RT Journal Article
T1 Surface temperature differences between minerals in crystalline rocks: Implications for granular disaggregation of granites through thermal fatigue
A1 Gómez Heras, Miguel
A1 Smith, Bernard J.
A1 Fort, Rafael
AB Thermal expansion differences between minerals within rocks under insolation have previously been assumed to drive breakdown by means of granular disaggregation. However, there have been no definitive demonstrations of the efficacy of this weathering mechanism. Different surface temperatures between minerals should magnify thermal expansion differences, and thus subject adjacent minerals to repeated stresses that might cause breakdown through fatigue failure. This work confirms the existence of surface temperature differences between minerals in granitic rocks under simulated short-term temperature fluctuations so as to discriminate their potential for initiating granular disaggregation. The influence of colour, as a surrogate for albedo, and crystal size, as a function of thermal mass are specifically identified because of their ease of quantification. Four rock types with a range of these properties were examined, and subjected to repeated short-term temperature cycles by radiative heating and cooling under laboratory conditions. Results show that while albedo is the main control for overall and individual maximum temperatures, crystal size is the main factor controlling higher temperature differences between minerals. Thus, stones with large differences of mineral sizes can undergo magnified stresses due to thermal expansion differences.
PB International Geosynthetics Society (IGS)
SN 0169-555X
YR 2006
FD 2006
LK https://hdl.handle.net/20.500.14352/118671
UL https://hdl.handle.net/20.500.14352/118671
LA eng
NO Gómez-Heras, Miguel, et al. «Surface Temperature Differences between Minerals in Crystalline Rocks: Implications for Granular Disaggregation of Granites through Thermal Fatigue». Geomorphology, vol. 78, n.o 3-4, agosto de 2006, pp. 236-49. DOI.org (Crossref), https://doi.org/10.1016/j.geomorph.2005.12.013.
DS Docta Complutense
RD 10 abr 2025