Porosity changes induced by salt weathering of sandstones, Bohemian Cretaceous Basin, Czech Republic

0359012 - GLÚ 2012 RIV CZ eng J - Journal Article
Adamovič, Jiří - Mikuláš, Radek - Schweigstillová, Jana - Böhmová, Vlasta
Porosity changes induced by salt weathering of sandstones, Bohemian Cretaceous Basin, Czech Republic.
Acta geodynamica et geomaterialia. Roč. 8, č. 1 (2011), s. 29-45. ISSN 1214-9705. E-ISSN 2336-4351
R&D Projects: GA AV ČR IAA300130806
Institutional research plan: CEZ:AV0Z30130516; CEZ:AV0Z30460519
Keywords : porosity * sandstone * rock crust * salt weathering * case hardening * honeycombs
Subject RIV: DB - Geology ; Mineralogy
Impact factor: 0.530, year: 2011
https://www.irsm.cas.cz/materialy/acta_content/2011_01/3_Adamovic.pdf

Pore parameters of weathered and non-weathered sandstones were determined using mercury intrusion porosimetry. Two types of rock crusts were distinguished on morphological basis: 1. patterned rock crusts with a variety of weathering forms (honeycombs, wandkarren), and 2. armoured rock crusts with a relatively smooth, hardened layer. Patterned rock crusts show an increase in the size of macropores relative to unweathered sandstone, which implies an increase in total effective porosity. This is explained by the subflorescent growth of salt crystals. Armoured rock crusts on fine-grained sandstone show a reduced volume and size of macropores, as these are filled with clay mineral aggregates and gypsum crystals. Insufficient passability of macropores in the armoured layer for pore waters shifts the evaporation front deeper into the rock. This results in contour scaling as the main process of rock-surface degradation, as opposed to granular disintegration on patterned rock crusts.
Permanent Link: http://hdl.handle.net/11104/0196891