The authenticity of much of the stone-work along Queen’s Lane in central Oxford, UK presented an opportunity to produce a photographic survey from which a weathering index could be established. This represents a site-specific approach to devising a weathering form. Because it is photo-based, weathering forms are visible for comparison and classification purposes across disciplines. Limestone pertaining to building ashlar and plinths along this roadway, which mainly belong to Queen’s College, St Edmund Hall, New College, and Hertford College, was classified according to this newly introduced weathering index, the size-extent (S-E) index, through consideration of type, size, extent, impact, and trigger. This size- (range) and extent-based classification system enables for the assessment of weathering forms of various types, including soiling and decay features as well as those potentially expected in the presence of vegetation and animals. Weathering forms of a range of sizes were present, with a slightly greater abundance of small types (mm-cm in the micro- to mesoscale) and more discrete types with a low extent. For this location in central Oxford, chemical weathering was found to be the predominant type of soiling and decay.
References
[1]
Fitzner, B.; Heinrichs, K.; La Bouchardiere, D. Limestone Weathering of Historical Monuments in Cairo, Egypt. In Natural Stone, Weathering Phenomena, Conservation Strategies and Case Studies; Siegesmund, S., Vollbrecht, A., Weiss, T., Eds.; Geological Society: London, UK, 2002; pp. 217–239. Geological Society Special Publication No. 205.
[2]
Rothert, E.; Eggers, T.; Cassar, J.; Ruedrich, J.; Fitzner, B.; Biegesmund, S. Stone Properties and Weathering Induced by Salt Crystallization of Maltese Globigerina Limestone. In Building Stone Decay from Diagnosis to Conservation; P？ikryl, R., Smith, B.J., Eds.; Geological Society: London, UK, 2007; pp. 189–198. Geological Society Special Publication No. 271.
[3]
Cassar, J.; Vella, A.J. Methodology to Identify badly weathering limestone using geochemistry: case study on the lower Globigerina limestone of the Maltese Islands. Q. J. Eng. Geol. Hydrogeol. 2003, 36, 85–96, doi:10.1144/1470-923602-007.
[4]
Warke, P.A.; Curran, J.M.; Turkington, A.V.; Smith, B.J. Condition assessment for building stone conservation: A staging system approach. Build. Environ. 2003, 38, 1113–1123, doi:10.1016/S0360-1323(03)00085-4.
[5]
T？r？k, á. Oolitic Limestone in a Polluted Atmospheric Environment in Budapest: Weathering Phenomena and Alterations in Physical Properties. In Natural Stone, Weathering Phenomena, Conservation Strategies and Case Studies; Siegesmund, S., Vollbrecht, A., Weiss, T., Eds.; Geological Society: London, UK, 2002; pp. 363–379. Geological Society Special Publication No. 205.
[6]
T？r？k, á.; Siegesmund, S.; Müller, C.; Hüppers, A.; Hoppert, M.; Weiss, T. Differences in Texture, Physical Properties and Microbiology of Weathering Crust and Host Rock: A Case of the Porous Limestone of Budapest (Hungary). In Building Stone Decay from Diagnosis to Conservation; P？ikryl, R., Smith, B.J., Eds.; Geological Society: London, UK, 2007; pp. 261–276. Geological Society Special Publication No. 271.
[7]
T？r？k, á. Hungarian Travertine: Weathering Forms and Durability. In Proceedings of the International Conference on Heritage, Weathering and Conservation; Fort, R., álvarez de Buergo, M., Gómez-Heras, M., Vázquez-Calvo, C., Eds.; A.A. Balkema Publishers: London, UK, 2006; 1, pp. 199–204.
[8]
Forgó, L.Z.; Vogt, T.; L？bens, S.; Siegesmund, S.; Weiss, T. The Influence of Lithology and Pore-Size Distribution on the Durability of Acid Volcanic Tuffs, Hungary. In Building Stone Decay from Diagnosis to Conservation; P？ikryl, R., Smith, B.J., Eds.; Geological Society: London, UK, 2007; pp. 251–260. Geological Society Special Publication No. 271.
[9]
Akin, M.; Ozsan, A. Rock mass weathering and weathering classification for Eskipazar Yellow Travertines. Jeoloji Muhendisligi Dergisi 2010, 34(2), 113–132.
[10]
Sousa, L.; del Rio, L.M.; Calleja, L.; de Argando？a, V.G.; Rodríguez Rey, A.R. Influence of microfactures and porosity on the physico-mechanical properties and weathering of ornamental granites. Eng. Geol. 2005, 77(1–2), 153–168, doi:10.1016/j.enggeo.2004.10.001.
[11]
Dagdelenier, G.; Sezer, E.A.; Gokceoglu, C. Some non-linear models to predict the weathering degrees of a granitic rock from physical and mechanical parameters. Expert Syst. Appl. 2011, 38(6), 7476–7485.
[12]
Deere, D.; Merritt, A.H.; Coon, R.F. Engineering Classification of In-SituRock; Technical Report AFWL-TR-67-144; US Air Force Systems Command, Air Force Weapons Laboratory: Washington, DC, USA, 1969.
[13]
Moh’d, B.K.; Howarth, R.J.; Bland, C.H. Rapid prediction of building research establishment limestone durability class from porosity and saturation. Q. J. Eng. Geol. 1996, 29(4), 285–297, doi:10.1144/GSL.QJEGH.1996.029.P4.03.
[14]
Fookes, P.G.; Hawkins, A.B. Limestone weathering: Its engineering significance and a proposed classification scheme. Q. J. Eng. Geol. 1988, 21(1), 7–31, doi:10.1144/GSL.QJEG.1988.021.01.02.
[15]
Figueiredo, C.A.M.; Aires-Barros, L.; Basto, M.J.; Gra？a, R.C.; Maurício, A. The Weathering and Weatherability of Basílica da Estrela Stones, Lisbon, Portugal. In Building Stone Decay from Diagnosis to Conservation; P？ikryl, R., Smith, B.J., Eds.; Geological Society: London, UK, 2007; pp. 99–107. Geological Society Special Publication No. 271.
[16]
Mottershead, D.N.; Baily, B.; Collier, P.; Inkpen, R.J. Identification and quantification of weathering by plant roots. Build. Environ. 2003, 38, 1235–1241, doi:10.1016/S0360-1323(03)00080-5.
[17]
Inkpen, R.J.; Collier, P.; Fontana, D. Close-range photogrammetric analysis of rock surfaces. recent advances in field and laboratory studies of rock weathering. Z. Geomorphol. Supp. 2000, 120, 67–81.
[18]
Campbell, I.A. Classification of rock weathering at writing-on-stone provincial park, Alberta, Canada: A study in applied geomorphology. Earth Surf. Proc. Land. 1991, 16(8), 701–711, doi:10.1002/esp.3290160804.
[19]
McIlroy de la Rosa, J.P.; Warke, P.A.; Smith, B.J. Microscale biopitting by the endolithic lichen Verrucaria baldensis and its proposed role in mesoscale solution basin development on limestone. Earth Surf. Process. Landf. 2012, 37, 374–384, doi:10.1002/esp.2244.
Thornbush, M.J. Building Decay. In Oxford Companion to Global Change; Cuff, D., Goudie, A., Eds.; Oxford University Press: New York, USA, 2009; pp. 85–86.
[22]
Thornbush, M.J.; Viles, H.A. Surface Soiling Pattern Detected by Integrated Digital Photography and Image Processing of Exposed Limestone in Oxford, England. In Air Pollution and Cultural Heritage; Saiz-Jimenez, C., Ed.; A.A. Balkema Publishers: London, UK, 2004; pp. 221–224.
[23]
Thornbush, M.J.; Viles, H.A. Photo-Based Decay Mapping of Replaced Stone Blocks on the Boundary Wall of Worcester College, Oxford. In Building Stone Decay: From Diagnosis to Conservation; P？ikryl, R., Smith, B.J., Eds.; Geological Society: London, UK, 2007; pp. 69–75. Special Publications No. 271.
[24]
Thornbush, M.J.; Viles, H.A. Photographic monitoring of soiling and decay of roadside walls in Oxford, England. Environ. Geol. 2008, 56(3-4), 777–787, doi:10.1007/s00254-008-1311-3.
[25]
Thornbush, M.J. Photographic surveys of building exteriors in central Oxford, UK. Int. J. Archit. Herit. 2010, 4(4), 351–369, doi:10.1080/15583050903131355.
[26]
ICOMOS-ISCS: Illustrated Glossary on Stone Deterioration Patterns; International Council on Monuments and Sites, International Scientific Committee for Stone: Paris, Franch, 2008; pp. 1–86.
[27]
Smith, B.J.; T？r？k, A.; McAlister, J.J.; Megarry, Y. Observations on the factors influencing stability of building stones following contour scaling: A case study of Oolitic limestones from Budapest, Hungary. Build. Environ. 2003, 38, 1173–1183, doi:10.1016/S0360-1323(03)00076-3.
[28]
Smith, B.J.; Srinivasan, S.; Gomez-Heras, M.; Basheer, P.A.M.; Viles, H.A. Near-surface temperature cycling of stone and its implications for scales of surface deterioration. Geomorphology 2011, 130, 76–82, doi:10.1016/j.geomorph.2010.10.005.
[29]
Thornbush, M.; Viles, H. Integrated digital photography and image processing for the quantification of colouration on soiled surfaces in Oxford, England. J. Cult. Herit. 2004, 5(3), 285–290, doi:10.1016/j.culher.2003.10.004.
[30]
Thornbush, M.J. Measurements of Soiling and Colour Change Using Outdoor Rephotography and Image Processing in Adobe Photoshop along the Southern Fa？ade of the Ashmolean Museum, Oxford. In Limestone in the Built Environment: Present-Day Challenges for the Preservation of the Past; Smith, B.J., Gomez-Heras, M., Viles, H.A., Cassar, J., Eds.; Geological Society: London, UK, 2010; pp. 231–236. Special Publications No. 331.
[31]
Thornbush, M.J. Digital photography used to quantify the greening of north-facing walls along Broad Street in central Oxford, UK. Géomorphologie 2013. in press.
[32]
Sweeting, M.M.; Lancaster, N. Solutional and wind erosion forms on limestone in the central Namib Desert. Z. Geomorphol. 1982, 26(2), 197–207.
[33]
T？r？k, á.; Licha, T.; Simon, K.; Siegesmund, S. Urban and rural limestone weathering; The contribution of dust to black crust formation. Environ. Earth. Sci. 2011, 63(4), 675–693, doi:10.1007/s12665-010-0737-6.
[34]
Thornbush, M.J.; Viles, H.A. Use of Portable X-Ray Fluorescence for Monitoring Elemental Concentrations in Surface Units on Roadside Stone at Worcester College, Oxford. In Proceedings of the International Conference on Heritage, Weathering and Conservation; Fort, R., álvarez de Buergo, M., Gómez-Heras, M., Vázquez-Calvo, C., Eds.; A.A. Balkema Publishers: London, 2006; pp. 613–619.
