S. Lin, D. Jiang & P. F. Williams write: Transpression and transtension are common geological processes that have been the focus of many recent studies. The international conference on 'Continental Transpressional and Transtensional Tectonics' held in London, England in March 1997 and the Geological Society, London, Special Publication No. 135 with the same title, arising from the conference, are both very timely. We commend the conveners and editors (R. E. Holdsworth, J. F. Dewey & R. A. Strachan) for the success of both the conference and the Special Publication. We presented a paper at the conference, which is included in the Special Publication (Lin et al. 1998), discussing oblique transpression/transtension (in the sense that the relative displacement across the zone has a dip-slip component) and the resultant general triclinic kinematics within such zone. The Special Publication contains two additional papers not presented at the conference (Dewey et al. 1998; Jones & Holdsworth 1998), which include discussion of triclinic kinematics. We welcome these additions since they provide an opportunity to discuss further triclinic kinematics, which we believe is probably common in nature and important in understanding fabric development (Lin et al. 1998; Jiang & Williams 1998).
The paper by Dewey et al. 1998 is concerned with many fundamental aspects of transpression and transtension that we consider to be important for future studies. The paper includes a summary of monoclinic transpression/transtension theory and some statements derived from modelling of triclinic transpression/transtension. Unfortunately, it is not always clear which statements apply to