Ce anomaly in I‒type granitic soil from Kuantan, Peninsular Malaysia: retention of zircon in the weathering product

This paper describes the Ce anomaly observed in granitic soil from the humid, tropical area of Kuantan, Pahang, Peninsular Malaysia. Three granite rock soil profiles from Kuantan, were sampled and all samples were analysed for rare earth elements. All the profiles of the granitic soil samples show prominent positive Ce anomalies, with the Ce/Ce* ratio values (Ce/Ce*= CeN/√LaN.PrN) ranging from 1.2 to 125. l. Ce4+ is compatible in zircon because it has also the same charge and a similar ionic radius as to Zr4+ (Ce4+ = 0.97 Å; Zr4+ = 0.84 Å). The retention of zircon in the weathering product of the granitic rocks will increase the Ce content in the soil. Thus it is likely that the positive Ce anomaly in the REE profile of the Kuantan Granites may also have resulted from retention of zircon in the weathering product

Kinematics and Timing of Brittle-Ductile Shearing of Mylonites along the Bok Bak Fault, Peninsular Malaysia

Study on the Bok Bak fault in Peninsular Malaysia reveals it to be a predominantly dextral brittle-ductile strike slip fault zone. This fault zone is characterized by gentle to sub-horizontal NE stretching lineation. The deformation occurred in a brittle-ductile domain. 40Ar/39Ar radiometric dating of biotite from the mylonite assigns an age of 136.1 ± 1.4 Ma. This age is the first reported radiometric dating of the Bok Bak fault, suggesting that the fault affected Sundaland prior to the collision between India and Asia, and therefore indicates an early faulting in the Malay Peninsula

Effects of Lateral Variation in Vegetation and Basin ‘Dome’ Shape on Tropical Lowland Peat Stabilisation in the Kota Samarahan-Asajaya Area, West Sarawak, Malaysia

Field surveys indicate lateral variation in peat humilIcation levels (von Post) in dominantly occurring fibric, fibric to hemic, sapric and hemic to sapric peats across a gradient from the margin towards the centre of tropical lowland peat domes. Cement-peat stabilisation can be enhanced by adding mineral soil fillers (silt, clays and line sands) obtained from Quaternary floodplain deposits and residual soil (weathered schist). The unconfined compressive strength (UCS) of the stabilised cement-mineral soil filler-peat mix increases with the increased addition of selected mineral soil filler. Lateral variation in the stabilised peat strength (UCS) in the top 0 to 0.5 m layer was found from the margin towards the centre of the tropical lowland peat dome. The variations in the UCS of stabilised tropical lowland peats along a gradient from the periphery towards the centre of the peat dome are most likely caused by a combination of factors due to variations in the mineral soil or ash content of the peat and horizontal zonation or lateral variation in the dominant species of the plant assemblages (due to successive vegetation zonation of the peat swamp forest from the periphery towards the centre of the tropical lowland peat dome). © 2014 Geological Society of China

Distribution and contamination assessment of potentially harmful elements (As, Pb, Ni, Cd) in top soil of Penang Island, Malaysia

This study discusses the distribution and contamination levels of potentially harmful elements (As, Pb, Ni, and Cd) in the urban top soil of Penang Island, one of the most important urban areas in Malaysia. The total surface area of Penang Island is 297 km2. Thirty-one surface soil samples (0–20 cm) were collected, digested and analysed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for As, Pb, Ni, and Cd. The result showed that the mean concentrations of selected metals in soils were arranged in the following decreasing order: Pb > As > Ni > Cd. In terms of different soil types, soils derived from quaternary deposit have higher mean concentration of Pb, Ni, and Cd as compared to the granite residual soils which accumulate higher mean concentration of As. On the spatial distribution maps, As, Pb, Ni, and Cd are mainly concentrated in the north-to-north eastern areas of Penang Island and near to the main city, which are characterized by major residential and business areas. Thus, it suggests that the anthropogenic source is the main contributor to the As, Pb, Ni, and Cd in the top soil of Penang Island. Both Pearson correlation analysis and principal component analysis showed a strong positive correlation between Pb and Cd which indicated that they may be derived from a similar source. The contamination factor assessment indicates moderate contamination level for Pb and Ni and no element enrichment level for As and Cd. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature

Impact of rapid urbanization on the modern sedimentary environments in a semienclosed embayment: Tong’an Bay, southeast China coast

Tong’an Bay (TAB) is a semienclosed embayment in the north of Xiamen Island. The sea area of TAB was mainly used for aquaculture in enclosed areas before 2003. Since 2003, the districts surrounding TAB have been undergoing a rapid urbanization process, and the scale of land used for urban construction in these districts has been continuously increasing. Under the backdrop of rapid urbanization, the coastline of TAB has largely been transformed into an artificial coastline. Due to the large scale of land reclamation and, dredging activities and the opening of the Gaoqi-Jimei (GJ) Seawall, there have been relatively significant changes in the coastal and submarine geomorphology in central northern, western, and southern TAB and Wuyuan Bay as well as a significant increase in the area where artificial submarine geomorphologies are distributed; the number of surface sediment types in the TAB has increased, and sediments in the sea area surrounding engineering projects have been coarsening; the sediment transport pattern has not significantly changed at the mouth of TAB and in central northern TAB, but the suspended sediment transport direction near the GJ Seawall has changed to a certain extent