Magnetomineralogical changes along the Kohistan-Karakoram collision zone in North Pakistan: implications for variable thermochemical activities

To identify remanence-carrying magnetic minerals and document their thermochemical behavior, detailed rock magnetic investigations were conducted on Cretaceous-Tertiary rocks collected from northwestern and northeastern Kohistan, northern Pakistan. Rock magnetic results from each area are clearly differentiated on the basis of site location. Detrital hematite is identified as a main magnetic carrier in red beds of northwestern Kohistan located at some distance from the Northern Suture Zone with subsidiary pigmentary hematite and altered magnetite. In contrast, the magnetic mineralogy of purple-colored rocks adjacent to the Northern Suture Zone is shared by unstable secondary pyrrhotite, magnetite, and hematite. The magnetic mineralogy of northeastern Kohistan is dominated by recently formed pyrrhotite with contributions from secondary hematite and magnetite. The widespread presence of pyrrhotite in the eastern sector indicates contrasting thermochemical regimes. Two geological implications are inferred from magnetization contrasts in the eastern and western sectors of the Kohistan Range. First, rocks at a distance from the Northern Suture Zone are less intensely remagnetized than those closer to it and provide a signature of the thermochemical gradient. Second, rocks in northeastern Kohistan are more intensely remagnetized compared to their counterparts in the northwest, implying an increase in the thermochemical gradient from west to east. The reported occurrences of numerous sulfide mineral zones in the study areas support our interpretation of intense remagnetization as a result of increased thermochemical activity near the Northern Suture Zone.

Magnetomineralogical changes along the Kohistan-Karakoram collision zone in North Pakistan: implications for variable thermochemical activities

To identify remanence-carrying magnetic minerals and document their thermochemical behavior, detailed rock magnetic investigations were conducted on Cretaceous-Tertiary rocks collected from northwestern and northeastern Kohistan, northern Pakistan. Rock magnetic results from each area are clearly differentiated on the basis of site location. Detrital hematite is identified as a main magnetic carrier in red beds of northwestern Kohistan located at some distance from the Northern Suture Zone with subsidiary pigmentary hematite and altered magnetite. In contrast, the magnetic mineralogy of purple-colored rocks adjacent to the Northern Suture Zone is shared by unstable secondary pyrrhotite, magnetite, and hematite. The magnetic mineralogy of northeastern Kohistan is dominated by recently formed pyrrhotite with contributions from secondary hematite and magnetite. The widespread presence of pyrrhotite in the eastern sector indicates contrasting thermochemical regimes. Two geological implications are inferred from magnetization contrasts in the eastern and western sectors of the Kohistan Range. First, rocks at a distance from the Northern Suture Zone are less intensely remagnetized than those closer to it and provide a signature of the thermochemical gradient. Second, rocks in northeastern Kohistan are more intensely remagnetized compared to their counterparts in the northwest, implying an increase in the thermochemical gradient from west to east. The reported occurrences of numerous sulfide mineral zones in the study areas support our interpretation of intense remagnetization as a result of increased thermochemical activity near the Northern Suture Zone.

Kaynakça

Ahmad MN, Fujiwara Y, Paudel LP (2001). Remagnetization of igneous rocks in Gupis area of Kohistan arc, northern Pakistan. Earth Planets Space 53: 373–384.

Appel E, Crouzet C, Schill E (2012). Pyrrhotite remagnetizations in the Himalaya: a review. In: Elmore RD, Muxworthy AR, Aldana M, Mena M, editors. Remagnetization and Chemical Alteration of Sedimentary Rocks. London, UK: Special Publication of the Geological Society of London 371, pp. 163–180.

Bouilhol P, Jagoutz O, Hanchar JM, Dudas FO (2013). Dating the India–Eurasia collision through arc magmatic records. Earth Planet Sc Lett 366: 163–175.

Burg JP (2011). The Asia–Kohistan–India collision. Review and discussion. In: Brown D, Ryan PD, editors. Arc–Continent Collision. Heidelberg, Germany: Springer, pp. 279–309.

Calkins JA, Jamiluddin S, Bhuyan K, Hussain A (1981). Geology and Mineral Resources of the Chitral-Partsan Area, Hindu-Kush Range, Northern Pakistan. Reston, VA, USA: US Geological Survey Professional Paper 761-G.

Crouzet C, Stang H, Appel E, Schill E, Gautam P (2001). Detailed analysis of successive pTRMs carried by pyrrhotite in Himalayan metacarbonates: an example from Hidden Valley, Central Nepal. Geophys J Int 146: 607–618.

Dekkers MJ, Linssen JH (1989). Rock magnetic properties of fine- grained natural low-temperature hematite with reference to remanence acquisition mechanisms in red beds. Geophy J Int 99: 1–18.

Elmore RD, Muxworthy AR, Aldana M (2012). Remagnetization and chemical alteration of sedimentary rocks. In: Elmore RD, Muxworthy AR, Aldana M, Mena M, editors. Remagnetization and Chemical Alteration of Sedimentary Rocks. London, UK: Special Publication of the Geological Society of London 371, pp. 1–22.

Horng CH, Huh CA, Chen KH, Lin CH, Shea KS, Hsiung KH (2012). Pyrrhotite as a tracer for denudation of the Taiwan orogen. Geochem Geophy Geosy 13: 19–30.

Katz B, Elmore RD, Cogioni M, Ferry S (1998). Widespread chemical remagnetization: orogenic fluids or burial diagenesis of clays? Geology 26: 603–606.

Klootwijk CT, Conaghan PJ (1979). The extent of greater India-I: Preliminary palaeomagnetic data from the Upper Devonian of the Eastern Hindukush, Chitral (Pakistan). Earth Planet Sc Lett 42: 167–182.

Klootwijk CT, Conaghan PJ, Nazirullah R, de Jong KA (1994). Further palaeomagnetic data from Chitral (Eastern Hindukush): evidence for an early India-Asia contact. Tectonophysics 237: 1–25.

Lowrie W (1990). Identification of ferromagnetic minerals in a rock by coercivity and unblocking temperature properties. Geophys Res Lett 17: 159–162.

McCabe C, Elmore RD (1989). The occurrence of Late Paleozoic remagnetization in the sedimentary rocks of North America. Rev Geophys 27: 471–494.

Meijers MJ, van Hinsbergen DJ, Dekkers MJ, Altıner D, Kaymakcı N, Langereis CG (2011). Pervasive Palaeogene remagnetization of the central Taurides fold-and-thrust belt (southern Turkey) and implications for rotations in the Isparta Angle. Geophys J Int 184: 1090–1112.

Morin FJ (1950). Magnetic susceptibility of α-Fe2O3 and α-Fe2O3 with added titanium. Physics Rev 78: 819–820.

Pudsey CJ (1986). The Northern Suture, Pakistan: margin of a Cretaceous island arc. Geol Mag 123: 405–423.

Pudsey CJ, Coward MP, Luff IW, Shackleton RM, Windley BF, Jan MQ (1985). Collision zone between the Kohistan arc and Asian plate in NW Pakistan. T Roy Soc Edin-Earth 76: 463–479.

Rochette P, Fillion G, Mattéi JL, Dekkers MJ (1990). Magnetic transition at 30-34 K in pyrrhotite: insight into a widespread occurrence of pyrrhotite in rocks. Earth Planet Sc Lett 98: 319–328.

Rowan CJ, Roberts AP (2008). Widespread remagnetizations and a new view of Neogene tectonic rotations within the Australia- Pacific plate boundary zone, New Zealand. J Geophys Res 113: 1978–2012.

Sagnotti L (2007). Iron sulphides. In: Gubbins D, Emilio HB, editor. Encyclopaedia of Geomagnetism and Paleomagnetism, Encyclopedia of Earth Sciences Series. Heidelberg, Germany: Springer, pp 454–458.

Shakirullah (2003). Metallogeny of District Chitral, Eastern Hindukush, Khyber Pakhtunkhwa, Northern Pakistan: Results of Integrated Drainage Geochemical Exploration. Peshawar, Pakistan: Exploration Promotion Division, Khyber Pakhtunkhwa Directorate General Mines & Minerals (unpublished report).

Sheikh L, Shah MT, Khan SD, Ahmad L (2104). Investigation for gold and base metals mineralization and petrochemical characteristics of the rocks of Golo Das and surrounding areas, District Ghizar, Gilgit-Baltistan, Pakistan. J Himalaya Earth Sci 47: 15–27.

Tahirkheli RAK, Mattauer M, Proust F, Tapponnier P (1979). The India-Eurasia Suture Zone in Northern Pakistan: synthesis and interpretation of recent data at plate scale. In: Farah A, DeJong KA, editors. Geodynamics of Pakistan. Lahore, Pakistan: Geological Survey of Pakistan, pp. 125–130.

Treloar PJ, Rex DC, Guise PG, Coward MP, Searle MP, Windley BF, Patterson MG, Jan MQ, Luff IF (1989). K-Ar and Ar- Ar geochronology of Himalayan collision in NW Pakistan: constraints on the timing of suturing, deformation, metamorphism and uplift. Tectonics 8: 881–909.

Turner P (1980). Continental Red Beds (Developments in Sedimentology 29). Amsterdam, the Netherlands: Elsevier.

Van Der Voo R, Torsvik TH (2012). The history of remagnetization of sedimentary rocks: deceptions, developments and review. In: Elmore RD, Muxworthy AR, Aldana M, Mena M, editors. Remagnetization and Chemical Alteration of Sedimentary Rocks. London, UK: Special Publication of the Geological Society of London 371, pp. 23–54.

Verwey EJ (1939). Electronic conduction of magnetite (Fe3O4) and its transition point at low temperature. Nature 144: 327–328.

Zaman H, Otofuji Y, Khan SR, Ahmad MN (2013). New palaeomagnetic results from the northern margin of the Kohistan Island Arc: un-ending tectonic activities in the India- Asia collision zone. Arab J Geosci 6: 1041–1054.

Zaman H, Torii M (1999). Palaeomagnetic study of Cretaceous red beds from eastern Hindukush ranges, northern Pakistan: palaeoreconstruction of the Kohistan Karakoram composite unit before the India-Asia collision. Geophys J Int 136: 719– 738.

Kaynak Göster

Bibtex @ { tbtkearth143934, journal = {Turkish Journal of Earth Sciences}, issn = {1300-0985}, eissn = {1303-619X}, address = {}, publisher = {TÜBİTAK}, year = {2015}, volume = {24}, pages = {179 - }, doi = {10.3906/yer-1409-8}, title = {Magnetomineralogical changes along the Kohistan-Karakoram collision zone in North Pakistan: implications for variable thermochemical activities}, key = {cite}, author = {Zaman, HAIDER and Bamousa, ABDULLAH O} }
APA Zaman, H , Bamousa, A . (2015). Magnetomineralogical changes along the Kohistan-Karakoram collision zone in North Pakistan: implications for variable thermochemical activities . Turkish Journal of Earth Sciences , 24 (2) , . DOI: 10.3906/yer-1409-8
MLA Zaman, H , Bamousa, A . "Magnetomineralogical changes along the Kohistan-Karakoram collision zone in North Pakistan: implications for variable thermochemical activities" . Turkish Journal of Earth Sciences 24 (2015 ): <https://dergipark.org.tr/tr/pub/tbtkearth/issue/12045/143934>
Chicago Zaman, H , Bamousa, A . "Magnetomineralogical changes along the Kohistan-Karakoram collision zone in North Pakistan: implications for variable thermochemical activities". Turkish Journal of Earth Sciences 24 (2015 ):
RIS TY - JOUR T1 - Magnetomineralogical changes along the Kohistan-Karakoram collision zone in North Pakistan: implications for variable thermochemical activities AU - HAIDER Zaman , ABDULLAH O Bamousa Y1 - 2015 PY - 2015 N1 - doi: 10.3906/yer-1409-8 DO - 10.3906/yer-1409-8 T2 - Turkish Journal of Earth Sciences JF - Journal JO - JOR SP - 179 EP - VL - 24 IS - 2 SN - 1300-0985-1303-619X M3 - doi: 10.3906/yer-1409-8 UR - https://doi.org/10.3906/yer-1409-8 Y2 - 2021 ER -
EndNote %0 Turkish Journal of Earth Sciences Magnetomineralogical changes along the Kohistan-Karakoram collision zone in North Pakistan: implications for variable thermochemical activities %A HAIDER Zaman , ABDULLAH O Bamousa %T Magnetomineralogical changes along the Kohistan-Karakoram collision zone in North Pakistan: implications for variable thermochemical activities %D 2015 %J Turkish Journal of Earth Sciences %P 1300-0985-1303-619X %V 24 %N 2 %R doi: 10.3906/yer-1409-8 %U 10.3906/yer-1409-8
ISNAD Zaman, HAIDER , Bamousa, ABDULLAH O . "Magnetomineralogical changes along the Kohistan-Karakoram collision zone in North Pakistan: implications for variable thermochemical activities". Turkish Journal of Earth Sciences 24 / 2 (Ağustos 2015): 179- . https://doi.org/10.3906/yer-1409-8
AMA Zaman H , Bamousa A . Magnetomineralogical changes along the Kohistan-Karakoram collision zone in North Pakistan: implications for variable thermochemical activities. Turkish Journal of Earth Sciences. 2015; 24(2): 179-.
Vancouver Zaman H , Bamousa A . Magnetomineralogical changes along the Kohistan-Karakoram collision zone in North Pakistan: implications for variable thermochemical activities. Turkish Journal of Earth Sciences. 2015; 24(2): 179-.
IEEE H. Zaman ve A. Bamousa , "Magnetomineralogical changes along the Kohistan-Karakoram collision zone in North Pakistan: implications for variable thermochemical activities", Turkish Journal of Earth Sciences, c. 24, sayı. 2, ss. 179, Ağu. 2015, doi:10.3906/yer-1409-8