Ali-Bik Mohamed W, Zafar Tehseen, Hassan Safaa M, Sadek Mohamed F, Abo Khashaba Saif M
Geological Sciences Department, Advanced Materials Technology and Mineral Resources Research Institute, National Research Centre (NRC), Cairo, Egypt.
Geosciences Department, College of Science, United Arab Emirates University, Al Ain, 15551, United Arab Emirates.
Sci Rep. 2025 Mar 25;15(1):10192. doi: 10.1038/s41598-025-91963-4.
Major Pan-African basement rock units are exposed at South Sinai, documenting a protracted geologic history from Late Mesoproterozoic to Late Neoproterozoic and forming the northeastern part of the Arabian-Nubian Shield (ANS). They form non-consanguineous diverse metamorphic and igneous rock units, which are frequently distributed throughout the entire ANS. The current study is focused on the Saint Katherine area, around Wadi Solaf-Wadi Harqus. Automatic lithological mapping has been carried out using Support Vector Machine (SVM), and Random Forest (RF) machine learning algorithms applied to hyperspectral PRISMA data with an overall accuracy (OA) of up to 91.41% and 86.64%, respectively. Six spectral signature characteristics of the widely exposed different rock units and their alteration minerals have been identified using the Halo Mineral Identifier Spectrometer Device (ASD). Six hyperspectral PRISMA hydrothermal alteration mineral indices, such as phyllic, carbonate/chlorite/epidote, clay minerals, kaolinite, ferrous silicates, and hydroxyl group, have been detected, highlighting the proposed zones for future mineral exploration in the study area. Post-collision calc-alkaline granitoids are the predominant rock varieties, represented by two magmatic series separated by NNE-SSW and NNW-SSE striking calc-alkaline dyke swarms of varied compositions (basalt, basaltic andesite, andesite, and rhyolite). The first series is dominated by granodiorite and biotite monzogranite, which is supposed to have evolved from the same magma mainly by plagioclase fractionation. The second granitic series is extremely evolved syenogranite and alkali feldspar granite. Petrography and mineral chemistry of the essential mineralogical constituents of granitoids impose constraints on their mutual relationships and evolution.
主要的泛非基底岩石单元出露于南西奈,记录了从中元古代晚期到新元古代晚期漫长的地质历史,构成了阿拉伯-努比亚地盾(ANS)的东北部。它们形成了非同源的多样变质岩和火成岩单元,广泛分布于整个ANS。当前的研究聚焦于圣凯瑟琳地区,索拉夫干河-哈库斯干河周边。利用支持向量机(SVM)和随机森林(RF)机器学习算法对高光谱PRISMA数据进行了自动岩性制图,总体精度(OA)分别高达91.41%和86.64%。使用Halo矿物识别光谱仪设备(ASD)识别了广泛出露的不同岩石单元及其蚀变矿物的六种光谱特征。检测到了六种高光谱PRISMA热液蚀变矿物指数,如叶理状、碳酸盐/绿泥石/绿帘石、粘土矿物、高岭石、亚铁硅酸盐和羟基,突出了研究区域未来矿产勘探的建议区域。碰撞后钙碱性花岗岩类是主要的岩石类型,由两个岩浆系列代表,这两个系列被北北东-南南西和北北西-南南东走向的不同成分(玄武岩、玄武安山岩、安山岩和流纹岩)的钙碱性岩脉群分隔。第一个系列以花岗闪长岩和黑云母二长花岗岩为主,推测主要通过斜长石分离作用从同一岩浆演化而来。第二个花岗岩系列是高度演化的正长花岗岩和碱性长石花岗岩。花岗岩类主要矿物成分的岩相学和矿物化学对它们的相互关系和演化施加了限制。