Twidale, C.Vidal Romani, J.2006-06-192006-06-192004Geodinamica Acta, 2004; 17(2):107-1230985-31111778-3593http://hdl.handle.net/2440/1789The identification and extent of etch surfaces depends primarily on the preservation of regolithic remnants and the coincidence in level of weathering front and surface. The occurrence of bornhardts, corestone boulders, flared slopes, basins, gutters and pitting on covered weathering fronts demonstrates that they can be initiated in the subsurface, and where they are preserved on exposed surfaces, particularly in assemblages of such features, they constitute sound evidence of an etch origin. In some instances the location of the front and hence of the related etch surface is determined by subtle variations in degree of weathering. There is some suggestion that the front advances episodically rather than continuously. © 2004 Taylor & Francis Group, LLC.enJournal article002004089710.3166/ga.17.107-1230002234817000012-s2.0-434466432656701