Dolomitization and Hypogenic Dissolution of the Eocene Avanah Formation, Iraqi Kurdistan
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F25%3A73633921" target="_blank" >RIV/61989592:15310/25:73633921 - isvavai.cz</a>
Result on the web
<a href="https://aro.koyauniversity.org/index.php/aro/article/view/2333/497" target="_blank" >https://aro.koyauniversity.org/index.php/aro/article/view/2333/497</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.14500/aro.12333" target="_blank" >10.14500/aro.12333</a>
Alternative languages
Result language
angličtina
Original language name
Dolomitization and Hypogenic Dissolution of the Eocene Avanah Formation, Iraqi Kurdistan
Original language description
This study constrains the mechanism of extensive dolomitization and its impact on reservoir quality of the shallow-water marine ramp carbonates of the Avanah Formation (Eocene), Iraqi Kurdistan. The presence of shoal deposits, which semi-isolate a lagoon water body from the open marine, suggests that dolomitization was by seepage reflux of brines. Nevertheless, the absence of eogenetic gypsum/anhydrite in the dolostones succession indicates that the dolomitizing fluids were mesohaline/penesaline brines formed during cycles of relative sea level (RSL) fall. Dolomitization resulted in the formation of abundant intercrystalline and moldic/vuggy pores. Restriction of dolomitization and related reservoir quality improvement to the lower part of the formation is attributed to an overall 3rd order fall in the RSL. Conversely, the lack of dolomitization in the upper part of the formation is attributed to deposition during 3rd order marine transgression, which prevented severe restriction and evaporation of the inner ramp and, consequently, inhibited the development of dolomitizing brines. It is suggested that hypogenic dissolution (karstification) by upward flow of aggressive fluids along faults and fractures during the Zagros Orogeny caused dissolution and considerable porosity and permeability improvement of the dolostones. A greater extent of dolostones dissolution in the flanks, which was accompanied by calcite cementation, compared to the crest, reflects the role of oil emplacement in the retardation of diagenetic reactions.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - 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
Result continuities
Project
—
Continuities
N - Vyzkumna aktivita podporovana z neverejnych zdroju
Others
Publication year
2025
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
ARO-The Scientific Journal of Koya University
ISSN
2307-549X
e-ISSN
2410-9355
Volume of the periodical
13
Issue of the periodical within the volume
2
Country of publishing house
IQ - IRAQ
Number of pages
13
Pages from-to
202-214
UT code for WoS article
001589101800002
EID of the result in the Scopus database
2-s2.0-105023554417