Comment and Reply

COMMENT

1

, Geology is a Field Science-but who cares?

(A comment on the Note by S. K. Tandon published in the Journal of the 'Geological Society of India, Vol. 33, No.5, 1989,383-386).

This Note is most timely. While talking about the paucity of field training of geology students in India, Tandon has not offered suggestions to remedy the situation, except that he has referred to the publication of guide books, as if the mere fact of their availability would alter the situation.

The attitude of the teachers and syllabus-makers is mainly responsible for this state of affairs. Most geology teachers in India-and I am saying this with the fullest sense of responsibility-themselves have poor aptitude and knowledge of field techniques and correct handling of field instruments because they themselves were not taught this, while they were students. And they do not like the hardships of field life, even for short durations. The reason why so many M.Sc. position-holders wish to join the teaching profession in preference to jobs in the Geological Survey of India and other professional organisations is that they would not have to do field work. Some of them have told me so.

Even those who join research in geology want to do minimal field work. Many research guides pay a cursory visit to the field to introduce the scholar. The poor student fends for himself as best as he can, and that is why his field maps and observations can hardly bear close scrutiny in many cases.

, Even correct location requires a great deal of experience-according to the late J.' A. Dunn, at least five field seasons. How many teachers put in sustained field work even for one month in a year? It is only constant handling of instruments which gives experience to use them correctly for accurate determinations of attitudes and other field features.

The solution lies in framing syllabi in such a manner that sustained field work becomes a basic requirement for the award ofa post-graduate degree in geology. For this, many if not most of the present-day teachers will have to be sent for refresher courses with either the G.S.r. Training Institute or attached to field parties of G.S.I., O.N.G.C., etc. In this connection, I recall that several years ago the Government of India had formulated a scheme for exchange of personnel between G .S.1. and academic institutions. The scheme failed because of poor response from the teachers who did not like to abandon the comforts of the class room.

Just as the University Grants Commission has made a doctorate an essential qualification for a University teacher, it should make knowledge of and experience in field work another and additional basic requirement for a job in a geology department.

It would simply not do to take students on annual excursions, which are mostly in the nature of sight-seeing trips: they are treated thus both by teachers and by students. From what I know, students are made to visit some mines and some geological sections, but learn nothing about use of field instruments and

428 COMMENT

techniques. My nephew, a position holder in M.Sc. from a prestigeous university, had been to several such trips, but was hardly taught the use even of a simple Brunton compass in field conditions.

The importance of teaching of field geology was recognised soon after inde-pendence when expansion in the G .S.l. was taking place and new organisations like the Oil and Natural Gas Commission were coming up, and geology departments were being established in many universities and colleges to cater to the growing requirements of geologists in these organisations. The Mining, Geological and Metallurgical Institute of Calcutta held a Symposium on Training of Personnel for the Mineral Industry, in October 1952, when detailed discussions took place for training of field geologists. Some excellent ideas were presented and published in a Special volume (1952), but sadly, they remain largely unimplemented. Had they been seriously adopted by the academic institutions then, the sorry state in which field geology has now fallen would have been avoided.

] would like to suggest here as a model, the programme followed by the Depatment ,of Applied Geology, University of Saugar, where the first year M. Tech. students have to stay in a field camp in tents for one month; and at the end of which they are examined by an external, right in the camp. Another year, the students are attached to field parties of G.S.1. and other organisations for a few weeks, where they learn all aspects of field work. How productive these field camps are is exemplified by a paper in the same issue of the Journal which records the outcome of one such camp (Roday et al. ] 989).

C-6 Mandir Park Mahanagar Extension Lucknow 226006

References

S. M. MATHUR

M.G.M.I.I. (1952) Symposium on Training of Personnel for the Mineral Industry. Tran s. Min Oeo!. Met. lnst. India, v. 49.

RODAY, P. P., CHOURASIA, L. P. and CHAUDHARI, S. (1989) Structural analysis of shear zones in basement granite and their relationship with folding, shearing and faulting in the cover sediments near Hirapur, District Sagar, Central India. Jour. Geo1. Soc. India, v. 33.

pp. 387-408.

REPLY

At the outset, I must thank S. M. Mathur for his comment. It has ensured that a matter of paramount importance does not go without debate. I wrote this article in ] 983. By then, I was convinced that the state of geological education in our country cannot improve unless there is a serious restructuring of our under-graduate geology programs-programs heavily burdened in favour of Field Geology.

REPLY 429

Like any other course, Field Geology also requires good course materials. Students and teachers, alike, will be able to test the observations made by those who prepared these course materials. There is a strong case for multiplying the efforts for pre-paring Field Guidebooks for students from the diverse geological terrains of India. For the benefit of the general readership of the Journal, I would like to recall that the main theme of my article was about the necessity of Field Geology in undergraduate programs and also the restructuring of undergraduate programs. My main thesis is that geology to a majority of undergraduate students is a vast array of terms, classification schemes, samples and maps, without adequate exposure to outcrops and field sections. The students are unable to understand concepts pre-sented to them. Apart from being unable to understand geological concepts, the ability to conceptualise by themselves is non-existent. This, therefore, calls for a reframing of the undergraduate syllabus. Mathur by addressing himself to the postgraduate syllabi has missed the main point of my argument. I am making a plea for a serious corrective measure at the undergraduate level. If that can be done successfully, students at the postgraduate level would be motivated sufficiently to handle field geology with ease.

Then again, in the matter of imparting field training, the perceptions of a teacher are different from that of a professional geologist. Field geology is a sub-ject by itself. This requires to be taught, as I had suggested in my article, in the B.Sc.(Hons.) First Year. (And I couldn't agree more with Mathur on the point that repeated training in field methods including location, surveying and geological mapping is the only way of gaining confidence in field work). So, one point which was clearly made in the article, and I reiterate now, is that Courses in Field Geology, Surveying and Geomorphology should be taught at the B.Sc. (First year) level. Second1y, in the second and third year B.Sc. programs, exercises in Geological Mapping should be carried out in carefully chosen areas. But field work is not to finish here. If we truly believe in the dictum that' Geology is a Field Science , -ali courses, be they in Stratigraphy, Structural Geology, Mineralogy, Petrology, Palaeontology, should have a component of field work. Many concepts in each one of these branches can be brought home more easily through examination of wel1-chosen exposures. Most universities in India are located in terrains having' a variety of geological settings. Teachers need to take their students out on short week-end field trips to discuss such cO:Rcepts in the field. So, we are now addressing ourselves to two types of field work. One pertains to the practice of Field Geology including Geological Mapping with all the attendant methods (surveying etc.). The other, actually pertains to using the relevant exposures as a method of present-ing or testpresent-ing a concept already introduced in the classroom, If this be the level of training in Field Geology of our undergraduates, they will certainly be in a position to go in for (almost) independent field projects at the postgraduate level. Also, as Mathur suggests, at the M.Sc. level, students can be encouraged to be apprentices with professional geologists from the GSI, ONGe, DAE, CGWB and so forth.

430 REPLY

are well looked after by dedicated teachers with a sense of commitment to Field Geology.

And now we turn our attention to human and other resources required to achieve the desired results. Mathur's critical assessment of the lack of appreciation of Field Geology on the part of a good majority of teachers is accurate. But then, the process of changing the attitudes of teachers will have to commence at some time. After some initial help in the form of training by professional geologists, the concerned teacher(s) will have to develop an aptitude for testing the information gathered from the books through sustained field work.

It is true that there may not be too many accomplished field trainers. They may be located anywhere - in the professional agencies, in research institutes or in University colleges as well. A stock should be taken of this manpower resource and a conscious effort made to disseminate this expertise amongst willing and motivated teachers and students in the Universities. For example, what is wrong with the suggestion that a G.S.1. Officer's services could be loaned for a month to conduct the field training camp of a M.Sc. lst year course of any University. Of course, there may be a lot of red tape to cut through. Similarly, methods should exist whereby a teacher, for example, in the University of Jammu may attend to the field course of a group of students from Andhra or vice versa. Finally, resources are required in term of field grants, field equipments and vehicular support. We, therefore, need to emphasise with our educational planners that a completely new look has to be taken with respect to funding of undergraduate geology programs. All of this will remain in the realm of tall talk unless an adequate resource structure exists to meet the challenge of the situation.

There is indeed no alternative. The alternative is producing, as is the case now, geology undergraduates whose minds are a jumble of confusion. This con-fusion is carried forth to the postgraduate level, and in many cases to the Ph.D. level. The solutions are there, the men who can achieve the desired results are there, possibly resources are there. What, then, prevents us from taking steps in the right direction?

.Department of Geology

.University of Delhi. Delhi 110007 S. K. TANDON

2

Vertebrate Fauna from the Infra-

and Inter-trappean

lJeds of Andhra Pradesh:

Implications

(A comment on the paper by G. V. R. Prasad, published in the Journal of the Geological Society of India Vol. 34, No.2, 1989, pp. 161-173).

COMMENT 431

reported from Western India, Central India, Andhra Pradesh and also from the Upper Cretaceous beds of Tiruchirapalli District, Tamil Nadu. The palaeomagne-tic and radiometric age referred in the paper by G. V. R. Prasad indicating the ·timespan during Deccan Trap activity also confirms the age assigned to the dinosaur bearing beds (middle to late Maestrichtian). In Tiruchirapalli District of Tamil Nadu, Kallamedu Formation overlies beds containing larger planktonic fora-'minifera, ammonoites, inoceramids of early Maestrichtian age (Kal1anakurchchi ·and Ottakoil Formations, M. V. A. Sastry et al. 1972). Here the beds yielding -dinosaur remains are also overlain by Niniyur Formation containing Hercoglossa

·danica, thus precisely indicating Middle to Late Maestrichtian age to horizon

yield-ing dinosaur remains. These findyield-ings positively show the homotaxial relation of -dinosaur-bearing Maestrichtian Upper Cretaceous beds in Peninsu1ar India.

B. R. J. RAO

Reference

:SASTRY, M. V. A., MAMGAIN, V. D. and RAO, B. R. J. (1972) Ostracod fauna of the Ariyalur Group (Upper Cretaceous), Tiruchirapalli district, Tamil Nadu. Palaeontol India, v. 40, pp. IA8.

3

The Nature of Bed rock at Petermann, I, Wohlthat Range,

Antarctica.

(A comment on the paper by S. M. Hussain in the Journal of the Geological 'Society of India, Vol. 33, No.5, pp. 429-436).

Author has indicated the 'bed rock' at Petermann I to be alkali-feldspar .granite porphyry and quartz alkali-feldspar syenite porphyry based on modal

ana-lysis and textural criteria. Mapping of the three Petermann Ranges and associated 'nunataks during the Sixth Antarctic Expedition and subsequent work shows that the 'rocks under discussion show field, petrological and chemical characteristics of the .anorogenic (A-type) granites. Though uncommon, the occurrence of rapakivi .as well as the pyterlitic (with ovoidal K-feJdspar) textures besides the typical mineral ,assemblages and paragenesis support this contention. It is further substantiated by high total alkalies (K20 + Na20 : 6.06-9.31 per cent), MgO « 0.35 per cent), impoverishment and lower abundance of CaO (0.8-1.98 per cent). Such nature is .also corroborated by high total REE content, significant enrichment of

incom-patible elements, LREE and a light negative to nearly no europium anomaly (EujEu* : .04-1.25)

432 COMMENT

As mentioned by the author, these rocks are extremely coarseA grained

with-megacrystic K-feldspars (3-5 em). It would have been more pertinent if normative or major oxide classification had been attempted. In an-ab-or or K20-Na20-CaO

classifications these rocks predominantly plot in a granitic field with spread towards. quartzmonzonite.

For the soda metasomatism of these rocks, a pressure of 5-7 kb is assumed guided by the garnet-biotite geobarometry from gneisses of Schirmacher area. The Schirmacher gneisses lie about 80 km north of Petermann Ranges and are not associated with the' bed rocks' of Petermann I. It will be worthwhile to add here that the Petermann I area also exposes large outcrops of older ortho and para-gneisses as well as granodiorites younger to the granites under discussion, besides. anorthositic dykes and outcrops of ferrodiorites.

One typographic error has crept in the latitude of Petermann I on p. 431 should be read as 71 "'20' to 71 °30'S.

Geological Survey of India Faridabad

References

A. JOSHI N. C. PANT M. L. PARIMOO

ANDERSON. J. L. and CULLERS, R. L. (1978) Geochemistry and evolution of the Wolf River batholith, a late Precambrian Rapakivi Massif in N-Wisconsin, USA. Precamb. Res., v. 7, pp. 287-324.

ANDERSON, J. L. (1980) Mineral equilibria and crystallisation conditions in the late Precambrian Wolf River Rapakivi Massif, Wisconsin. Amer. Jour. Sci., v. 280, pp. 289-332.

(1987) Proterozoic anorogenic granites of the South~western United States. In: J. P.

Jenny and S. J. Reynolds (eds.). Geological evolution of Arizona> Arizona Geological Digest, v. 17.

COLLER SON. K. D. (l982) Geochemistry and Rb-Sr geochronology of associated Proterozoic peralkaline and subalkaline anorogenic granites from Labrador. Contrib. Min. Petrol.. v. 81, pp. 126·147.

COLLINS, W. J., BEAMS, S. D., WHlTE. A. J. R. and CHAPPELL, B. W. (1982) Nature and. origin of A·type granites with particular reference to SE Australia. Contrib. Min. Petrol., v. 80, pp. 11:',9-200.

EMSLIE, R. F. (1978) Anorthosite Massifs-Rapakivi Granites and late Proterozoic rifting of N-America. Precamb. Res., v. 7, pp. 61-98.

HUBBARD. F. H. and WHITLEY, J. E. (1978) Rapakivi granite, anorthosite and charnockite plutonism. Nature, v. 271, pp. 439-440.

JOSHI, A., PANT, N. C. and PARIMOO, M. L. (in prep.) Anortbositic dykes and the associated. ferrodiorite suite in Petermann Ranges, East Antarctica.

KRANCK, E. H. (1969) Anorthosites and rapakivi magmas from the lower crust. In: Y. W.

Isachen (ed.). Anorthosites and Related Rocks. Memoir NY State Museum and Sci. Service, 118, pp. 93-98.

MARTIN, R. F. and PIWINSKII, A. J. (1972) Magmatism and Tectonic Settings. Jour. Geophy. Res., v. 77, 4966-4975.

REPLY

While thanking Joshi et at. for their comments on my paper, I wish to clarify as follows:

1. The field, megascopic and petrographic studies including the photomicrographs (which were edited and not published) clearly speak that the bedrock of Petermann I area is a orthoclase microperthite megacrystic granitoid which on the basis of modal mineral composition can be classified as 'alkali feldspar granite' to . quartz alkali-feldspar syenite'. Rock name has to be given on the basis of modal mineral composition only.

2. The chemical compositions are really not the true representatives for classifi-cation of any rock type, specially granitoids where, in a single suit large scale variation in major and trace elements can be observed.

J. The overall chemistry of the samples from our analyses slightly differs, especially the alkalies from what is reported by Joshi et

at.

4. Joshi et at. are suggesting that the origin of this bed rock at Petermann I and the Gruber anorthosite massif are the minimum melting products of

metasedi-mentary source and have a comagmatic origin which, in my opinion, (at this stage) is not possible. Contrary to their argument the plagioclase feldspar in K-feldspar megacrysts is secondary and a post formational phenomena (Figure).

However, detailed work on this aspect which is in progress may throw more light.

5. My paper is only a preliminary report on the nature of bedrock and I have not attempted any genetic model, as this requires more information both from field and laboratory studies which are in progress.

6. Regarding geothermometry and barometry, as all the required mineral assemblages are not available in Petermann I and as the overall character of the gneisses at Schirmacher and Petermann l are similar, the barometry is assumed from the Schirmacher and calculated temperature from Petermann area are reported. It is possible that wiih some more data the results can be verified.

7. I acknowledge the typographical mistake of 77 for 71.

National Geophysics Research Institute

Hyderablld. 560007