Plutons in crustal shear zones may exploit inherited structures, interfere with strain localizing or be deformed passively. To constrain the relative timing of such tectono-magmatic relationships in natural settings is not always straight-forward. We here present sandbox-type analogue model experiments simulating magma emplacement into simple and transtensional crustal shear zones to test the diagnostic potential of pluton shape with respect to timing and setting. Observations based on surface deformation and intrusion shape exemplify the interplay between evolving and inherited tectonic structures and magma uprising. We observe markedly asymmetric intrusions in association with dikes reflecting the regional stresses, fault pattern and finite strain field. At the same time, the presence of an intrusion modifies the tectonic evolution, but only transiently, resulting in short-lived faults, reactivation and inversion. Diagnostic attributes include the pluton’s aspect ratio, its orientation and amplitude as well as dike association. Accordingly, syn-tectonic intrusions show the highest pluton amplitudes, but only intermediate elongation compared to other scenarios. They are oriented parallel to Riedel shears in simple shear, respectively to the compression direction in transtension. Post-tectonic intrusions are least elongated, have medium amplitudes and exploit Riedel shears. Pre-tectonic intrusions are characterized by lowest amplitudes but the highest aspect ratios and are parallel to the finite elongation direction. Intrusions in transtensional shear zones are generally of less elongate than those in simple shear zones. Experimental results are tested against observations from natural examples validating the diagnostic potential of pluton shape for the timing and the tectonic setting of the emplacement.

地壳剪切带中的岩体可能利用继承结构，干扰应变定位或被动变形。在自然环境中限制这种构造-岩浆关系的相对时间并不总是直截了当的。我们在这里展示了模拟岩浆侵位进入简单和横张地壳剪切带的沙箱型模拟模型实验，以测试岩体形状在时间和环境方面的诊断潜力。基于地表变形和侵入体形状的观测证明了演化和继承的构造结构与岩浆上升之间的相互作用。我们观察到与反映区域应力、断层模式和有限应变场的堤防相关的明显不对称侵入。同时，入侵的存在改变了构造演化，但只是暂时的，导致短暂的故障、重新激活和反转。诊断属性包括岩体的纵横比、方向和振幅以及岩脉关联。因此，同构造侵入显示出最高的岩体振幅，但与其他情况相比只有中等的伸长。它们在简单剪切中平行于 Riedel 剪切，在拉伸中分别平行于压缩方向。后构造侵入体伸长最少，具有中等振幅并利用里德尔剪切。前构造侵入体的特点是振幅最低但纵横比最高，并且平行于有限的伸长方向。横张剪切带中的侵入体通常比简单剪切带中的侵入体伸长小。