Scientific Quarterly Journal of Geosciences

Scientific Quarterly Journal of Geosciences

New Palaeomagnetic Data from Iran

Document Type : Original Research Paper

Authors
G. Soffel 1
M. Davoudzadeh 2
C. Rolf 3
S. Schmidt 1
1 Institut fur Allgemeine und Angewandte Geophysik, Universitat Munchen
2 Institut fur Allgemeine und Angewandte Geologie, Universitat Munchen
3 Niedersachsisches Landesamt fur Bodenforschung, Aussenstelle Grubenhagen
Abstract
New Palaeomagnetic sampling was carried out in Central Iran in 1986 and in 1991-92 with the aim to extend our previous studies. Several new reliable pole positions could be obtained for the Central East Iran Microplate (CEIM) confirming the general trend of its Apparent polar Wander path (APWP) from the Triassic through the Tertiary: (i) Area of Nakhlak (33. 35N, 53.50 E), Triassic limestones and tuffs, 12 samples, D= 94. O, I= 25. O, a95 = 24. 7, virtual geomagnetic pole position (VGP) at 310. 9 E, 3.9 S. (ii) Area of Saghand (32.5 N, 55. 3 E), Cretaceous limestones, 17 samples, D= 338. 5, 1= 25. 2, a95 5.2, VGP at 285. 9 E,62. 5 N. (iii) Area of Sirjan (29. 4 N, 55.1 E), Triassic volcanics, 19 samples, D=115.5, I=35.4, a95 3.9, VGP at 295.1 E, 10.9 N. Combining all Triassic pole positions for the CEIM yields a new Triassic pole at 313. O E, 12.4 N, N=5, A95= 16.2, which confirms the large rotation of the CEIM since the Triassic.
In the area of Natanz (33. 35 N, 51.50 E; 100 km N of Esfahan), Triassic dolomites, limestones, sandstones and siltstones (161 specimens from 5 sites) gave a mean direction of the 5 sites at D= 33.3, = 25.1, a95 = 9.3 (passing a positive fold test on the level of 99%) and a VGP at 167. 6 E, 53.6 N, A95 9.3. This pole position is in fairly good agreement with the mean Triassic pole position of the Turan plate (149 E, 49 N). It indicates that the area of Natanz has not undergone the large anticlockwise rotation relative to the Turan plate since the Triassic.
Keywords
Palaeomagnetic
Subjects
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Scientific Quarterly Journal of Geosciences
Volume 4, Issue 14
Winter 1995, Vol. 4, No. 14
Spring 1995
Pages 68-79