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华北克拉通破坏的时间一直是地质学家们争论的焦点问题之一.鲁西铁铜沟岩体中纯橄岩捕虏体的锆石SHRIMPU-Pb定年结果对此给出了制约.结果显示,4个纯橄岩样品的18颗锆石阴极发光图像中,15颗呈条痕状吸收,2颗具岩浆环带特点,结合它们的Th(49～3569μg/g,平均值为885μg/g),U(184～5398μg/g,平均值为1277μg/g)含量和Th/U比值(0.15～2.04),暗示岩浆成因特征.岩浆锆石的206Pb/238U表面年龄分成5组:131～145,151～164,261～280,434～452和500～516Ma.131～145Ma年龄与寄主岩浆(铁铜沟岩体)的形成时代相一致;151～164Ma年龄对应于华北克拉通东部中-晚侏罗世少量幔源岩浆和主体的酸性岩浆事件;261～280Ma年龄与峨眉山大火成岩省的时代相类似;434～452Ma年龄与华北克拉通东部古生代时期富硅质岩浆的时代相一致;500～516Ma年龄可能是全球泛非事件在华北克拉通东部的响应.华北克拉通东部岩石圈地幔经历了多期次不同程度熔体的改造,其中以中生代晚期(131～164Ma)的改造最为强烈.
The time of destruction of North China craton has been one of the focal points of debate among geologists. The zircon SHRIMPU-Pb dating results of the dunite xenolith in the Luxi West Tectonic Station give some constraints on the results. , Of the 18 zircons in 4 samples of dunou samples, 15 were streak-like and 2 were characterized by magmatic zonation. Th (49-3569 μg / g, average 885 μg / g ), U (184-5998 μg / g, average 1277 μg / g) and Th / U ratio (0.15-2.04), suggesting that the 206Pb / 238U surface ages of magmatic zircons are divided into five groups: 131-145,151 ~ 164,261 ~ 280,434 ~ 452 and 500 ~ 516Ma. The age of 131 ~ 145Ma is consistent with the formation age of the host magma (Tietonggou pluton). The age of 151 ~ 164 Ma corresponds to the middle-late Jurassic mantle source in the eastern part of North China craton Magma and the main acidic magmatic event; 261 ~ 280Ma age and Emeishan large igneous province similar to the era; 434 ~ 452Ma age and the North China Craton eastern Paleozoic enriched magmatic age consistent; 500 ~ 516Ma age may be global pan Response of Non-Incidents to Eastern China Craton, North China The mantle underwent several stages of melt alteration, of which the transformation was the most intense in the late Mesozoic (131 ~ 164Ma).