TY - JOUR
T1 - Subsurface profiling of granite pluton using microtremor method
T2 - southern Aravalli, Gujarat, India
AU - Joshi, Aditya U.
AU - Sant, Dhananjay A.
AU - Parvez, Imtiyaz A.
AU - Rangarajan, Govindan
AU - Limaye, Manoj A.
AU - Mukherjee, Soumyajit
AU - Charola, Mitesh J.
AU - Bhatt, Meghnath N.
AU - Mistry, Sagar P.
N1 - Funding Information:
AUJ was supported by DST PURSE fellowship. AUJ, DAS, MAL, MJC, MNB and SPM thank Prof. L.S. Chamyal (Head, Department of Geology, MS University Baroda) for support and encouragement. IAP thanks Head, CSIR Fourth Paradigm Institute, for support. GR was supported by JC Bose National Fellowship and UGC Centre for Advanced Study. SM was funded by IIT Bombay’s CPDA grant. Discussion with M. Mamtani (IIT Kharagpur) and JL Vigneresse (University of Lorraine) is acknowledged. We further acknowledge numerous constructive suggestions from both anonymous reviewer and Lucie Nováková. Thanks to the anonymous Handling Editor, Chief Editor: Christian Dullo and the Managing Editor: Monika Dullo. SM thanks IIT Bombay for providing him a research sabbatical for the year 2017.
Publisher Copyright:
© 2017, Springer-Verlag Berlin Heidelberg.
PY - 2018/1/1
Y1 - 2018/1/1
N2 - We report, using the microtremor method, a subsurface granitic pluton underneath the Narukot Dome and in its western extension along a WNW profile, in proximity of eastern fringe of Cambay Rift, India. The dome and its extension is a part of the Champaner Group of rocks belonging to the Mesoproterozoic Aravalli Supergroup. The present finding elucidates development of an asymmetric double plunge along Narukot Dome. Microtremor measurements at 32 sites were carried out along the axial trace (N95°) of the dome. Fourier amplitude spectral studies were applied to obtain the ratio between the horizontal and vertical components of persisting Rayleigh waves as local ambient noise. Fundamental resonant frequencies with amplitude ≥1-sigma for each site are considered to distinguish rheological boundary. Two distinct rheological boundaries are identified based on frequency ranges determined in the terrain: (1) 0.2219–10.364 Hz recorded at 31 stations identified as the Champaner metasediment and granite boundary, and (2) 10.902–27.1119 Hz recorded at 22 stations identified as the phyllite and quartzite boundary. The proposed equation describing frequency–depth relationship between granite and overlaying regolith matches with those already published in the literature. The morphology of granite pluton highlights the rootless character of Champaner Group showing sharp discordance with granitic pluton. The findings of manifestation of pluton at a shallower depth imply a steep easterly plunge within the Champaner metasediments, whereas signature of pluton at a deeper level implies a gentle westerly plunge. The present method enables to assess how granite emplacement influences the surface structure.
AB - We report, using the microtremor method, a subsurface granitic pluton underneath the Narukot Dome and in its western extension along a WNW profile, in proximity of eastern fringe of Cambay Rift, India. The dome and its extension is a part of the Champaner Group of rocks belonging to the Mesoproterozoic Aravalli Supergroup. The present finding elucidates development of an asymmetric double plunge along Narukot Dome. Microtremor measurements at 32 sites were carried out along the axial trace (N95°) of the dome. Fourier amplitude spectral studies were applied to obtain the ratio between the horizontal and vertical components of persisting Rayleigh waves as local ambient noise. Fundamental resonant frequencies with amplitude ≥1-sigma for each site are considered to distinguish rheological boundary. Two distinct rheological boundaries are identified based on frequency ranges determined in the terrain: (1) 0.2219–10.364 Hz recorded at 31 stations identified as the Champaner metasediment and granite boundary, and (2) 10.902–27.1119 Hz recorded at 22 stations identified as the phyllite and quartzite boundary. The proposed equation describing frequency–depth relationship between granite and overlaying regolith matches with those already published in the literature. The morphology of granite pluton highlights the rootless character of Champaner Group showing sharp discordance with granitic pluton. The findings of manifestation of pluton at a shallower depth imply a steep easterly plunge within the Champaner metasediments, whereas signature of pluton at a deeper level implies a gentle westerly plunge. The present method enables to assess how granite emplacement influences the surface structure.
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U2 - 10.1007/s00531-017-1482-9
DO - 10.1007/s00531-017-1482-9
M3 - Article
AN - SCOPUS:85018293930
SN - 1437-3254
VL - 107
SP - 191
EP - 201
JO - International Journal of Earth Sciences
JF - International Journal of Earth Sciences
IS - 1
ER -