GEOCHEMISTRY OF GROUNDWATER OVER SUKINDA ULTRABASIC- BASIC ROCKS, JAJPUR DISTRICT, ORISSA, by S.K. Som, R. Joshi,
G. Neogi and M. M. Mukherjee. Jour. (3eoI. Soc. India, v.54, pp.73-8 1 , 1999
S. Das, 18 Madhu Sudan Nagar, Bhubaneshwar comments:
1. The authors erroneously give an impression that theirs is a pioneering work. Central Ground Water Board has been working on hydrogeology of the Sukinda valley since the seventies and has issued a number of reports. (e.g., CGWB, 1977; I. Radhakrishan, 1979). A detailed reappraisal of hydrogeological studies was presented at the National Seminar on Role of Earth Sciences in Environmental Management held in February 1997 at the Geology Department, Presidency College, Calcutta. A paper entitled "Hydrogeology around Sukinda valley in Orissa with reference to mining activities" by S. Das and A. Kar was published in the May 1997 issue of this Indian Journal of Earth Science, v.24 (no.3-4), pp. 10-26.
This paper contains details such as the hydrogeological set up of the area, water table, piezometric heads of deeper aquifers, aquifer parameters, ground water flow pattern, recharge- discharge, groundwater quality and contan~ination from hexavalent chromium etc. In fact the rarige of major constituents in Table 6 of this paper show striking similarity to the same in Table 1 of paper by Soin et al.
2. The water table contour ]nap (Fig. 1 a of Sorn et al.) does not indicate the time period, which is essential. Further, in the E-W transect, the line joining 9 to 14 coinciding with the course of the Sukinda river shows the river as influent. But, as established in the water table contour map Nov-Dec 199 1 (Fig. 1 b of the paper by Das and Kar), the river is effluent and this holds good for the pre-monsoon period as well. It is likely that the water level data utilised by Sorn et al. were tneasured in different periclds and from different aquifers (shallow-dug wells and deeper monitoring tube wells) or the data suffer from inadequate control and misinterpretation. As a result, although the: master flow direction remains the same, the flow pattern otherwise depicted in Fig. I a of Sorn et al. appears to be incorrect and confusing. 3. Sorn et al. may consult the already available literature or data before working further on
hydrageology of the area. It is suggested that GSI may work in close co-ordination with
CGWB to take advantage of the already arvailable data and for better output, which is not difficult as there is Stale Level Programming Board for the. purpose.
4. Lastly, in keeping with the high tradition of scientific writing, previous work should find a
mention in the paper or in the "References" for the benefit of the scientific community.
S.K. Som, Geological Survey of India, Calcutta - 700 01 6 replies:
We welcome the comments given by S. Das.
1. According to Dr. Das, the Sukinda river is effluent, which we have shown as influent (Fig. 1 a). Most probably he has referred to the Damsal nala, because the nomenclature "Sukinda river" does not.
The water table contour map should always correlate with the sub-surface geology (if available). The area has developed thick laterite cover (Som et al. 1998), which Das and Kar (1997) have also reported in their paper to be of 117 m at Kansa. The weather condition of
by ground water, typical of tropical Savanna climate (Twidale, 1982). In this Savanna climate with heavy seasonal rainfall, chemical weathering extends to great depths (Faniran and Jeje, 1983) and a thick lateritic cover thus develops over Sukinda ultrabasic-basic rocks. In this condition, the stream run-off i n addition to evaporation, will always infiltrate into the porous iateritic ground, which on the other hand pushes the "weathering front" to deeper levels with enhanced chemical weathering. The low drainage density of the area has been attributed by Sorn et al. (1 998) to the presence of permeable laterites. Moreover, Das and Kzr (1 997) have
also reported that the laterite - limonite layers form the most extensive and potential aquifers in the area. So, under the above conditions, the stream flowing over the lateritic terrain can never be effluent in nature.
2. All data are recorded in the month of February, 1995.
3. Das has commented that the authors have given an impression that the work is pioneering. In
the paper, this type of impression is never given. Indeed, the authors do feel that thz work is new because is has dealt with the water-rock interaction and can explain the development of laterite mineralogy. Moreover, the paper has a major contribution in the development of mineral stability diagram i n the system MgO - SiO,
-
H,O (Fig.4) with the required mineral phases.4. The work of Das and Kar(1997) is mainly on the physical parameters of aquifer characteristics (viz. aquifer parameters, recharge-discharge, etc.) and work of Sorn et al. (1999) is on the geochemistry of ground water in the light of water - rock interactions, mass balance calculation, development of mineral stability relations and therefore the work was not referred to.
References
DAS, S. and KAR, A. ( 1 997). Hydrogeology around Sukinda valley in Orissa with reference to mining activities. Indian Jour. Earth Sci., v.24(3-4), pp.10-26.
FANIRAN, A . and JWE, L.K. (1983). Humid Tropical Geomorphology. Longman Inc., New York, 414p.
SOM, S.K., JOSHI, K.,' ROY, I?K. and MUKHERJEE, M.M. (1998). Morphotectonic evolution of the laterite profiles over Sukinda ultramafics, Jajpur district, Orissa. Jour. Geol. Soc, India, v.52, pp.449-456.
TWIDALE, C.R. (1982). Granite Landf~rrns. Elsevier, Amsterdam, 37233.
(It is always a healthy practice to cite the relevant previous work. - Editor)
110 DISCUSSION
1. ON THE DISCOVERY OF MIDDLE EOCENE LARGER FORAMINIFERA FROM
A LIMESTONE BED IN CHURU DISTRICT, RAJASTHAN, by K.S. Raghav, Jour. Geol. Soc. India, 2000, v.55, pp.269-274.
2. DISCOVERY OF F0RAlWNWER.A FROM B E A M GROUP, JODHPURDISTRICT, RAJASTHAN, by K.S. Raghav, Jour, Geol.
Soc.
India, 2000, v.55, pp.395-397.P.K. Kathal, Centre of Advanced Study in Geology, H.S. Gour University, Sagar - 470 003 comments:
, ,
The author has highlighted the need to revise the age of the BiIara Group, Marwar Supergroup, Rajasthan, considered earlier as Neoproterozoic to Lower Cambrian. The study was based on the occurrences of larger foraminifera in Jogira limestone bed, Churu district (hitherto considered as Pondolo Formation, Bilara Group, Raghav, 2000a) and two smaller foraminifera, ?Discorbis and
Quinqueloculina in a 'fossiliferous horizon' at Bilara, Jodhpur, Rajasthan (Raghav, 2000b). The assignment of the Jogira limestone bed, Churu district to Jogira Formation (Middle Eocene) based on larger foraminifera with a suggestion to extend the limits of the 'Eocene Sea' 80 krn
eastward in Rajasthan seems unambiguous. However, assigning an older limit of Upper Cretaceous to all formations of the Bilara Group hastily, only mars the inferences drawn earlier (Raghav,
2000a). The following clarifications are sought: •
1 . The species illustrated in Fig.3a and b (Raghav, 2000b) is Rotorboides granulosum Heron- Allen & Earland (1915). Its identification as ?Discorbis is erroneous.
2. Fixing an age of the 'Upper Cretaceous' as an 'older limit' of all the formations of rather varied lithologies (Raghav, 2a)Oa, b) but purported to be BiIara Group by the author (Raghav, 2000b) vis-a-vis a 'tentative biostratigraphic correlation' of the rocks exposed at two distinct localities (over 350 krn from each other) in the Churu and Jodhpur districts seems hasty.
The first report of the fossils of R. granulosum, an 'Atlanto-Carribean foraminifer' in the
Indian Tertiary, calls for a serious reconsideralion of the 'older age limit' of the fossil-yielding rocks in Jodhpur area, instead of a assigning a 'Upper Cretaceous age' tentativeIy. The following aspects of this species need emphasis:
(a) Reneging in age from Middle Pliocene (Chrabo Formation, east of Cuba, Burmudez, 1949) to Recent (Panamanian Province, Crouch and Poag, 1987; East Coast of India and elsewhere, Kathal and Bhalla, 1-996a, b; 1998; Bhalla and Kathal, 1998) R. granulosum migrated into the Pacific and Indian Oceans only in Middle Miocene under the influence the westward flowing 'Middle Miocene equatorial currents' (Glaessner, 1943; Kennett et al. 1985; Crouch
and Poag, 1987; Gibson, 1989; Kathal and Bhalla, 1996a, b).
(b) This calcareous, tropical, benthic, epifaunal species (top 0.5 cm of sediments) occurred in very shallow and protected marine waters of low oxygen in the restricted latitudes of around
25" N to 25" S since Middle Pliocene (Kathal and Bhalla, 1996a, b).
Saif ud din, Remote Sensing Applications Centre, Aligarh Muslim University, Aligarh comments:
The fossils reported by Raghav from Bilara Group correspond to ages of Upper Cretaceous to Recent and Jurassic to Recent. His illustrious predecessors in Geological Survey of India, Late PC. Sogani and E.A. Khan, while mapping the Trans-Aravalli Vindhyan to which they assigned status of Marwar Supergroup, reported some fossils from Marwar basin some 30 years ago. At that time, the people who saw their fossils could not muster courage to go beyond the Paleozoic (Cambrian) as the age of the Marwar sediments (Barman, 1980). Raghav (Paper 2) has assigned the Cambrian Marwar Supergroup to Eocene. The observation has raised a question on the cause and effect relationship between MaIani volcanism and Marwar sedimentation. Does the Marwar Supergroup represent the dismembered sequence of Mesopotamian geosyncline? Marwar block of Rajasthan has thermal history which is alien to Aravalli region (Gupta et al. 1997). Qureshy and Iqbaluddin (1 992) suggested the juxtaposition of the Trans-Aravalli block of Arabian-Nubian shield with.the Bundelkl~and block, and the separation of the Trans-Aravalli block along with the rest of the Indian Plate from the Arabian Plate around 10 Ma during the mid-Tertiary (Miocene?). Does the occurrence of middle Eocene in Churu and Eocene of Bilara Group i n the Trans-Aravalli block and the younger thermal history of Trans-Aravalli block suggest that the block was evolved in a geotectonic environnlent different from the Aravalli-Delhi orogen?
Raghav's observation that the Marwar Supergrohp is Tertiary in age will place the geotectonic evolution of the Aravalli (which is considered Paleoproterozoic to Neoproterozoic by various authors) as a Phanerozoic event, if plate tectonic models suggested for Aravafli-Delhi rocks are to be believed. Does the find of younger fauna in the Marwar basin suggest that the Cretaceous sedimentation of Narrnada valley which extends up to Banswara in Rajasthan, was an incursion from the west, and the Bagh beds fauna was not Gondwanic but Mesopotamian i n origin?
(3)
S.B. Bhatia, No.441, Sector 6, Panchkula - 134 109, Haryana, comments:
These two papers by Raghav reporting the occurrence of Tertiary foraminifera from limestone beds hitherto mapped and considered as part of the Marwar Supergroup (Neoproterozoic-Cam b~ian) appear to the significant as they will, if the assumption is correct, not only necessitate the revision of the stratigraphy of eastern Rajasthan but also confirm the extension of Eocene sea further east of Bikaner and Jodhpur. My comments are as foIIows:
Paper I
I . One gets the impression from the opening sentence that Eocene for3rninifet-a from the Jaisalmer and Bikaner basins,are known only through the works of Kalia and Banerjee (1995) and Sinha-Roy et al. (1998). The author is apparently unaware of the pioneering works in the area by Blanford (1 877), Oldham (1 886) and Vredenburg ( 1908) who recorded Tertiary foraminifera from Rajasthan, as well as the later works of Singh (1951. 1952,
1953).
2. One of the species identified by me when I saw Raghav's several thin sections many years ago, was Nummulites obesus d' Archiac & Haime, a characteristic species of shallow
DISCUSSION
Benthic Zone (SBZ 13) or Planktonic Zone (P,,). However, the species illustrated by the author as N. cf. Obtusus Sowerby (Figs.3 C+-D) appears to be suspect. As opined by Samanta (198 l), this is one of the most distinctive species of Nunznzulites from the Indian region with a tripartite spire, intercalary whorls and with nearly 13-14 whorls in a radius of 4.5 mrn, The specimen illustrated (Fig.3c, an axial section), though poor, does not warrant comparison with N. obtusus. Incidentally, the diameter of this species as mentioned in the text is 9 rnm, while tlie bar scale given in F i g . 3 ~ indicates a diameter of approximately I mm. The identification of Assilincr as A. c:f. Suteri Schaub from one axial section alone is not justified.
3. The fossil illustrated in Fig.lA is identified (p.271) both as "possibly a pelecypod,
brachiopod". It is surprising that the author could not be more precise, despite the fact that the external and internal moulds are well preserved (p.271). There was no need to include photographs of specimens which cannot be precisely identified even at the "phylum" level. 4. There are several spelling mistakes e.g. on p.272 - synonymy is spelt as synonimy, Messina
is spelt as Hessina and on p.274, Eoconulc~ides is spelt as Eonuloides.
5. While the author quotes several references which are either irrelevant e.g. Ellis and Messina
(1965), Racey (1995) and Pareek (1984) or are unpublished e.g. Kumar et al. (1 993), he
fails to make any reference to the pertinent works like those of Singh (1951, 1952, 1953) and Khosla (1973). Singh (1952), in fact, was the first to suggest the extension of Kirthar (Lutetian) sea up to Sri Kolayatji, WSW of Bikaner. The author has missed the opportunity of picking up the threads from where Singh (1952) had left by writing a detailed paper on further extension of Eocene sea eastwards based on precise identifications and illustrations of the foraminifera1 fauna. The author's failure to even refer to Singh's work is inexcusable. 6. The propriety of retaining the term Jogira Formation (Table 1 and p.273) for the marine Middle Eocene sequence is questionable, as the Jogira village (near Mudh in Bikaner district), after which the formation is named, is located on non-marine post-Lutetian grits, as opined by Singh (1969), Khosla (1973) and Kalia and Banerjee (1995). The more appropriate tertninoIogy would be either Bandah Formation (as opined by Khosla, 1973) or else Bikaner Formation (as suggested by Kaila and Banerjee, 1995).
Paper 2
1. This paper deals with the finding of two obscure-looking, poorly-photographed smaller foraminifera, identified only up to generic level-?Discorbis sp, and Quinqueloculina sp. -
from the Gotan Formation of the Bilara Group, south of Bilara town. The author has tnade no attempts to identify them up to the specific level, which would have helped in fixing the age of the foraminifera. In his anxiety to piibIish quickly, the author did not consult several works on Eocene smaller foraminifera of Rajasthan e.g. Borooah, (1946) and Bhatia and Khosla (I970), to cite only a few, or even the catalogue of foraminifera by Ellis and Messina (1965).
2. Judging from the photographs, one gets the impression that the two foraminifera are 'sticking' to the rock surface and have not been obtained by usual maceration techniques. The author does not mention as to how many specimens of foraminifera were obtained by him. The
Eocene foraminifera from the Fullers' Earth and marls of Rajasthan are usually well preserved. According to the author (p.397) Discorbis is ill-preserved. It is more likely that these foraminifers are e x ~ t i c - either leaked from Tertinry rocks into the underlying rocks of the Gotan Formation or else are wind-borne Quaternary species, of which there are several records from the Rajasthan desert (Goudie and Sperling, 1977).
In view of the foregoing discussion, the author's surmise that the entire Marwar Supergroup may not be older than Cretaceous/Tertiary is premature. The two records of Tertiary rocks mentioned in these papers are from the two attenuated extremities of the nearly N-S trending outcrops of the Bilara Group (see Fig. 1, Paper 1). It is more likely that they represent isolated outliers of Tertiary rocks which had previously remained unnoticed, or as stated by the author himself
(p.273, Paper l ) , had been erroneously mapped as belonging to the Pondolo Formation or Gotan Formation (GSI, 1997). Shallow boreholes in the two focalities would confirm if these are outliers. However, if the author's contention of the Marwar Supergroup being not older than Tertiary is correct, then a richer and varied assemblage of foraminifera should be present in the thick outcrop of the Bilara Group exposed west of Nagaur town (Fig. 1, Paper I), in the ridge between Bidasar and Bilara, and in the limestone bands exposed in the Barna quarry at 3, 7, 11 and 15 m levels from the surface (Fig.2, Paper 2).
B.S. PaliwaI, Office of the Dean, Faculty of Science, Jai Narain Vyas University, Jodhpur -
342 005 comments:
Recent discovery of Eocene foraminifera from the rocks of the Bilara Group from Sandwa, Bidasar and Bilara by Raghav has raised a question on the age of the Bilara Group (Marwar Supergroup). The sandstone-shale-carbonate-evaporite sequence overlying the Malani Suite of igneous rocks and the Precambrian metasediments in the region to the west of the Aravalli mountain were considered to be the part of the Vindhyan (Upper Vindhyan) and were named as the Trans- Aravalli Vind hyan on the basis of lithological similarities (Heron, 1932; Pascoe, 1 959; Mishra, 1969). Later on, these rocks were assigned a separate identity as the Marwar Supergroup (Pareek, 198 1) comprising the lower siliciclastic rocks of the Jodhpur Group (also Randha Formation in Jaisalmer area), the middle carbonate rocks of the Bilara/Hanseran Group (also Birmania Formation in Jaisalmer area) and the upper siliciclastic and evaporitic sediments of the Nagaur Group. Rocks of the Marwar Supergroup (Pareek, 1981) were correlated with the Cambrian of the Saline Series in the Salt Range of Pakistan on the basis of (1) occurrence of salt pseudomorph shales (Shrivastava and Srinivasan, 1964), (2) evaporite sequence (Virendra Kurnar, 1995, 1999), (3) stromatolites (Barman, 1980; Paliwal, 1975) and (4) a doubtful brachiopod fossil (Ortlzis) of the Cambrian age (Khan, 1973). The sandstones of Nagaur Group was equated with the purple sandstone (Virendra Kumar, 1999).
In the light of recent findings of Lower Eocene foraminifera, four possibilities have evolved:
I. That the rocks of the Bilara and Nagaur Groups are Tertiary in age and not older as suggested by earlier workers.
2. That the Tertiary carbonates unconformably overlie the Bilara Group in some isolated patches, and the foraminifera reported are associated with these Tertiary rocks.
3. That the Bilara rocks are somewhat cavernous in nature and the unconformabl y overlying
Tertiary rocks, which have been eroded at these places, have contributed these foraminifera through water percolating down through cracks and cavities.
4. That the limestones of the Bilara Group are older, and during the Tertiary transgression they were exposed to the sea water. Perhaps, during this period, partial dolomitization of the pre-existing limestones took place in some areas and the Tertiary foraminifera were added.
Long back, UNDP (1976) carried out a detailed geophysical exploration in the region and suggested the following stratigraphic succession, which supports the views of Raghav (2000a, b).
Quaternary Alluvium
Palana Series
-I
-Sandstone (with lignite) - Clay
-
Sandstone
Clay stone Sandstone Claystone
Gypsum-Anhydrite, Halite and , Limestone.
L
Lower Paleozoic Jodhpur Sandstone Sandstone
Precambrian Schist, Granitc, Rhyolite
(5)
Kantimati G. Kulkarni and V.D. ,Borkar, Agharkar Research Institute, G.G. Agarkar Road, Pune 41 1 001 comment:
Raghav claims to have recovered Discorbis sp. and QuinquelocuIina sp. from the Gotan Formation, Bilara Group (Marwar Supergroup, Neoproterozoic). These findings sound interesting as they assign an age not older than Upper Cretaceous as stated in the conclusion (or not older than lower Eocene as stated in the Abstract). However, one fails to understand how the following phenomena are to be explained vis-a-vis this discovery:
1. In a couple of reconnoitary field tours recently undertaken, profuse development of stromatolites was noticed by us in the belt of Bilara Group extending from Gotan-Sodawas in the north, t h r o ~ g h Bilara, to Sojat in the south. Khilnani (1968) and Barman (1980, 1987) have described stromatolites indicative of Neoproterozoic-Cambrian affinity from the Dhanapa, Gotan, and Pondolo Forma.tions of the Bilara Group. Son~e 7.0 m above the horizon yielding the so-called forarr~ini:Fera, Raghav himself has noticed a 2.0 m thick limestone band containing stromatolites (vide his Fig.2, Paper 2).
2. I n parts of the Jodhpur and Nagaur districts, the Bilara Group is overlain unconformably
by the Bap Forination of Permian age (Heron, 1932). The belt of Bilara Group from which
the foraminifera are claimed to have been recovered, itself was seen overlain by isolated outcrops of the Bap Formation east of Gilgrana and Digrana.
In view of these two points, it is extremely enigmatic - let alone unbelievable or erroneous -
that Discorbis sp. and Quinqueloculincl sp. occur in limestones containing strornat~lite~s overlain by a Permian bed. It is, therefore, evident that the presence of foraminifera may be due to laboratory contamination.
B.P. Shrivastava, 17, Panch Sheel Enclave, Durgapur, Jaipur - 302 018 comments:
Raghav has opined that the discovery of fossils from scanty, unconnected exposures at five localities in the Bidasar area (2000, p.269) and Barna Phase I quarry near Bilara (2000, p.397), have larger implications for stratigraphy and dating of Phanerozoic rock units in western Rajasthan. To the present author, such inferences based on isolated occurrences of poorly fossiliferous beds in localities near Bidasar, in absence of connecting exposures in the intervening area or its known occurrence in the subsurface, are far fetched in the light of comprehensive geological mapping by many workers (Misra et ai. 1961 ; Shrivastava, 197 1; Pareek, 1984; Chakravarty and Bhattacharya, 1996).
To establish a new order of stratigraphy of the rock formations in the western Rajasthan, as has been attempted by Raghav (2000, p.397), at least some of the following questions need to be addressed:
(a) Raghav builds his opinion on the basis of geological observation that "the presence of limes tone in dug wells in the sandy flats establishes the continuity of the isolated outcrops beIow the sand cover" (2000, p.269, para 4) without enumerating that those limestone beds are also similarly fossiliferous.
(b) Further Raghav (2000, p.295) claims the discovery of fossils from Barna Phase I limestone quarry and maintains "larger number of quarries exposing limestone were examined from Mandla-Atbara ... . and Kamthi" without mentioning whether these sections are also fossiliferous.
(c) Do the limestone beds of the Pondolo Formation mapped in the type area extend to Bidasar? (d) Raghav mentions only the presence of two or three types of foiarninifer and does not
describe any assemblage as is normally observed.
(e) The limestone-marl-clay sequence of highly fossiliferous Middle Eocene mapped as Palana Formation in the Palana area has been seen to extend for almost 20 km further east (e.g. SurdanaIKesardesar hand-dug wells) by Shrivastava (1979). However, still further east, Shrivastava mapped the post-Eocene Marh Formation directly overlying Jodhpur Formation. Evidences from the seismic traverses undertaken by ONGC (per:. comm., 1992) also envisage the absence of sediments above the Jodhpur Formation. Therefore, how the Palana Formation was connected with the known Eocene exposures of Kolayatji, Bikaner is a big question.
(0
MiddleKJpper Eocene formations unitized by Shrivastava and Srinivasan ( 1962) as Jogiraf Palana Formations and by (Pareek, 1984) and other GSI geologists as PalanalMarhIJogira Formations are mappable as twolthree distinct rock formations correlatable with Bandah1 Khuiala Formations or Jaisalmer area of RanikoUKirthar of Sindh-Baluchistan region (Shrivastava, 1971). Would it be right to correlate the meagerly fossiliferous limestones of Bidasar with these well-estabIished rock formations?116 DISCUSSION
(h) Bap Boulder Bed and Badhaura Formation have been dated as Permocarboniferous on fossil evidences and extensive mapping (Shrivastava, 1971; Pareek, 1984). They contain ice-rafted boulders and cobbles of Jodhpur Sandstone. How is this possible when Bilara Formation or the Marwar Supergroup was laid down in the Eocene period?
K.S. Raghav, 228, Shreeji Nagar, Durgapur, Tank Road, Jaipur - 302 01 8 replies:
I express my sincere thanks' to the leading st:ientists for showing keen interest in my papers' on the discovery of foraminifera from Bidasar area in Churu district and Barna area in Jodhpur district of Rajasthan. My consolidated reply to their queries is as follows:
2 . The author apologises for the inadvertent omission of not referring to the extensive work of Singh an Khosla as pointed out by Prof. S.B. Bhatia.
2. The author also agrees with the observations of Prof. Bhatia from the photographs on the 'sticking' nature of the two foraminifera to the rock surface. However, subsequent to the discovery of fossils, the author critically examined about 200 samples from the different sections of Bilara Group under binocular microscope. During these studies, two specimens of foraminifera were picked up by needle and brush from the samples, collected from Barna limestone quarry. Later on, some part of the samples was disintegrated by treatment with acetic acid. The disintegrated samples were found to be full of micro-fossils with abundant foraminifera. During subsequent work, the fossil-yielding rock samples were collected from Sojat to Gotan covering a stretch of 50 km, and most of sampIes were found to be fossiliferous. However, only two specimens were published in a short note because these were the first finds till that point of time.
3. Prof. S.B. Bhatia has raised a doubt about the identification of Nummulites c? Obtusus
Sowerby and that it could instead be Nurnnlulites obesesd' Archiene and Haime. The results received from Shri O.N. Bhargava, Charidigarh have indicated presence of N . obtusus. Possibly there is a communication gap and it is very likely that Prof. Bhatia is right about the identification of N. Obeses d' Archienr: and Haime.
4. Since no confirnzed megafossil has been reported so far from the rocks of Bilara Group, it was decided to include Fig.la, which suggests that either the fossil-bearing rock is not part of Pondolo Formation or Pondolo Formation is profusely fossiliferous.
5. The author has concluded that the fossil-yielding rocks of Rarna area cannot be older than Upper Cretaceous, on the basis of identification of two specimens of f~rarninifera, whereas the fossil-yielding rock type of Bidasar area is of Middle Eocene age as evidenced by the
* ,
presence of Nummulite assemblage. These two localities, about 150 km apart, have been described separatety to avoid confusion.
.z 6. Dr. Kathal has expressed the opinion that the specimen illustrated in Fig.3a and b is
Rotorbaides granulosum Heron-Allen & 'Earland 1915 (Middle Miocene to Recent). The author appreciates the studies supplemented by Dr. Kathal by critically scanning the photographs. The earlier interpretation was based on the identification of foraminifera genus ?Disarbis sp. by the Palaeontology Division of Geological Survey of India, Western Region,
(GSI, WR), Jaipur. Both these specimens are deposited in the repository of GST, WR, Palaeontology Laboratory. The repository number is RNRI18. During the subsequent work
in the vicinity of Barna area, some genus of foraminifera such asAmmonia sp. and ostracodes of Miocene to Recent have also been recorded by Raghav (2000~) and Ravindra Kumar (2000) respectively, from the fossil-yieldling rock types, and this also suggests that the fossit-yielding rocks of Bilara Group are not older than Miocene.
7. The author appreciates Prof. Bhatia's comments on some spelling mistakes as well as scale of the Fig.3a (Raghav, 2000a). The corrections in bar scale (4 mm rather than 0.5 mm) and in 3e (0.9 mm rather than 1 mm) could not be introduced in the print copy at a late stage in the press. Similarly, the year of publication of pre-Quaternary geological map of the area (Raghav,.2000b) is (GSI, 1985) instead of GSI (1997).
8. Regarding the questions raised by different workers about the contamination of fossils due to leaching, development of cavity dolomitization, Iaboratory handling and aeolian transportation, the author would like to point out that the fossil-yieIding lithounit is bound between the overlying grey limestone, chert and whitish dolomite of approximately 5 to 15 m thick and the underlying Jodhpur Group at Barna Phase-I limestone quarry section and at Pichak, respectively. Barna is the type area of Gotan Formation of Bilara Formation/ Bilara Group as described by S hrivastava ( 1 97 1) and Pareek (1 984). These areas are open for further detailed study by desirous personslgroups.
9. The author appreciates the suggestions made by Dr. Saif ud din in connection with significance of fossil find in Bilara Group. Some more detailed work is required to establish the significance of fossiIs in the stratigraphic and tectonic set up of the basin, palaeogeography as well as the possibility of occurrence of hydrocarbons in the evaporite basin.
10. On the basis of iithological character and fossiliferous nature of Jogira Formation, an inference was drawn about the possibility of calling the fossiliferous bed of Bidasar area as Jogira Formation. However, this has to be confirmed by detailed mapping in future. 1 I. The earlier concept of limiting the distribution of stromatolite to the Proterozoic and Early
Palaeozoic has been chaIlenged recently (Garhia et al. 1997). The presence of stromatoloite is recorded even in Quaternary (Garhia et al. 1992).
12. Nowhere a clear contact between Bap Boulder Bed and the overlying the Bilara Group has been noticed. Moreover, Mukhopadhyay and Ghosh (1976) have raised a doubt about the stratigraphic status of the Bap Boulder Bed. The sediments noticed around Gagrana and Digrana in the eastern part of the Bilara Group belong to Quaternary according to GSI (1985).
13. In reply to the points raised by Dr. B.P. Shrivastava, most of which are already answered in the foregoing paragraphs, the author would like to emphasize that he has utilised GSI's basemap for these studies. SampIes collected from the depth of 8 and 15 m in the pit opened for limestone mining in Barna area show that the fossil-yielding rock types cannot be older than the age range of the fossils. The presence of foraminifera in Barna rocks raises doubt about the stratigraphic status of Bilara Group. The author has also found foraminifera and other unidentified microfossils from Jodhpur Group in the Chaukaria area of Jodhpur district. Therefore, the present author is not convinced about the stratigraphic status assigned to Marwar Supergroup by earlier workers. Further detailed studies are now in progress in the Jodhpur Group of Marwar Supergroup.
References
BARMAN, G. (1 980). An analysis of the Marwar basin in the light of strornatolite study. In: Workshop on Stromatolites: Characteristics and Utility, M.V.N. Murthy et al. (Eds.), Geol. Surv. India Misc. Publ. No.44, pp.292-297. BARMAN, G . (1987). Stratigraphical position of the Marwar Supergroup in the light of stromatolite study. In: Three
Decades of Developments in Palaeontology and Stratigraphy in India, M.V.A. Sastry et al. (Eds.), Geol, Surv. India Spec. Publ. no. I I , pp.72-80.
BHALLA, S.N, and KATHAL P.K. (1998). Recent foraminifera1 thanafocoenoses from the Gulf of Mannar, India. N. Jb. Geol. Palaeont. Abh., v.207, pp.419-43 1 .
BHATIA, S.B. and KHOSLA, S.C. (1970). Some smaller foraminifem from the Kirtharbeds near Mudh, District Bikaner, Rajxthan. Res. Jour. Roorkee Univ., v. 12, pp. 1-13.
BLANFORD, W.T. (1 877). Geological note on the Great Indian Desert between ~ i n d and Rajputana. Rec. Geol. Surv. India, v.10, pp.10-21.
BOROOAH, S.K. (1946). Occurrence of Laki Series in Jodhpur State. Cum Sci., v. 15, p.3 17.
BURMUDEZ, P.J. (1949). Tertiary smaller foraminifera of the Dominican Republic. Cush. Found. Foram. Res., v.25,322p. CHAKRAVARTY, C, and BHATTACHARYA, A. (1996). The Vindhyan basin: An overview in the light of current perspectives. In:
Recent Advances in Vindhyan Geology. A. Bhattacharya (Ed.), Mem. Geol. Soc. India, 110.36, pp.301-3 12.
CROUCH, R.W. andPoAc, C.W. (1987). Benthic foraminifera of the Panamanian Province: distribution and origin, Jour. Foram, Res., v. 17, pp. 13- t74.
ELLIS, B.F. and MESSINA, A.R. (1965). Catalogue of Index Foraminifera. Amer. Mus. Nat. Hist. Spec. Bull., v. 1, Ill. CSI (1985). Geological Quadrangle map no.45F, Rajasthan. (3eol. Surv. India, Calcutta. '
GARHIA, S.S., S I ~ A R M A , V.P. and YADAV, M.L. (1992). Quaternaries of Gujarat. Rec. Geol. Sum. India, v. 124(7), pp.40-41. GARHIA, S.S., SHARMA, V.P. and YADAV, M.L. (1997). Occurrence of stromatolites in the miliolite Formation of Saurashtra.
Gujarat, India. Jour. Geol. Soc. India, v.49, pp.73 1-734,
GIBSON, T.G. (1989). Miocene evolution of Tubulogenerina i n the Indo-Pacific and African areas. Jour. Foram. Res., v. 19, pp. 126- 145.
GLAESSNER, M.E (1943). Problems of stratigraphic correlation in the Indo-Pacific region: Proc. Royal Soc. Victoria, v.5511, new ser., pp.41-80.
GOUDIE, A. and SPBRLING, G.H.B. (1977). Long distance transport of foraminifera tests by wind in the Thar desert, northwest IRdia. J O U ~ Sed. Petr., v.47, pp.630-633.
GUITA, S.N., ARORA, Y.K., MATHUR, R.K., IQBALUDDIN, PRASAD, B., SARAI, T . N . ~ ~ ~ S H A R M A , S.B. (1997). The synthesis ofthe Precambrian lithostratigraphy and tectonomagmatic sequence of Aravalli region. Geol. Surv. India Mem, no. 123, 24633.
HERON, A.M. (1932). The Vindhyans of western Rajasthan. Rec. Geol. Surv. India, v.65, pp.457-489.
HERON-ALLEN, E. and EARLAND, A. (191 5). Foraminifera of the Karirnba Archipelago (Portuguese East Africa). Trans. Geol.
' Soc. London, v.20, pp.543-754.
KALIA, P. ~ ~ ~ B A N E R J E E , A. (1995). Occurrence of the genus Eoconuloides Cole and Besmudez Gun 1994, Rajasthan, India and its palaeogeographic significance. Micropalaeontology, v.41, pp. 187-1 94.
KATHAL, P.K. and BHALLA, S.N. (1996a). Intnspecifrc variation and palaeolatitudinal significance ofRororboidea gmnulosum - a less known Recent foraminifera of tropical waters. Rev, de Paleobio., v. 15, pp.79-85.
KATHAL, P.K. and BHALLA, S.N. (1 996b). On the first report from the Indo-Pacific region, migratory trends and paleolatitudinal significance ofRoturboides grunulosurn - a tropical water foraminifer since Middle Pliocene (Late Miocene?). XV Indian Colloq. Micropal. Strat. (J. Pandey, R.J. Azmi, A. Bhandaui & A. Dave, Eds.), pp.317-320.
KATHAL, P.K, and BHALLA, S.N. (1998). Taxonomy and paleolatitudinal significance of Rotorboides grunulosum - a less known Recent foraminifer of tropical region. Jour. Geol. Soc. India, v.5 L, pp.799-802.
KEMJETT, J.l?, KEUER, G. and SRINIVASAN, M. (1985). Miocene foraminifera biostratigraphy and paleoceanographic development of the Indo-Pacific region. In: J.P. Kennett, (Eds.), Geol. Stoc. America Spec. Paper, no, 163, pp. 197-236,
KHAN, E.A. (1973). Discovery of fossil brachiopod of Cambrian affinity near Jodhpur. Proc. Sem. Recent Advances in the Geology of Rajasthan and Gujarat, pp.74-75 (abs).
KHILNANI, V.V. (1968). Stromatolites of undhyan limestone from Bilara, District Jodhpur, Rajasthm. Quart. Jour. Geol. Min. Met. Soc. India, v.40, pp. 1-6.
KHOSLA, S.C. ( I 973). Stratigraphy and microfauna of the Eocene beds of Rajasthan. Jour. Geol. Soc. India, v. 14, pp. 142- 152. KUMAR, V., SAHA, C.R. and RAIAWAT, R.S. (1993). Report on potash investigation in northwestern Rajasthan. Geol. Surv. India
(unpublished report), 16 lp.
MISHRA, R.C. (1969). The Vindhyan System. Presidential Address. Indian Sci. Cong., Mumbai, Sec. Geol. Cong.,
pp. 1-32.
Misra, J.S., Shrivastava. B.P. and lain, S.K. (1961). Discovery of marine Permo-oqboniferous in Western Rajasthan. Cum.
Sci., v. 18, pp.26 1-262.
MUKHOPADHYAY, A.K. ~ ~ G H O S H , R.N. (1976). The problem of the stratigraphic position of the Bap Boulders in Rajasthan. Indian Jour. Earth Science, v.3, no.2, pp.220-228.
OLDHAM, R.D. (1886). Preliminary note on the geology of northern Jaisalrner. Rec. Geol. Surv. India, v. 19, pp. 1 57- 160. PALIWAL, B.S. (1975). Phosphatic algal strornatolites in the Trans-Aravalli Vindhyan of Badi-Khatu, District Nagaur, Rajasthan.
CUR. Sci., v.44(5), pp.161.
PAREEK, H.S. (1981). Basin configuration and sedimentary stratigraphy of western Rajasthan. Jour. Geol, Soc. India, v.22, pp.517-527.
PAREEK, H.S. (1984). Pre-Quaternary geology and mineral rc:sources of northwestern Itajasthan. Mern. Geol. Surv. India,
v. 115, pp. 1-27.
PASCOE, E.H. (1959). A Manual of the Geology of India and Burma, v.2, pp.485-1343.
QURESHY, M.N. and IQBALUDDIN (1992). A review of the geophysical constraints in modelling the Gondwana crust in India. Tectonophysics, v.212, pp. 141-15 1 .
RACEY, A. (1995). Paleoenvironrnental significance of larger foraminifera1 biofabrics: implications for petroleum exploration.
In: M.I.H. Hussain (Ed.), Middle East Petroleum Geosciences (Geo '94), v.2, pp.793-8 10.
RAGHAV, K.S. (2000a). On the discovery of Middle Eocene larger foraminifera from a limestone bed in Chum district, Rajasthq. Jour. Geo. Soc. India, v.55, pp.269-274.
RAGHAV, K.S. (2000b). Discovery of foraminifera from Bilara Group, Jodhpur district, Rajasthan. Jour Geol. Soc. India, v.55, pp.395-397.
RAGHAV, K.S. (2000~). Sedimentational history of Marwar Supergroup, Jodhpur diqrict. Rec. Geol Surv. India, v. 133, pt.7, pp. l & 2.
RAINDRA K U M A R (2000). Search for early Metazoa in Bilara Group of Marwar Supergroup in parts of Jodhpur and Pali districts. Rec. Geol. Surv, India, v.133, pt.7, p.46.
SAMANTA, B.K. (1981). Two stratigraphically important Nummulites from the Middle Eocene of Indiaand Europe. Palmntology, v.24, pp.803-826.
SINGH, S.N. (195 1). Kirthar Foraminifera from Rajasthan. Curr. Sci., v.20(9), p.230.
SINGH, S.N. (1952). On theextension of Kirthar seain Rajasthan. Proc. Nat. Acad. Sci. India, v.52, pp.7-10.
SINGH, S.N. (1953). Geology of the area of WSW of Marh village near Kolayat, Bikaner, Rajasthan. Proc. Nat. Acad. Sci. India, v.23, pp. 13-20.
SINGH, S.N. (1969). Stratigraphy of the Eocene of Rajasthan. Proc. 56th Indian Sci. Cong., pp.2 16-217 (abs). SINHA-ROY, S., MALHOTRA, G. and MOHANTY, M. (1998). Geology of Rajasthan. Geol. Soc. India, Bangalore, 278p. SHRIVASTAVA, B.P. ( I 971). Rock-stratigraphic ~omenclature for the sedimentaries of west-central Rajasthan. Bull. Geol, Min.
Met. Soc. India, v,44, pp. 1 - 19.
SHRIVASTAVA, B.P. (1979). Contribution to the stratigraphy of the west-central Rajasthan. Ph.D. Thesis, Banaras Hindu University, Vamnasi.
SHRIVASTAVA, B P (1992). Significant fourth dimensional stratigraphic markers in Paleozoic sediments of west-tend Rajasthan - Paleogeographic implications and petroleum habitat. lndian Jour. Pet. Geol., v. l,pp.234-244.
SHRIVASTAVA, B.P. and SRINIVASAN, S. (1962). On the occurrence of the Eocene sediments near Kolayat, District Bikaner, Rajasthan. Sci. Culture, v.30, pp.336-337.
SHRIVASTAVA, B.P. and SRINIVASAN, S. ( 1964). Salt pseudomorph shales in Jodhpur Formation. Cum. Sci., v.33, pp.273-274. UNDP (1 976). Groundwater surveys in Rajasthan and Gujarat, India: Technical Report (unpublished), United Nations
Development Programme. United Nations Organisation, New York, 240p.
VIRENDRA KUMAR (1 995). Eocarnbrian sedimentation in Nagaur-Ganganagar evaporite basin, Rajasthan. Convention of Indian Association of SedimentoIogists. Roorkee, pp.27-29.
VIRENDRA KUMAR (1999). Evolution and Geological set up of the Nagaur-Ganganagar basin, northwestern Rajasthan. In: B.S. Paliwal (Ed.), Geological Evolution of Northwe~tern India. Scientific Publishers, Jodhpur, pp.34-60.
VREDENBURC, E.N. (1 908). Preliminary note on the geological age of the coal at Palana in Bikaner, Rajasthan. Mem. Geof. Surv. India, v.36, pp.3 14-3 15.
BOOK REVIEW
HIMALAYAN GLACIERS: HYDROLOGY AND HYDROCHEMISTRY
by Syed Iqbal Hashain, Allied Publishers, Mumbai, 1999, 234p., Rs.450/-
H i ~ a l a y a n gIaciers are fascinating. They have attracted sages and scientists alike from time immemorial. Himalayan glaciers assume importance from the fact that all the north Indian rivers originate from these glaciers and have supported civilization through the ages. These glaciers have influenced the hydrology of north Indian rivers, thereby having impact on ecology and climatic changes not only in the Himalayan region but also globally. During the twenty first century, supply of high quality water will form a critical issue because of population pressure and industrialization. Effective management of water resources, therefore, assumes utmost importance not only for
