The Mayo-Kebbi massif (Chad) exposes a Neoproterozoic juvenile crustal segment that has been tectonically accreted in the Central African Orogenic Belt and reworked during the Pan-African orogeny. It comprises a syntectonic high-K magmatic suite including the Zabili A-type granitic pluton. The Zabili pluton is made of a highly differentiated granite generated by fractional crystallization of a magma formed by partial melting of a Neoproterozoic juvenile protolith. Syn- to post-magmatic ductile to brittle deformation of the Zabili pluton is associated with metasomatism and deposition of uranium. Primary magmatic U-bearing minerals are zircon, monazite, and uranothorite. Late-magmatic deformation and Na-metasomatism are marked by the development of R’ antithetic shear zones with high-temperature dynamic recrystallization of K-feldspar and Ca-plagioclase phenocrysts coeval with crystallization of albite along deformation bands and grain boundaries, and crystallization of interstitial amphibole, calcite epidote and albite also affected by intracrystalline deformation. At this stage, U-bearing minerals are monazite, uraninite, brannerite (pseudomorphosed in ekanite). This late-magmatic event is dated by U–Th–Pb on monazite at 599 ± 4 Ma. Brittle deformation and Ca-metasomatism are marked by cataclastic zones and veins containing albite, epidote, calcite, chlorite, apatite, metamict zircon, pitchblende, U-silicates, and iron oxides. U-bearing minerals are altered and/or remobilized in ekanite, kasolite, and uranophane. These data suggest that the uranium mineralization hosted by the Zabili pluton records a superposition of processes and traces extreme crustal differentiation of a Neoproterozoic juvenile crustal segment reworked during the Pan-African orogeny.

中文翻译：

---

与泛非 A 型 Zabili 同构造岩体（Mayo-Kebbi 地块，SW Chad）的晚期岩浆延性至脆性变形和 Na-Ca 交代相关的铀矿化

Mayo-Kebbi 地块（乍得）暴露了新元古代幼年地壳段，该段在中非造山带中构造增生并在泛非造山运动期间重新加工。它包括一个同构造高 K 岩浆组，包括 Zabili A 型花岗岩岩体。Zabili 岩体由高度分化的花岗岩构成，由新元古代幼年原岩部分熔融形成的岩浆分步结晶而成。Zabili 岩体的同质至后岩浆延性至脆性变形与铀的交代和沉积有关。原生岩浆含 U 矿物是锆石、独居石和铀钛矿。晚期岩浆变形和钠交代作用的标志是 R' 对立剪切带的发展，钾长石和钙斜长石斑晶的高温动态再结晶与钠长石沿变形带和晶界结晶以及间隙结晶同时期闪石、方解石绿帘石和钠长石也受晶内变形的影响。在这个阶段，含U的矿物有独居石、铀矿、镁铝榴石（假晶石）。这个晚岩浆事件由独居石上的 U-Th-Pb 定年为 599 ± 4 Ma。脆性变形和 Ca 交代作用的标志是碎裂带和含有钠长石、绿帘石、方解石、绿泥石、磷灰石、metamict 锆石、沥青闪石、U-硅酸盐和氧化铁的矿脉。含 U 的矿物在 ekanite、kasolite、和铀。这些数据表明，由 Zabili 岩体承载的铀矿化记录了过程的叠加，并追踪了泛非造山运动期间重新加工的新元古代幼年地壳部分的极端地壳分异。