I. Maghfouri Moghaddam
Abstract
Sedimentary setting and paleoecology of the rudist-bearing Upper Cretaceous strata were studied in three sections in Khorram abad. The sections include: Tang Shabi Khone, Cham Sangar (Tarbur Formation) and Pir Shams Eldin (upper part of Amiran Formation). The Tang- E Shabi Khone and Chamsangar ...
Read More
Sedimentary setting and paleoecology of the rudist-bearing Upper Cretaceous strata were studied in three sections in Khorram abad. The sections include: Tang Shabi Khone, Cham Sangar (Tarbur Formation) and Pir Shams Eldin (upper part of Amiran Formation). The Tang- E Shabi Khone and Chamsangar sections are located in Zagros Trust zone while, the Pir Shams Eldin in Lorestan zone. On the basis of the recognized fossils, the three sections are assigned to the Late Cretaceous (Middle to Late Masstrichtian) and are comparable to Omphalocyclus- Loftusia Assemblage Zone. The petrography study showed that the three sections contain nine microfacies that deposited in an open marine, shoal and restricted marine that based on rudist sedimentary models, are comparable to the Inner- shelf basin prograding margin complexes (Tarbur Formation) and the low- angel open shelf margin complexes (Amiran Formation). Probably, Sepid Kuh Fault was detaching the these settings. Augmentation of entering the detrital and silica due to river injection and runoff and consequently to the eurotrophic conditions in the Tnage Shabi Khone and Pir Shams Eldin, frequency of agglutinate foraminifera were increased but in the chamsangar section due to oligotraphy condition , frequency of hyaline foraminifera is increased. Distribution of the foraminifera and algae indicated that the Tarbur Formation is deposited in a photic zone though, some parts of the carbonates of the Amiran Formation were deposited in a aphotic zone.
Stratigraphy and Palaeontology
A. Abdolnia; I. Maghfouri Moghaddam; D. Baghbani
Abstract
The Shahbazan Formation deposited in the Lorestan foreland basin and northeastern part of Dezful embayment zone during the Middle-Late Eocene age. In order to study the stratigraphy of the Shahbazan Formation, four surface sections of this formation in northeastern flank of Langar anticline, southeastern ...
Read More
The Shahbazan Formation deposited in the Lorestan foreland basin and northeastern part of Dezful embayment zone during the Middle-Late Eocene age. In order to study the stratigraphy of the Shahbazan Formation, four surface sections of this formation in northeastern flank of Langar anticline, southeastern flank of Chenareh anticline, northeastern flank of Maleh Kuh anticline and southwestern flank of Poshte-Jangal anticline, have been selected. The Shahbazan Formation in Langar and Chenareh sections is composed of limestone with intercalation of dolomite. In other parts of the Lorestan such as Maleh kuh and Poshte Jangel, it consists of dolomite and intercalations of limestons. In these areas, the Shahbazan and Asmari formations form a prominent topographic unit and separating their boundary is often difficult to place, thus making it necessary to map the two formations as one unit. In this case, the two names are hyphenated as Shahbazan- Asmari Formation. According to study of benthic foraminifera in Chenareh and Langar sections, two biozone have been distinguished. The age of the Shahbazan Formation in these areas is determined as Middle- Late Eocene (Bartonian- Priabonian). In the Maleh Kuh section, the lower part of the Shahbazan- Asmari Formations is dolomitic but in the upper part it contains limestone beds with foraminifera that belong to two assemblage zones, in Aquitanian- Burdigalian age. In the Poshte Jangal section, the lower and middle parts of Shahbazan- Asmari formations are dolomitic but the upper part contains limestone beds with rare foraminifera which have been reported at the Chattian- Burdigalian beds of the Asmari Formation.
P. Rajabi; I. M. Moghadam; F. Gharib
Abstract
In this study, the Sediments of Taleh-Zang Formation was investigated in South West of Khoramabad. The thickness of Taleh-Zang Formation in Qalebi section measured 200m. In this section the sediment of Taleh-Zang Formation is isoclines between Amiran Formation at the base, and Kashkan Formation at the ...
Read More
In this study, the Sediments of Taleh-Zang Formation was investigated in South West of Khoramabad. The thickness of Taleh-Zang Formation in Qalebi section measured 200m. In this section the sediment of Taleh-Zang Formation is isoclines between Amiran Formation at the base, and Kashkan Formation at the top. This Formation composed of gray limestone with chert nodules and Sandy Limestone. The study of samples taken from the studied section led to identification 28 genera and 4 species of benthonic Foraminifera and 6 genera and 2 species of green algae. The benthonic Foraminifera of the measured section were used to recognized the age of Succession and justify their correlation Based on the recognized Foraminifera such as Miscellanea miscella. The Qalebi section is Comparable to biozonation introduced by Wynd (1965). It is analogous to Miscellanea – Kathina assemblage zone (No# 43). According to distribution of the index Foraminifera, the age of the Sediments in Qalebi Section is Thanetian.
I. Maghfouri Moghaddam
Abstract
Rudists of the Tarbur Formation, in 7 km southwest of Semirum and 10 km north of Khorramabad, have been studied. Paleontological studies indicate that the age of the Tarbur Formation in both sections is Masstrichtian, and has a rich macrofossil fauna of rudist. The important types of rudist include Radiolites, ...
Read More
Rudists of the Tarbur Formation, in 7 km southwest of Semirum and 10 km north of Khorramabad, have been studied. Paleontological studies indicate that the age of the Tarbur Formation in both sections is Masstrichtian, and has a rich macrofossil fauna of rudist. The important types of rudist include Radiolites, Hippurites and Caprinidae. The assemblage shows a close similarity with those reported from south Turkey, Mediterranean, Saudi Arabia and Oman.
