Circular features in the Trans-Mexican Volcanic Belt

One hundred and ninety-one circular or elliptical features have been locate d on Landsat imagery of the Trans-Mexican Volcanic Belt (TMVB). The origin of most of these features is unknown. Nine have been recognized as collapse calderas (clearly visible on Landsat imagery) and studied in detail, while an equally small number have been tentatively identified as such but not t horoughly investigated. On the basis of the identification of at least five of the nine calderas through their detection on Landsat images, it is prop osed that the present inventory is a reliable base to extend the census of the TMVB confirmed calderas, now clearly too small for a population of roug hly 8000 volcanic centers, many of which emitted large volumes of felsic py roclastic products. (C) 2001 Elsevier Science B.V. All rights reserved.