Diagenetic Model of Carbonate Rocks of Guri Member of Mishan Formation (Lower to Middle Miocene) SE Zagros Basin, Iran

Abstract

In order to understand the post-depositional history of carbonate rocks of Guri Member (Lower to Middle Miocene), three stratigraphic sections were selected in north Bandar-Abbas in southeast of Iran. Sampling was carried out, analyzed for selective parameters such as oxygen and carbon isotopic compositions (δ18O and δ13C) and interpreted in the present study. We recognized several diagenetic processes including micritization, cementation, neomorphism, compaction, dissolution, silicification, dolomitization, fracturing and vein filling. Some of the diagenetic processes occurred at different conditions, so in order to achieve precise interpretation, samples from different carbonate components such as, micrite, fracture cement, solution pore cement, intergranular cement, and some biotic allochems were analyzed. In this study micrite samples were subdivided into two groups including micro-spary and micrite. They were recognized under Cathodoluminescence microscope. In addition, micrite samples were classified into five groups based on their depositional environments: supratidal, lagoon, coral bar, open sea, and open basin. There were minor changes in stable isotope ratios based on the sedimentary environments, stratigraphy successions, and micro-spary or micrite properties. In this study, similar calcite cements in petrography studies were differentiated by stable isotope data. Those calcite cements have formed in different diagenetic environments such as meteoric and burial cements. Paragenetic sequence of carbonate rocks were interpreted by integration of petrographic and isotopic studies. We have reconstructed diagenetic models of Guri Member into four stages including marine, meteoric, burial, and uplifting.

Facies analysis and sequence stratigraphy of the Middle Miocene Marmarica Formation at Siwa area, north Western Desert, Egypt

“…The micrite matrix (less than 4 μm) is locally or even totally replaced by microspar (crystal sizes between 4 and 10 μm) and pseudospar (10–50 μm) (Javanbakht et al, 2018; Tucker, 2001). This process takes place mainly in meteoric phreatic environments (Budd & Haitt, 1993; Choquette & James, 1987; Haeri‐Ardakani, Al‐Aasm, Coniglio, Samson, & Pope, 2013; Heidari et al, 2014). In the present work, aggrading neomorphism of the micrite matrix into microspar is recorded in some microfacies (Figure 7h).…”

Microfacies and diagenetic overprints in the limestones of Middle Jurassic Fort Member (Jaisalmer Formation), Western Rajasthan, India: Implications for the depositional environment, cyclicity, and reservoir quality

“…However, sometime participated in other diagenetic environments such as meteoric and burial diagenesis (Ahmad et al, 2006). Syntaxial overgrowth on the echinoderm fragments (syntaxial rim cement) observed in the studied samples (Figure 6(f)), which was stained by Alizarin Red‐S solution and suggested an early marine cementation (Flügel, 1982; McGill & Walker, 1982), was formed in the meteoric phreatic diagenetic environment (Heidari et al, 2014; Li, Goldstein, & Franseen, 2017).…”

“…This type neomorphism is well developed in the micritic matrix, whereas coarse blocky calcite usually ensues in the centre and decreases towards the edges (Khalifa, Kumon, & Yoshida, 2009; Melim, Westphal, Swart, Eberli, & Munnecke, 2002). This process reflects the effect of meteoric water phreatic environment (Choquette & James, 1987; Heidari et al, 2014; Kiefer‐Ollier, Loisy, & Cerepi, 2010; Shaaban, 2004).…”

New reports of decapod Portunus monspeliensis A. Milne Edwards, 1860 from Miocene beds of eastern Slovenia with notes on palaeoecology and palaeobiogeography

“…Further fossil species of Portunus were present either eastward in the Indo-Pacific waters or westward in the Caribbean waters. Different species of Portunus have so far been reported in Miocene outcrops in Iran (Glaessner, 1928;heiDari et al, 2012;yazDi et al, 2013), India (ralte et al, 2009tiwari & veGa, 2014), Pakistan and Burma (satsanGi & PariDa, 1980), Malaysia (collins et al, 2003), Indonesia (van straelen, 1924), Taiwan (hu, 1984), andFiji (rathBun, 1945). The genus was first recorded in Japan only from strata that date to the Pliocene period (Karasawa & noBuhara, 2008).…”