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presents either a massive, earthy limestone or a calcareous gritty sandstone, varying in colour between grey and brown. Irregular concretions of secondary silica and quartzitic pebbles, both rounded and angular, are often seen to characterise the component bands. Cherty and chalcedonic stringers and veinlets are also seen in considerable force in the upper stages of the series. Often the limestone is mottled with limonitic spots and blotches.
It has been suggested by Sir L. L. Fermor and Dr. C. S.Fox1 that the secondary silica of these concretions and veins has been derived by solution from the overlying Deccan trap.
Indeterminate fossil fragments have been found in the Balasinor exposures, but not in any of the other Lametas here.
Numerous lenticular outcrops of the Lametas, generally forming narrow fringes along the base of the Deccan trap, have been recorded
Of these the following occurDistribution.
rences are most noteworthy :
Panch Mahals district.
Typical Lameta beds overlying the Aravallis and forming an irregular horizontal shelf protruding from below the Deccan trap,
have been mapped from Rænia Naika (23° 14' : Kushalgarh-Banswara.
74° 18') southwards to Dungra (23° 11': 74° 19'). The greatest thickness of the outcrops is about ten feet, the maximum width being about half a mile. The formation is chiefly impure, pale purple, massive limestone, slightly crystalline, and containing grains and pebbles of quartz as well as irregular concretions of pinkish chalcedony, which stand out on the weathered surface. The pebbles are dull white or colourless and translucent. Towards the south the chalcedony forms a band of about one foot in thickness on the top of the limestone.
In the neighbourhood of the Sunth-Sanjeli border and near Jhalod, patches of Lameta limestones unconformably overlie the
1 Rec. Geol. Surv. Ind., XLIII, Pt. 1, p. 33, (1913).
Aravallis. The outcrops form irregular horizontal shelves protruding
from below the Deccan trap. The greatest Sunth.
thickness measures about 15 feet. The rock is usually a pale purple massive limestone, frequently with grains and small pebbles of white translucent quartz. Irregular concretions of secondary silica and quartzite pebbles are common. Cherty and chalcedonic stringers and veinlets also occur in the rock. The limestone is often mottled with limonitic spots and blotches (44/132). On microscopic examination (22084) the rock shows subangular grains of quartz held by granular calcite cement. The limestone is variable in composition and has a sharp contact with the underlying Aravallis. The lithology and mode of occurrence suggests sedimentary deposition in shallow inland basins.
About four miles north-west of Dohad (22° 50' : 74° 15') an exposure of Lameta beds forms an elongated tableland in the midst
of the Aravalli schists and phyllites. Not Dohad.
rising more than a few feet above the general level of the surrounding country, the exposure stretches north and south for about ten miles, with a variable width which nowhere exceeds two or three miles. The outcrop is not overlain by the Deccan trap.
The largest of the patchy outcrops of the Lametas in Bariya State constitutes the rectangular table-land of Jhabu (22° 40':
74° 10') covering an area of about four square Bariya.
miles and forming a thin horizontal capping on the steeply folded Aravalli schists.
The outcrop is composed of impure siliceous limestone, associated with conglomeratic and concretionary sandstone. The total thickness is nearly forty feet.
The Lametas are exposed extensively along the western frontier of the Balasinor State. Near Balasinor town they occur as thin
cappings over the granite. Farther to the north
the Lametas rise abruptly above the ground level of the alluvial tracts. At the north-western corner of the State they overlie the Aravalli schists anil phyllites unconformably.
The beds are varyingly siliceous and calcareous. The outcrops generally form irregularly shaped, flat-topped shelves. The maximum thickness observed is nearly thirty feet. Most of the outcrops show an impure, massive limestone, often with pebbly and
concretionary bands. Cherty or jasperoidal intercalations have also been noticed.
Indistinct fragments of fossil lamellibranch shells have been occasionally noticed in the siliceous limestone in many places (46/510). In the hand-specimen the fragments appear as white or horny specks. These give the weathered rock a rather rough and variegated appearance on the surface. The white fragmentary chips effervesce strongly in dilute cold hydrochloric acid. Under the microscope (23615) they show rounded or subangular grains of quartz embedded in a ramifying calcareous groundmass often tinged with limonite. Minute flakes of biotite, partly chloritised, have also been noticed in the slide.
The Lametas form thin and discontinuous outcrops occurring as narrow fringes along the margin of the Deccan trap in Lunavada
State. Their mode of occurrence and their Lunavada. lithological characters are identical with those
of the Lametas of Balasinor State. A small outcrop of the Lametas has been mapped south of Gabat (23° 15' : 73° 20'). The formation is composed of gritty, siliceous
limestone often containing irregular, lenticular Gabat.
masses or pebbles of quartz and red jasper. The rock is locally used as a building material and also burnt as a source of lime.
The Bagh beds. The Bagh beds are generally composed of a series of calcareous rocks underlaid by beds of sandstone, the characters of the com
ponent beds being variable. Occasionally Lithology.
there are beds of conglomerate, more or less calcareous, forming the basal members of the series. Marine fossils are usually found in the uppermost limestone beds. The maximum thickness of the series usually does not exceed 60 or 70 feet, though further south, in Rajpipla State, these beds are said to have attained an enormous thickness, often exceeding a thousand feet.
Thin, lenticular, disconnected outcrops of the Bagh beds occur as narrow fringes along the margin of the Deccan trap in the Jhabua
and Alirajpur States of the Central India Distribution. Agency and Vajiria, Agar, Naswadi,
Naswadi, Boriad and Chhota Udepur States of the Rewa Kantha Agency.
1 Mem. Geol. Surv, Ind., XXXVII, Pt. 2, pp. 170-172, (1908).
Well preserved lamellibranch and gastropod shells have been
found in many places in the Bagh beds of Fossils.
Jhabua. Of the lamellibranchs the following genera, all of marine habit, have been found in the collection, Cardium, Macrocallista, Protocardium, Astarte, Mactra (?), Aucella (?), Grotriana and Crassinella. The following specific identifications have been made :
Protocardium pondicherriense d'Orbigny.
Crassinella cf. planissima (Forb.). Of the gastropod fossil shells one could be specifically identified as Turritella multistriata Reuss. With the indistinct shells of Turritella, several shells of the order Pulmonata, family Auriculidæ, have also been noticed. The bulk of the fossils are marine, with the exception of the pulmonate shells.
Well preserved fossil shells belonging to the Lamellibranchia, Gastropoda, Bryozoa and Echinoidea have been found in the Bagh beds of Alirajpur. The following identifications have been made :Lamellibranchia.--Cardium (Trachycardium) incomptum Sowerby,
Crassinella cf. trigonoides (Stol.). Macrocallista, Mactra,
Nucula, Ostrea, Protocardium.
Indeterminate lamellibranchs belonging to the genus Ostrea have heen noticed in the calcareous shale beds in the Boriad exposures.
History of the age of the Bagh beds established by previous workers in
the Narbada Valley. The earliest collection from the Bagh beds was made in 1857, near Bagh, by Keatinge and Blackwell, who recorded their Cenomanian age. The collection was examined in 1865, by P. Martin Duncan", who stated that the echinoids are mostly identical with the species found in Europe in the Upper Greensand (Cenomanian). From
a general review of the mollusca and the echinoderms collected by Keatinge, Blackwell and Bose from the Bagh beds, Duncanassigned a Cenomanian age to the fauna. P. N. Bose, 2 in the course of his geological work in the Narbada Valley, divided the marine Cretaceous of the area into three divisions : (A) Nodular limestone, (B) Deola and Chirakhan marl, (C) Coralline limestone, and tentatively classified the three divisions with the Utatur, Trichinopoly and Ariyalur stages of the Cretaceous of South India. Duncan, however, observed that the three divisions of the Bagh beds established by Bose are conformable in their stratification and are characterised by the presence of common species of Hemiaster cenomanensis and Hemiaster similis and others which are characteristic Cenomanian forms. He further remarked that Bose's correlation of the Bagh beds, being based on rough identification of the fossils, cannot be of much stratigraphical value. In the course of his work in the Narbada Valley, Blanford4 noticed marine Cretaceous fossils, and from field observations and general faunal assemblage regarded the Bagh beds as of the same age as the fresh-water Lametas, corresponding in age in Europe with the Aptian to Cenomanian. Vredenburg) regarded the three divisions of the Bagh beds established by Bose as successive facies of a single palæontological stage. From his field observations in the Dhar Forest, Central India, Vredenburg6 corroborated Blanford's views that the Lametas are of the same age as the Bagh beds, the former being deposits laid down in fresh water on the Gondwana Continent, whilst the latter are those formed at the same time in the adjoining sea. From an examination of a collection of ammonites made by Bose from the Bagh beds, Vredenburg? assigned an age to the fauna ranging from the Gault to Lower Senonian. Vredenburg observed that the presence of Placenticeros mintoi in the Bagh fauna is not inconsistent with the attribution of the Bagh beds to the Cenomanian. In the course of the geological survey of the Jhabua State in 1909, Mr. H. Walker and Dr. A. M. Heron noticed marine fossils in the Bagh beds, containing specimens of Rhynchonella and some lamellibranchs, gastropods and bryozoa, in sheet 46 J/10, 14, which were found to join up with similar formations mapped
1 Rec. Geol. Surv. Ind., XX, pp. 81-87, (1887). 2 Mem. Geol. Surv, Ind., XXI, p. 135, (1884). 3 Rec. Geol. Surv. Ind., XX, pp. 81-87, (1887). • Mem. Geol. Surv. Ind.., VI, p. 132, (1863-64). 5 Rec. Geol. Surv. Ind., XXXVI, p. 110, (1907-8). 6 General Report, Geol. Surv. Ind., p. 20, (1902-3). ? Rec. Geol. Surv. Ind., XXXVI, pt. 2, p. 109, (1907).