Localized zones of Roan Breccia with very large clasts, termed écaille, occur throughout the arcuate Lufilian Arc of Central Africa. The breccia zones consist of mineralized Mines Subgroup rocks with Roches Argilo-Talcqueuses (R.A.T.) at their base. Several of these areas, such as Mashitu/Tenke-Fungurume, Kamoya-Kambove and Shinkolobwe, contain significant Cu and Co resources. A new model, termed the Thrust Belt Boudinage model, ascribes their formation and mineralization to localized lateral extension of the fold-and-thrust belt as the arc flexed during its development. Roan Breccia-rich areas, termed Double Cuspate Zones (DCZs), initiated from early, major, strike-perpendicular fractures. These progressively dilating areas became sumps for detritus shed from — and pushed ahead of — advancing thrust units. Detritus entrained into the base of advancing thrust units, which adopted a pseudo-lamination, was incorporated into R.A.T. Over-riding thrust units were locally unsupported by these dilating Roan Breccia-filled DCZs, resulting in delamination of the highly fractured, pervasively veined and mineralized lower portions of the Mines Subgroup, which slumped into DCZs at various attitudes. These écaille preserve disharmonic folding, with respect to longer-wavelength Kundelungu Group folds that are evident on Lufilian Arc maps. DCZs bear a remarkable resemblance to zones of foliation boudinage, suggesting that they were low-pressure depositional sites for metal- and brine-rich fluids. The process is encapsulated in a physically-and geologically-accurate animation video. While the new model does not replace the role of halite-rich fluids transporting mineralization, it obviates the requirement for very large volumes of salt transporting écaille physically and en masse.

Roan 角砾岩的局部区域具有非常大的碎屑，称为écaille，出现在整个中非弧形 Lufilian Arc。角砾岩带由矿化的Mines亚群岩石组成，其底部有Roches Argilo-Talcqueuses (RAT)。其中几个区域，如 Mashitu/Tenke-Fungurume、Kamoya-Kambove 和 Shinkolobwe，含有大量的铜和钴资源。一种称为逆冲带布丁尼奇模型的新模型将它们的形成和矿化归因于折叠逆冲带的局部横向延伸，因为弧在其发展过程中弯曲。罗恩角砾岩丰富的区域，称为双尖峰带（DCZ），起源于早期的主要走向垂直裂缝。这些逐渐扩张的区域变成了碎屑的集水池，这些碎屑从推进的推力装置中脱落——并推向前方。夹带在推进推力单元底部的碎屑，采用假层理，并入 RAT Mines Subgroup的较低部分，以不同的姿态陷入 DCZ。这些écaille相对于 Lufilian Arc 地图上明显的较长波长的昆德伦古群褶皱，保留不和谐的褶皱。DCZ 与叶状布丁带非常相似，表明它们是富含金属和盐水流体的低压沉积场所。该过程被封装在一个物理和地质准确的动画视频中。虽然新模型并没有取代富含岩盐的流体输送矿化的作用，但它消除了对大量盐的物理和整体输送écaille的要求。