scholarly journals Youngest Cretaceous dinosaur tracksite from the Middle East (Maastrichtian, Farrokhi Formation, Central Iran)

2021 ◽  
Author(s):  
Markus Wilmsen ◽  
Franz Theodor Fürsich ◽  
Mahmoud Reza Majidifard
Keyword(s):  
Middle East ◽  
Central Iran ◽  
Carbonate Sand ◽  
Fine Grained ◽  
Two Generations ◽  
Foot Morphology ◽  
Cracking Pattern

Abstract A late early Maastrichtian dinosaur trampling site is reported from the Farrokhi Formation of the Khur area, Central Iran. The largely indeterminate footprints, some of which may represent undertracks, can be classified as natural moulds (i.e. concave epireliefs) bordered by a raised rim of displaced sediment. They reach diameters of up to 0.5 m and were impressed under very shallow to subaerial conditions in an inter- to supratidal environment. Two generations of traces have been imprinted, initially into a soft, fine-grained carbonate sand and afterwards into a superficially hardened substrate that was still plastic underneath; the change in substrate consistency is supported by a conspicuous cracking pattern around the footprints. As a result, hardly any details of the foot morphology of the trackmakers are recorded. Nevertheless, the occurrence improves our knowledge about dinoturbation and its preservation in different kinds of substrates. Furthermore, it is the youngest record (ca. 70 Ma) of dinosaur locomotion traces from Iran and, in all probability, the entire Middle East.

scholarly journals Two generations of exsolution lamellae in pyroxene from Asuka 09545: Clues to the thermal evolution of silicates in mesosiderite

2019 ◽  
Vol 104 (11) ◽  
pp. 1663-1672
Author(s):  
Lidia Pittarello ◽  
Seann McKibbin ◽  
Akira Yamaguchi ◽  
Gang Ji ◽  
Dominique Schryvers ◽  
...  
Keyword(s):  
Thermal Evolution ◽  
Parent Body ◽  
Cooling History ◽  
Equilibrium Conditions ◽  
Slow Cooling ◽  
Temperature Range ◽  
Fine Grained ◽  
Two Generations ◽  
Mantle Component ◽  
The Antarctic

Abstract Mesosiderite meteorites consist of a mixture of crustal basaltic or gabbroic material and metal. Their formation process is still debated due to their unexpected combination of crust and core materials, possibly derived from the same planetesimal parent body, and lacking an intervening mantle component. Mesosiderites have experienced an extremely slow cooling rate from ca. 550 °C, as recorded in the metal (0.25–0.5 °C/Ma). Here we present a detailed investigation of exsolution features in pyroxene from the Antarctic mesosiderite Asuka (A) 09545. Geothermobarometry calculations, lattice parameters, lamellae orientation, and the presence of clinoenstatite as the host were used in an attempt to constrain the evolution of pyroxene from 1150 to 570 °C and the formation of two generations of exsolution lamellae. After pigeonite crystallization at ca. 1150 °C, the first exsolution process generated the thick augite lamellae along (100) in the temperature interval 1000–900 °C. By further cooling, a second order of exsolution lamellae formed within augite along (001), consisting of monoclinic low-Ca pyroxene, equilibrated in the temperature range 900–800 °C. The last process, occurring in the 600–500 °C temperature range, was likely the inversion of high to low pigeonite in the host crystal, lacking evidence for nucleation of orthopyroxene. The formation of two generations of exsolution lamellae, as well as of likely metastable pigeonite, suggest non-equilibrium conditions. Cooling was sufficiently slow to allow the formation of the lamellae, their preservation, and the transition from high to low pigeonite. In addition, the preservation of such fine-grained lamellae limits long-lasting, impact reheating to a peak temperature lower than 570 °C. These features, including the presence of monoclinic low-Ca pyroxene as the host, are reported in only a few mesosiderites. This suggests a possibly different origin and thermal history from most mesosiderites and that the crystallography (i.e., space group) of low-Ca pyroxene could be used as parameter to distinguish mesosiderite populations based on their cooling history.

Petroleum migration in the Miocene Monterey Formation, California, USA: constraints from fluid-inclusion studies

1990 ◽  
Vol 54 (375) ◽  
pp. 295-304 ◽  
Author(s):  
Robert J. Bodnar
Keyword(s):  
Petroleum Reservoir ◽  
Monterey Formation ◽  
Fine Grained ◽  
Geological Past ◽  
Seawater Salinity ◽  
Fluorescence Characteristics ◽  
Heating Event ◽  
Two Generations ◽  
Calcite Deposition ◽  
Petroleum Fluid

AbstractThe Miocene Monterey Formation constitutes a fracture-controlled petroleum reservoir, with intercalated calcareous and fine-grained siliceous rocks serving as both the source and reservoir for oil accumulations. Petroleum is produced from macroscopic fractures, and numerous tar and asphalt seeps at the surface attest to the present-day movement of hydrocarbons through fractures in the Monterey Formation. Many fractures are filled with carbonate (mostly calcite and dolomite), quartz, baryte and anhydrite. These same fractures often contain tar or oil filling openings, and occasionally a thin layer of oil can be seen coating growth surfaces between two generations of vein-filling minerals.Evidence for migration of fluids through these fractures in the geological past is provided by aqueous and petroleum fluid inclusions contained within vein-filling minerals. Vein-filling dolomite from Jalama Beach contains three different types of primary petroleum inclusions (based on fluorescence characteristics)—indicating that oils with significantly different API gravities flowed through the fractures. Petrographic and microthermometric analyses of oil and coexisting aqueous inclusions indicate that the fracture-filling minerals precipitated from aqueous solutions of seawater salinity at ∼75–100°C, and that oil was introduced into the fracture system episodically during mineral growth. A sample from the Lion's Head area consists of early calcite and late quartz, both of which contain aqueous inclusions with seawater salinity. Inclusions in quartz homogenize at slightly higher temperatures than those in calcite. These data are consistent with calcite deposition during an early heating event, followed by quartz deposition during cooling. No petroleum inclusions were observed in the Lion's Head sample.

scholarly journals MIDDLE EAST GEOLOGIC TIME SCALE 2010: Early Cambrian Asfar Sequence

GeoArabia ◽  
2010 ◽  
Vol 15 (1) ◽  
pp. 137-160 ◽  
Author(s):  
Moujahed I. Al-Husseini
Keyword(s):  
Saudi Arabia ◽  
Middle East ◽  
Time Scale ◽  
Lower Boundary ◽  
Early Cambrian ◽  
Middle Cambrian ◽  
Geologic Time ◽  
Fine Grained ◽  
Geologic Time Scale ◽  
Arkosic Sandstone

ABSTRACT This paper is the first in a series dedicated to the Phanerozoic Cambrian Period, and Neoproterozoic Ediacaran and Cryogenian periods, as represented in the Middle East Geologic Time Scale (ME GTS, see enclosed Chart). It introduces the term Asfar Sequence to represent a regional Early Cambrian time-rock unit, consisting mainly of continental quartz-rich arkosic sandstone, shale and siltstone, which attain a thickness of at least 750 m in Jordan and more than 700 m in Oman. The term “Asfar”, meaning yellow in Arabic, was chosen because it is the standard color for sandstone in ME GTS. To describe its stratigraphy, four representative formations are reviewed in lexicon format: Salib Arkosic Sandstone of Jordan, Siq Sandstone of Saudi Arabia, Amin Formation of Oman and Lalun Sandstone of Iran. The stratigraphic geometry of the lower boundary of the Sequence varies considerably by locality. In some regions in Iran it is conformable above the shales of the Zaigun Formation. In other regions, such as western Jordan, it is an onlap surface over Proterozoic and/or Lower and Middle Cambrian paleohighs, or a pronounced angular unconformity (e.g. central and southern Saudi Arabia). The paleo-relief represented by the unconformity surface, in many regions, forms a regional peneplain (e.g. central and eastern Jordan) implying erosion; in other paleohigh regions, the Sequence is absent by non-deposition. The age of the base Asfar Sequence is estimated at ca. 530 Ma, based on radiometric data and depositional rates in basinal areas. The top boundary of the Sequence, in Iran, Jordan, and northern and northeastern Saudi Arabia, is represented by a sequence boundary (or its correlative unconformity), above which marine, fine-grained siliciclastics and carbonates of late Early to early Mid-Cambrian age were deposited: Mila Formation in Iran, and Burj Formation in Jordan and Saudi Arabia, implying an age older than ca. 510 Ma in GTS 2004. In Oman, however, continental rather than marine deposition (Miqrat and coeval Mahwis formations) continued above the unconformity in ?Middle Cambrian. For the purpose of regional correlations it is proposed that the Angudan Unconformity of Oman be taken as the name for the basal boundary of the Sequence and the Burj Sequence Boundary for its top.

scholarly journals KRAS and NRAS testing in metastatic colorectal cancer in Central Iran (Tehran): A review on literature of the middle east

2018 ◽  
Vol 39 (2) ◽  
pp. 210 ◽  
Author(s):  
Masoud Sadeghi ◽  
Ali Shahriari-Ahmadi ◽  
Nafise Ansarinejad ◽  
Farshid Fardad ◽  
Mehrdad Abbaszadeh
Keyword(s):  
Colorectal Cancer ◽  
Middle East ◽  
Metastatic Colorectal Cancer ◽  
Central Iran

scholarly journals GLI IDROCARBURI TRA IMPATTO ECONOMICO, RICERCA E PROSPETTIVE

2014 ◽  
Author(s):  
Roberto Aniello Calabrò
Keyword(s):  
Organic Matter ◽  
Middle East ◽  
Oil Sands ◽  
Fossil Fuels ◽  
Renewable Energy Sources ◽  
Animal Origin ◽  
Porous Rocks ◽  
Fine Grained ◽  
Post War ◽  
And Migration

Fossil fuels are the only non-renewable energy sources on which the world economy is based directly affect development. The main producer countries are located in the Middle-East (oil) and Russia and Middle East (gas). The oil search began in 1860 and has had a significant development during the Second World War, and in particularly in the post-war development, linked to the reconstruction. The formation of hydrocarbons is linked to the presence of fine-grained rocks (shales and limestone) that contain organic matter (1-14%), of vegetable (such as algae and leaves) and animal origin (microorganisms). When the rocks that contain this organic substance are buried subjected to high lithostatic load and the temperature reaches about 90°C, the organic matter begins to be transformed and at a temperature of about 120°C, begins to form oil, and at a temperature of about 140°C, gas is generated. After generation and migration the hydrocarbons accumulate in porous rocks (reservoirs), characterized by a geometry structures allowing their accumulation. Above the reservoir there should be a fine-grained and impermeable rock, that does not allow oil to disperse. In recent years, oil & gas companies have started to invest on non-conventional hydrocarbons, in particular, represented by shale gas and oil sands. To date, proven oil reserves amounted to 1.333 billion barrels of oil and 187.490 billion cubic meters of gas, reserves estimated to last for about approximately 50 years. If we add unconventional hydrocarbon reserves available and take into account the current consumption rate we could estimate that we would have oil for about 100 years more.

scholarly journals Urban Planning in Libya

1983 ◽  
Vol 14 ◽  
pp. 9-15 ◽  
Author(s):  
S. K. Kezeiri
Keyword(s):  
Middle East ◽  
Urban Planning ◽  
Full Coverage ◽  
Urban Amenities ◽  
Two Generations

AbstractLibya is one of the few countries in the Middle East to have a full coverage of Urban Plans and two generations of Master and Layout Plans have been provided by foreign consultants. The aim of urban planning in Libya is to provide urban amenities and infrastructures to all towns large or small and this article reviews how this has developed.

Crony Capitalism in the Middle East

2019 ◽  
Keyword(s):  
Middle East ◽  
Middle Eastern ◽  
Major Advance ◽  
Fine Grained ◽  
Form And Function ◽  
Crony Capitalism ◽  
Essential Resource ◽  
And Function ◽  
First Time ◽  
Time Information

The popular uprisings in 2011 that overthrew Arab dictators were also a rebuke to crony capitalism, targeted against both rulers and their allied businessmen who had monopolized profitable economic opportunities. While the Middle East has witnessed a growing nexus between business and politics in the wake of economic liberalization, little is known about the nature of business cronies, the sectors in which they operate, the mechanisms used to favor them, and the possible impact of such crony relations on the region’s development. Combining inputs from leading scholars in the field, this volume presents a wealth of empirical evidence on the form and function of crony capitalism in the Middle East. The volume is unique in both its empirical focus and comparative scale. Analysis in individual chapters is empirically grounded, based on fine-grained data on the business activities of politically connected actors—furnishing, for the first time, information on the presence, numerical strength, and activities of politically connected entrepreneurs. This volume also substantially enhances our understanding of the mechanisms used to privilege connected businesses, and their possible impact on undermining growth and job creation of firms in the Middle East. It offers a major advance on our prior knowledge of Middle Eastern political economy, and constitutes a distinct contribution to the global literature on crony capitalism and the politics of development. The book will be an essential resource for students, researchers, and policymakers alike.

scholarly journals Compression behaviour of hydrate bearing carbonate sand - fines mixtures

2020 ◽  
Vol 205 ◽  
pp. 11001
Author(s):  
Lu MA ◽  
Abraham C.F. CHIU ◽  
Y.P. CHENG
Keyword(s):  
Stress Level ◽  
High Stress ◽  
Carbonate Sand ◽  
Stress Regime ◽  
Fine Grained ◽  
Compression Behaviour ◽  
Significant Difference ◽  
Hydrate Saturation ◽  
Soil Mixtures ◽  
High Stress Level

High gas hydrate content has been found in fine-grained sediments containing substantial amount of foraminifera in the South China sea. One of the possible hydrate accumulation habits is filling the intra- particle voids in the foraminifera. To understand the effects of this hydrate accumulation habit on the compression behaviour of the fine-grained sediment, two series of isotropic compression tests were conducted. Due to high intra-particle porosity, carbonate sand (CS) was mixed with the fines to mimic the hydrate formation in the intra-particle voids in the laboratory prepared soil specimens. The compression test results revealed that the mixtures of fines with as high as 40% CS content can exhibit the transitional behaviour such that non-convergent compression lines are observed at the high stress level. It is evident that breakage of CS grains is negligible in these mixtures. Hence, the initial fabrics are not erased under the high stress level resulting in non-convergent compression lines. The compression curves of the hydrate bearing CS-fines mixtures can be classified into three different stress regimes. There is no significant difference in the compressibility of the soil mixtures with and without hydrate in the low stress regime. As the stress increases further reaching the medium stress regime, the hydrate reduces the compressibility of the soil mixtures with increasing hydrate saturation. Upon reaching the high stress regime, the bond breakage at the inter-particle contacts becomes significant leading to the convergence of compression curves between the hydrate bearing and host soil mixtures. It is also found that a new effective hydrate saturation, representing the amount of hydrate in the inter-particle voids, is better correlated to the compressibility of the hydrate bearing soil mixtures.

scholarly journals Textural and mineral-chemistry constraints on columbite-group minerals in the Penouta deposit: evidence from magmatic and fluid-related processes

2018 ◽  
Vol 82 (S1) ◽  
pp. S199-S222 ◽  
Author(s):  
P. Alfonso ◽  
S. A. Hamid ◽  
M. Garcia-Valles ◽  
T. Llorens ◽  
F. J. López Moro ◽  
...  
Keyword(s):  
Fluid Phase ◽  
Mineral Chemistry ◽  
X Ray Diffraction ◽  
Mineralogical Characterization ◽  
Fine Grained ◽  
Two Generations ◽  
Alteration Processes ◽  
Native Bismuth ◽  
Liberation Analysis

ABSTRACTThe Penouta Sn-Ta deposit, in the northwest of Spain, is a greisenized granitic cupola where Ta minerals occur mainly as disseminations in a leucogranite body intruded in Precambrian–Lower Cambrian gneisses and mica-schists. This leucogranite is a medium- to fine-grained inequigranular rock consisting mainly of quartz, albite, K-feldspar and muscovite. Accessory minerals are mainly of spessartine, zircon, cassiterite, Nb-Ta oxides, monazite, xenotime, native bismuth and pyrite. The alteration processes were mainly albitization, muscovitization and kaolinitization.This leucogranite is peraluminous and P-poor, with 0.03–0.07 wt.% P2O5, 900–1500 ppm Rb, 30–65 ppm Cs, 120–533 ppm Li, 80–140 ppm Ta, 51–81 ppm Nb and up to 569 ppm of Sn.Mineralogical characterization of Nb-Ta oxide minerals was determined by X-ray diffraction, scanning electron microscopy, electron microprobe analysis and mineral liberation analysis. Mn-rich members of the columbite-group minerals (CGM) are the most common Ta-bearing phases, but microlite, wodginite, tapiolite and Ta-rich cassiterite occur also. CGM crystals are commonly zoned concentrically, with a Nb-rich core surrounded by a Ta-rich rim, with a sharp boundary between them. Convoluted zoning occurs also. Dissolution textures resulting from the corrosion of columbite and tantalite rims, in particular, are common. The Mn/(Mn + Fe) ratio varies between 0.33 and 0.97 and the Ta/(Ta + Nb) ratio between 0.07 and 0.93. Wodginite and microlite formed as late replacements of CGM and occur associated with tantalite and cassiterite. Subhedral to anhedral cassiterite crystals, usually up to 200 μm across, occur in two generations: the earlier one is Nb,Ta-poor whereas in the later generation, the Ta content can reach >9 wt.% of Ta2O5and 1.7 wt.% of Nb. The presence of a fluid phase in the apical zone of the granite, probably related to the separation of a fluid/vapour of the melt, could explain the sponge-like textures, the Ta enrichment associated with these textures, the occurrence of Ta-enriched mineral phases (microlite and wodginite) and their common interstitial character.

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