Punya Charusiri

The Pilok Sn–W deposit in western Thailand is hosted by peraluminous S‐type granites that intruded Silurian–Devonian metasedimentary rocks. This study presents whole‐rock geochemistry, zircon U–Pb geochronology, and trace element data to constrain the timing of emplacement, petrogenesis, and regional metallogenic processes. Two granite types occur in the deposit: biotite–muscovite granite and tourmaline–biotite–muscovite granite, both showing high SiO ₂ (72.6–75.2 wt%) and Sn (12.8–27.4 ppm) contents, strongly peraluminous characteristics (A/CNK = 1.20–1.38), pronounced negative Eu anomalies (Eu/Eu* = 0.13–0.27), and elevated Rb/Sr ratios (14.1–22.6), indicating extensive fractional crystallization. Zircon textures and chemistry of the host granites reveal four distinct types: Types I and II zircons displaying magmatic oscillatory zoning and heavy REE‐enriched patterns, and Types III and IV zircons showing hydrothermal characteristics with LREE enrichment in chondrite‐normalized REE patterns. U–Pb dating of magmatic zircons from four granite samples yielded ²⁰⁶ Pb/ ²³⁸ U ages of 208 ± 5.3 to 212 ± 1.5 Ma, synchronous with the granites in the Late Triassic tin metallogenic belt in Southeast Asia. Ti‐in‐zircon thermometry indicates crystallization temperatures of 698°C–829°C (average 754°C), and trace elements of zircon indicate strongly reduced conditions (ΔFMQ: −0.8 to −4.5, average −1.9), which were favorable conditions to retain Sn ²⁺ in a residual melt. REE patterns of zircon suggest a magmatic to hydrothermal transition, recording late‐stage fluid exsolution that mobilized Sn and W. The combination of Late Triassic ages, S‐type peraluminous geochemistry, extreme fractional crystallization, and reduced magmatic conditions can be used as criteria for identifying tin‐fertile granites in the Sibumasu Terrane and other terranes with similar tectonic settings.

Geochemical, petrographic, and geochronological analyses of granitoids from Kan-chanaburi Province, western Thailand, reveal key insights into magmatic evolution and metallogenesis within the Western Granite Belt. U–Pb zircon dating identifies two main magmatic episodes: Late Triassic (227-214 Ma), and Late Cretaceous (79-68 Ma). The granitoids, including quartz monzonite, granodiorite, and quartz-rich gran-ite, are composed of quartz, plagioclase, K-feldspar, and biotite, with minor horn-blende and accessory minerals such as titanite, zircon, magnetite, ilmenite, and garnet. Magnetic susceptibility values (0.0001 × 10-3 to 0.0199 × 10-3 SI units) indicate pre-dominantly ilmenite-series granitoids, with localized magnetite-series occurrences. Geochemical data classify these intermediate to felsic plutonic rocks as calc-alkaline to shoshonitic, with a peraluminous, S-type affinity. U-Pb cassiterite and wolframite ages of 80-77 Ma suggest that W-Sn mineralization occurred during the Late Cretaceous at early-stage magmatism. The temporal and spatial distribution of these granitoids is closely linked to Pb–Zn–W–Sn mineralization, reflecting the influence of post-collisional magmatism on regional metallogenesis in the Sibumasu Terrane. This study refines the tectono-magmatic framework of western Thailand and underscores the importance of granitoid emplacement timing in controlling mineral deposit for-mation.

The Nam Phong Formation, a key unit of the pre-Khorat Group in the western Khorat Plateau, provides critical insights into the Mesozoic geological evolution of northeastern Thailand. This study presents the first integrated petrographic and geochemical investigation of the formation within Khon Kaen Geopark to reconstruct its Late Triassic–Early Jurassic depositional settings, provenance, and paleoclimate. A detailed stratigraphic section and five supplementary sites reveal litharenite and lithic wacke sandstones, interbedded with red paleosols and polymictic conglomerates. Sedimentary structures—such as trough and planar cross-bedding, erosional surfaces, and mature paleosols—indicate deposition in a high-energy braided fluvial system under semi-arid to subhumid conditions with episodic subaerial exposure. Petrographic analysis identifies abundant quartz, feldspar, and volcanic lithic fragments. Geochemical data and REE patterns, including diagnostic negative Ce anomalies, provide compelling evidence for provenance from active continental margins and oxidizing weathering conditions. These findings point to a tectonically active syn-rift basin influenced by climatic variability. Strikingly, the Nam Phong Formation exhibits paleoenvironmental and sedimentological features comparable to the modern Ebro Basin in northeastern Spain, highlighting the relevance of uniformitarian principles in interpreting ancient continental depositional systems.

The Loei Mineral Belt hosts numerous significant iron mineral deposits in Thailand, including Khao Lek and Khao Mae Lek skarn deposits, associated with Triassic I‐type granites. In contrast, the Phetchaburi and Songkhla Mineral Belts contain iron mineralization, such as contact‐metasomatic or skarn Khao Um Khlum deposit related to Triassic S‐type granites. The mineral assemblages of magnetite veins and iron contents in the magnetite of these deposits differ and remain poorly understood. This research investigates the mineralogy, textures, and geochemistry of magnetite veins of each deposit to understand the magnetite's origin, which formed by hydrothermal fluids or magmatic‐related processes. Three distinct magnetite textures are recognized across the deposits, reflecting sequential stages of hydrothermal mineralization. Type A granular magnetite exhibits a well‐crystallized texture with growth zoning, characterized by high FeO _tot content with minor impurities, and indicates formation under stable oxidizing conditions. Type B displays a massive magnetite, fine‐grained texture with lower FeO _tot but elevated SiO ₂ , MnO, and CaO contents, suggesting rapid crystallization under decreasing temperatures. Type C mushketovite magnetite is characterized by platy shapes with zoning and the lowest FeO _tot content. The iron veins from Khao Mae Lek and Khao Lek deposits contain high FeO _tot content (61.27–77.74 wt.%) resulting from a diorite intrusion into Permian limestone. Conversely, the iron veins at Khao Um Khlum deposit exhibit lower FeO _tot content (55.67–70.61 wt.%) and were formed by Triassic granite intrusion into Ordovician limestone. Geochemical discrimination using Fe, Mg, Al, Mn, Ti, V, and Cr in magnetite indicates a hydrothermal origin for all deposits. The highest concentration of iron in magnetite is associated with I‐type granites, while the highest manganese with the lowest iron concentrations in magnetite is observed in the deposits linked to S‐type granite. Magnetite of the three deposits is inferred to have formed under varying temperatures, ranging from 300°C to 500°C for the granular and massive magnetite in the Khao Mae Lek and Khao Lek deposits and below 200°C–300°C for the mushketovite in the Khao Um Khlum deposit. These findings provide implications for regional exploration strategies.

Conducted within the scope of geochemical exploration in eastern Thailand, this study aims to detect geochemical anomalies and potential mineral deposits. The objective was to interpret intricate spatial dispersion patterns and concentration levels of deposit pathfinder elements, specifically arsenic (As), copper (Cu), and zinc (Zn), using a comprehensive array of stream sediment geochemistry data. Methodologies involved integrating multifractal properties and traditional statistics, facilitated by the GeoDAS and ArcGIS platforms as instrumental analytical tools. In total, 5376 stream sediment samples were collected and evaluated, leading to the development of an in-depth geochemical map. The results indicated distinct geological units marked by substantially elevated average values of the aforementioned elements. Identification of geochemical anomalies was achieved through the spatial distribution method and the subsequent application of the spectrum-area (S-A) multifractal model. An intriguing link was found between high As concentrations and gold deposits in the area, suggesting As as a viable pathfinder element for gold mineralization. The anomaly maps, generated from the stream sediment data, spotlighted potential zones of interest, offering valuable guidance for future mineral exploration and geological inquiries. Nonetheless, it is vital to recognize that the increased values noted in these maps may be influenced by regional geological factors, emphasizing the necessity for a diverse set of analytical methods for accurate interpretation. This study’s significance lies in its pioneering use of the S-A multifractal model in geochemical data analysis. This innovative approach has deepened our comprehension of geochemical dispersion patterns and improved the precision of mineral exploration.

Conducted within the scope of geochemical exploration in Eastern Thailand, this study aims to detect geochemical anomalies and potential mineral deposits. The objective was to interpret intricate spatial dispersion patterns and concentration levels of deposit pathfinder elements, specifically arsenic (As), copper (Cu), and zinc (Zn), using a comprehensive array of stream sediment geochemistry data. Methodologies involved integrating multifractal properties and traditional statistics, facilitated by the GeoDAS and ArcGIS platforms as instrumental analytical tools. In total, 5,376 stream sediment samples were collected and evaluated, leading to the development of an in-depth geochemical map. The results indicated distinct geological units marked by substantially elevated average values of the aforementioned elements. Identification of geochemical anomalies was achieved through the spatial distribution method and the subsequent application of the Spectrum-Area (S-A) multifractal model. An intriguing link was found between high As concentrations and gold deposits in the area, suggesting As as a viable pathfinder element for gold mineralization. The anomaly maps, generated from the stream sediment data, spotlighted potential zones of interest, offering valuable guidance for future mineral exploration and geological inquiries. Nonetheless, it is vital to recognize that the increased values noted in these maps may be influenced by regional geological factors, emphasizing the necessity for a diverse set of analytical methods for accurate interpretation. The study's significance lies in its pioneering use of the S-A multifractal model in geochemical data analysis. This innovative approach has deepened our comprehension of geochemical dispersion patterns and improved the precision of mineral exploration.

Ground source heat pump (GSHP) systems have been used worldwide in buildings because of their advantages of highly efficient performance in terms of energy and environment for space cooling and heating; however, cooling demand is predominant in tropical climates. This paper reviews of the GSHP systems applications in Southeast Asia; several applications of GSHP in Thailand, Indonesia, Malaysia, Singapore, and Vietnam have been addressed. Experiments were initiated in 2006 in Kamphaengphet; the latest experiment found in the Scopus searching tool is the GSHP simulation in Kuantan in 2019 using EnergyPlus using the ground loop design software. GSHP systems have the potential to be used in Southeast Asia despite the dominance of cooling demand, leading to a thermal imbalance within the subsurface. This imbalance can reduce the performance of the system; however, groundwater flow is considered as a key factor in preventing the effect of thermal distribution owing to GSHP operation. These results suggest that the GSHP has the potential to reduce emissions and electricity consumption within areas having tropical climates, such as Southeast Asia, for sustainability and future generation.

The deployment of highly efficient cooling equipment is expected to promote energy savings and greenhouse gas emissions reductions in the tropics. A ground source heat pump (GSHP) has high energy-savings potential for use in Bangkok, Thailand. This study aimed to elucidate the operational conditions of a GSHP when used in Bangkok which was expected to achieve a higher efficiency than an air source heat pump (ASHP) over the long term. An operational experiment on a pilot facility in Bangkok and a simulation over a three-year GSHP operation were conducted. As a result of the operational experiment and simulation, the proposed operational condition was that the 90th percentile value of the hourly heat pump (HP) inlet temperature did not exceed 5 °C above that of the hourly annual ambient temperature during the third year of operation. When a GSHP designed based on this condition was utilized for a small government building, the required number of boreholes were 24, 4, and 3 for air-conditioned areas of 200, 40, and 25 m², respectively, which achieved 40% energy savings. Thus, a small-scale GSHP in Bangkok designed based on the proposed condition can achieve high efficiency within space limitations.

The cooling of spaces in tropical regions, such as Southeast Asia, consumes a lot of energy. Additionally, rapid population and economic growth are resulting in an increasing demand for space cooling. The ground-source heat pump has been proven a reliable, cost-effective, safe, and environmentally-friendly alternative for cooling and heating spaces in various countries. In tropical countries, the presumption that the ground-source heat pump may not provide better thermal performance than the normal air-source heat pump arises because the difference between ground and atmospheric temperatures is essentially low. This paper reports the potential use of a ground-source heat pump with horizontal heat exchangers in a tropical country—Thailand. Daily operational data of two ground-source heat pumps and an air-source heat pump during a two-month operation are analyzed and compared. Life cycle cost analysis and CO₂ emission estimation are adopted to evaluate the economic value of ground-source heat pump investment and potential CO₂ reduction through the use of ground-source heat pumps, in comparison with the case for air-source heat pumps. It was found that the ground-source heat pumps consume 17.1% and 18.4% less electricity than the air-source heat pump during this period. Local production of heat pumps and heat exchangers, as well as rapid regional economic growth, can be positive factors for future ground-source heat pump application, not only in Thailand but also southeast Asian countries.

In order to reduce electricity consumption, the vertical loop geothermal heat pump (GHP) system coupled with a normal air conditioner was installed in an experimental room in the Parot Racha Building, Chulalongkorn University, Bangkok, Thailand for a comparative, long-term measurement program. The decrease in electricity consumption was approximately 30%. On the basis of the data derived from our measurements, the underground temperature seemed to be consistent and lower than the average outside air temperature, over two years. The underground system consisted mainly of two 50-m-long drilling wells and pipes with a total length of 170 m. The well performance was not examined, but both soil and groundwater aquifer (Bangkok aquifer) at 25 to 50 m. could be utilized for the cooling operation. Moreover, the major controlling factors of electricity consumption were found to be the outside air temperatures and the underground water circulation temperatures. In addition, we considered the geology, underground temperature, and aquifer of Bangkok concluding that almost all Bangkok areas are suitable for GHP installation, except for those where the subsurface temperature is too high compared with the outside air temperature.