Department of Oceanography and Marine Geology
http://ir.lib.ruh.ac.lk/xmlui/handle/iruor/7367
2024-03-28T18:52:41ZGlobal Blue Economy Analysis Developments and Challenges
http://ir.lib.ruh.ac.lk/xmlui/handle/iruor/9150
Global Blue Economy Analysis Developments and Challenges
Cooray, N.S; Premarathne, U.; Atapaththu, K.S.S.; Priyadarshana, T.
Oceans are approximately three- quarters of the earth’s surface, accountable for more than 90% of
the biosphere, providing an array of goods and services to the global community which includes
food, employment, recreation and cultural well- being, minerals, oxygen production, greenhouse gas
absorbance, climate change impact mitigation, and serve as highways for seaborne international
trade (United Nations, 2017). For the development of economies along with the threats posed by
the climate change and global warming the concept of the Blue Economy was first introduced in
1994 by Professor Gunter Pauli of the United Nations University (UNU). Because of this significant
role played by the oceans, the importance of implementing sustainable development measures for
marine environment was discussed at the United Nations Conference on Sustainable Development
(Rio+ 20) held in Rio de Janeiro, Brazil in June 2012. Consequently, the conference adopted a set of
ground- breaking guidelines on green economic policies which are considered as essential tools for
achieving sustainable development goals (United Nations, 2012). With strong support from coastal
and island nations at the conference, because of the contribution made by the oceans to their economies, the ocean derived green economy was accepted as the blue economy.
2022-01-01T00:00:00ZRevelation of depositional features in the Paleocene and Eocene in the Mannar basin using amplitude analysis of a 3D data set
http://ir.lib.ruh.ac.lk/xmlui/handle/iruor/9148
Revelation of depositional features in the Paleocene and Eocene in the Mannar basin using amplitude analysis of a 3D data set
Dushyendra, A.; Premarathne, U.; Weerasinghe, D.
The Mannar Basin is located between the western coasts of
Sri Lanka and the southern coast of India. The Sri Lankan portion of the basin
extends over 45,000 km2. It is a deep-water frontier with only two natural gas
discoveries. Studies show that the Paleogene and the Late Cretaceous sections
have potential hydrocarbon reservoirs. However, little is known regarding their
depositional features. The objective of this study was to understand the
depositional features in the Paleocene and Eocene sediments in the M2
exploration block in the Mannar basin using a three-dimensional seismic
volume. IHS Kingdom software was used for seismic data interpretation. The
root mean square amplitude was used to characterise sediment facies in seven
time windows having 50-millisecond intervals. The results show the occurrence
of an interpreted turbidite fan system in the Paleocene and Eocene sections. A
NE-SW trending deep-water canyon channel system occurs in the early Eocene
section.
2022-01-01T00:00:00ZReservoir potential of the Campanian sandstone in the Dorado North well on the Mannar Basin, offshore Sri Lanka
http://ir.lib.ruh.ac.lk/xmlui/handle/iruor/9146
Reservoir potential of the Campanian sandstone in the Dorado North well on the Mannar Basin, offshore Sri Lanka
Bandara, M.; Premarathne, U.
The Mannar Basin is located offshore in between the west coast of Sri Lanka and the east coast of India. It is
a Mesozoic failed rift basin filled with Late Jurassic to recent sediments. The basin is one of the main targeted
areas for oil and gas exploration in Sri Lanka. In 2011, the existence of an active petroleum system in the
basin was confirmed by discovering natural gas from Dorado and Barracuda wells. Although the petroleum
system of the Mannar Basin is known to some extent, the porosity and permeability of potential reservoirs in
the basin are little known. Previous basin modeling studies have reported that the Late Cretaceous section in
the northern part of the Mannar Basin has potential reservoirs. However, their porosity and permeability have
not been investigated in detail due to the lack of availability of well data. The objective of this study was to
estimate the porosity of approximately 431 m thick Late Cretaceous (Campanian) sandstone section in the
Dorado-North well, located on the northern part of the Mannar Basin. The results show that the Campanian
section is mainly composed of shaly sandstone. Almost half of the section shows very good reservoir potential,
while the rest of the section has fair to good reservoir potential. The quality of a hydrocarbon reservoir depends
on its shale fraction. Shale degrades the reservoir quality. Caving in give rise to uncertain data in petrophysical
logs. The Campanian section in the Dorado-North has very good hydrocarbon potential.
2021-01-01T00:00:00ZContinental flood basalt magmatism contemporaneous with Deccan traps in the Mannar basin, offshore Sri Lanka
http://ir.lib.ruh.ac.lk/xmlui/handle/iruor/9143
Continental flood basalt magmatism contemporaneous with Deccan traps in the Mannar basin, offshore Sri Lanka
Premarathne, U.; Ranaweera, L.V.
The Gulf of Mannar and adjoining Cauvery basin to the north between India and Sri
Lanka are associated with a failed rift, which initiated during the late Jurassic to early
Cretaceous as a precursor to the breakup of East Gondwana. Despite the occurrence
of igneous rocks that can be noted in seismic profiles, offshore, and deep seated occurrence of those have lead only to the limited understanding of igneous activity in the
Mannar basin. Rock cuttings recovered in the Barracuda exploratory well in the Mannar basin shows approximately 700 m thick basalt rock sequence interlayered with
sediments at a depth of 3500–4200 m below mean sea level. Here, we analyzed samples recovered from the Barracuda well for major and trace element composition.
Major and trace element data suggest that the basalts were crystallized from two
different degrees of partial melts from a similar source. Chondrite normalized rare earth
element (REE) patterns indicate that the basalts are similar to continental flood basalt,
though they show a distinct Ba positive anomaly. Importantly, supported with previously available K–Ar data, we decipher that these basalts are contemporaneous with
the Deccan traps. Rifting between Seychelles and India which had occurred at 62 Ma
approximately 3.5 Ma after the main Deccan eruption is synchronous with the Barracuda volcanism suggesting coeval rifting between Seychelles–India and India–Sri
Lanka. Thus, our data suggest simultaneous rifting between Seychelles–India and
India–Sri Lanka. Large plate reorganizations that took place during this time period in
the Indian Ocean have likely caused consequent passive rifting in the Mannar basin.
2021-01-01T00:00:00Z