Abstract
Despite the recent upsurge in rock coast research, many aspects of abrasion and their relationships to other processes remain poorly understood. In this paper, mechanisms subsumed under the general term abrasion were investigated at the beaches of Oia and Sartaña along the Galician coast of NW Spain, in particular at the micro- to meso-scale (mm–cm). Relationships between abrasion and mechanical rock strength served to explore feedbacks between weathering and abrasion on rock coasts, based on measurements of rock surface strength by means of the Equotip (Proceq) method, and stereomicroscope analyses of rock surfaces undergoing varying degrees of abrasion. The results suggest that (1) abrasion along near-vertical rock surfaces leads to a decrease in rock strength with elevation above the top of the basal sediment layer, (2) abrasion processes encompass two different modes, namely, the wave-induced sweeping and dragging of sand and gravel, and the projection of clasts against rock surfaces, each mode depending predominantly on the grain size of the abrasive agent, and (3) the two abrasion modes produce different rock surfaces whose roughness is strongly influenced by the properties of diverse minerals, in particular fracture and cleavage.
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References
Aagaard T, Masselink G (1999) The surf zone. In: Short AD (ed) Handbook of beach and shoreface morphodynamics. Wiley, Chichester, pp 72–118
Aoki H, Matsukura Y (2007) A new technique for non-destructive field measurement of rock-surface strength: an application of the Equotip hardness tester to weathering studies. Earth Surf Proc Land 32:1759–1769
Aoki H, Matsukura Y (2008) Estimating the unconfined compressive strength of intact rocks from Equotip hardness. Bull Eng Geol Environ 67:23–29
Blanco-Chao R, Costa-Casais M, Martínez-Cortizas A, Pérez Alberti A, Trenhaile AS (2003) Evolution and inheritance of a rock coast: western Galicia, northwestern Spain. Earth Surf Proc Land 28:757–775
Blanco-Chao R, Pérez-Alberti A, Valcárcel-Díaz M, Costa-Casais M (2006a) Alteración y abrasión en plataformas litorales: Canal Beagle (Argentina) y costa NW de la Península Ibérica. In: Pérez Alberti A, López Bedoya J (eds) Geomorfología y territorio. Servicio de Publicacións da USC, Santiago, pp 323–336
Blanco-Chao R, Pérez Alberti A, Costa-Casais M, Valcárcel Díaz M (2006b) Abrasion processes in coarse-clastic beaches linked to rock shore platforms. In: Alonso I, Cooper JAG (eds) Coastal geomorphology in Spain. Proc 3rd Spanish Conf Coastal Geomorphology, Las Palmas, Gran Canaria. J Coast Res SI 48:21–28
Blanco-Chao R, Pérez-Alberti A, Trenhaile AS, Costa-Casais M, Valcárcel-Díaz M (2007) Shore platform abrasion in a para-periglacial environment, Galicia, northwestern Spain. Geomorphology 83:136–151
Blott SJ, Pye K (2001) GRADISTAT: a grain size distribution and statistics package for the analysis of unconsolidated sediments. Earth Surf Proc Land 26:1237–1248
Bluck BJ (1967) Sedimentation of beach gravels: examples from South Wales. J Sediment Petrol 37:128–156
Dasgupta R (2011) Whither shore platforms? Progr Phys Geogr 35(2):183–209
Feal-Pérez A, Blanco-Chao R, Valcárcel-Díaz M (2009) Influencia de formas y procesos heredados en la evolución reciente y en los procesos morfodinámicos actuales en un sector de costa rocosa: Punta Gallín, costa cantábrica gallega. Rev Soc Geol España 22:67–78
Folk RL, Ward WC (1957) Brazos River bar: a study in the significance of grain size parameters. J Sediment Petrol 27:3–26
Foote Y, Plessis E, Robinson DA, Hénaff A, Costa S (2006) Rates and patterns of downwearing of chalk shore platforms of the Channel: comparisons between France and England. Z Geomorphol Suppl 144:93–115
Hack HRGK, Hingira J, Verwaal W (1993) Determination of discontinuity wall strength by Equotip and Ball rebound tests. Int J Rock Mech Min Sci 30:151–155
Kanyaya JI, Trenhaile AS (2005) Tidal wetting and drying on shore platforms: an experimental assessment. Geomorphology 70:129–146
Masselink G, Li L (2001) The role of swash infiltration in determining the beachface gradient: a numerical study. Mar Geol 176:139–156
McCarroll D, Nestje A (1996) Rock surface roughness as an indicator of degree of rock surface weathering. Earth Surf Proc Land 21:963–977
Meulenkamp F, Grima MA (1999) Application of neural networks for the prediction of the unconfined compressive strength (UCS) from Equotip hardness. Int J Rock Mech Min Sci 36:29–39
Mol L, Viles HA (2010) Geoelectric investigations into sandstone moisture regimes: implications for rock weathering and the deterioration of San Rock Art in the Golden Gate Reserve, South Africa. Geomorphology 118:280–287
Mol L, Villes HA (2012) The role of rock surface hardness and internal moisture in tafoni development in sandstone. Earth Surf Proc Land 37(3):301–314
Moses C, Robinson D (2011) Chalk coast dynamics: implications for understanding rock coast evolution. Earth Sci Rev 109(3/4):63–73
Naylor LA, Stephenson WJ, Trenhaile AS (2010) Rock coast geomorphology: recent advances and future research directions. Geomorphology 114:3–11
Naylor LA, Coombes MA, Viles HA (2012) Reconceptualising the role of organisms in the erosion of rock coasts: a new model. Geomorphology 157(158):17–30
Porter NJ, Trenhaile AS, Prestanski KJ, Kanyaya JI (2010a) Shore platform downwearing in eastern Canada: the mega-tidal Bay of Fundy. Geomorphology 118:1–12
Porter NJ, Trenhaile AS, Prestanski KJ, Kanyaya JI (2010b) Shore platform downwearing in eastern Canada: micro-tidal Gaspé, Québec. Geomorphology 116:77–86
Robinson LA (1977) Marine erosive processes at the cliff foot. Mar Geol 23:257–271
Stephenson WJ (2000) Shore platforms: a neglected coastal feature? Progr Phys Geogr 24:311–327
Stephenson WJ, Kirk RM (1996) Measuring erosion rates using the micro-erosion meter: 20 years of data from shore platforms, Kaikoura Peninsula, South Island, New Zealand. Mar Geol 131:209–218
Stephenson WJ, Kirk RM (1998) Rates and patterns of erosion on shore platforms, Kaikoura Peninsula, South Island, New Zealand. Earth Surf Proc Land 23:1071–1085
Stephenson WJ, Kirk RM, Kennedy DM, Finlayson BL, Chen Z (2012) Long term shore platform surface lowering rates: revisiting Gill and Lang after 32 years. Mar Geol 299(302):90–95
Sunamura T (1992) The geomorphology of rock coasts. Wiley, Chichester
Swantesson JOH, Gómez-Pujol L, Cruslock EM, Fornós JJ, Balaguer P (2006) Processes and patterns of erosion and downwearing on micro-tidal rock coasts in Sweden and the Western Mediterranean. Z Geomorphol Suppl 144:137–160
Trenhaile AS (1987) The geomorphology of rock coasts. Oxford University Press, Oxford
Trenhaile AS (1997) Coastal dynamics and landforms. Oxford University Press, Oxford
Trenhaile AS (2000) Modeling the development of wave-cut shore platforms. Mar Geol 166:163–178
Trenhaile AS (2012) Cliffs and rock shores. In: Flemming BW, Hansom JD (eds) Estuarine and coastal geology and geomorphology. Treatise on Estuarine and Coastal Science, vol 3. Elsevier, Amsterdam, pp 171–191
Trenhaile AS, Lakhan VC (2011) Transverse micro-erosion meter measurements; determining minimum sample size. Geomorphology 134(3/4):431–439
Verwaal W, Mulder A (1993) Estimating rock strength with the Equotip Hardness Tester. Int J Rock Mech Min Geomech Sci 30:659–662
Viles HA, Goudie AS, Grab S, Lalley J (2010) The use of the Schmidt Hammer and Equotip for rock hardness assessment in geomorphology and heritage science: a comparative analysis. Earth Surf Proc Land 36:320–333
Wakasa S, Matsuzaki H, Tanaka Y, Matsukura Y (2006) Estimation of episodic exfoliation rates of rock sheets on a granite dome in Korea from cosmogenic nuclide analysis. Earth Surf Proc Land 31:1246–1256
Williams AT, Caldwell NE (1988) Particle size and shape in pebble-beach sedimentation. Mar Geol 82:199–215
Williams RBG, Swantesson JOH, Robinson DA (2000) Measuring rates of surface downwearing and mapping microtopography: the use of micro-erosion meters and laser scanners in rock weathering studies. Z Geomorphol Suppl 120:51–66
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The authors gratefully acknowledge constructive assessments by A.S. Trenhaile and an anonymous reviewer.
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Feal-Pérez, A., Blanco-Chao, R. Characterization of abrasion surfaces in rock shore environments of NW Spain. Geo-Mar Lett 33, 173–181 (2013). https://doi.org/10.1007/s00367-012-0300-4
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DOI: https://doi.org/10.1007/s00367-012-0300-4