TY - JOUR A1 - Dorani, Maryam A1 - Arvin, Mohsen A1 - Oberhänsli, Roland A1 - Dargahi, Sara T1 - P-T evolution of metapelites from the Bajgan complex in the Makran accretionary prism, south eastern Iran JF - Chemie der Erde : interdisciplinary journal for chemical problems of the geo-sciences and geo-ecology = Geochemistry N2 - The Bajgan Complex, one of the basement constituents of the arc massif in Iranian Makran forms a rugged, deeply incised terrain. The complex consists of pelitic schists with minor psammitic and basic schists, calc silicate rocks, amphibolites, marbles, metavolcanosediments, mafic and felsic intrusives as well as ultramafic rocks. Metapelitic rocks show an amphibolite facies regional metamorphism and contain garnet, biotite, white mica, quartz, albite ± rutile ± apatite. Thermobarometry of garnet schist yields pressure of more than 9 kbar and temperatures between 560 and 675 °C. The geothermal gradient obtained for the peak of regional metamorphism is 19 °C/km, corresponding to a depth of ca. 31 km. Replacement of garnet by chlorite and epidote suggest greenschist facies metamorphism due to a decrease in temperature and pressure through exhumation and retrograde metamorphism (370–450 °C and 3–6 kbar). The metapelitic rocks followed a ‘clockwise’ P–T path during metamorphism, consistent with thermal decline following tectonic thickening. The formation of medium-pressure metamorphic rocks is related to presence of active subduction of the Neotethys Oceanic lithosphere beneath Eurasia in the Makran. KW - Bajgan Complex KW - Makran KW - Metapelitic rock KW - Garnet schist KW - Thermobarometry KW - Clockwise P-T path Y1 - 2017 U6 - https://doi.org/10.1016/j.chemer.2017.07.004 SN - 0009-2819 SN - 1611-5864 VL - 77 IS - 3 SP - 459 EP - 475 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Kober, Florian A1 - Zeilinger, Gerald A1 - Ivy-Ochs, Susan A1 - Dolati, A. A1 - Smit, J. A1 - Kubik, Peter W. T1 - Climatic and tectonic control on fluvial and alluvial fan sequence formation in the Central Makran Range, SE-Iran JF - Global and planetary change N2 - The geomorphic evolution of the Makran Range of SE-Iran and SW-Pakistan has been controlled by the prevailing SW-Asian monsoon and Mediterranean winter rainfall climate and the surface uplift processes resulting from the Arabia-Eurasia collision. The impact of climate on Quaternary fluvial and alluvial sequence formation and their regional correlation has been little investigated due to limited age control of these sequences. Using Be-10 cosmogenic nuclide exposure ages we established a Middle to Late Pleistocene terrace chronology. Our record tentatively indicates that terrace levels were abandoned towards the transition to or during warmer/pluvial periods (interglacials and/or interstadials) back to Marine Isotope Stage (MIS) 7, but abandoned ages show a large spread. It is hypothesized that pluvial phases correspond with times of enhanced SW-monsoons and a northward shift of the Intertropical Convergence Zone (ITCZ). Furthermore, orbital periodidties can be deduced on frequencies related to obliquity and precession cycles. Overall, caution has to be placed in sampling and interpreting alluvial deposits, which may have complex inheritance patterns and spatially and temporarily variable catchment erosion histories and terrace-channel dynamics. Beside the dominant climate control on terrace formation, elevated channel steepness indices around major thrusts and numerous knickpoints indicate an additionally tectonic influence on terrace formation. Local incision rates (mean similar to 0.6-0.8 min.a(-1)) are variable in space and time but are similar to uplift rates obtained from coastal terraces and thus suggest a regional surface uplift. (C) 2013 Elsevier B.V. All rights reserved. KW - Cosmogenic nuclides KW - Monsoon KW - Climate KW - Tectonics KW - Terraces KW - Makran Y1 - 2013 U6 - https://doi.org/10.1016/j.gloplacha.2013.09.003 SN - 0921-8181 SN - 1872-6364 VL - 111 SP - 133 EP - 149 PB - Elsevier CY - Amsterdam ER -