Porosity and pore and throat size distributions in carbonate-rich salt caprock of halite diapirs: effect of deformation and geochemical processes

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F25%3A00638138" target="_blank" >RIV/67985530:_____/25:00638138 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11310/25:10499473

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0191814125001580?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0191814125001580?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jsg.2025.105483" target="_blank" >10.1016/j.jsg.2025.105483</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Porosity and pore and throat size distributions in carbonate-rich salt caprock of halite diapirs: effect of deformation and geochemical processes

Popis výsledku v původním jazyce

Microscopic porosity of salt caprock on two salt diapirs, Karmostaj and Siah Taq in southern Iran, was studied on a range of samples that represent the major lithological types of salt caprock in the area: the gypsum matrix-supported and clast-supported dissolution breccia, the dolomite and limestone stringers of the Hormuz Formation and gypsum mylonites. Mercury intrusion porosimetry alongside the microstructural analysis with digital image analysis of resin-saturated thin-sections was employed and revealed a large variation in porosity of 2-35 % and in the median throat size of 0.1-50 mu m. The highest porosity values are associated with vuggy dolomites and limestones interspersed by a dense network of gypsum veins and gypsum matrix-supported breccia with low degree of deformation. In contrast, low porosity is linked with strongly deformed gypsum matrix-supported breccias and dark micritic carbonate stringers that were not interspersed with the gypsum. Large variation in porosity and pore throat size and pore shape is attributed to 1) metasomatization of carbonate to gypsum due to reaction of H2SO4 with carbonate after oxidation of H2S or elemental sulfur in caprock and subsequent dissolution of gypsum in metasomatized carbonates creating the abundant vuggy porosity and 2) deformation of the caprock that was responsible for recrystallization and mechanical closure of pores in the frontal, downslope margins of both reactivated diapirs. While the deformed and gypsum-rich parts of the diapir caprocks (similar to 30-60 % of caprock on the diapirs) are associated with estimated permeabilities of similar to 10(-1)(6) 10(-1)(5) m(2), caprocks in central parts of reactivated diapirs with less deformed caprock (undeformed gypsum- and clast-supported breccia) display higher permeabilities ranging between similar to 10(-15) m(2) and 10(-13) m(2).

Název v anglickém jazyce

Porosity and pore and throat size distributions in carbonate-rich salt caprock of halite diapirs: effect of deformation and geochemical processes

Popis výsledku anglicky

Microscopic porosity of salt caprock on two salt diapirs, Karmostaj and Siah Taq in southern Iran, was studied on a range of samples that represent the major lithological types of salt caprock in the area: the gypsum matrix-supported and clast-supported dissolution breccia, the dolomite and limestone stringers of the Hormuz Formation and gypsum mylonites. Mercury intrusion porosimetry alongside the microstructural analysis with digital image analysis of resin-saturated thin-sections was employed and revealed a large variation in porosity of 2-35 % and in the median throat size of 0.1-50 mu m. The highest porosity values are associated with vuggy dolomites and limestones interspersed by a dense network of gypsum veins and gypsum matrix-supported breccia with low degree of deformation. In contrast, low porosity is linked with strongly deformed gypsum matrix-supported breccias and dark micritic carbonate stringers that were not interspersed with the gypsum. Large variation in porosity and pore throat size and pore shape is attributed to 1) metasomatization of carbonate to gypsum due to reaction of H2SO4 with carbonate after oxidation of H2S or elemental sulfur in caprock and subsequent dissolution of gypsum in metasomatized carbonates creating the abundant vuggy porosity and 2) deformation of the caprock that was responsible for recrystallization and mechanical closure of pores in the frontal, downslope margins of both reactivated diapirs. While the deformed and gypsum-rich parts of the diapir caprocks (similar to 30-60 % of caprock on the diapirs) are associated with estimated permeabilities of similar to 10(-1)(6) 10(-1)(5) m(2), caprocks in central parts of reactivated diapirs with less deformed caprock (undeformed gypsum- and clast-supported breccia) display higher permeabilities ranging between similar to 10(-15) m(2) and 10(-13) m(2).

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

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

Název periodika

Journal of Structural Geology

ISSN

0191-8141

e-ISSN

1873-1201

Svazek periodika

199

Číslo periodika v rámci svazku

Oct.

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

18

Strana od-do

105483

Kód UT WoS článku

001528134300001

EID výsledku v databázi Scopus

2-s2.0-105009502589