DOCUMENTATION AND SIGNIFICANCE OF TECTONIC EVENTS IN THE NORTHERN TABAS BLOCK (EAST-CENTRAL IRAN) DURING THE MIDDLE AND LATE JURASSIC

Apart from global sea-level fluctuations, the sedimentary pattern of the northern Tabas Block during the Middle and Late Jurassic was mainly governed by tectonic events of varying intensity and areal extent. These events took place during the Middle Bajocian (mid-Cimmerian tectonic phase), Early Bathonian, Late Bathonian, Early Callovian, Late Oxfordian, and Late Kimmeridgian. The importance and extent of each event and its influence on the facies pattern of the northern Tabas Block is briefly discussed and demostrated by some examples

A summary of the Jurassic System in North and East-Central Iran

The rocks of the Jurassic System in North and Central Iran are represented by very thick sedimentary successions reflecting the deposition during two tectono-stratigraphic megacycles, bounded by three important unconformities. The older (Early to early Middle Jurassic) cycle starts, after the Late Triassic closure of the Palaeotethys and the collision of the Iran Plate with the southern margin of Eurasia (Turan Plate), with an abrupt uplift of the Cimmerian Mountains around the Triassic–Jurassic boundary (Main-Cimmerian Event) and is terminated by the Mid-Cimmerian Tectonic Event in the mid-Bajocian. The predominantly siliciclastic sediments of this tectono-stratigraphic cycle are accommodated in the Ab-e-Haji Subgroup of the (upper) Shemshak Group. The Ab-e-Haji Subgroup consists of thick and widespread, partly coal-bearing siliciclastic strata and also records some important marine ingressions, especially in the Toarcian and Aalenian. The younger tectono-stratigraphic cycle starts with an extensive marine transgression in the Late Bajocian and ends around the Jurassic-Cretaceous boundary with the Late Cimmerian Tectonic Event. In the aftermath of the Mid-Cimmerian Tectonic Event, the Iran Plate was dissected into several structural units, the geological histories of which differed and so did their facies patterns. Thus, in North Iran two main sedimentary areas developed, namely the Alborz and Koppeh Dagh basins, which show moderate diffe-rences in lithology and thicknesses. However, the differentiation is much more pronounced on the Central-East Iranian Microcontinent, which comprises three N–S-oriented and independent structural units, i.e., from east to west the Lut, Tabas and Yazd blocks. During the Jurassic Period, the sea mostly covered the Tabas and Lut blocks, whereas the Yazd Block remained largely emergent. The lithologically diverse and numerous formations of the area are combined in the Magu and Bidou groups. Early to Early Middle Jurassic ammonite fau-nas of North and Central Iran are palaeobiogeographically closely related to Northwest European (Subboreal) ammonite faunas, allowing a similar biozonation. Concurrent with the Late Bajocian transgression, there is an abrupt change in faunal composition and the Middle and Late Jurassic ammonite faunas of North and Central Iran are much more similar to those of epicontinental seas bordering the nort-hern margin of the western Tethys and occupy an intermediate position between the Mediterranean and the Submediterranean Province. The results of the studies on ammonoid palaeobiogeography are in line with Early Jurassic palaeogeographic reconstructions that place the Iran Plate at fairly high palaeo-latitudes of about 45°N, followed by a rapid southward shift throughout the Middle and Late Jurassic to a position of about 30°N

SOME INOZOID SPONGES FROM UPPER TRIASSIC (NORIAN-RHAETIAN) NAYBAND FORMATION OF CENTRAL IRAN

Some small-scaled Norian-Rhaetian reefs and reef mounds are imbedded within the shales, siltstones and siliciclastic-carbonate deposits of the Nayband Formation in central Iran. These deposits belong to the central Iranian plate as part of the Cimmerian Continent. Most of the biogenic rocks have a biostromal geometry, biohermal constructions are rare. Inozoid, sphinctozoid, and chaetetid sponges are, beside of corals and other reef builders, the most important reef organisms within these bioconstructions. In some reefs a variety of hexactinellid sponges also occur. The following inozoid sponges are described in this paper: Radiofibra norica n. sp., Permocorynella maxima n. sp., ?Sestrostomella robusta, Marawandia iranica, n. gen., n. sp. and Enaulofungia? triassica n. sp. The first four taxa are among the most abundant sponges within the Nayband Formation where it is exposed in several localities in central Iran. Enaulofungia? triassica, however, is not an abundant sponge there. These inozoid sponges have never been reported from the Triassic deposits of this region. Radiofibra, until now known only from the Upper Permian of Djebel Tebaga (Tunisia), is reported here for the first time from Triassic rocks. The stratigraphic as well as the paleogeographic distribution of all the genera are discussed.  &nbsp

Thermal maturity of the Upper Triassic-Middle Jurassic Shemshak Group (Alborz Range, Northern Iran) based on organic petrography, geochemistry and basin modelling: implications for source rock evaluation and petroleum exploration.

International audienceOrganic petrography and geochemical analyses have been carried out on the shales, carbonaceous shales and coals of the Shemshak Group (Upper Triassic-Middle Jurassic) from fifteen localities along the Alborz Range of Northern Iran. Organic matter (OM) has been investigated using Rock-Eval pyrolysis, elemental analysis of kerogen, vitrinite reflectance (VRr) and Thermal Alteration Index (TAI). Reflectance of autochthonous vitrinite varies from 0.6 to 2.2 % indicating thermally early mature to over mature OM in the Shemshak Group, in agreement with other maturity parameters used. The shales of the Shemshak Group are characterized by poor to moderate residual organic carbon contents (0.25 to 8.5 %) and the presence of hydrogen-depleted OM, predominantly as a consequence of petroleum generation and of oxidation of OM. According to light-reflected microscopy results vitrinite/vitrinite-like macerals are dominant in the kerogens concentrated from the shaly facies. The coals and carbonaceous shales of the Shemshak Group show a wide range in organic carbon concentration (3.5 to 88.6 %) and composition (inertinite- and vitrinite-rich types), and thereby different petroleum potentials. Among the studied sections only the coals and carbonaceous shales of the Hive locality show good residual petroleum potential and may still generate oil. Thermal modelling results suggest that low to moderate paleo-heat flow, ranging from 47 to 79 mW.m-2 (57 mW.m-2 on average), affected the Central-Eastern Alborz. The maximum temperature which induced OM maturation of the Shemshak Group seems to be related to its deep burial rather than to a very strong heat flow related to an uppermost Triassic-Liassic rifting. The interval of petroleum generation in the most deeply buried part of the Shemshak Group (i.e., Tazareh section) corresponds to Late Jurassic-Early Cretaceous times. Exhumation of the Alborz Range during Late Neogene time, especially along the axis of the Central-Eastern Alborz, where maxima of VRr values are recorded, probably destroyed possible petroleum accumulations. However on the northern flank of the Central-Eastern Alborz, preservation of petroleum accumulations may be better. The northern part of the basin therefore seems the best target for petroleum exploration

Effect of Squill Oxymel on Knee Osteoarthritis: A Triple-Blind, Randomized, Controlled Clinical Trial

Osteoarthritis (OA) of the knee is a major health problem in the society. Iranian Traditional Medicine (ITM) or Persian Medicine (PM) as a branch of complementary medicine has been practiced in Iran for many centuries. An herbal medication known as squill oxymel has been used by PM physicians for OA. Our aim is to investigate the effect of squill oxymel on OA of the knee joint. Eighty eight patients were assigned to receive a placebo or squill oxymel syrup (10 ml each morning on empty stomach) for 8 consecutive weeks. Acetaminophen tablets were considered as the rescue medicine. Ultimately, 43 patients in the placebo group and 40 patients in the treatment group completed the trial and were included in the statistical analysis. Patients were followed for 4 weeks after cessation of treatment. The Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire and Visual Analog Scale (VAS) were considered as the main outcome measures. Laboratory tests including AST, ALT, BUN, Cr plus inflammatory tests including WBC, ESR, and CRP with specific tests i.e. IL6 and SOD at the beginning and the end of intervention were measured. The results showed the positive effect of treatment on the outcome of knee pain (p=0.04) and daily activity (p=0.01) of KOOS after Cessation of treatment. On the other hand, VAS decreased in both treatment and placebo groups while it showed significance intra-group and showed no significance between the two groups. After 4 weeks of cessation of treatment, the positive effect of the squill oxymel on the treatment group continued in some of the subscales of KOOS, including symptoms, knee pain and daily activities, but stopped in the placebo group. In general, both clinically and statistically significant improvement was observed after cessation of treatment. Squill oxymel syrup showed promising results in management of knee OA but future researches with larger sample size and longer duration are necessary

Scaphiten aus dem Oberen Alb und Cenoman der Umgebung von Esfahan (Zentral-Iran)

Volume: 17Start Page: 125End Page: 13

Leymeriella (Ammonoidea) aus dem unteren Alb von Zentraliran

Volume: 20Start Page: 17End Page: 2

Morphoceras Douvillé, 1880 and Ebrayiceras Buckman, 1920 from the Dalichai Formation (Lower Bathonian) North and Northeast of Damghan (Northeast Alborz), Iran

Several species of the genera Morphoceras Douvillé, 1880 and Ebrayiceras Buckman, 1920 are described from the Dalichai Formation of eastern Alborz Mountains (northeast Iran), including one new species, M. kelarizis. The fauna comes from a few meters of red nodular limestones and marls in “Ammonitico Rosso” facies. It represents a typical Northwest-Tethyan fauna, closely related to Central Europe (Subboreal / Submediterranean provinces).Mehrere Exemplare der Gattungen Morphoceras Douvillé, 1880 und Ebrayiceras Buckman, 1920 werden aus der Dalichai Formation m östliche Alborz Gebirge (Nordost Iran) beschrieben, darunter eine neue Art, M. kelarizis. Die Fauna stammt aus einigen Metern eines roten nodularen Kalksteins und Mergeln in “Ammonitico Rosso” Fazies; sie ist eine typische Nordwest-Tethys Fauna mit engen Beziehungen zu Zentraleuropa (subboreale / submediterrane Provinzen)

Die Kreideammoniten des Glaukonitkalkes (O. Alb - O. Cenoman) des Kolah-Qazi-Gebirges s\ufcd\uf6stlich von Esfahan (Zentraliran)

Volume: 12Start Page: 87End Page: 13