Metamorphic rock sequences of the Eastern Himalaya

400 tion to aquifers, Varahamihira noted the occurrence of various animals underground: fish, frog, snake, lizard, tortoise, scorpion, mongoose, rat, etc. (about a dozen in all). Says Prasad: 'Obviously the reference is to aestivation commonly undergone by the poikilothermic or cold-blooded forms which have the body temperature corresponding closely with that of the environment.' (p. 189) Ancient western literature is replete with egregious fallacies and wild theories about the origin and behavior of ground water. The modern concept of the hydrological cycle did not emerge in the western world until late in the seventeenth century. Prasad discounts the western belief that modern scientific hydrology was born near the end of the seventeenth century (Pierre Perrault, Edme Mariotte, Edmund Halley). According to Prasad, however, Vedic texts which may be as much as 3000 years old, contain sound remarks about ground water and the hydrological cycle. Varahamihira perpetuated this tradition. His methods for ground-water exploration, devoid of mysticism, were entirely empirical. Citing a definition of hydrology adopted by the former Federal Council on Science and Technology in the United States, Prasad said that, 'It is a restatement of the ideology of the hydroscience as visualized and set forth in Varahimihira's work, and the credit and distinction of being the father of hydroscience must unreservedly be accorded to Varahamihira whose work on the subject remains even today unique and unparalleled in the comprehensiveness of its scope and the sweep of its findings.' (p. 266) This assertion is not acceptable. Ancient Indian Knowledge was completely unknown to western writers and hydrologists. The ancient writings could have had no influence where they were unknown. Western science developed independently of India lore. Modern scientific hydrology as practiced and understood throughout the West, is a western product. Prasad observes that, 'From a superficial study one may be tempted to dismiss this ancient contribution of Varahamihira as a collection of isolated observations lacking system and rationale and hence a scientific character as it is under-

stood in the present day context.' (p. ix) This is precisely the reaction of the present reviewer. Prasad advocates that the knowledge embodied in Varahamihira's work should be used in modern times to discover and exploit ground water in arid and semiarid areas of the third world. This suggestion is not apt to be followed unless the factual data used for exploration are organized and systematized. Prasad's book is a useful contribution to the history of hydrology. It should be consulted by all who are interested in that history. English is not Prasad's first language. Nevertheless, the book is well written despite its linguistic awkwardness here and there. The photographic illustrations, unfortunately, are very poorly reproduced. Raymond L. Nace, Gooding, Idaho

EASTERN H I M A L A Y A OROGENESIS P.K. Verma (Editor), 1980. Metamorphic Rock Sequences of the Eastern Himalaya. (with a foreword by John Hailer.} K.P. Bagchi and Company, Calcutta, 166 pp., Rs. 100.00, U.S. $25.00. Outside of the foreword by John Hailer and the introduction by I.C. Pandle, this is a potpourri of papers, mostly of local significance. They seem to add little to any comprehensive understanding of the eastern Himalaya for the general student of orogenesis. This conclusion is, perhaps, not surprising to those familiar with the development of ideas on stratigraphy and tectonometamorphic evolution in other orogenic belts where there is much easier accessibility and where coverage by geologic maps and special studies is greater and more detailed. A certain critical mass of carefully organized data accumulation seems to be necessary before there can be significant extension of understanding of the field geology beyond that to be gained from reconnaissance studies such as the major effect of Gansser (1964). Because of inadequacy of maps showing locations and relating included topics to the larger-scale geology, the reader will want

401 to have at hand a map such as the foldout Geologic Map of the Himalayas from Gansser's bt)ok. There are three groupings of topics, each consisting of three short papers: (1) structural geology and tectonics; (2) stratigraphy and regional geology; and (3) petrology and geochemistry. Papers are followed individually by discussions and comments by participants in the volume. Some of the latter resemble squabbles about points that most of the potential readership will hardly be able to evaluate. A frustrating characteristic of the book is its failure to tie together the contained studies even where that seems both possible and desirable. Pande's introduction does not serve that purpose. Thus, the structure map for the area around Darjeeling by P.K. Gangopadhyay is not coordinated with the metamorphism map of the same area by N.C. Ghose 'largely based on Ray (1947)'. Neither of these maps shows the relations of the contained information to the famous Main Central Thrust wherein rapid relative displacement has been believed by many to be tied to inverted metamorphic zonation (cf. S. Sinha Roy, p. 77). An understanding of those relations and the relative timing is of great importance to those interested in applying plate-tectonic theory to the Himalayas such as Bird (1978), who has introduced an important modification to that theory with his ideas on crustal delamination, including an effect on metamorphic zoning. There is a chapter on the inverted metamorphic zonation by Amalbikash Mukherjee containing a most unconvincing demonstration of 'qualitative temperaturemodelling'. Readers interested in Gondwana fossils and their distribution will want to read the pollen study by Trilochan Singh. Perhaps of most interest to readers of Earth~cience Reviews will be Haller's provocative foreword, entitled Himalayan Orogenesis in Perspective. In the current stage of its rapid development, devotees of plate-tectonic theory have long needed an experienced 'devil's advocate' with the mastery of the facts of geology enjoyed by the distinguished student of East Greenland geology. Hailer plays the currently unpopular but necessary role of the heretic, questioning elements of the basic foundation of the 'geological revolution' such as the mag-

netic 'isochrons' in the oceans. One can hope that he will elsewhere amplify his counter-arguments so that the ensuing debate will inform geologists worldwide, particularly those who apply plate-tectonic theory uncritically to geology as seen in the field by 'landlubbers' (Haller's appellation). There can be little doubt that that theory is much more difficult to apply within the continents than it is within the oceans and that difficulties increase as the rocks get older. A theory is only as good as its ability to withstand confrontation with facts, whatever their source. REFERENCES Bird, P., 1978, Initiation of intracontinental subduction in the Himalaya. J. Geophys. Res., 83 : 4 9 7 5 4 9 8 7 . Gansser, A., 1964. Geology of the Himalayas. Wiley-lnterscience, New York, N .Y., 289 pp. John L. Rosenfeld, Los Angeles, Calif.

W E S T E R N U.S. G E O L O G Y A.M. Bassett and Sl O'Dunn, 1980. Genera/ Geology of the Western United States - A Laboratory Manual. Peek Publications, Mountain View, Calif., V I I I + 2 5 4 pp., U.S. $9.95. This book is not a 'General geology of the Western United States' but in the first line (see the second title!) a laboratory manual based on geologic examples from the western states. Preferences are given to California and Arizona, besides some other western states, also including Kilauea, Hawaii, and glaciers in Alaska. It simply begins with minerals and rocks; next come aerial 'photographs and topographic maps. Finally follow chapters on structural geology, fossils and geologic time, geologic maps, landform of the western U.S., and marine geology. There are many instructive graphs and photos (some not very indicative). Each chapter provides simple practical exercises, especially review questions, and for the advanced student some 'more challenging questions'. A good supplement is the selected