Interrelationships between deformation and metamorphic events across the western hinterland zone, NW Pakistan

Abstract

Microscopic to mesoscopic structural investigations and foliation intersection axes (FIAs) preserved in porphyroblasts reveal a very complex history of deformation and tectonism within the southwestern part of the western hinterland zone along the northern margin of the Indian plate, NW Pakistan. D₁, D₂, and D₃ related structures in the southwestern part resemble the F₁/F₂, F₃, and F₄ related structures in the northeastern part of the western hinterland zone. These structures developed at the same time through the same changes in the direction of bulk shortening in southwestern and northeastern parts of the western hinterland zone. FIA set 1 indicates NW-SE shortening. The D₂ fabrics, mineral lineations and fold axes indicate E-W shortening. FIA set 2, D₃ fold axes and mineral lineations indicate NNE-SSW shortening. D₃ deformation event is equivalent to the F₄ deformation event in the northeastern part of the western hinterland zone. D₄ fold axes, mineral stretching lineations and axial plane foliation suggest ENE-WSW shortening. The D₄ NNW-SSE fabrics, which formed in the region after the formation of the MMT (main mantle thrust), Khairabad-Panjal thrust fault, Hissartang thrust fault and MBT (main boundary thrust), likely resulted from ENE-WSW bulk shortening related to development of the Hazara-Kashmir syntaxis.

Keywords

FIA / western hinterland zone / microstructure / mesostructure / metamorphism / tectonics / NW Pakistan

References

Abu Sharib A. S. A. A., Bell T. H. Radical Changes in Bulk Shortening Directions during Orogenesis: Significance for Progressive Development of Regional Folds and Thrusts. Precambrian Research, 2011, 188(1–4): 1-20.

Adshead-Bell N. S., Bell T. H. The Progressive Development of a Macroscopic Upright Fold Pair during Five Near-Orthogonal Foliation-Producing Events: Complex Microstructures versus a Simple Macrostructure. Tectonophysics, 1999, 306(2): 121-147.

Aerden D. Comment on “Reference Frame, Angular Momentum, and Porphyroblast Rotation” by Dazhi Jiang and Paul F. Williams. Journal of Structural Geology, 2005, 27(6): 1128-1133.

Ahmad M., Ali K. S. S., Khan B., . The Geology of the Warsak Area, Peshawar, West Pakistan. Geological Bulletin University of Peshawar, 1969, 4: 44-78.

Ali A. The Tectono-Metamorphic Evolution of the Balcooma Metamorphic Group, North-Eastern Australia: A Multidisciplinary Approach. Journal of Metamorphic Geology, 2010, 28(4): 397-422.

Anczkiewicz R., Burg J. P., Hussain S. S., . Stratigraphy and Structure of the Indus Suture in the Lower Swat, Pakistan, NW Himalaya. Journal of Asian Earth Sciences, 1998, 16(2/3): 225-238.

Bell T. H. Foliation Development—The Contribution, Geometry and Significance of Progressive, Bulk, Inhomogeneous Shortening. Tectonophysics, 1981, 75(3/4): 273-296.

Bell T. H., Rubenach M. J. Sequential Porphyroblast Growth and Crenulation Cleavage Development during Progressive Deformation. Tectonophysics, 1983, 92(1–3): 171-194.

Bell T. H. Deformation Partitioning and Porphyroblast Rotation in Metamorphic Rocks: A Radical Interpretation. Journal of Metamorphic Geology, 1985, 3: 109-118.

Bell T. H. Foliation Development and Refraction in Metamorphic Rocks: Reactivation of Earlier Foliations and Decrenulation due to Shifting Patterns of Deformation Partitioning. Journal of Metamorphic Geology, 1986, 4(4): 421-444.

Bell T. H., Hickey K. A. Multiple Deformations with Successive Subvertical and Subhorizontal Axial Planes in the Mount Isa Region: Their Impact on Geometric Development and Significance for Mineralization and Exploration. Economic Geology, 1998, 93(8): 1369-1389.

Bell T. H., Ham A. P., Hickey K. A. Early Formed Regional Antiforms and Synforms that Fold Younger Matrix Schistosities: Their Effect on Sites of Mineral Growth. Tectonophysics, 2003, 367(3/4): 253-278.

Bell T. H., Ham A. P., Kim H. S. Partitioning of Deformation along an Orogen and Its Effects on Porphyroblast Growth during Orogenesis. Journal of Structural Geology, 2004, 26(5): 825-845.

Bell T. H., Bruce M. D. The Internal Inclusion Trail Geometries Preserved within a First Phase of Porphyroblast Growth. Journal of Structural Geology, 2006, 28(2): 236-252.

Bell T. H., Sanislav I. V. A Deformation Partitioning Approach to Resolving the Sequence of Fold Events and the Orientations in which They Formed across Multiply Deformed Large-Scale Regions. Journal of Structural Geology, 2011, 33(7): 1206-1217.

Bell T. H., Sapkota J. Episodic Gravitational Collapse and Migration of the Mountain Chain during Orogenic Roll-on in the Himalayas. Journal of Metamorphic Geology, 2012, 30(7): 651-666.

Bell T. H., Rieuwers M. T., Cihan M., . Inter-Relationships between Deformation Partitioning, Metamorphism and Tectonism. Tectonophysics, 2013, 587: 119-132.

Bossart P., Dietrich D., Greco A., . The Tectonic Structure of the Hazara-Kashmir Syntaxis, Southern Himalayas, Pakistan. Tectonics, 1988, 7(2): 273-297.

Bossart P., Ottiger R., Heller F. Paleomagnetism in the Hazara-Kashmir Syntaxis, NE Pakistan. Eclogae Geologicae Helvetiae, 1989, 82: 585-601.

Cao H., Fletcher C. FIA Trends along the Precambrian Rocky Mountains: A New Approach to Timing Continental Docking. Journal of Metamorphic Geology, 2012, 30(7): 639-650.

Cihan M., Parsons A. The Use of Porphyroblasts to Resolve the History of Macro-Scale Structures: An Example from the Robertson River Metamorphics, North-Eastern Australia. Journal of Structural Geology, 2005, 27(6): 1027-1045.

DiPietro J. A., Ahmad I., Hussain A. Cenozoic Kinematic History of the Kohistan Fault in the Pakistan Himalaya. Geological Society of America Bulletin, 2008, 120(11/12): 1428-1440.

Dipietro J. A., Lawrence R. D. Himalayan Structure and Metamorphism South of the Main Mantle Thrust, Lower Swat, Pakistan. Journal of Metamorphic Geology, 1991, 9(4): 481-495.

Etheridge M. A., Vernon R. H. A Deformed Polymictic Conglomerate—The Influence of Grain Size and Composition on the Mechanism and Rate of Deformation. Tectonophysics, 1981, 79(3/4): 237-254.

Fernandez A. Shams F. A. Strain Analysis of a Typical Granite of the Lesser Himalayan Cordierite Granite Belt: The Mansehra Pluton, Northern Pakistan. Granites of the Himalayas, Karakoram, and Hindu Kush. Institute of Geology, 1983, 183-200.

Hayward N. Determination of Early Fold Axis Orientations in Multiply Deformed Rocks Using Porphyroblast Inclusion Trails. Tectonophysics, 1990, 179(3/4): 353-369.

Hickey K. A., Bell T. H. Resolving Complexities Associated with the Timing of Macroscopic Folds in Multiply Deformed Terrains: The Spring Hill Synform, Vermont. Geological Society of America Bulletin, 2001, 113(10): 1282-1298.

Huston D. L. The Stratigraphic and Structural Setting of the Balcooma Volcanogenic Massive Sulphide Lenses, Northern Queensland. Australian Journal of Earth Sciences, 1990, 37(4): 423-440.

Kazmer C. The Main Mantle Thrust Zone at Jowan Pass Area: Swat, Pakistan: [Dissertation], 1986.

Kazmi A. H., Rana R. A. Tectonic Map of Pakistan Scale 1: 2 000 000, 1982.

Khan A., Aslam M., Khan R. N. Revised Stratigraphy of the Paleozoic Rocks, Khyber Agency, NWFP, Pakistan. Geological Survey of Pakistan, 1989, 431: 1-11.

Opdyke N. D., Johnson N. M., Johnson G. D., . Paleomagnetism of the Middle Siwalik Formations of Northern Pakistan and Rotation of the Salt Range Decollement. Palaeogeography, Palaeoclimatology, Palaeoecology, 1982, 37(1): 1-15.

Pogue K. R., Hylland M. D., Yeats R. S., . Stratigraphic and Structural Framework of Himalayan Foothills, Northern Pakistan. Geological Society of America, Special Papers, 1999, 328: 257-274.

Sanislav I. V. A Long-Lived Metamorphic History in the Contact Aureole of the Mooselookmeguntic Pluton Revealed by In Situ Dating of Monazite Grains Preserved as Inclusions in Staurolite Porphyroblasts. Journal of Metamorphic Geology, 2010, 29(2): 251-273.

Shah A. A. FIAs (Foliation Intersection/Inflection Axes) Preserved in Porphyroblasts, the DNA of Deformation: A Solution to the Puzzle of Deformation and Metamorphism in the Colorado, Rocky Mountains, USA. Acta Geologica Sinica: English Edition, 2009, 83(5): 971-984.

Shah S. M. I., Siddiqi R. A., Talent J. A. Geology of the Eastern Khyber Agency, North West Frontier Province, Pakistan. Records of the Geological Survey of Pakistan, 1980, 44: 1-30.

Spear F. S. Metamorphic Phase Equilibria and Pressure Temperature-Time Paths, 1993.

Treloar P. J., Williams M. P., Coward M. P. Metamorphism and Crustal Stacking in the North Indian Plate, North Pakistan. Tectonophysics, 1989, 165(1–4): 167-184.

Treloar P. J., Coward M. P., Chambers A. F., . McClay K. R., . Thrust Geometries, Interferences and Rotations in the Northwest Himalaya. Thrust Tectonics, 1992, 325-342

Zeh A., Holness M. B. The Effect of Reaction Overstep on Garnet Microtextures in Metapelitic Rocks of the Ilesha Schist Belt, SWNigeria. Journal of Petrology, 2003, 44(6): 967-994.