Skip to Main Content
GEOREF RECORD

The first record of the Permian Glossopteris flora from Sri Lanka; implications for hydrocarbon source rocks in the Mannar Basin

G. Edirisooriya, H. A. Dharmagunawardhane and Stephen McLoughlin
The first record of the Permian Glossopteris flora from Sri Lanka; implications for hydrocarbon source rocks in the Mannar Basin
Geological Magazine (May 2018) 155 (4): 907-920

Abstract

Strata exposed near Tabbowa Tank, Tabbowa Basin, western Sri Lanka have yielded the first representatives of the distinctive Permian Glossopteris flora from that country. The assemblage includes gymnosperm foliage attributable to Glossopteris raniganjensis, roots referable to Vertebraria australis, seeds assigned to Samaropsis sp., sphenophyte axes (Paracalamites australis) and foliage (Sphenophyllum emarginatum), and fern foliage (Dichotomopteris lindleyi). This small macroflora is interpreted to be of probable Lopingian (late Permian) age based on comparisons with the fossil floras of Peninsula India. Several Glossopteris leaves in the assemblage bear evidence of terrestrial arthropod interactions including hole feeding, margin feeding, possible lamina skeletonization, piercing-and-sucking damage and oviposition scarring. The newly identified onshore Permian strata necessitate re-evaluation of current models explaining the evolution of the adjacent offshore Mannar Basin. Previously considered to have begun subsiding and accumulating sediment during Jurassic time, we propose that the Mannar Basin may have initiated as part of a pan-Gondwanan extensional phase during late Palaeozoic - Triassic time. We interpret the basal, as yet unsampled, seismically reflective strata of this basin to be probable organic-rich continental strata of Lopingian age, equivalent to those recorded in the Tabbowa Basin, and similar to the Permian coal-bearing successions in the rift basins of eastern India and Antarctica. Such continental fossiliferous strata are particularly significant as potential source rocks for recently identified natural gas resources in the Mannar Basin.


ISSN: 0016-7568
EISSN: 1469-5081
Coden: GEMGA4
Serial Title: Geological Magazine
Serial Volume: 155
Serial Issue: 4
Title: The first record of the Permian Glossopteris flora from Sri Lanka; implications for hydrocarbon source rocks in the Mannar Basin
Affiliation: University of Peradeniya, Department of Geology, Sri Lanka
Pages: 907-920
Published: 201805
Text Language: English
Publisher: Cambridge University Press, London, United Kingdom
References: 117
Accession Number: 2018-055794
Categories: StratigraphyEconomic geology, geology of energy sources
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. geol. sketch map
N09°00'00" - N10°00'00", E78°00'00" - E80°00'00"
Secondary Affiliation: Swedish Museum of Natural History, SWE, Sweden
Country of Publication: United Kingdom
Secondary Affiliation: GeoRef, Copyright 2018, American Geosciences Institute. Abstract, Copyright, Cambridge University Press. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 2018
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal