The Quaternary calcareous tufas precipitated in the Kurkur Oasis area in the southern Western Desert of Egypt were analyzed to determine their implications for the construction of environmental conditions during their formation. X-ray diffraction analysis showed that the tufas consist of low-Mg calcite, whereas macroscopic and microscopic analyses showed the presence of both allochthonous (clastic) and autochthonous components consisting predominantly of pisoliths, oncoids, intraclasts, lithoclasts, stromatolites and encrusted plant materials. These tufas form four facies associations that represent pisolitic intraclastic/lithoclastic oncoidal rudstones, phytohermal /bryophyte framestones, stromatolite-algal boundstones, and speleothem-like flowstones. These tufa associations were formed within a karstified carbonate terrain by a rainwater-fed paleospring system comprising waterfalls, slopes, dammed areas, lacustrines-paludal, and fluvial channel margin environments. Early diagenetic features are cementation, neomorphism and subaerial dissolution. Isotope-geochemical analysis indicated that the negative δ¹⁸O values (between – 13.26 and – 8.89‰ V-PDB) and the negative δ¹³C values (between – 3.16 and – 1.62‰ V-PDB) of the studied tufas are consistent with carbonates deposited from meteoric water in regions with much precipitation.

分析了埃及西部沙漠南部库尔库尔绿洲地区沉淀的第四纪钙质凝灰岩，以确定它们在形成过程中对环境条件建设的影响。X 射线衍射分析表明，凝灰岩由低镁方解石组成，而宏观和微观分析表明存在外来（碎屑）和本土成分，主要由 pisoliths、oncoids、intraclasts、岩石碎屑、叠层石和结壳植物材料组成。这些凝灰岩形成了四种相组合，分别代表了紫苏质内碎屑/岩屑碎屑类陆生陆心石、植物热/苔藓植物框架石、叠层石-藻类边界石和类似洞穴的流石。这些凝灰岩协会是在喀斯特碳酸盐岩地形内由雨水供给的古泉系统形成的，该系统包括瀑布、斜坡、坝区、湖泊-paludal 和河流通道边缘环境。早期成岩特征为胶结作用、新形态作用和陆下溶蚀作用。同位素地球化学分析表明，负 δ^{所研究的凝灰岩的18} O 值（在 – 13.26 和 – 8.89‰ V-PDB 之间）和负的 δ ¹³ C 值（在 – 3.16 和 – 1.62‰ V-PDB 之间）与大气水沉积的碳酸盐相一致。沉淀。