ravinementn.

1858 G. R. Burnell Rudiments Hydraulic Engin. I. 145 The second system of irrigation..is applied in hilly districts as much for the purpose of obviating any ravinement, so to speak,..as it is for the purpose of irrigation.

1921 L. D. Stamp in Geol. Mag. 58 109 A ‘ravinement’ may be defined as an irregular junction which marks a break in sedimentation... Although one of the commonest of geological phenomena, there is no English word which expresses quite so aptly the relationship.

1921 L. D. Stamp in Geol. Mag. 58 109 The period between two successive ‘ravinements’ constitutes a ‘cycle of sedimentation’.

1923 L. D. Stamp Introd. Stratigr. i. 17 When such an unconformity is traced laterally into a continuous series of marine deposits it is frequently found that..there are signs that the sea, in depositing the upper series, has slightly eroded the top of the lower series. Such an erosion line is termed a ‘ravinement’.

1969 G. M. Bennison & A. E. Wright Geol. Hist. Brit. Isles i. 8 In the field an unconformity can..be proved because the erosion surface or ravinement is conspicuous.

2001 Paleobiology 27 243/1 Deposits are only rarely preserved in such settings because of the pervasive nature of erosion associated with both sequence boundaries and transgressive ravinement surfaces.