M. Paknia; Habib Alimohammadian; M. R. Majidifard; J. Sabouri; A. Aghanabat
Abstract
The Golbini section comprising of continuous succession of sediments ranging in age from Triassic – Jurassic formations, is situated at 35 Km north – east of Jajarm city. On the bases of studies on Dalichai Formation at this section and at about Middle Jurassic (Bathonian–Callovian ...
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The Golbini section comprising of continuous succession of sediments ranging in age from Triassic – Jurassic formations, is situated at 35 Km north – east of Jajarm city. On the bases of studies on Dalichai Formation at this section and at about Middle Jurassic (Bathonian–Callovian boundary), 3 Member, 31 Genus and 13 species of Ammonite, has been identified. For paleomagnetic analysis, with the help of portable coring machine, the total number of 155 oriented core samples were collected from limestone and clayey– limestone of this section. Then the samples were prepared for paleomagnetic analysis at Environmental and Paleomagnetic Laboratory based at Geological Survey of Iran, Tehran, Iran. The conducted paleomagnetic analysis include measurement of NRM, Susceptibility, Thermal and AF demagnetizing, Virtual Geomagnetic Polarity (VGP), identification of normal and reversal magnetic polarities and calculation of sedimentation rate. The obtained paleomagnetic results then composed with GPTS and also with proposed Bathonian–Callovian boundaries in Russia and Germany. This comparison reveals that the magnetic polarity of Golbini section is co-relatable with GPTS and also with Bathonian–Callovian boundary in Russia and Germany.
Habib Alimohammadian; F Mahdipour Haskouei; J Sabouri
Abstract
The study area is situated at about 8 km away of Neka city, on the main road of Sari-Behshahr, in MazandaranProvince, north of Iran. It is bounded by Alborz fault in the south and Caspian Sea coast line in the north. We applied new environmental magnetism technique and methods including magnetic susceptibility, ...
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The study area is situated at about 8 km away of Neka city, on the main road of Sari-Behshahr, in MazandaranProvince, north of Iran. It is bounded by Alborz fault in the south and Caspian Sea coast line in the north. We applied new environmental magnetism technique and methods including magnetic susceptibility, magnetic mineralogy, IRM and S-IRM to reconstruct the past 50 ka climate conditions and also investigate relationship between climate change and magnetic variations. We also compared the geochemistry and magnetic analysis of the loess/palaeosol deposits and the results were used to correlate these variations with climate change in the study area. The pattern of variation of geochemical data shows similarity with those of magnetic one. The increase/decrease in magnetic susceptibility is coinciding with palaeosol/loess sequences. Plotting magnetic susceptibility variation versus lithological column of Kolet section enabled us to recognize short period of climatically cycles known as stadials/interstadials in loess/palaeosol sequences. We recognized 4 stadials for upper palaeosol, single stadial for lower palaeosol, 6 interstadials for upper loess and one interstadial for lower loess deposites.