Sedimentological characterisation of sea bottom samples collected offshore Muara and Tutong, Brunei Darussalam

The study aims to get some additional knowledge on the modern seafloor composition offshore Brunei Darussalam by looking at the recent stratigraphic succession of the deposited sediments and their distribution patterns. For this reason, 10 shallow cores (22 to 46 cm thick) have been collected by scuba diving along two depth transects spanning from water depth of 20 to 60 m. One of the transects has been sampled north-northwest of the Muara village, just in front of the Brunei Bay and the other one off the coast near Tutong town, away from major sedimentary inputs. The results obtained portray two different sea bottom compositions and two different depth-related sediment distributions. The Muara transect is highly rich in mud and yielded abundant biogenic component at all investigated depths. The Tutong transect has a higher sand content but display constant changes along with depth. The sediment is mostly composed by biogenic grains such as rests of sponges, foraminifera, molluscs and echinoderms; the not biogenic grains are for the vast majority made of quartz. The sandy fractions of both transects have been tested for cyclicity and all cores can be described by functions with comparable periods, thus indicating that an oscillatory environmental event such as the alternation of the monsoon seasons, has similar influence on the seafloor of both transects

Tracing migration of larger benthic foraminifera across atolls in the South China Sea

The distribution of modern benthic foraminifera is studied from offshore reefs of Brunei Darussalam located in northwest Borneo with enhanced siliclastic influence, and from Louisa Reef, an atoll in the Southern Spratly Islands under fully carbonatic environment. The main families of larger benthic foraminifera found from offshore reefs of Brunei are the Calcarinidae, Amphisteginidae and the Operculinidae, while at the Louisa Reef are the Calcarinidae, Amphisteginidae and the Soritidae. Larger benthic foraminifera are mainly concentrated in the tropical regions and in shallow waters, and their distribution depends on important environmental factors such as water depth, sunlight and type of sediment. Migration of LBF has been recorded since the Paleogene from the Americas to Africa and the Mediterranean Sea, and later to the Indo-Pacific where the modern biodiversity hotspot occurs. Hence looking into any possible migration throughout certain groups of LBF could help in understanding their biogeographic distribution through time within the Indo-Pacific region. Along the atolls in South China Sea the marine environments meet their living preferences, hence tracing their presence, distributions, and abundances could shed further light on their regional migration pattern

Palynology of miocene sediments in brunei darussalam: First SEM investigations of pollen and spores, and their taxonomy and palaeoenvironmental interpretation

Brunei Darussalam\u2019s geology is characterized by extensive Neogene fluvio-deltaic to shallow marine siliciclastic deposits, which have been studied here to highlight their palynological content. So far, there are only few reports that investigate fossil pollen and only one focuses on detailed taxonomical description using light microscopy (LM). The rest are studies on a wider regional scale in northwest Borneo sometimes including Brunei but without much emphasizes on taxonomy. To investigate pollen thoroughly, the use of scanning electron microscopy (SEM) is important, as this can provide valuable information on the sculptures of the pollen grains which with LM alone cannot be observed. Our study here provides LM images alongside the first SEM images of pollen and spores from Miocene sediments in Brunei Darussalam. The results point to a moderate-diverse flora comprising 37 families and 62 pollen and spore taxa. Most common ones are mangrove types which are Rhizophoraceae and Lythraceae taxa. The families of Combretaceae, Malvaceae, and other less common pollen groups are typical of tropical floral elements. The recovered families of Anacardiaceae, Arecaceae (five taxa), Calophyllaceae, Dilleniaceae, Dipterocarpaceae (two taxa), Elaeocarpaceae, Euphorbiaceae (four taxa), Phyllanthaceae (two taxa), Podocarpaceae, Proteaceae, Rubiaceae, Sapindaceae and Sapotaceae indicate mixed Dipterocarpaceae forests ranging from hinterland to peat swamp areas

Towards implementation of reverse electrodialysis for power generation from salinity gradients

Reverse electrodialysis is a conversion technique to obtain electricity from salinity gradients. Over the past few years, the performance of reverse electrodialysis on laboratory scale has improved considerably. In this paper, we discuss the challenges we are still facing concerning the economic and technological feasibility and the developing path of reverse electrodialysis. We focus on the following issues: (i) the development of low-cost membranes, (ii) pre-treatment in relation to stack design and operation, and (iii) the economics of reverse electrodialysis. For membranes, the challenge is to increase availability (>km(2)/year) at reduced cost

Catalogue of modern smaller benthic foraminifera from offshore brunei darussalam

The present study provides a catalogue (presence / absence data) of modern smaller benthic foraminifera (SBF) with descriptions and illustrations from 17 sites offshore from Brunei Darussalam, located along the northern coast of Borneo Island. The study area is at the edge of the Coral Triangle diversity hotspot and a comprehensive study on modern benthic foraminifera has not yet been undertaken here. Such research is particularly important in Brunei as the Neogene sedimentary successions cropping out onshore have been deposited under similar conditions to the modern environment hence the modern taxa tend to be similar to those preserved in the stratigraphic record. This catalogue is therefore also intended as a valuable tool for stratigraphers working in the oil industry in the region. A clear taxonomy of the modern fauna would help in the systematics of fossil benthic foraminifera assemblages. The investigated sites include proximal reef settings (Pelong Rocks and Abana Reef), muddy to sandy seafloors near sunken wrecks (Oil Rig Wreck, Dolphin Wreck, American Wreck, Australian Wreck and Bluewater Wreck), and two depth transects located as far as possible from artificial or environmental disturbances in relatively muddy environments. The samples are between 8 to 63 metres water depth (mwd). A total of 207 species of SBF (87 of which are left in open nomenclature), belonging to 88 genera, have been identified, thus indicating a much higher number of taxa than previously documented in nearby regions

Palaeoenvironmental interpretation of late Miocene outcrops (Miri and Seria formations) along jalan Tutong in Brunei Darussalam

Eleven Neogene outcrops (seven of the Miri Formation and four of the Seria Formation) from Brunei Darussalam are described. Detailed stratigraphic columns are presented with special emphasis on the sedimentary sequences, providing insights into the depositional environments. The rocks are comprised mostly of sandstone, claystone and a mix of both lithologies, and are piled up in cycles of coarsening upward successions, which are here interpreted as parasequences. Most sections are characterized by abundant and diverse sedimentary structures, reworked fossiliferous deposits and organic fragments such as ambers and wood remains. Certain beds are rich in fossils: among the macrofossils, the most common are bivalves, gastropods and followed by fish remains (teeth and otholiths), crustaceans, corals and echninoderms, which are abundant at specific locations. Among the microfossils, the most common are foraminifera, which are mostly dominated by either rotaliids or textulariids; the most common genera are Ammonia, Elphidium and Trochammina. Porcelaneous and planktonic foraminifera are rare. Ostracods are also found. Ichnofossils are quite abundant in all sections but are represented mostly by Ophiomorpha and Thalassinoides. In view of the observations, the sections are interpreted as evidence of shallow-marine conditions, in which wave, fluvial and tidal actions strongly influenced the depositional environment. In a few cases, deposition of sediment seems to reflect the transition from wave-dominated to tide-dominated conditions. Our findings indicate that in such shallow marine deposits, the interpretation of sediment type and sedimentary structures alone cannot indicate one specific sedimentary environment, but such observations should include palaeontological evidence to generate more accurate palaeoenvironmental reconstructions. Lastly, our results are discussed in relation to the sedimentary evolution of the region