DIVERSITY OF EPHEMEROPTERA, PLECOPTERA AND TRICHOPTERA IN VARIOUS TRIBUTARIES OF TEMENGGOR CATCHMENT, PERAK, MALAYSIA

Ephemeroptera(mayfly),Plecoptera(stonefly)and Trichoptera(caddisfly)(EPT,3 kinds of insectorders)reach their maximum development in streamsand contain families that are entirely or almost con-fined to running water.Ross(1963)suggested thatthe early evolut…     

Radioactive element distribution and rare-metal mineralization in anorogenic acid volcano-plutonic rocks of the Neoproterozoic Malani Felsic Province,western Peninsular India

The Anorogenic Malani Felsic Province (MFP) of western Peninsular India consists of peralkaline, metaluminous to mildly peraluminous A-type granites-acid volcanics with minor basic volcanics and dykes. The suite is bimodal in nature that characterized by volcano-plutonic ring structures and radial dykes. The granitoids of Siwana and Kundal areas of MFP are traversed by numerous quartz veins with fluoride, iron encrustations, druses and knots of pegmatite phases. Petrographically, they show cloudy, patchy perthitic textures; spherulite form of alkali amphibole and alkali pyroxenes; alteration of K-Na-feldspar to kaolin/sericite, magnetite to haematite; growth of granophyres/perthite/rapakivi like textures. They are enriched in SiO₂, Na₂O+K₂O, Fe/Mg, Rb, Zr, Y, Ga, REE (except Eu) and depleted in MgO, CaO, Mg#, P, Ti, Sr, Ni, Cr, Co and V. Uniform REE patterns, parallel to sub-parallel, LREE enriched over HREE and prominent negative Eu-anomalies are the characteristics of these granitoids. Geochemical parameters satisfy the A-type nature of granitoids and crustal origin of these rocks. These granitoids are high heat producing granitoids because of their high content of radioactive elements (U, Th, K), and can be classified as granite (Type I) (avg. 7.18 μWm⁻³), rhyolite and trachyte (Type II) (avg. 4.47 μWm⁻³) and acid dyke (Type III) (avg. 14.53 μ Wm⁻³). The average total heat generation unit (HGU) of Type I (17.10 HGU), Type II (10.64 HGU) and Type III (35.31 HGU) are much higher than the average value of continental crust (3.8 HGU), which imply a possible linear relationship among the surface heat generations in the MFP. Field, petrography and whole rock geochemical characteristics suggest potentiality for rare metals and rare earth elements mineralization in the studied granitoids of the MFP.     

Knowledge gaps in tropical Southeast Asian seagrass systems

Seagrasses are habitats with significant ecological and economic functions but we have limited knowledge of seagrasses in Southeast Asia, the hypothesized centre-of-origin for tropical seagrasses. There have been only 62 ISI-cited publications on the seagrasses of Southeast Asia in the last three decades and most work has been in few sites such as Northwest Luzon in the Philippines and South Sulawesi in Indonesia. Our understanding of the processes driving spatial and temporal distributions of seagrass species here has focussed primarily on backreef and estuarine seagrass meadows, with little work on forereef systems. We used Pulau Tinggi, an island off the southeast coast of Peninsular Malaysia, as an example of a subtidal forereef system. It is characterized by a community of small and fast growing species such as Halophila ovalis (mean shoot density 1454.6 ± 145.1 m⁻²) and Halodule uninervis (mean shoot density 861.7 ± 372.0 m⁻²) growing in relatively low light conditions (mean PAR 162.1 ± 35.0 μmol m⁻² s⁻¹ at 10 m depth to 405.8 ± 99.0 μmol m⁻² s⁻¹ at 3 m water depth) on sediment with low carbonate (mean 9.24 ± 1.74 percentage dry weight), organic matter (mean 2.56 ± 0.35 percentage dry weight) and silt-clay content (mean 2.28 ± 2.43 percentage dry weight). The literature reveals that there is a range of drivers operating in Southeast Asian seagrass systems and we suggest that this is because there are various types of seagrass habitats in this region, i.e. backreef, forereef and estuary, each of which has site characteristics and ecological drivers unique to it. Based on our case study of Pulau Tinggi, we suggest that seagrasses in forereef systems are more widespread in Southeast Asia than is reflected in the literature and that they are likely to be driven by recurring disturbance events such as monsoons, sediment burial and herbivory.     

Holocene coastal response to monsoons and relative sea-level changes in northeast peninsular Malaysia

Sedimentological, geomorphic, and ground penetrating radar (GPR) data are combined with optically stimulated luminescence data to define the Holocene evolution of a coastal system in peninsular Malaysia. The Setiu coastal region of northeast Malaysia comprises five geological and geomorphic units representing distinct evolutionary phases of this coastline. Estimated marine limiting point elevations indicate deposition of an early aggradational shoreline associated with a sea-level elevation of −0.1 to +1.7 m (MSL_PMVGD datum) between ∼6.8 ka and 5.7 ka, in agreement with previous sea-level studies from the Malay–Thai peninsula. A hiatus occurs in the record between ∼5.7 ka and 3.0 ka, possibly due to a relative sea-level oscillation and shoreline erosion. Long-term relative sea-level fall and possible still-stands created strandplains that are interrupted by aggradational to transgressive paleo-barrier and estuary formation corresponding with brief episodes of RSL rise. Analyses of GPR facies and OSL ages suggest annual clinoform deposition, with geometries dictated by variations in ENSO. These data demonstrate the utility of high resolution studies of coastal facies as useful proxy indicators for paleoclimate studies at subdecadal to millennial time-scales.     

Ethnic politics and ambivalent imaginaries of the future at the Melaka Straits

This article examines the ambivalent relationship between members of the Portuguese-Melakan Kristang minority and the state from the 1940s to the present day through the lens of ethnic politics. It reveals how ambivalent imaginaries of the future have shaped the politics of community members and what strategies they have used to assert their place. Moreover, it analyses how partly contradictory, partly converging imaginaries of the future of the Melaka coastline fuelled the failure of the Melaka Gateway land reclamation project. Grounded in ethnographic fieldwork in Melaka in 2018 and 2019, it focuses on the Melaka Gateway, a large-scale land reclamation project located in the Melaka Straits where three man-made islands and one natural island with high-rise buildings, a cruise terminal and a deep sea port have been planned.     

雷州半岛降雨特性与地表径流关系的小区试验

通过对试验小区观测值的分析和研究 ,发现本地区径流量与降雨量呈线性正相关 ,径流量与各瞬时雨强表现出幂函数的关系。径流量与降雨参数 (降雨量、30min最大瞬时雨强和降雨历时 )之间的三元线性回归分析表明 ,除裸地相关性不显著外 ,林地和农地相关性都达到极显著水平 ,可作为估测该区径流量大小的指标。     

康定MS6.3级地震斜坡地震动响应监测分析

芦山MS7.0地震、鲁甸MS6.5地震诱发了大量的次生山地灾害,一些学者认为地形放大效应是其中的一个影响因素,但目前斜坡地震动响应研究仍然缺乏大量的实测数据支撑。通过在冷竹关两岸斜坡不同部位掘进平硐并放置强震监测仪器的方法,对沟谷两岸斜坡地震动响应特征进行研究,剖面较为完整地记录了康定地震两岸斜坡的地震动响应特征。监测数据揭示,(1)相对于康定姑咱参考站,位于右岸半岛状凸出山梁顶部1#监测点的水平和竖直向PGA放大系数分别达到了10.6～11.5、7.1,阿里亚斯强度最大,水平东西向比竖直向HVSR频比值达到11.1,卓越周期在低频部分;位于右岸山梁中部2#监测点水平和竖直向PGA放大系数分别达到了4.3～5.0、2.3;(2)左岸地形坡面起伏较小,记录的峰值加速度较小,仅在坡折部位5#监测点有明显的放大,水平与垂直峰值加速度放大系数分别为3.0～4.5、2.3,各监测点频比存在多个卓越周期,其放大效应在高频段更突出;(3)近直线型斜坡内(6#及7#监测点)放大效应相对较弱,且监测洞外侧放大系数大于水平深度较大的内侧。结果表明冷竹关两岸斜坡存在明显的地形放大效应,且右岸半岛状凸出山脊地形较左岸中高山斜坡地形放大效应显著。对比芦山地震该剖面放大系数,揭示了背坡面效应。     

Malaysian diaspora strategies in a globalized Muslim market

This paper explores Malaysia’s efforts to develop and dominate a global market in halal (literally, ‘lawful or ‘permitted’) commodities as a diaspora strategy and how Malaysian state institutions, entrepreneurs, restaurants and middle-class groups in London respond to and are affected by this effort. The empirical focus is on London because this city not only holds a special position in the Malaysian state’s halal vision but also historical linkages that evoke diaspora strategies. I argue that Malaysian diaspora strategies should be explored in the interfaces between Islam, state and market. Among the political elite, and, thus, the Malaysian state, there exists a fascination with discovering or even inventing a cosmopolitan ‘Malay diaspora’ and current diaspora strategies try to address this challenge. An important question explored is how the Malaysian diaspora in London understand and practise Malaysian diaspora strategies in the globalized market for halal products and services. This paper is based on ethnographic material from fieldwork among state institutions, entrepreneurs, restaurants and middle-class groups in Kuala Lumpur and London, namely participant observation and interviewing.     

Brunei Darussalam: Characteristics of selected petroleums and source rocks

The development of three Tertiary deltaic complexes has resulted in the deposition of up to 10 km of sandstones and shales comprising the sources and reservoirs for crude oils that occur onshore, near-offshore and, with future exploration efforts, those likely to be encountered in deepwater reservoirs north of the Brunei coastline. We examined a series of offshore oils and onshore rock samples in Brunei Darussalam (a) to delineate oil family groups and their source rock characteristics, and (b) to assess the source potential of the sedimentary sequence with respect to lithology and depositional setting. Twelve offshore oils and 53 shales, coaly shales and coals were examined. The oils contain indicators of allochthonous (e.g. bicadinanes, oleananes) and autochthonous (e.g. cholestanes and methylcholestanes) components in the source organic matter. Predictable geographic variations of this mixed input are clearly evident in the sample set (e.g. allochthonous input appears to increase in offshore Brunei to the northeast). Although this molecular source signature is relatively clear, migration of these oils from deep (and unidentified) source rocks has resulted in extensive migration-contamination with respect to the tetracyclic and pentacyclic hydrocarbons. This contamination has resulted in strong correlations between certain molecular maturity indicators and the present-day temperature of the reservoirs. Liquid hydrocarbon source rock potential is present in the tidal and coastal embayment facies, and is greatest in the Miocene coals. Neither the shales nor coaly shales contain significant oil generative potential. The thermal immaturity of the sample set precludes valid oil–source rock correlations without conducting artificial maturation experiments on the coals.     

Transitional I S type characteristic in the Main Range Granite,Peninsular Malaysia

The dominantly Triassic Main Range Granite of Peninsular Malaysia that occurs west of the Paleo-Tethyan Bentong–Raub suture zone was regarded exclusively as an S-type granite. The Main Range dominantly biotite granites are of batholithic proportion and host one of the world’s largest tin provinces. The S-type characteristics include high initial ⁸⁷Sr/⁸⁶Sr isotope ratios (>0.710), a narrow range in silica, presence of ilmenite and occasional cordierite and andalusite, and the presence of pelitic or quartzose meta-sedimentary xenoliths. However, the present review shows that the Main Range Granites also have many features that are more characteristic of I-type granites such as the very large scale of plutonism, the presence of primary titanite and amphibole, occurrence of hornblende-bearing mafic enclaves, increasing peraluminosity towards the more differentiated end-members of the suite and decreasing P₂O₅ with increasing SiO₂ contents. The moderately peraluminous nature of the bulk Main Range Granite, without containing cordierite, Fe–Mg garnet or sillimanite, is consistent with derivation from a meta-sedimentary protolith that was itself undersaturated with respect to Al₂SiO₅.