Effects of volcanic loading on regional compressive structures: new insights from natural examples and analogue modelling.

We present natural examples and experimental models of volcanic cones locat ed above brittle substratum undergoing regional compressive deformation. Th e volcanic loading induces a strain partitioning involving deflection and f lattening of regional compressive structures. The main control is the topog raphic load. Anticlinal thrust ridges, observed around many volcanoes, have generally been interpreted as being due to gravitational spreading; howeve r, this study shows that this is not necessarily the case, as they can also be a symptom of regional compression. (C) 2001 Academie des sciences / Edi tions scientifiques et medicales Elsevier SAS.