فهرس المقالات Lut block

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  1 - Distribution and geochemical variations among paleogene volcanic rocks from the north-central Lut block, eastern Iran
  Saeed Saadat Charles Stern
  The Lut block in eastern Iran is a micro-continental block within the convergent orogen between the Arabian, Eurasian and Indian plates. Large areas of the north-central, eastern, and western Lut block are covered by volcanic rocks of Paleogene, Neogene and Quaternary a أکثر

  The Lut block in eastern Iran is a micro-continental block within the convergent orogen between the Arabian, Eurasian and Indian plates. Large areas of the north-central, eastern, and western Lut block are covered by volcanic rocks of Paleogene, Neogene and Quaternary age.  Peak volcanic activity took place in the north-central part of the Lut block during the Eocene, and then dramatically decreased, becoming more restricted to the eastern and western margins of the block during the late Miocene and Quaternary. There is also significant variation in chemistry between the Paleogene igneous rocks from the north-central part compared to the Neogene and Quaternary volcanic rocks from the western and eastern margins of the Lut block. The Neogene and Quaternary olivine basalts, which were erupted along both margins of the Lut block, are similar in trace element chemistry to the average composition of oceanic island basalt. In contrast, the Paleogene volcanic units of the north-central Lut block, which include basalts through rhyolites, follow both calc-alkaline and alkaline trends. Low TiO2 and high Ba/Nb and La/Nb ratios for both Paleogene basalts and andesitic samples from the north-central Lut block suggest affinities, at least for some of these samples, with convergent plate boundary arc magmas. LILE/HFSE ratios, interpreted as an indication of subduction signature, increase to the south-southwest of the central Lut block, where Neotethys oceanic crust was subducted beneath Iran in a northeastern direction from approximately Late Triassic to Late Oligocene time. We suggest that components derived from low angle subduction of this crust during the Mesozoic and early Tertiary were stored in the mantle lithosphere below the north-central Lut block until the Paleogene, when changing subduction geometry, associated with the collision of Arabia with Iran and the closing of Neotethys, caused hot asthenosphere to well up under the Lut block. This created the Eocene peak in volcanic activity, generating basalts from asthenospheric mixed with lithospheric melts, with both alkaline and calc-alkaline affinities. After this volcanism waned, becoming restricted during the Neogene to OIB-type alkaline basalts erupted through deep lithospheric structures along both the western and eastern margins of the Lut block. تفاصيل المقالة
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  2 - Accumulation of lead, antimony and arsenic in soil and water in Khunik gold prospecting area, Eastern Iran
  Saeed Saadat Maliheh Zafarimoghadam Aliasghar Ariaee
  10.30495/ijes.2022.1950343.1711
  Khunik gold prospecting area is located in the eastern part of Lut block, eastern Iran. Main rock units are andesite, agglomerate, latite, dacitic lava, rhyodacite, volcanic breccia and conglomerate. Geological and geochemical evidences indicate low to medium sulfide go أکثر

  Khunik gold prospecting area is located in the eastern part of Lut block, eastern Iran. Main rock units are andesite, agglomerate, latite, dacitic lava, rhyodacite, volcanic breccia and conglomerate. Geological and geochemical evidences indicate low to medium sulfide gold mineralization. Mining activates accumulate heavy metals in soil and water that are associated with harmful effects on human health. The object of this research is to evaluate the concentration of heavy metals in soil and groundwater resources and assess the effects of the mineralization zone. All investigated metals in soil samples are below world concentration except arsenic, antimony, and iron. Based on the assessment of pollution, high enrichment of silver, medium to high enrichment of antimony, arsenic, lead, and selenium in some samples were detected. The high correlation of silver, gold, and arsenic is due to the sulfide mineralization of gold in the Khunik area. Chemical analysis of water samples comparing International Standards confirms that water resources in this area have been polluted by heavy metals and it is not drinkable. MI and HPI values denote the dangerous pollution of groundwater, which has been described as serious in most sites. تفاصيل المقالة
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  3 - Petrochemical Characteristics of Neogene and Quaternary Alkali Olivine Basalts from the Western Margin of the Lut Block, Eastern Iran
  S. Saadat M. H. Karimpour Ch. Stern
  The Nayband strike-slip fault forms the western margin of the micro-continental Lut block in Eastern Iran. Neogene and Quaternary mafic volcanic rocks collected near Tabas, along the northern part of the fault (NNF; 15 Ma), and further to the south, along the middle par أکثر

  The Nayband strike-slip fault forms the western margin of the micro-continental Lut block in Eastern Iran. Neogene and Quaternary mafic volcanic rocks collected near Tabas, along the northern part of the fault (NNF; 15 Ma), and further to the south, along the middle part of the fault (MNF; 2 Ma), are within-plate sodic-series alkali olivine basalts with high TiO2 and up to >16% normative nepheline. Their high MgO, Ni and Cr contents indicate that they crystallized from relatively primitive magmas. Their low La/Nb and Ba/Nb ratios are similar to oceanic island basalts (OIB) and unlike convergent plate boundary arc basalts (IAB). These alkali olivine basalts show enrichment in LREE relative to HREE and limited variation in Sr, Nd and Pb isotopic values which all plot in the range of OIB. Ce/Pb (>39), Nb/U (44-120) and P2O5/K2O (~0.4) ratios suggest that crustal contamination was not significant for MNF basalts. The data may be interpreted as indicating the participation of upwelling mantle asthenosphere and the deeper continental mantle lithosphere in the generation of these basalts. They formed by generally low, but variable degrees of partial mantle melting, which decreased with time from 15 Ma NNF relative to2 Ma MNF basalts. The small volume of melts that formed the MNF basalts rose to the surface along the deep Nayband strike-slip fault with no interaction with the continental crust. The larger volume of NNF basalts interacted to some degree with the crust and are associated with basaltic andesites and andesites. تفاصيل المقالة