Geological Survey of India
Study of Lycopods of the Kulti Formation, West Bengal Palaeontology Division Eastern Region carried out the field investigation during the Field Season 2001‐2002 and 2002‐2003 in Kulti‐Barakar area of West Bengal to study the appearance of lycopods in Kulti Formation and their dwindling upward character in the Gondwana sequence and their palaeo‐
ecological setup. Rocks exposed around Boldih in Kulti area of Raniganj coalfield, West Bengal were selected for studies. The sequence, which is devoid of any workable coal seams and occurring between Barakar and Raniganj formations is known as “Kulti Formation” (=Barren Measures) in Raniganj Coalfield of Damodar Valley. It is represented by dark grey and black micaceous shale, siltstone, and sandstone along with thin to moderately thick ironstone bands. The formation separates the Barakar Formation from the Raniganj Formation. The contacts of Kulti Formation with both Barakar and Raniganj are gradational in character. The gradational contact of Raniganj‐Kulti Formation is observed along east bank of Barakar river, northwest of Hatinal (230 42’ 25’’ N: 860 48’15’’E).The rocks of Kulti Formation are well exposed around Bodih village (230 42’ 31’’ N: 860 48’ 28’’ E). The ironstone bands are bluish grey or brown to reddish brown in colour, hard and compact and are 5 to 25 cm thick (Fig.1). These bands occur through out the sequence as exposed in Boldih area and yield lycophytes along with leaf and stem impressions of Glossopterids and Sphenopterids. A generalized stratigraphic succession (after Gee, 1932and Sastry et al.1977, 1977a) of the area is as follows: FORMATION Raniganj Formation LITHOLOGY Coarse to medium grained sandstone with siltstone, carbonaceous and grey shale and coal seam ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Gradational Contact ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ Kulti Formation Grey shale, siltstone and greyish black micaceous shale with thin interbands of Ironstone and medium grained sandstone. ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Gradational Contact ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ Barakar Formation Thin to thickly bedded medium to coarse grained feldspathic sandstone, grey shale, carbonaceous shale and coal. The Lower Gondwana succession of India is rich in coal‐forming Glossopteris flora that flourished during the Permian. Occurrence of lycophytes along with Glossopterids is much more Contributed by Dr. K.M. Wanjarwadkar, Palaeontology Division, Eastern Region
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Geological Survey of India
important to work out the palaeoecological set up and a record of this association is quite scanty in India. A fragmentary stem of lycopod like plant was reported by Bunbury (1881) from the Lower Gondwana from near Nagpur and described as Knorria? (Conifer). Schmalhausen (1879 ref. in Kar, 1968) described similar specimen as Rhipidopsis gingkoides. The stem possessing oval spindle‐shaped leaf scars with quinquncial arrangement were described by Feistmantel (1881) as Rhipidopsis gingkoides from ‘Kulti Iron shale’ of Raniganj Coalfield and Palissya sp. from Nagpur. Seward and Sahni (1920) regarded them as Bothrodendron. The lycophytes identified as Bothrodendron were reclassified as Cyclodendron which flourished during the deposition of Kulti Formation (Surange, 1966), and it is now considered as the characteristic plant form for the stage, and represented by Cyclodendron leslii. Maithy (1965) reported cf. Cyclodendron sp. from Karharbari beds of Lower Gondwana from Giridih Coalfield. Kar (1968) reported Cyclodendron leslii from Barren Measures of Jharia Coalfield. Srivastava and Kapoor (1967) reported Lepidostrobus from Lower Gondwana of Kashmir. Recently Cyclodendron leslii, Barakarodendron raniganjensis, Viatscheslavia kultiensis were provisionally identified by Pal from Kulti Formation, Raniganj Coalfield, West Bengal (GSI Coal Wing News, 1988). Excepting Cyclodendron leslii, rest of the species of lycophyte were revised and transferred to Boldihadendron raniganjensis from Boldih and Mahismara (Pal et. al., 1991). While studying plant fossils of Barren Measures from Katri Nala section of Jharia Coalfield, Srivastava and Tiwari (1997) recorded 11 species of Glossopteris and one species each of Cyclodendron, Neomariopteris, Rhabdstaenia, Gangamopteris and Noeggerathiopsis. The present collection of plant fossils show rich assemblage of lycophytes along with Glossopteris flora. The Glossopterids assemblage is represented by Glossopteris indica, G. stenoneura, G. feistmentalii, G. intermittens, G. conspicua, G. communis, G. clarkei and G. cf. damudica, Cordaitales by Noeggeratheopsis sp. besides eqisetaceous stems. The lycophytes are represented by Brasilodendron cf. pedroanum (Fig.2), Cyclodendron leslii (Fig.3, 7), Sigillaria sp. (Fig.4, 6) and Boldihadendron raniganjensis (Fig.5). The Brasilodendron reported from Early / Middle Permian of Candiota Coalfield, Brazil and the Sigillaria reported from Carboniferous and Permian of Europe are reported for the first time from Indian Gondwana. Though in the present study none of the sample revealed the palynofloral elements, the palyno assemblage reported by Tiwari and Tripathi (1987) from Kulti Formation, especially richness of Densipollenites and diversification of palynomorphs, does not support the views for a dry arid climate during Kulti depositional period. With the warm, humid and temperate climate prevailing during Kulti Contributed by Dr. K.M. Wanjarwadkar, Palaeontology Division, Eastern Region
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Geological Survey of India
period, it was favourable for plant growth but unfavorable for their preservation (Chandra and Chandra, 1987). Maheshwari (1974) stated that the lycopsid like plants existed throughout the Lower Gondwana times but due to some unknown factors their mega‐remains were preserved only during the Ironstone shale and Kamthi times. They were laid down in arid climatic conditions and inhabit in moist environment. The Lepidodendron flora of the northern hemisphere is typified for a warm humid ecological condition. From the southern hemisphere, the lepidodendraleans were also reported from Gondwanas of Australia, South Africa, and Brazil (Srivastava and Kapoor, 1967). Banerjee (1988) considered the occurrence of lycophytes and other northern hemisphere elements in the Glossopteris flora and described the warmer climate in the Gondwana continents during Permian. Cridland and Morris (1963) while reconstructing the habitat of late Palaeozoic lycophytes described that lycophytes grew in low lying marshy ground and formed tall canopy. The lycophytes in the present study area grew in similar environment along with Glossopteris flora. The chemical and petrological study of the rocks indicates the near shore environment with siderite and hematite in good amount as compared to silica and ankerite. It appears that the lycophytes grew during the Kulti (=Barren Measure) time in thickets of mangrove type in near shore environment. Increase in siderite and hematite might have developed the ecological condition that constrained survival of lycophytes in further stages resulting into their population dwindling upward in the sequence. Contributed by Dr. K.M. Wanjarwadkar, Palaeontology Division, Eastern Region
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Geological Survey of India
Fig.1. Thin Ironstone bands along with plant fossils, underlain by grayish black micaceous shale and
overlain by grey shale at northeast of Boldih, near Barakar.
2. Brasilodendron cf. pedroanum
3. Cyclodendron leslii
Contributed by Dr. K.M. Wanjarwadkar, Palaeontology Division, Eastern Region
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Geological Survey of India
4. Sigillaria sp
5. Boldihadendron raniganjensis
6. Sigillaria sp
. 7. Cyclodendron leslii
Contributed by Dr. K.M. Wanjarwadkar, Palaeontology Division, Eastern Region
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