Biologically-initiated rock crust on sandstone: Mechanical and hydraulic properties and resistance to erosion

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F17%3A00475873" target="_blank" >RIV/67985831:_____/17:00475873 - isvavai.cz</a>

Alternative codes found

RIV/67985891:_____/17:00475873 RIV/00216208:11310/17:10363676

Result on the web

<a href="http://dx.doi.org/10.1016/j.geomorph.2016.09.040" target="_blank" >http://dx.doi.org/10.1016/j.geomorph.2016.09.040</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.geomorph.2016.09.040" target="_blank" >10.1016/j.geomorph.2016.09.040</a>

Result language

angličtina

Original language name

Biologically-initiated rock crust on sandstone: Mechanical and hydraulic properties and resistance to erosion

Original language description

Biocolonization on sandstone surfaces is known to play an important role in rock disintegration, yet it sometimes also aids in the protection of the underlying materials from rapid erosion. There have been few studies comparing the mechanical and/or hydraulic properties of the BIRC (Biologically-Initiated Rock Crust) with its subsurface. As a result, the overall effects of the BIRC are not yet well understood. The objective of the present study was to briefly characterize the BIRC, and especially to quantify the effect of the BIRC upon the mechanical and hydraulic properties of friable sandstone. The mineralogical investigation of a well-developed BIRC showed that its surface is enriched in kaolinite and clay-to silt-sized quartz particles. Total organic carbon increases with the age of the BIRC. The BIRC is formed by various fungi, including components of lichens and green algae. Using the method of drilling resistance, by measuring tensile strength, and based on water jet testing, it was determined that a BIRC is up to 12 times less erodible and has 3-35 times higher tensile strength than the subsurface friable sandstone. Saturated hydraulic conductivity of the studied BIRC is 15-300 times lower than the subsurface, and was measured to also decrease in capillary water absorption (2-33 times). The BIRC thus forms a hardened surface which protects the underlying material from rain and flowing water erosion, and considerably modifies the sandstone's hydraulic properties. It was shown that a major contribution to the surface hardening is provided by organic matter. In firmer sandstones, the BIRC may still considerably decrease the rate of weathering, as it is capable of providing cohesion to strongly weathered sandstone surfaces. However, only a near-surface zone of the sandstone is stabilized by the BIRC, and additional sources of stabilization contribute to the resistance of the subsurface zone of sandstone exposures.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10505 - Geology

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Geomorphology

ISSN

0169-555X

e-ISSN

—

Volume of the periodical

278

Issue of the periodical within the volume

FEB 1

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

16

Pages from-to

298-313

UT code for WoS article

000392555000022

EID of the result in the Scopus database

2-s2.0-85002637762