Turbidite-associated black shale of the Semanggol Formation is extensively distributed in the northwestern part of the Western Belt, Peninsular Malaysia. The black shale occurs as a dark grey to black and thick to medium-bedded deposit. It represents the distal part of submarine fan system (outer-fan) overlying interbedded sandstone to shale facies of the mid-fan and conglomeratic pebbly sandstone facies of the inner-fan. Field observations and its widespread occurrence have resulted in the black shale being considered as a potential analog for a source rock in offshore Peninsular Malaysia. The present study includes detailed mineralogical (XRD, SEM, and EDX analysis), inorganic geochemical (major oxides, trace elements TEs, and rare earth elements REEs), and Rock-Eval pyrolysis analyses of the black shale samples, collected from the Gunung Semanggol, Bukit Merah, and Nami areas in northwestern Peninsular Malaysia. The primary focus of this study is to investigate the provenance, paleoredox conditions, paleoclimate, sedimentary rate, paleoproductivity, and upwelling system that would be helpful to understanding the role of these parameters in the enrichment of organic matter (OM) in the black shale. The Rock-Eval analysis shows that the black shale of the Semanggol Formation comprises type-III kerogens, which suggests organic input from a terrestrial source. The black shale also contains mature to postmature organic matter. Based on the mineralogical analysis, the mineral composition of the black shale comprises illite and kaolinite, with abundant traces of quartz and feldspar as well as few traces of titanium and zircon. Inorganic geochemical data designate black shale deposition in a passive margin setting that has experienced moderate to strong weathering, semi-arid to hot arid climate, and moderate sedimentation rate. Ratios of Ni/Co, U/Th, and V/(V+Ni) along with slightly negative to positive Ce* anomalies and U_EF-Mo_EF cross-plot unanimously indicate anoxic/dysoxic water conditions that are suitable for organic matter preservation. Geochemical proxies related to modern upwelling settings (i.e., Cd/Mo, Co vs. Mn) show that the deep marine black shale was strongly influenced by persistent upwelling, a first-order controlling factor for organic matter enrichment in the distal part (outer fan of the submarine fan system) of the Semanggol Basin. However, productivity-controlled upwelling and a high sedimentary rate, as well as high-productivity in oxygen-depleted settings without strong anoxic conditions, has played an essential role in the accumulation of organic matter.

Deepwater lobes constitute a significant volume of submarine fans and are primarily believed to exhibit a simple sheet geometry. However, recent studies interpret the geometries of these deep-marine lobes as distinct with respect to the complexity of the facies and their distribution. Hence, a conceptual model of deep-marine sediments is essential to discuss the deep-marine sediments associated with the fan and lobe architecture. The present study highlights the facies heterogeneity and distribution of various lobe elements at a multiscale level by considering a case study of the West Crocker Formation of Sabah in northwest Borneo. The formation was logged on a bed-to-bed scale from recently well-exposed sections, with a total vertical thickness of more than 300 m. The lithological characteristics, bed geometry, sedimentary textures and structures of individual beds were used to categorize the rock units into nine sedimentary lithofacies: five sandstone lithofacies (S1–S5), one hybrid bed facies (H), two siltstone facies (Si1 and Si2) and one shale or mudstone facies (M). These facies were grouped into four facies associations (FA1–FA4), which were interpreted as lobe axis (FA1), lobe off-axis (FA2), lobe fringe (FA3) and distal fringe to interlobe (FA4) facies associations. This study is applicable for the distribution of lobes and their subseismic, multiscale complexities to characterize the potential of hydrocarbon intervals in deep-marine sand-shale system around the globe.

Landslides are geological hazards that claim lives and affect socio-economic growth. Despite increased slope failure, some constructions, such as road constructions, are still being performed without proper investigation of the susceptibility of slope mass movement. This study researches the susceptibility of landslides in a study area encompassing a major highway that extends from Taiping to Ipoh, Malaysia. After a comprehensive literature review, 10 landslide conditioning factors were considered for this study. As novel research in this study area, multi-criteria decision-making (MCDM) models such as AHP and fuzzy AHP were used to rank the conditioning factors before generating the final landslide susceptibility mapping using Geographical Information System (GIS) software. The landslide susceptibility map has five classes ranging from very low (9.20%) and (32.97%), low (18.09%) and (25.60%), moderate (24.46%) and (21.36%), high (27.57%) and (13.26%), to very high (20.68%) and (6.81%) susceptibility for the FAHP and AHP models, respectively. It was recorded that the area is mainly covered with moderate to very high landslide risk, which requires proper intervention, especially for subsequent construction or renovation processes. The highway was overlayed on the susceptibility map, which concludes that the highway was constructed on a terrain susceptible to slope instability. Therefore, decision-makers should consider further investigation and landslide susceptibility mapping before construction.

The Pulai gold deposit is one of the most promising gold prospects in the Central Belt of Peninsular Malaysia. It is found within the Permian-Triassic Gua Musang sequence of metasediments and metavolcanics and in a structurally controlled NE-SW major fault. Various ore minerals, including pyrite, arsenopyrite, chalcopyrite, sphalerite, pyrrhotite, and galena are typically associated with this deposit. Four types of pyrite (Pyrite 1, Pyrite 2, Pyrite 3, and Pyrite 4) and two types of arsenopyrite (Arsenopyrite 1 and Arsenopyrite 2) were characterised based on their morphological and textural differences. In this region, gold occurs as refractory gold in the nanoparticle form and in the state of Au⁺ within the structure of sulphides of variable concentrations. Through the detailed laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) trace element mapping analysis of pyrite and arsenopyrite, the main Au-bearing sulphides were found within vein-hosted Pyrite 4 and Arsenopyrite 2 during late phase mineralisation, while Pyrite 3 had the lowest Au concentration. Two phases of Au enrichment were recorded in Pyrite 4, mainly in the core (2 to 11.7 ppm; average 1.4 ppm) and margin of the grain (0.3 to 8.8 ppm; average 1.2 ppm), whereas the highest Au content was detected in the core of Arsenopyrite 2 (0.3 to 137.1 ppm; mean 31.9 ppm). The enrichment of Au is associated with As, forming a zoning elemental pattern distribution. Other trace elements, including Co, Ni, Sb, Pb, Bi, Cu, and Zn, show systematic variation in their composition between the various types of pyrite and arsenopyrite. For early-phase sulphides, the Au enrichment localised at the margin of Pyrite 2 and Arsenopyrite 1, together with Co–Ni, Pb–Bi–Sb, and Ag in the same oriented pattern, suggesting the remobilisation and redistribution of Au in sulfides. Meanwhile, the late crystallisation phase of vein-hosted sulphides formed a rich Au–As ore zoning pattern in the core of Arsenopyrite 2 and Pyrite 4. The second phase of Au enrichment continued at the margin of Pyrite 4 through the remobilisation and precipitation of Au together with Ni, Co, Sb, Pb, Bi, Ag, and Cu. Subsequent deformation then reactivated the late fluid system with the enrichment of Sr, Ba, Rb, Ag, and Zn along the fractures and outermost rim of Pyrite 4 and Rb–Sr–Ba–Pb–Bi along the rim of Arsenopyrite 2. The Pulai gold prospect is interpreted as an orogenic-style gold mineralisation where arsenic can be used as an indicator for proximity to ore mineralisation in exploration.

Hydrocarbons in self-sourced reservoirs are determined by the concentration and maturation of organic matter in sediments. As a result, lowering risk in unconventional resource research and development requires knowledge of hydrocarbon potentiality factors. The geochemical data for the Montney Formation samples studied suggest that it is a fair to good source rock with type IV kerogen that can generate gas in general. The statistical modelling of the analyzed data reveals a valuable technique for identifying characteristics, clusters, and linkages that affect source rock assessment. The Spearman’s correlation coefficient showed a good positive correlation between the total organic carbon (TOC) and free hydrocarbons (S₁), generating potential (S₂), and potential yield (GP). There was a weak correlation with the maturity index (Tmax) and hydrogen index (HI) and a highly negative correlation between the TOC and oxygen index (OI). On the other hand, the principal component analysis (PCA) showed the presence of three factors affecting the source rock evaluation. Factor 1 included TOC, S₁, and S_2, which are related to organic richness and hydrocarbon potentiality; factor 2 contained the production index (PI), and the generated CO₂ (S₃) was related to the organic matter source. Factor 3 included the Tmax and HI related to the type of organic matter and thermal maturity. In addition, the TwoStep cluster analysis separated the source rock in the study area into two major groups. Cluster 1 is characterized relatively by high HI, TOC, S₁, S₂, and PI, with Tmax < 455 °C indicating good source rock in the mature level with the capability to generate little oil and condensate gas. Cluster 2 is characterized by relatively low HI, TOC, S₁, S₂, and PI, with Tmax > 455 °C, indicating an over-mature source rock in the dry gas window.