Geological Significance of Marine Molluscan Beds : Evidence From Southern Coastal Zone of Sri Lanka

Katupotha, Jinadasa

doi:10.4038/jnsfsr.v22i2.8119

Cited by 17 publications

(33 citation statements)

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“…Sea levels in the Permian Period remained generally low, and near-shore environments were limited by the collection of almost all major landmasses into a single continent called Pangaea (ICS 2009). (Katupotha 1988a;1988b;1988c and1995).…”

Section: Resultsmentioning

confidence: 99%

“…• Stranding evidence of sea level fluctuations, sand dunes, gravel deposits, formation of Red Beds, laterite, nodular ironstone (Katupotha 1995;Cooray 1984). …”

Section: 0117-0126 (Upper)mentioning

confidence: 99%

“…Source: See References Cooray 1984;ICS 2009(Retrieved 2009Katupotha 1988aKatupotha , 1988bKatupotha , 1988cKatupotha and 1995King 1962;Sommerville, 1907 andDeraniyagala, 1958. In Sri Lanka, nearly 90% of its rock types are composed of crystalline Precambrian metamorphic rocks. They are subdivided as Highland Complex, Wanni Complex and Vijayan Complex and other small divisions (Cooray, 1984(Cooray, , 1994Hölzlet al 1991, Kröneret al 1991.…”

Section: -4895mentioning

confidence: 99%

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Palaeoclimate change during Glacial Periods: Evidence from Sri Lanka

Katupotha

2013

JTFE

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In the Earth's history, there were five major glaciations, namely, Huronian (2,300 Ma), Cryogenianor , and the Quaternary (2.58 Ma to Present) that occurred between 2,300 Ma and 0.0114 Ma. It is revealed that Gondwanaland emerged between the Huronian glaciation (2300-2100 Ma) in the Paleoproterozoic Era and the Andean-Saharan glaciation . Huge rocky blocks (erratic boulders) have been transported to different places by continental ice sheets due to climatic changes in the Permian, Triassic and Jurassic Periods, but erratic pebbles (2 to 8 cm or more in size) and streams fed deposits have been transported by glacifluvial processes. These glaciofluvial processes occurred on four occasions during the Jurassic Period and Eocene, Miocene and Pliocene Epochs on Sri Lankan landmass, which fallowed the climatic changes and sea level fluctuations that broke up the sedimentary beds, initiating establishment of the present topography and structural configuration. As a result, the earlier sedimentary deposits were obliterated from greater part of Sri Lanka. During the Quaternary Period the erosional rate increased and the resultant erratic boulders along with glaciofluvialdeposits can still be found on "Planated Surfaces"of Sri Lanka.

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Section: Resultsmentioning

confidence: 99%

“…• Stranding evidence of sea level fluctuations, sand dunes, gravel deposits, formation of Red Beds, laterite, nodular ironstone (Katupotha 1995;Cooray 1984). …”

Section: 0117-0126 (Upper)mentioning

confidence: 99%

Section: -4895mentioning

confidence: 99%

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Palaeoclimate change during Glacial Periods: Evidence from Sri Lanka

Katupotha

2013

JTFE

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“…Compared to the size of the Indian subcontinent, Sri Lanka had a lesser diversity of vast areas of habitat necessary to sustain the extinct megafaunal mammals. Furthermore, challenges to survival would have been made worse by substantial local climate-related habitat turn-overs during the Pleistocene in Sri Lanka (Katupotha, 1995(Katupotha, , 2013.…”

Section: The Quaternary Period: Extinction Of Megafaunal Mammals Globmentioning

confidence: 99%

The biogeography and ecology of Sri Lankan mammals point to conservation priorities

Dittus

2017

Ceylon J. Sci.

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All mammals originated on the supercontinent of Pangaea in the Mesozoic era during the "Age of Reptiles." However, the crown ancestors of contemporary mammals did not flourish until major environmental and biotic changes had occurred. An asteroid collided with earth at the end of the Cretaceous Period (the K-Pg boundary event) wiping out nonflying dinosaurs and primitive mammals. It was followed by large-scale volcanism, a spike in atmospheric oxygen and the proliferation of flowering plants. New niches became available for the ancestors of today's mammals to fill. Evidence suggesting whether the ancestors of the Sri Lankan and Indian mammals originated on the tectonically marooned Indian plate before crashing into Asia or on the Laurasian supercontinent is inconclusive. Modern Sri Lankan mammals show their greatest affinity with those of southern India, and were more diverse in the Pleistocene when rhinoceros, hippopotamus, wild dogs, gaur and lions enriched the island's landscapes. Native Sri Lankan land-based mammals are diversified into about 108 unique taxa (among 91 species and 53 genera), differentiated as phenotypic adaptations to sharply contrasting environments among seven major phyto-climatic zones. Endemic subspecies are distributed fairly equally across different phyto-climatic zones (n=24 to 29), except in the highlands where they are fewer (n=14) having evolved rapidly to species and genera among the insectivores and rodents whose reproductive rates are high. Conversely, greater numbers of endemic species (n=13) and genera (n=3) occur in the highlands than in the other zones (2-6 endemic species, no endemic genera). The prevalence of endemism is inversely related to body size or vagility. This suggests a greater probability of genetic exchange among distant populations of large bodied mobile mammals within Sri Lanka, as well as with Indian fauna during periods of land bridges in the Pleistocene. Most (8 of 13) endangered and critically endangered endemic mammals occur in the wet montane regions that offer the least Protected Areas (PAs). More than 85% of PAs occur in the extensive dry zone about half of which is not suited for water dependent mammals whose distributions are restricted to alluvial forests (less than 1% of PAs). Historically, the national cost of conservation has been low and therefore politically palatable. Current conservation urgently requires a major change in management policy combined with realistic investment to prevent extinctions of many endemic mammals and other unique Sri Lankan biota.

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“…In the southern coastal belt of Sri Lanka, amidst shallow lagoons and deltas, naturally and artificially accumulated shell deposits are encountered. Many shell accumulations of the island are attributed to natural processes, such as the intermittent lowering of the sea levels during the mid-Holocene (Katupotha, 1995). However, the deposition of several shell accumulations in Udamalala, Pallemalala, and Mini-athiliya are attributed to human activity (Somadeva and Ranasinghe, 2006;Perera, 2009).…”

Section: Introductionmentioning

confidence: 99%