Weathering of sandstone lotus petals at the Angkor site: a 1,000-year stone durability trial

Abstract

International audienc

Contrasting weathering and climate regimes in forested and cleared sandstone temples of the Angkor region

“…Beyond the Cambodian case study, it would be of interest to assess the effects of forest clearance at other similar sites such as Mayan temples in Yucatan. This Mesoamerican region displays not only a range of climate conditions (from dry to humid), but also a variety of limestone types, and the severity of damage provoked by forest clearance is known to be modulated by stone properties (André et al, 2011).…”

“…At Ta Keo, where mechanical weathering is dominant, solution and oxidation also operate, as shown by the presence of salt efflorescences and the superficial colour change of the stone material from grey to yellow (Uchida et al ., ; André, ; Hosono et al ., ). The rusty iron oxidation of the Ta Keo grey sandstone was also observed at Baphuon temple, and is similar to the blackish manganic oxidation that has appeared at the pink sandstone surface since the forest clearance around Banteay Srei, 25 km from Angkor (Hyvert, , ; André et al ., ). Concerning the salts such as gypsum, they are generally considered as an additional but not necessary factor controlling sandstone decay, which is basically driven by wetting–drying cycles, with or without salts (e.g.…”

“…These micaceous arkosic sandstones, which are the dominant building stone used in the area, have been shown to be highly susceptible to mechanical stress induced by diurnal wetting–drying cycles (Siedel et al ., ), in contrast to the green and pink sandstones also represented in the Angkor region (e.g. Saurin, ; Delvert, ; Uchida et al ., ; Reucher et al ., ; André et al ., ).…”

Influence of microclimate on the directional dependence of sandstone pillar weathering in Angkor Wat temple, Cambodia

“…Several weathering processes are present for sandstone weathering at Angkor (e.g., Uchida et al 1999;Waragai 2002Waragai , 2005aArchaeological survey of India 2006;Hosono et al 2006;André et al 2008André et al , 2011Siedel et al 2008Siedel et al , 2010. However, there are very few discussions regarding the directional dependence of these processes (e.g., Waragai 2005bWaragai , 2016Waragai et al 2006;Hiki and Waragai 2014).…”

“…In terms of natural deterioration, sandstone and laterite building materials rapidly deteriorate under tropical climates. Although chemical weathering is a major process in the tropics, as well as biochemical weathering (e.g., Liu et al 2018), other forms of mechanical rock weathering such as wet-dry weathering (e.g., Waragai 2002Waragai , 2005aSiedel et al 2010;André et al 2011), salt weathering (e.g., Uchida et al 1999;Hosono et al 2006;André et al 2008;Siedel et al 2008Siedel et al , 2010, and root wedging processes (Archaeological survey of India 2006) are also significant. For instance, Waragai (2002Waragai ( , 2005a suggested that, at the Angkor Wat temple, deterioration occurs because the sandstone blocks contain clay minerals, which are constantly exposed to severe cycles of wet-dry weathering.…”