Mineralogical investigation of fine clastic rocks from Central Sarawak, Malaysia

Abstract

The reduction in the conventional resources and insistent request for hydrocarbons and energy lead us to look forward for the increasing interest in unconventional resources by exploring new technologies for the national economy and local utilization in Malaysia. Upper Mesozoic-Cenozoic is considered the age of Central Sarawak Formations. This paper attempts to evaluate the clay mineralogy, depositional environment, gamma ray evaluation and the relationship between total organic carbon and uranium concentration of the Nyalau, Tatau, Begrih, Liang and Belaga Formation which eventually comprise black shales and mudstones using spectral gamma ray (SGR), field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), XRD clay separation and total organic content (TOC%). The results from SGR indicate that the formations composed mainly of kaolinite, smectite and chlorite. These results are confirmed by XRD, XRD clay separation and FESEM with the presence of illite as a dominant clay mineral component. Based on Th/U ratios which vary between 0.42 and 3.95, the formations are expected to be deposited in the reduced marine environment. Results from calculated API (90.76-233.32 API) reveal the ability of the clay minerals to absorb uranium and thorium through cation exchange capacity. The relationship between TOC% and U cross plots also show a significant positive correlation. The presence of high U concentrations in the formations is possible because of their relatively higher clay contents and the existence of organic matter.

Biostratigraphy, facies analysis and sequence stratigraphy of the Sachun Formation (Interior Fars, Zagros, SW of Iran)

“…The bioclastic debris indicate that the shales and marl were deposited in a low energy marine setting in an intermediate continental-marine environment (Warren 2006). However, similar facies data were previously documented as low energy paleoenvironment from China (Ibrahim et al 2020;Zhao et al 2017;JiTao et al 2010).…”

Oil Occurrence States in Shale Mixed Inorganic Matter Nanopores

“…The most widely used method of mineral percentages determination is XRD (Cody and Thompson, 1976). The principle behind XRD is to obtain the characteristics of X-ray signal using the diffraction phenomenon of an X-ray interacting with the crystalline structure of a material; the crystal structure is analyzed according to the spectrum information (Han et al, 2019;Ibrahim et al, 2020). Shale oil is rich in alkanes, arenes, nitrogen-, sulfur-, and oxygen-containing non-hydrocarbons (Ibrahim et al, 2020).…”

“…The principle behind XRD is to obtain the characteristics of X-ray signal using the diffraction phenomenon of an X-ray interacting with the crystalline structure of a material; the crystal structure is analyzed according to the spectrum information (Han et al, 2019;Ibrahim et al, 2020). Shale oil is rich in alkanes, arenes, nitrogen-, sulfur-, and oxygen-containing non-hydrocarbons (Ibrahim et al, 2020). The physical and chemical properties of the oil composition significantly impact the subsequent exploitation; hence, it is critical to understand the components and their contents in shale oil.…”

Assessment of Radioactive Materials in Albite Granites from Abu Rusheid and Um Naggat, Central Eastern Desert, Egypt

“…The potassium-thorium cross plot is widely used to recognize clay mineral associations and to discriminate micas and feldspars [26]. As both thorium (by adsorption) and potassium (chemical composition) are associated with clay minerals, the ratio eTh/K expresses relative potassium enrichment as an indicator of clay-mineral species and might be diagnostic of other radioactive minerals [27,28]. Therefore, if eTh/K ≥ 2 × 10 −4 , the rock is thorium-rich, and if eTh/K ≤ 1 × 10 −4 , the rock is potassium-rich [29,30].…”