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Hoffmann. However, Dalziel suggested that the former insistence does not f i t the geological data. Smethurst and others gave paleomagnetic data from Aldan Shield and pointed out the problem of the location of Siberia in the Rodinia ensemble. Other talks of symposium 9 involved Cawood and Leitch, E Torcq and others, T.H. Torsvik, S.R. Boble and others, C. Mac Niocaill and others, and W.E. Stephens and others.

After 17:30 in the big hall, the poster session was held every day. The hall was so great such as an aircraft garage and in this big area were arranged poster corners of several tens of symposia and sessions. There were only small number of cancellations of the posters, and the posters were arranged orderly and therefore was very easy to find out the poster that we hoped to see. At the four corners of the hall were opened the free beer drinks by some beer company. Because of this, all participants rushed to the poster session soon after the oral presentations, and the discussions ahead the posters were so vivid to spit bubbles from the mouse.

Posters of the symposium 9 were convened by Hoffmann, Jacobs and Torsvik visited by most members of IGCP-288 and 368 and thus was so friendly, appearing as if the old boys circle.

#A geotectonic map of Gondwana presented by R. Unrug and others, and the Rodinia to Pangea maps by C. Powell and Li attracted much of participants. There were 12 posters in the symposium 9 as below. B. Bingen and others, Buehn and Stanistreet, S. Fachmann and others, Khudoley and Guriev, Lowman and Jarvis, B. Muco, T. Palacios and others, S. Piazolo and others, G.R. Sadowski, B. Seth and others, G. Shields, and Weber and Kohler.

On the 26th night was an open forum “Discovering Supercontinents” chaired by C. Powell and myself. Although participants were not many as to reach 20 persons, most of active scientists interested in the supercontinent tectonics from various countries attended. Future research plan and the new proposal of IGCP projects related with the supercontinents were discussed. The new IGCP proposal will be centered to the Rodinia research, and C. Powell will elaborate the plan, and R.V. Schmus will take charge for the practical arrangement. Those who have any ideas on these points are requested to take a direct contact to C. Powell. Related news will also appear in the Gondwana News Letter and people who are interested in the topics are required to pay attention to the Newsletter.

Gondwana Resecirch (Gonrlwimn Newsletter Section) V l , No. I , pp. 159-161. 0 I997 Inrerncitionul Associntion fur Gondwnnii Resecirch

CONFERENCE REPORT

IGCP-368 International Conference and Field Workshop, Trivandrum, India

Anand Mohan

Department of Geology, Banaras Hindu Universig, Varanasi-221 005, India

The evolution of the regional granulite terrains, which are exhumed portions of the lower-mid crustal levels, is a key problem of today, Recent research publications have confirmed that the southern Indian shield presents several slices of different age and tectonometamorphic history of the crustal section developed over an extended period. Southern India, regarded as home for charnockites and granulites, thus offers a unique terrain to study the evolution of the continental crust. An integrated approach in respect of petrotectonic imprints, geochemical signatures, geochronological and P-T constraints address fundamental questions related to the origin and formation of granulite grade rocks and eventual stablization

of the continental crust of southern India. Great geologic significance is attached to the study of the continental crust of southern India as the currently ongoing researches point to remarkable coherence among the mobile belts within the Gondwana framework. These salient issues comprised the main basis of the International Conference and Field Workshop of IGCP-368 on the “Proterozoic Continental Crust of Southern India”.

A well planned and admirably accomplished International Conference and Field Workshop organized by UNESCO- IUGS-IGCP-368 held at Trivandrum (India) from August 20- 27, 1996 was co-sponsored by the Centre for Earth Science

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Studies (CESS). The international event comprised of two days' symposium at Trivandrum (21st and 22nd August) followed by intensive five days' field excursion concluding at Bangalore on the evening of 27th August 1996.

Conference The symposium was attended by I70 participants including

123 UNESCO delegates representing 1 1 countries (Sri Lanka, Japan, Russia, Germany, Italy, Switzerland, USA., Canada, South Africa, Namibia and India). Prof. N. Babu, Vice- Chancellor of the Kerala University inaugurated the conference. Prof. K.S. Valdiya presided over the function and stressed the significance of Neoproterozoic reworking of the Archaean crust of southern India. Dr. K.M. Nair, Director, CESS welcomed the delegates. Prof. M. Yoshida, Co-Leader of IGCP-368 released the Seminar Proceedings volume and Dr. K.R. Gupta, Director, Department of Science and Technology received the copy. Dr. M. Santosh, Co-Leader of IGCP-368 proposed the vote of thanks. Besides the UNESCO-IGCP delegates, several eminent academicians and active researchers graced the inaugural function.

Memoir Volume Prof. K.S. Valdiya released the Gondwana Research Group

Memoir-3 (text book and field guide on the Archaean and Proterozoic Terrains of Southern India within East Gondwana) and the copy was received by Prof. P.K. Rajendran Nair. Memoir-3, a timely collection of 16 review papers is an excellent resource book concerned with current state of petrological, geochemical, geochronological and tectonic aspects of southern Indian geology. Active researchers will find that the synoptic views presented in this memoir open new avenues of future research. Students and professionals looking for an overview of the ongoing research in southern India will be benefitaed. The book begins with an appropriate coverage on the emerging concepts of the Gondwanaland since the early times and describes the configuration of disperesed mobile belts within East Gondwana (Chapters 1,2,3). There are strong papers which elucidate the deep continental structures (Chapter 4), geochronological constraints (Chapter 5) and major shear zones (Chapter 6) in southern India. Subsequent useful Chapters (7 and 8) are devoted to alkaline magmatism and Proterozoic mineralization. Interesting papers on charnockitization and the role of fluid-rock interaction, and on the exciting possibilities of extreme metamorphic P-T conditions in the Kerala Khondalite Belt make up Chapters 9 and 10 respectively. Commendable concise reviews on the geology of Nilgiri, Madurai and Trivandrum blocks are presented in Chapters 12, 13 and 14.

Section 2 of the Memoir is exclusively devoted to the information on landmark field spots which guide explanations to fundamental questions addressed in Section 1. On the whole, it succeeds remarkably on both counts and brings together the work of a large collaborative team committed to the cause of southern Indian geology.

Broad Themes and Presentations

Seven main themes identified for nearly 45 oral presentations in the symposia under three scientific sessions were chaired by eminent scholars. 1. Gondwann terrains and their correlation

Session 1 : R.J. Thomas and A.S. Janardhan Session 2: J. Jacobs and G. Schreurs

2. Structure and tectonics P.K. Rajendran Nair and P.B. Groenewald

3. Gondwana Sediments M.M. Nair

4. Metamorphic processes T. Chacko and H. Wada

5. Metamorphic P-T-t history Session 1 : Y. Osanai Session 2: Anand Mohan and Y.J. Bhaskara Rao Session 3: A.T. Rao and V.I. Fonarev

H.J. Peach and C.B. Dissanayake

G.H. Grantham and V. Glebovitsky

6. Mineralization

7. Magmatism

New data, novel ideas, exchange of scientific views and enlightened discussions during presentations always kept the audience alert. Prof. M. Yoshida, in his opening talk (Session 1) presented Sm-Nd isotopic constraints on India-Antarctica sector pointing that crustal signatures and tectonic characteristics of the Circum East Antarctic Mobile Belt played the chief role for the birth of East Gondwana. Dr. Jayananda spoke on the recent geochronological data on southern India and stressed on the currently accumulating Pan-African ages from Madurai block. Dr. Bhaskar Rao expressed Cauvery shear zone as part of Neoproterozoic reworking of Archaean crust supported by Sm-Nd and Rb-Sr ages. Dr. Jacobs described evidence for Pan-African overprinting of Meso- to Palaeoproterozoic crust along a section from Southeast Africa to East Dronning Maud Land. During Session 2, Dr. Santosh summarised major imprints of Pan-African phase of tectonothermal activity in different East Gondwana crustal fragments. Dr. Thomas narrated on the role of crustal material within the Natal embayment that is crucial with regard to delimitation and possible correlation of various Grenvillian terrains in Southeast Africa and East Antarctica. Dr. Janardhan used mineral assemblages, P-T-t paths and radiometric data to evolve the concept of common metamorphic histories of southern granulite terrain, Rayner complex and southern Madagascar. Theme 2 witnessed a talk by Dr. Bauer on structural evolution of polyphased metamorphosed basement rocks from East Antarctica. Dr. Chetty focussed on the tectonic studies in the Cauvery shear zone. Dr. Kehelpannala debated on the compositional layering in high grade gneisses of Sri Lanka. Dr. Sengupta presented an account of the ductile shear zones and discrete shear fractures in the Precambrian gneisses of Shirmacher Hills. Dr. Tani used structural and kinematic

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analyses along with geochronological data to elucidate the collision tectonics of the Wani and Highland Complexes in Sri Lanka. During theme 3, besides other talks Dr. Bhushan attempted a discussion on the Archaean-Proterozoic boundary in Rajasthan backed by REE data of clastic and carbonate rocks. Dr. Farquhar made an interesting presentation within theme 4 on the timing and nature of fluid-rock interaction at Ponmudi quarry utilizing oxygen isotope geochemistry. Dr. Satish Kumar emphasized on the failure of cation exchange themometers in preserving the peak metamorphic conditions and favored application of carbon isotope thermometery in marbles from Kerala Khondalite Belt to estimate P-T conditions. Dr. Radhika discussed about the significance an mode of occurrence of graphite in the Precambrian terrains of East Gondwana. Dr. Fonarev envisaged an early extensional phase followed by compressional tectonic regime for the evolution of Eastern Ghats granulite belt. In theme 5, Dr. Chacko tried to push the P-T conditions in Kerala Khondalite Belt to ultrahigh temperature metamorphism on the presumption that earlier studies underestimated the peak temperatures. Dr. Mohan showed important reaction textures coupled with mineral- chemical data to establish a clock-wise decompressional P-T metamorphic regime for the sapphirine granulites from Kodaikanal. Dr. Rao gave an account of the geochmistry of calc-silicates from Visakapatanam region. Dr. Shaw demonstrated textural and P-T data in favor of isobaric cooling followed by decompressional P-T segment for the Rayagada high grade granulites, Eastern Ghats. In section 2 of theme 5, the audience heard an excellent commentry on the overall geology of Madagascar from Dr. Ashwal. Dr. Grantham presented views in favour of an anticlockwise P-T path for the granulite grade rocks from South Natal, South Africa. Dr. Divakara Rao had a presentation on the metamorphic history of the granulite facies rocks from Eastern Ghats. Session 3 continued with a talk by Dr. Srikantappa on polymetamorphic evolution of Coorg granulites, Dr. Yamamoto gave a preliminary account of P-T estimates of Tekkala area, northeast Visakapatanam. Dr. D.V. Subba Rao described sapphirine occurrence in metamorphic conditions of metasediments from Andipatti-Usilampatti region. Aspects of gem occurrences in Gondwanaland by Dr. Rupasinghe, and tungsten mineralization in Northwest India related to late Proterozoic acid magmatism by Dr. Pandian broadly covered theme 6. Dr. Paech focused on the new structural observations in Central Dronning Maud Land in the beginning of theme 7. Dr. Ram Mohan presented evidence for late Proterozoic alkaline ultramafic magmatism in Sanialpatti complex. Dr. Narayana stated the presence of 1900 Ma old granulites in Eastern Ghats from Rb-Sr whole rock isotopic studies. Dr. Rajesh concentrated on the petrogenetic significance of pyroxene megacrysts in massif anorthosite from Kerala. Besides, there was a separate poster session with nearly 30 well illustrated posters.

Business Meetings Lively Business Meetings held during the pre-dinner

sessions on 21 st, 22nd and 23rd August focused on the main

objectives and provided a common platform to freely share the experience. Important Business Meetings included UNESCO-IGCP-348 (Mozambique and related belts) on August 20 summarized by Dr. M. Santosh (National Chairman), and UNESCO-IGCP-368 meeting (Proterozoic Events in East Gondwana) on August 21 summarized by Prof. M. Yoshida (Co-Leader). Business Meeting of Asia and Pacific International Fluid Inclusion Society (APIFIS) and Indian National Working Committee of IGCP-368 (Dr. M.M. Nair, Convenor) were also held on August 22. 1996.

International Association for Gondwana Research

IAGR, a wide-spectrum scientific body, is committed to promote scientific research and encourage academic pursuit in Gondwana terrains with a notion to furnish a common forum for the intergration and exchange of information. A general assembly meeting of the IAGR held on August 21 was presided over by Dr. R.J. Thomas and Dr. K.M. Nair. Elections of the office bearers formed the council of following members:

Dr. M. Yoshida (President) Dr. M. Santosh (Secretary General) Dr. S.R. Divi,Dr. B. Storey, Dr. R.J. Thomas, Dr. S. Yoshikura, Dr. T.R.K. Chetty (Secretaries) Dr. H. Wada (Treasurer)

Besides other important declarations, it was decided to bring out an international geoscience Journal, "Gondwana Research".

Field Excursion Field excursion was the major attraction of this workshop.

Field guide books with exact locations, sketch illustrations, generalised geological maps, and cross-section views served the adequare geological background for the different field stops. Additionally, the lithological descriptions, petrographic details, supplemented with probe and geochemical data enriched the merit of the field guide book. The schedule of the field excursion was hectic, but it was an enjoyable experience to see the spectacular in situ rock exposures.

With a total of 14 field stops during the five days long field traverse, there were foud field camps at Kanya Kumari, Madurai, Ootty and Bangalore, that provided star comforts. Visits to classic spots of incipient charnockites of Kottavattom, calc-silicate rocks adjacent to massive charnockites at Nuliyam, massif anorthosite body at Oddanchathram, development of pseudotachylites at Gudiyar quarry, exposures of typical khondalite quarry at Chittikara, retrogressed and bleached granulites at Mettupalayam were worthwhile. Pack lunches, strict timings and longer working hours enabled the excursion team to cover the substantial distance by road from Trivandrum to Bangalore. Never ending on-the-spot debates brought the participants to get to know each other very well. The rocks as well as the host made a lasting impression on the minds of the participants and the farewell party announced the next meeting at Madagascar.

Condwcinri Reseurrh, KI. No. I , 1997