Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

P. Kundal ¹, M. B. Bhagat ², Sumedh K. Humane ¹

Affiliations
1 postgraduate Department of Geology, R. T. M. Nagpur University, Law College Square, Nagpur - 440 001, IN
2 Shri Mathuradas Mohota college of Science, Sakkardara Square, Nagpur 440 009, IN

Abstract

This note records four nongeniculate coralline algal species viz. Neogoniolithon sp., Sporolirhon sp., Mesophyllum sp. and Lithoporella sp. and 3 geniculate coralline algal species Jania sp., Corallina sp. ancl Subterraniphyllum sp, from the Early Miocene Bombay Formation, Bombay Offshore Basin, India. Based on coralline algal assemblage, it is inferred that the limestone of Bombay Formation was deposited under low to moderate energy conditions with 10 to 20 rn water depth.

Keywords

Coralline algae, Early Miocene, Bombay Formation, Paleoenvironment, Bombay Offshore Basin.

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P. Kundal ¹, Sumedh K. Humane ¹

Affiliations
1 Postgraduate Department of Geology, R. T. M. Nagpur University, Law College Square, Nagpur- 440 001, IN

Abstract

Amongst all fossil calcareous algae, the fossil dasycladales are the most important group of calcareous green algae as these are highly useful for paleoenvironmental and paleobathymetric inferences. The fossil dasycladales comprise over 40 genera and 200 species and these have been documented from different parts of the world in Paleocene-Eocene. However, the record of dasycladales from Indian Cenozoic sediments is very scanty as only 24 dasycladacean species are known. In view of this, the present report of a rich dasycladacean algal assemblage comprising 7 additional species belonging to 6 genera viz., Cymopolia sp., Neomeris ramwadaensis sp. nov., N. plagnensis Deloffre, Acroporella sp., Broeckella sp., Orioporella sp., Clypeina sp. from the limestones of the Maniyara Fort Formation (Chattian) and the Chhasra Formation (Burdigalian) in Kachchh, India is of much significance. The algal assemblage indicates that these limestones were deposited in a shallow marine tropical waters at a depth of about 10-12 m below low tide level.

Keywords

Dasycladacean Algae, Chattian, Burdigalian, Tropical Waters, Low Tide Level, Kachchh, India.

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Sumedh K. Humane ¹

Affiliations
1 Postgraduate Department of Geology, RTM Nagpur University, Nagpur - 440 001, IN

Abstract

The asymmetric micro scale cross ripple laminations formed under unidirectional traction current are noted from the Aquitanian sandstone of Laiyari area of south western Kachchh, Gujarat. The micro facies of micro scale cross laminations represent lower velocity migration at shallow depth waves in littoral and marine environments. Asymmetric ripples signify net landward unidirectional transport of shallow marine water.

Keywords

Sandstone, Cross-Laminations, Khari Nadi Formation, Kachchh, Gujarat.

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P. Kundal ¹, Sumedh K. Humane ¹

Affiliations
1 Postgraduate Dept of Geology, RTM Nagpur University, Law College Square, Nagpur 440 001, IN

Abstract

The present communication documents for the first time Six species of Jania Lamouroux, a geniculate coralline alga of Subfamily Corallinoideae of Family Corallinaceae, Division Rhodophyta from Fulra Limestone Formation (Middle Eocene) exposed at Babia Hill and Jadwa, Maniyara Fort Formation( Oligocene) at Maniyara Dam, Bermoti Hill, Bermoti Nadi Section and Khan Nadi Formation (Lower Miocene) at Mokhra in Kachchh district of Gujarat. Six species of Jania including two new species Jania badvei and J sripadaraoi are reported in this study. The species of Jania suggest clear water shelf depositional environment under low energy for limestone of Fulra Limestone Formation and Khan Nadi Formation, while high energy shelf depositional environment for limestone of Maniyara Fort Formation.

Keywords

Geniculate Coralline Algae, Jania Middle Eocene to Lower Miocene, Depositional Environment, Kachchh, Gujarat.

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Sumedh K. Humane ¹

Affiliations
1 Postgraduate Department of Geology, Nagpur University, Law College Campus Amravati Road, Nagpur-44 001, IN

Abstract

No Abstract.

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Sumedh K. Humane ¹, Savita N. Chaurpagar ¹, Samaya S. Humane ¹, P. Kundal ¹

Affiliations
1 Postgraduate Department of Geology, RTM Nagpur University, Law College Square, Nagpur - 440 001, IN

Abstract

A very rich and diversified dasycladalean algal assemblage has been discovered from the Sylhet Limestone Formation (lower-middle Eocene) of the Bengal Basin of India for the first time. The depositional environments of the Sylhet Limestone Formation have been discussed based on the presence of the 11 species of the dasycladalean algae belonging to the three families Dasycladaceae (Cymopolia inflataramosa Segonzac, C. mayaenese Johnson and Kaska, C. paronai Raineri, Cymopolia sp.), Triploporaceae (Dissocladella lunata Segonzac, Dissocladella sp., Jodotella sloveniaensis Deloffre and Radoicic) and Acetabulariaceae (Clypeina socanensis Deloffre and Radoicic, Clypeina sp., Terquemella sp., Neomeris sp.). The lower Eocene Sylhet Limestone Formation revealed predominance of dasycladalean algal assemblage with the halimedacean and udoteacean algae and rare occurrence of coralline algae. This suggests their luxuriant growth in the open lagoonal to shelf environment at the depth of 5-6 m in the warm waters. There is a gradual decrease in the dasycladalean species and genera in the middle Eocene Sylhet Limestone Formation. The predominance of coralline algae associated with the Sporolithon indicates that the limestone of middle Eocene Sylhet Limestone Formation have been deposited at the littoral to shallow, high energy open shelf marine environments at a depth of about 40-60 m in warm tropical waters.

Keywords

Dasycladalean Algae, Lower-Middle Eocene, Sylhet Limestone Formation, Depositional Environment, Bengal Basin.

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