Response to Owen, H.G. (2014), discussion on “Aldiss, D.T., Under-representation of faults on geological maps of the London region: reasons, consequences and solutions” [Proc. Geol. Assoc. 124 (2013) 929–945]

I thank Dr. Owen for his comments on my paper (Aldiss, 2013) and for his useful exploration of several aspects of the tectonic development of the London region. I am especially grateful for him drawing attention to his evidence for Quaternary faulting of the Gault in the south London area, and to several other pertinent and useful papers, notably Lake's (1975) discussion of the tectonics of the Weald and those by Owen, 1971 and Owen, 2012. However, I feel that his remarks mainly concern topics that are beyond the scope of my paper. My paper was not about the ‘distribution of current faults in the London region’, as much as being about the current understanding of the distribution of faults in the London region. I was not attempting to demonstrate that the London region has, in reality, been tectonically inactive nor that no faults have been recognized in the area – only that faulting is greatly under-represented on the local geological maps. In introducing this topic briefly, it appears that I have perhaps described the tectonic development of the region in an over-simplified manner. Also, it would have been useful to emphasize the distinction, within the term ‘tectonic activity’, between regional crustal uplift and subsidence (which may or may not be accompanied by faulting, and which is not directly relevant to the main subject of the paper) and fault displacement, either vertical or lateral. However, my principal point remains the same: few faults are shown on geological maps of the London area and this is both a consequence of and a contributory cause of a perception that the London Platform is an area of long-term relative crustal stability, compared with the Weald Basin