张广才岭福兴屯组的形成时代、物源及构造背景

前人对张广才岭福兴屯组研究程度较低，限制了对区域古生代构造演化的认识.福兴屯组凝灰岩锆石30个测点加权平均年龄为392±3 Ma，砂岩碎屑锆石最小一组年龄为393 Ma，指示福兴屯组形成于中泥盆世.Al₂O₃/TiO₂平均值为19.58，稀土元素球粒陨石标准化曲线具有轻稀土富集、重稀土稳定和负Eu异常特征，结合碎屑锆石年龄峰值，确定福兴屯组物源主要为晚古生代中酸性火成岩和早古生代花岗质岩.地球化学和区域火山岩特征共同揭示福兴屯组形成于伸展构造环境.松嫩-张广才岭地块和佳木斯地块晚古生代早期地层均广泛分布有489~551 Ma的碎屑锆石，暗示两地块在福兴屯组沉积之前已完成拼合，为两地块于早古生代晚期拼合提供了新的证据. 

Age,Provenance and Tectonic Setting of Fuxingtun Formation in Zhangguangcai Range

Previous studies on the Fuxingtun Formation in Zhangguangcai Range are relatively inadequate, which has limited the understanding of regional Paleozoic tectonic evolution. The weighted average age of zircons from tuff of 30 test points in the Fuxingtun Formation is 392±3 Ma, and the minimum age of detrital zircons from arkose is 393 Ma, indicating that the Fuxingtun Formation was formed in the Middle Devonian. Al₂O₃/TiO₂ average value is 19.58, and chondrite-normalized REE patterns have the characteristics of enrichment in light rare earth, stability in heavy rare earth and negative Eu anomaly, which, combined with detrital zircons age populations, indicates that the provenance of the Fuxingtun Formation was mainly derived from the Late Paleozoic intermediate-acid igneous rocks and the Early Paleozoic granitic rocks. The geochemical and regional volcanic characteristics reveal that the Fuxingtun Formation was formed in extensional environment. 489-551 Ma detrital zircons are widely distributed in the Late Paleozoic early strata in Songnen-Zhangguangcai Range massif and Jiamusi massif, suggesting that the two blocks had been combined before the deposition of the Fuxingtun Formation, which provides a new evidence for the combination of the two blocks in the late Early Paleozoic.