Depth distribution and chemistry of salts as factors controlling tafoni and honeycombs development

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F22%3A00560573" target="_blank" >RIV/67985831:_____/22:00560573 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11310/22:10449782

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0169555X22002677" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0169555X22002677</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.geomorph.2022.108374" target="_blank" >10.1016/j.geomorph.2022.108374</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Depth distribution and chemistry of salts as factors controlling tafoni and honeycombs development

Popis výsledku v původním jazyce

Salts play a pivotal role in the processes forming tafoni and honeycombs but only few studies have focused on their areal and depth distribution. An X-ray diffraction, rock leachates chemistry, and evaporation front depth were combined to get a deeper insight into factors controlling salt composition and distribution. Five sites representing various lithological and/or climate conditions were studied. The data show that salt composition is a result of the interaction between chemical compositions of rainwater and lithology. Gypsum was found to be a major salt on all sites with halite dominating in arid sites. On humid sites the high relative air humidity prevents its precipitation. Gypsum and epsomite dominate also on sites where the rock contains a considerable amount of pyrite. Alum-(K) occurs in quartz sandstones when affected by acid rain. Some ions probably occur in residual brines, rather than precipitated salts (Ca–Cl in arid or Na–Cl in humid sites). On arid sites, the salt content in the tafoni backwalls is 4–20 times higher than in outer walls and rapidly decreases with depth which is consistent with shallow evaporation front in backwalls. The low salt content in the outer walls reflects the dilution effect of surface runoff after rains and the infiltration of water through the outer walls toward depth. In two humid sites, on the contrary, no differences were found between the salt content of the backwalls and the outer walls. At one site the data shows that the whole surface of tafoni serves as the salt precipitation zone and tafoni are thus recently degrading. The honeycomb site differs from all tafoni sites since the honeycombs are mostly protected from rain runoff, which prevents the washing-out of salts even from the outer walls.

Název v anglickém jazyce

Depth distribution and chemistry of salts as factors controlling tafoni and honeycombs development

Popis výsledku anglicky

Salts play a pivotal role in the processes forming tafoni and honeycombs but only few studies have focused on their areal and depth distribution. An X-ray diffraction, rock leachates chemistry, and evaporation front depth were combined to get a deeper insight into factors controlling salt composition and distribution. Five sites representing various lithological and/or climate conditions were studied. The data show that salt composition is a result of the interaction between chemical compositions of rainwater and lithology. Gypsum was found to be a major salt on all sites with halite dominating in arid sites. On humid sites the high relative air humidity prevents its precipitation. Gypsum and epsomite dominate also on sites where the rock contains a considerable amount of pyrite. Alum-(K) occurs in quartz sandstones when affected by acid rain. Some ions probably occur in residual brines, rather than precipitated salts (Ca–Cl in arid or Na–Cl in humid sites). On arid sites, the salt content in the tafoni backwalls is 4–20 times higher than in outer walls and rapidly decreases with depth which is consistent with shallow evaporation front in backwalls. The low salt content in the outer walls reflects the dilution effect of surface runoff after rains and the infiltration of water through the outer walls toward depth. In two humid sites, on the contrary, no differences were found between the salt content of the backwalls and the outer walls. At one site the data shows that the whole surface of tafoni serves as the salt precipitation zone and tafoni are thus recently degrading. The honeycomb site differs from all tafoni sites since the honeycombs are mostly protected from rain runoff, which prevents the washing-out of salts even from the outer walls.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GA19-14082S" target="_blank" >GA19-14082S: Napětím a hydraulickým polem řízené zvětrání a eroze granulárních hornin</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

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

Název periodika

Geomorphology

ISSN

0169-555X

e-ISSN

1872-695X

Svazek periodika

414

Číslo periodika v rámci svazku

October

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

16

Strana od-do

108374

Kód UT WoS článku

000864865200001

EID výsledku v databázi Scopus

2-s2.0-85135139661