| || || Lal, Kirti Kamna.|
| || || Palaeogeography of the Rove-Bourewa area, Southwest Viti Levu Island, Fiji Islands|
Author:Lal, Kirti Kamna.
Institution: University of the South Pacific.
Call No.: pac In Process
Copyright:Under 10% of this thesis may be copied without the authors written permission
Abstract: Physical, chemical, and radiocarbon analyses of a 6-m sediment core from the Bourewa palaeolagoon, located adjacent to the Bourewa archaeological site, provide Holocene palaeosea-level data for southwest Viti Levu Island (Fiji Islands, southwest Pacific). The core dates as far back as 11,470 cal BP, marking the end of the Last Glacial Maximum and the beginning of the Holocene Interglacial. Sediment colour determination from Munsell Colour Charts, texture from particle-size analysis, and percent organic and carbonate content using the loss-on-ignition method was used to reconstruct sedimentary environments subsequent to the Last Glacial Maximum. Marine shells preserved in the sediment core show subsequent environmental conditions for the Rove-Bourewa area. Five distinct environmental conditions associated with the Holocene succession are noted, initial terrestrial environment to a mudflat zone to a brackish lagoon system back to the mudflat zone and finally to the present dry land. The mudflat zones were the transition period from terrestrial to marine and then from marine to terrestrial environment. These conditions were associated with the rising sea level of the Holocene Interglacial. The palaeoenvironmental transformation from organic-rich terrestrial sedimentation to carbonate-rich marine sediments in the Rove-Bourewa palaeolagoon occurred around 6000 cal BP with the transformation to the brackish lagoon system. The highest sea-level proxy data in the sediments recorded 4000 years ago when the climate conditions were optimum with the maximum diversity of marine organisms. Sea level was about 2 m above the present level during the Holocene Climate Optimum that lasted for about 300 years. Sea level gradually started to decline around 3400 cal BP, the end of the Holocene Climate Optimum as the brackish lagoon was exposed and it was slowly transformed into the present dry flat land. It was during the early stages of late-mid-Holocene sea-level fall when the southwest Pacific Islands were colonised by people, 3210 cal years BP. v Keywords: Bourewa, Holocene, Holocene Climate Optimum, Lapita, Palaeoclimatology, Palaeolagoon, Rove Peninsula, Sea level, Marine Shells.