This paper reports on the elemental geochemistry of 47 shale samples from the uppermost Hirnantian–lowermost Rhuddanian Tanezzuft Formation, collected from drill core (depth interval 20.8–73.2 m) from borehole JA-2 at the eastern Kufra Basin, SE Libya. Eighteen of these samples were also analysed by X-ray diffraction. This study was carried out (i) to search for shales with high total organic carbon (TOC >3 wt%) and associated high uranium (U > 30 ppm) concentrations, commonly referred to as ‘hot’ shales, (ii) to test whether TOC and U correlate, (iii) to study the effects of surface weathering on the behaviour and mobility of major oxides, trace elements and rare earth elements (REE), and (iv) to examine the relationship of the elemental composition obtained in this study and Rock-Eval pyrolysis and kerogen data obtained in previous studies on the same core samples. The studied core can be divided into three intervals: upper weathered section (20.8–46.5 m, influenced by Quaternary weathering), unweathered section (46.5–68.5 m), and lower weathered section (68.5–73.9 m, influenced by latest Ordovician weathering). Overall, the shales have low TOC values (<1 wt%) and low U concentrations (<12 ppm). TOC and U do not show any correlation likely due to their low values. Hence, ‘hot’ shale has not yet been proven in this part of the Kufra Basin. Trace elements such as Mn and Sc show significant changes from the weathered into the unweathered core section. In contrast, the majority of the major oxides, trace elements and REE seem to be unaffected or at least largely unaffected by weathering processes. The exception is the transition from the unweathered section into the lower weathered section of the core. Here, most of the major oxides, trace elements and REE show either abrupt or gradual shifts towards lower or higher element concentrations. The observed whole-rock geochemical (e.g., K₂O, Rb, Sr, Th/K) and mineralogical (e.g., kaolinite/illite, K-feldspar/quartz) changes suggest either a switch from one source area to another or, more likely, climatic influence. The deepest part of the core may have been influenced by a more humid and warm climate that has led to intensive chemical weathering and dissolution of K-feldspar. During the latest Hirnantian–earliest Rhuddanian a temporary emersion event may have occurred due to post-glacial rebound, which has led to the weathering of older strata.

本文报告了从位于利比亚东南部 Kufra 盆地东部的钻孔JA-2 的钻孔岩心（深度间隔 20.8-73.2 m）收集的 47 个页岩样品的元素地球化学，这些样品来自最上部的 Hirnantian-最下部的 Rhuddanian Tanezzuft 组。这些样品中的 18 个也通过 X 射线衍射进行了分析。进行这项研究的目的是 (i) 寻找具有高总有机碳 (TOC > 3 wt%) 和相关高铀 (U > 30 ppm) 浓度的页岩，通常称为“热”页岩，(ii) 测试TOC 和 U 是否相关，(iii) 研究表面风化对主要氧化物、微量元素和稀土元素的行为和迁移率的影响(REE) 和 (iv) 检查本研究中获得的元素组成与先前研究中对相同岩心样品获得的Rock-Eval 热解和干酪根数据之间的关系。研究的岩心可分为三个区间：上风化段（20.8-46.5 m，受第四纪风化影响）、未风化段（46.5-68.5 m）和下风化段（68.5-73.9 m，受奥陶系最新风化影响） . 总体而言，页岩的 TOC 值较低（<1 wt%）和 U 浓度较低（<12 ppm）。TOC 和 U 可能由于其低值而没有显示任何相关性。因此，“热”页岩尚未在库夫拉盆地的这一部分得到证实。微量元素，如锰和Sc 显示了从风化到未风化核心部分的显着变化。相比之下，大多数主要氧化物、微量元素和 REE 似乎不受或至少基本上不受风化过程的影响。例外是从未风化部分到核心的较低风化部分的过渡。在这里，大多数主要氧化物、微量元素和 REE 显示出向更低或更高元素浓度的突然或逐渐变化。观测到的全岩地球化学（如 K ₂O、Rb、Sr, Th/K) 和矿物学（例如，高岭石/伊利石、钾长石/石英）的变化表明从一个源区切换到另一个源区，或者更有可能是气候影响。岩心的最深处可能受到了更加潮湿和温暖的气候的影响，这导致了钾长石的强烈化学风化和溶解。在最新的 Hirnantian - 最早的 Rhuddanian 期间，由于冰川后回弹可能发生了暂时的再现事件，这导致了旧地层的风化。