伊拉克巴比伦大学 Al-Owaidi, Mohanad R. A. 的研究小组使用稀土元素地球化学的方法，对阿拉伯半岛东部和伊拉克西部地区晚中新世—更新世碎屑沉积物的物源和沉积环境进行了研究。该项研究成果发表在2023年12月9日出版的《地球化学学报》上。

研究表明，砂岩中的稀土元素(REE)和微量元素(Sc、Co、V、Th)含量显示它们可能源于单一地层。砂岩中轻稀土元素(LREE)曲线斜率较陡、重稀土元素(HREE)较平、Eu 元素负异常、高 ΣREE 值都表明其来源于被动大陆边缘环境，源于长英质烃源岩。ΣREE 的平均浓度为 93.5 ppm，低于上陆壳和后太古宙澳大利亚页岩等地壳成分的平均浓度。

轻稀土元素比例高于重稀土元素的现象说明这些砂岩是从远源再循环而来。Th/Co、Th/Sc、La/Sc、La/Co、Eu/Eu* 和 (La/Lu)cn 元素比值表明，晚中新世—更新世砂岩来源于阿拉伯地体边缘的长英质岩。

据研究人员介绍，他们对 Najaf 至 Karbala 高原晚中新世—更新世 Dibdibba 组的砂岩进行了探测，以确定其源岩和物源。

附：英文原文

Title: Provenance and depositional setting of the Late Miocene- Pleistocene clastic sediments in the eastern Arabian Peninsula and western Iraq using rare earth elements geochemistry

Author: Awadh, Salih M., Al-Ankaz, Zinah S., Al-Owaidi, Mohanad R. A., Armstrong-Altrin, John S.

Issue&Volume: 2023-12-09

Abstract: The sandstones of the Late miocene–Pliocene Dibdibba Formation in the Najaf–Karbala Plateau and Basra were examined to determine their source rocks and origin. The rare earth elements (REE) and trace elements (Sc, Co, V, and Th) concentrations in these sandstones revealed that they likely derived from a single source. The steep light rare earth elements (LREE) and flat, heavy rare earth element (HREE) patterns, negative Eu anomaly, and high ΣREE contents in sandstones suggest its derivation from a suggests that a passive continental margin environment and originated from felsic source rocks. The average concentration of ΣREE is 93.5 ppm, which is lower than that of the average crustal compositions like Upper Continental Crust and Post Archean Australian Shale. The higher proportion of LREE compared to HREE implies that these sandstones were recycled and derived from a distal source. The Th/Co, Th/Sc, La/Sc, La/Co, Eu/Eu* and (La/Lu)cn elemental ratios indicated that these Late Miocene–Pliocene sandstones were derived from felsic rocks located in the marginal region of the Arabian Shield.

DOI: 10.1007/s11631-023-00658-y

Source: https://link.springer.com/article/10.1007/s11631-023-00658-y