The question of whether oroclines form by orogen-parallel buckling or orogen-perpendicular bending is a matter of debate. To address this problem, we conducted two-dimensional numerical models that investigate differences in the characteristics of oroclines caused by buckling, bending or a combination thereof. Our models consider a simple setup of a viscous layer embedded in a less viscous matrix and subjected to buckling and bending conditions. Models were run with varied layer thicknesses and viscosity contrasts. We applied a spectrum of deformation regimes, with pure buckling and pure bending as end members. Buckling models produced significant layer compression in inner fold hinges, whereas bending models produced widespread extension. Fold geometry also differed between buckling and bending models, as observed through relationships in fold amplitude, fold width, layer thickness, and interlimb angles. A comparison of the numerical results with three real-world examples (Kazakhstan, Gibraltar and Cantabrian oroclines) reveals significant similarities in geometrical features (particularly for the Kazakhstan and Gibraltar oroclines), and some discrepancies. The models show that geometric relationships, such as amplitude-width, thickness-width, thickening, and interlimb angles, provide limited information on the deformation. However, the distribution of stress across the fold hinge and limbs is a primary factor that might be used to understand whether oroclines formed by buckling or bending.

是否通过造山带平行屈曲或造山带垂直弯曲形成斜球的问题尚有争议。为了解决这个问题，我们进行了二维数值模型，研究了由弯曲，弯曲或其组合引起的斜齿特性的差异。我们的模型考虑了将粘性层嵌入粘性较低的矩阵中并经受屈曲和弯曲条件的简单设置。在变化的层厚度和粘度对比下运行模型。我们应用了一系列变形方式，并以纯屈曲和纯弯曲作为端部构件。屈曲模型在内部折叠铰链中产生了显着的层压缩，而弯曲模型则产生了广泛的延伸。弯曲和弯曲模型之间的折叠几何形状也有所不同，通过对折幅度，对折宽度，层厚度和中间夹角的关系观察到。将数值结果与三个实际示例（哈萨克斯坦，直布罗陀和坎塔布连斜交线）进行比较后，发现几何特征（尤其是哈萨克斯坦和直布罗陀的斜交线）在几何特征上具有显着相似性，并且存在一些差异。这些模型表明，几何关系（例如幅度-宽度，厚度-宽度，加厚和中间角度）提供了有关变形的有限信息。但是，应力在折页铰链和四肢上的分布是一个主要因素，可以用来了解折线是通过屈曲还是弯曲形成的。直布罗陀和坎塔布连斜交线显示出几何特征上的显着相似性（尤其是哈萨克斯坦和直布罗陀交织斜线），并且存在一些差异。这些模型表明，几何关系（例如幅度-宽度，厚度-宽度，加厚和中间角度）提供了有关变形的有限信息。但是，应力在折页铰链和四肢上的分布是一个主要因素，可以用来了解折线是通过屈曲还是弯曲形成的。直布罗陀和坎塔布连斜交线显示出几何特征上的显着相似性（尤其是哈萨克斯坦和直布罗陀交织斜线），并且存在一些差异。这些模型表明，几何关系（例如幅度-宽度，厚度-宽度，加厚和中间角度）提供了有关变形的有限信息。但是，应力在折页铰链和四肢上的分布是一个主要因素，可以用来了解折线是通过屈曲还是弯曲形成的。