DOI：
10.1016/0040-1951(84)90105-7
发表时间：
1984
期刊：
影响因子：
--
作者：
J. Kayal;Euan Smith
通讯作者：
Euan Smith
新西兰东部飞马盆地：古代和现代沉降和俯冲的地层记录
影响因子：
2.2
作者：
K. J. Bland;C. Uruski;M. Isaac
通讯作者：
M. Isaac