- GeoRef, Copyright 2004, American Geological Institute. Reference includes data from Bibliography and Index of Geology Exclusive of North America, Geological Society of America, Boulder, CO, United States
"Minor folds in the Gramscatho beds at the mouth of the Helford river have two predominant trends: W.S.W.-E.N.E., and N.W.-S.E. Main folds on W.S.W.-E.N.E. axes and cross folds on N.W.-S.E. axes have sub-parallel apical planes and occur in alternate zones which trend N.E.-S.W., parallel to the strike of the cleavage. The relations between the two systems of folding suggest that they are virtually synchronous. It is concluded that the style of folding can be explained by a unidirectional regional stress acting normal to the apical planes of the folds."