Nasrollah Abbassi
Abstract
Cretaceous flysch deposits of the Abshar-e Asyab Kharabeh (30 meters) in west of Siah-rud village in the Jolfa area, NW Iran, consist of conglomerate, sandstone, siltstone and mud- or marlstone layers, which mainly belong to A, B, D and E divisions of Bouma sequence. A divers trace fossils preserved ...
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Cretaceous flysch deposits of the Abshar-e Asyab Kharabeh (30 meters) in west of Siah-rud village in the Jolfa area, NW Iran, consist of conglomerate, sandstone, siltstone and mud- or marlstone layers, which mainly belong to A, B, D and E divisions of Bouma sequence. A divers trace fossils preserved on the lower bedding planes of sandstones and siltstones as positive hyporelief, includes: Bergaueria hemispherica, Bergaueria isp., Cochlichnus isp., Granularia isp., Halopoa imbricate, Helminthoida crassa, Helminthopsis abeli, Imponoglyphus torquendus, Neonereites multiserialis, Paleodictyon latum, Paleodictyon cf. majus, Paleodictyon nodosum, Palaeophycus alternatus, Palaeophycus sulcatus, Phycodes templus, Phycodes isp., Planolites annularis, Planolites beverleyensis, Protovirgularia longespicata, Squamodictyon isp., Strobilorhaphe isp., Thalassinoides isp., Taphrhelminthopsis recta, Taphrhelminthopsis convolute, Treptichnus pollardi. These trace fossils are mainly grazing-feeding or feeding traces of Nereites Ichnofacies and classifiable in six rang/frequency, based ichno-assemblages. Obtained trace fossils were produced during post-event calm periods. So, muddy sediments deposited after turbulence currents and traces have been made on these layers, activates of trace makers were developing when accessible feeding materials or dissolved oxygen increased in environment. Base on founded Nereites trace fossils, these sediments deposited in the deep marine abyssal zone environment.
A. Akbarpour; A. Rasa; M. Mehrpartou
Abstract
The Masjeddaghi area is a part of Alborz-Azarbaijan Zone and located in the Jolfa 1:100000 geological map sheet. The oldest rock units cropped out widely in the south and northeast of the area belong to the Eocene flysch-type sediments. The other outcrops consist mainly of volcanic rock complex of andesites ...
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The Masjeddaghi area is a part of Alborz-Azarbaijan Zone and located in the Jolfa 1:100000 geological map sheet. The oldest rock units cropped out widely in the south and northeast of the area belong to the Eocene flysch-type sediments. The other outcrops consist mainly of volcanic rock complex of andesites and trachyandesites affected by quartz monzonite intrusion and caused alteration of phyllic and carbonate phyllic type. The mineralization in volcanic complex is also accompanied by quartz and barite veins. The study of alterated zone around veins shows sericite, silicified, prophillitic, chloritic and alunite (jarosite) alterations. Investigation of alteration zones around mineralized veins shows epithermal gold ore in which alunitic alteration (jarocite) is the most important characteristics. The result of the study on alteration and extension of altered zones in the whole study area give rise to the probability of porphyry type copper deposit (potassic, phyllic, argillic and prophylitic alteration zone).