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The Indus Suture Zone and India-Asia Plate Margins: Workshop-Cum-Field Meeting
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starting from Gopalpur-on-Sea through the higher ranges of Rayagada right upto the western scarp face of the Eastern Ghats (west of Jcypore town). The geology included the patchy charnockite-leptynite association of the Hatia quarry, glimpses of the anortliosite complex of the Chilka lake bordered on the south by the calc-silicate rocks, and coarse charnockite-mafic granulite association with pseudotachylite veins and bands indicating shearing features. Courtesy Orissa Tourism Development Corporation, we had a night halt at Taptapani with the hot springs providing an attraction of more general interest. The journey from Taptapani to Jeypore revealed the megacrystic granites apparently invading the charnockites, banded gneiss and khondalites and according to some interpretation sealing tlie major slaear zones following tracts of Nagavalli and Vamsdhara rivers. Tlae flat topped hills of the RayagadaKhoraput Ghat section unfolded the huge bauxite deposits capping the hill ranges on klaondalitic foundation. This also demonstrated the metasedimentary nature of khondalites by their interbanding with quartzites. We had cut through the western charnockitic belt twice one on the evening of 2nd November and tlae other on 3rd November morning, tlae latter traverse showing
juxtaposition of charnockites against the granite gneisses of the Bastar craton quickly followed by outcrops that show late dolerite dykes cutting the charnockites. We had to face the words of our instructors at face value for the existence of tlie Silleru shear zone, apparently the westernmost and the longest one in the Sileru River bed are now under water (what a miss!). The last leg of the traverse took the participants through Araku Valley megacrystic granitoid, again bauxitic tops of the Anantagiri hills and by now world famous sapphirine granulites one km NE of Anantagiri. The Borra Caves and adjacent railway cuttings again provided the metasedimentaries in the form of interbanded marble and calc silicate rocks in the EGMB. The last stop at S.Kota with its structural details within charnockite was made possible under the head lights of the GSI jeeps. For this participant who had his first experience in the EGMB, this field workshop offered a kaliedoscope at the frontier of high grade to ultra high grade metamorphism, migmatisation and magmatism. My only wish was that the traverse could have been spread over four days rather than three, so that some finer but important points of field geology could have been better discussed and demonstrated in the field spots.
Coirdiirniin Rcsenrdi ( G o l i d m i i n Nr7usletter Section) V 2,No 2,p 327 01999 Iirteriintioirnl Associntion for Gondruriiin Resenrch, Jnpnii
ANNOUNCEMENTS
The Indus Suture Zone and India-Asia Plate Margins: Workshop-Cum-Field Meeting Leh, Ladakh (Jammu and Kashmir, India), September 6-11,1999 Tlae Wadia Institute of Himalayan Geology, Dehra Dun is organizing an international workshop-cum-field meeting from 6-11 September, 1999. The workshop will give an opportunity to present and discuss data related to the Indus Suture Zone and its eastern and western extensions, Himalaya and Karakoram ranges. The workshop will focus on the following major themes: Lithospheric dynamics across Himalaya, Indus Suture Zone (ISZ) and Karakoram Plutonic-volcanic arc magmatism Neo-Tethys oceanic crust, accretionary prism and intraarc sediments Evolution of northern and southern passive margins of Neo-Tethys Syn- to post-collision intra-montane basins Deformation and exhumation of metamorphic complexes
Active tectonics and natural hazards Palaeoclimate A post-workshop field trip of 4-5 days will be organized along the Indus Suture Zone in Ladakh, depending on the participant’s response. For more information: Dr. V.C. Thakur Director, Wadia Institute of Himalayan Geology, PB No. 74, Dehra Dun-248 001, India, or Dr. Hakim Rai Organizing Secretary, Wadia Institute of Himalayan Geology, PB No. 74, Dehra Dun-248 001, India. Fax: (+91) 135- 62 52 12 e-mail: wihg8giasdlOl.vsnl.net.in
starting from Gopalpur-on-Sea through the higher ranges of Rayagada right upto the western scarp face of the Eastern Ghats (west of Jcypore town). The geology included the patchy charnockite-leptynite association of the Hatia quarry, glimpses of the anortliosite complex of the Chilka lake bordered on the south by the calc-silicate rocks, and coarse charnockite-mafic granulite association with pseudotachylite veins and bands indicating shearing features. Courtesy Orissa Tourism Development Corporation, we had a night halt at Taptapani with the hot springs providing an attraction of more general interest. The journey from Taptapani to Jeypore revealed the megacrystic granites apparently invading the charnockites, banded gneiss and khondalites and according to some interpretation sealing tlie major slaear zones following tracts of Nagavalli and Vamsdhara rivers. Tlae flat topped hills of the RayagadaKhoraput Ghat section unfolded the huge bauxite deposits capping the hill ranges on klaondalitic foundation. This also demonstrated the metasedimentary nature of khondalites by their interbanding with quartzites. We had cut through the western charnockitic belt twice one on the evening of 2nd November and tlae other on 3rd November morning, tlae latter traverse showing
juxtaposition of charnockites against the granite gneisses of the Bastar craton quickly followed by outcrops that show late dolerite dykes cutting the charnockites. We had to face the words of our instructors at face value for the existence of tlie Silleru shear zone, apparently the westernmost and the longest one in the Sileru River bed are now under water (what a miss!). The last leg of the traverse took the participants through Araku Valley megacrystic granitoid, again bauxitic tops of the Anantagiri hills and by now world famous sapphirine granulites one km NE of Anantagiri. The Borra Caves and adjacent railway cuttings again provided the metasedimentaries in the form of interbanded marble and calc silicate rocks in the EGMB. The last stop at S.Kota with its structural details within charnockite was made possible under the head lights of the GSI jeeps. For this participant who had his first experience in the EGMB, this field workshop offered a kaliedoscope at the frontier of high grade to ultra high grade metamorphism, migmatisation and magmatism. My only wish was that the traverse could have been spread over four days rather than three, so that some finer but important points of field geology could have been better discussed and demonstrated in the field spots.
Coirdiirniin Rcsenrdi ( G o l i d m i i n Nr7usletter Section) V 2,No 2,p 327 01999 Iirteriintioirnl Associntion for Gondruriiin Resenrch, Jnpnii
ANNOUNCEMENTS
The Indus Suture Zone and India-Asia Plate Margins: Workshop-Cum-Field Meeting Leh, Ladakh (Jammu and Kashmir, India), September 6-11,1999 Tlae Wadia Institute of Himalayan Geology, Dehra Dun is organizing an international workshop-cum-field meeting from 6-11 September, 1999. The workshop will give an opportunity to present and discuss data related to the Indus Suture Zone and its eastern and western extensions, Himalaya and Karakoram ranges. The workshop will focus on the following major themes: Lithospheric dynamics across Himalaya, Indus Suture Zone (ISZ) and Karakoram Plutonic-volcanic arc magmatism Neo-Tethys oceanic crust, accretionary prism and intraarc sediments Evolution of northern and southern passive margins of Neo-Tethys Syn- to post-collision intra-montane basins Deformation and exhumation of metamorphic complexes
Active tectonics and natural hazards Palaeoclimate A post-workshop field trip of 4-5 days will be organized along the Indus Suture Zone in Ladakh, depending on the participant’s response. For more information: Dr. V.C. Thakur Director, Wadia Institute of Himalayan Geology, PB No. 74, Dehra Dun-248 001, India, or Dr. Hakim Rai Organizing Secretary, Wadia Institute of Himalayan Geology, PB No. 74, Dehra Dun-248 001, India. Fax: (+91) 135- 62 52 12 e-mail: wihg8giasdlOl.vsnl.net.in