Petrogenesis of Malaysian granitoids in the Southeast Asian tin belt: Part 1. Geochemical and Sr-Nd isotopic characteristics

Abstract

The Malaysian granitoids of the Southeast Asian tin belt have been traditionally divided into a Permian to Late Triassic "I-type"dominated arc-related Eastern province (Indochina terrane) and a Late Triassic "S-type"-dominated collision-related MainRange province (Sibumasu terrane), separated by the Bentong-Raub Paleo-Tethyan suture that closed in the Late Triassic. The present study, however, shows that this model is oversimplifi ed and that the direct application of Chappell and White's (1974) I-and S-type classifi cation cannot account for many of the characteristics shared by Malaysian granitoids. Despite being commonly hornblende bearing, as is typical for I-type granites, the roof zones of the Eastern province granites are hornblende free. In addi tion, the Main Range province granitoids contain insignifi cant primary muscovite, and are dominated by biotite granites, mineralogically similar to many of the plutons of the Eastern province. In general, the Malaysian granitoids from both provinces are more enriched in high fi eld strength elements than typical Cordilleran I-and S-type granitoids. The mineralogy and geochemistry of the Eastern province granitoids, and their relationship with contemporaneous volcanics, confi rm their I-type nature. The bulk liquid lines of descent of both granitic provinces largely overlap with one another. Sr-Nd isotopic data further demonstrate that the Malaysian granitoids, especially those of the Main Range, were hybridized melts derived from two "end-member" source regions, one of which is isotopically similar to the Kontum orthoamphibolites and the other akin to the Kontum paragneisses of the Indochina block. However, there are differences in the source rocks for the two provinces, and it is suggested in this paper that these are related to differing proportions of igneous and sedimentary protoliths. The incorporation of sedimentary-sourced melts in the Eastern province is insignifi cant, which allowed the granites in this belt to maintain their I-type nature. The presence of minor primary tin mineralization in the Eastern province compared to the much more signifi cant tin endowment in the Main Range is considered to refl ect the incorporation of a smaller proportion of sedimentary protolith in the melt products of the former.

Geochronology and lithogeochemistry of granitoid rocks from the central part of the Central plutonic belt, New Brunswick, Canada: implications for Sn-W-Mo exploration

“…The highest average values are present in the Burnthill, Nashwaak, Lost Lake, and Beadle Mountain granites, accompanied by maximum abundances of 31, 23, 17.5, and 13 ppm Sn, respectively. Although there is a wide range in the average Sn content of granites associated with tin deposits, the latter figures compare well with those reported for Sn-specialized granites in various "tin belts" world-wide, e.g., Malaysia (~7-40 ppm; Ishihara and Terashima 1974;Ng et al 2015), Thailand (7.7-20.0 ppm; Ishihara et al 1980), Bolivia (~7-29 ppm; Lehmann et al 1990), Nigeria (~22 ppm;Olade 1980), and Nova Scotia (~50 ppm; Chatterjee et al 1983). Furthermore, most of the New Brunswick plutons are poorly exposed, and have not been sampled systematically; highly evolved phases or cupolas containing greater enrichment in Sn (or W or Mo) may therefore locally underlie the surficial cover.…”

“…Strongly differentiated granites are characterized by elevated Rb at the expense of Ba and Sr (e.g., see Fig. 11a), so that Rb/ Ba and Rb/Sr ratios have been used as estimators of the Sn, W, or Mo-bearing potential of granitic rocks (Tauson and Kozlov 1973;Neiva 1984;Ng et al 2015). Ternary diagrams illustrating relative abundances of Ba, Rb, and Sr are therefore useful in identifying the most fractionated granites, which are normally those that carry the greatest Sn endowment (Fig.…”

Did Oligocene crustal thickening precede basin development in northern Thailand? A geochronological reassessment of Doi Inthanon and Doi Suthep

“…50 Ma (Green et al, 2008). The suturing of the Palaeo-Tethys resulted in the emplacement of two major granite belts: the Main Range Provinceand the Eastern Province, which together run broadly north-south through west-central Thailand into the Malay Peninsula ( Cobbing et al, 1986, Cobbing et al, 1992,Hutchison, 1977and Ng et al, 2015a. These belts delineate the Palaeo-Tethys suture in Malaysia, Thailand, and Myanmar (Fig.…”

Ce Anomaly in I-Type Granitic Soil from Kuantan, Peninsular Malaysia: Retention of Zircon in the Weathering Product

“…The collision occurred in the Lower Permian to the Middle Triassic period, which marked the closure of the Tethys Ocean (Metcalfe 2000). The Sibumasu terrane, west of the Bentong Raub Suture, is characterized by Tin bearing, transitional I-S type granites and was emplaced around 198 to 227 Ma (Cobbing et al 1992;Jamil et al 2016;Ghani 2009Ghani , 2000Ghani et al 2014Ghani et al , 2013aNg at al. 2015a;Searle et al 2012).…”

“…The area is dominated by basalt and granitic rocks surrounding the capital of Pahang state, Kuantan. The granite is an isolated pluton mainly composed of I-type fractionated hornblende biotite granite of Late Permian age (Cobbing et al 1992;Ng et al 2015a). Extensive land development and quarry activity had fortunately exposed a lot of the rock profiles to allow this study to be carried out.…”