Middle Eocene calcareous algae from Southwestern Kachchh, Gujarat

作者：Singh S K^*; Kishore S; Misra P K; Jauhri A K; Gupta Anjali

来源：Journal of the Geological Society of India, 2010, 75(5): 749-759.

DOI：10.1007/s12594-010-0059-z

• Calcareous algae
• middle Eocene
• Fulra limestone
• Kachchh
• Gujarat

The Fulra limestone (middle Eocene) exposed in the areas around Jhadwa and Harudi villages, southwestern, Kachchh reveals presence of a rich assemblage of calcareous algae belonging to the Chlorophyceae and Rhodophyceae along with abundant foraminifera. In the present paper, eight species belonging to eight genera of calcareous algae are described. These include Dissocladella longijangensis, Sporolithon keenani, Corallina crossmanni, Arthrocardia sp. Misra et al. 2001, Lithothamnion ishigakiensis, Melobesioideae gen. et spec. indet. 1, Melobesioideae gen. et spec. indet. 2 and Lithoporella melobesioides. Out of these, one taxon belongs to the family Dasycladaceae. Among the remaining taxa, one taxon to the family Sporolithaceae, three taxa to the family Corallinaceae and three to the family Hapalidiaceae. Two coralline species, Corallina crossmanni and Lithothamnion ishigakiensis, are recorded for the first time from India. Another species (Dissocladella longijangensis), though known from other areas of India, is new to the study area.
The dominant group of the calcareous algal association in the study area is represented by non-geniculate coralline algae comprising Hapalidiaceae, Corallinaceae and Sporolithaceae; the minor component is represented by dasyclads (chlorophyceae). These algal groups, together with their growth-forms (arbosescent, encrusting to fruticose, warty), and the associated foraminifera indicate that the depositional environment of the Fulra limestone ranged from deeper innerto mid-ramp environment (40-80 m) in the upper photic zone.

• 出版日期2010-5