Bulletin of the Geological Society of Malaysia, Volume 54, November 2008, pp. 75 – 80
Program Geologi, Pusat Pengajian Sains Sekitaran dan Sumber Alam, Fakulti Sains dan Teknologi, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
Abstrak— Selinsing Gold Mine yang terletak di baratlaut Pahang, Semenanjung Malaysia merupakan lombong emas yang aktif dilombong hingga sekarang. Litologi kawasan ini terdiri daripada batuan sedimen dan batuan volkanik termetamorf gred rendah sebahagian daripada batuan Formasi Gua Musang berusia Perm Akhir-Trias. Pemineralan emas kebanyakannya berlaku dalam telerang kuarza yang memotong batuan induk dan berkaitan dengan jalur-jalur sesar dan zon ricih utama berarah hampir utara-selatan dan timurlaut-baratdaya. Mineral-mineral berasosiasi dengan emas dalam telerang kuarza terdiri daripada pirit, arsenopirit, surihan kalkopirit, tetrahedrit dan sfalerit. Perubahan batuan dinding yang berlaku di Selinsing Gold Mine menunjukkan perkaitan secara langsung wujud antara larutan hidroterma, struktur, pembentukan telerang kuarza dan pemineralan emas. Gabungan data cerapan lapangan, mineral ubahan yang hadir dan tren komposisi kimia mengenalpasti perubahan batuan dinding yang berkaitan dengan pemineralan emas terdiri daripada pensilisifikasian, pengargilitan dan penserisitan yang terjadi di sekitar zon telerang kuarza dan zon sesar. Perubahan pensilisifikasian ditandai oleh hadirnya mineral kuarza sekunder dan sedikit serisit, menunjukkan pengurangan kandungan K2O, Al2O3, LOI, Fe2O3 dan peningkatan kandungan SiO2 bersama Na2O. Zon pengargilitan ditunjukkan oleh kehadiran mineral lempung seperti kaolinit, muskovit atau serisit dan kuarza serta peningkatan kandungan K2O, Al2O3, LOI bersama pengurangan SiO2. Perubahan penserisitan dicirikan oleh pembentukan mineral serisit dominan, mineral lempung, kuarza, klorit, karbon, sulfida dan surihan emas halus. Perubahan ini dicirikan oleh peningkatan kandungan K2O, Al2O3, LOI, Fe2O3 dan Mg, pengurangan sedikit kandungan Na2O dan pengurangan mendadak SiO2.
Kata kunci: perubahan batuan dinding, Selinsing Gold Mine, pensilisifikasian, pengargilitan, penserisitan
Abstract— Selinsing Gold Mine is an active gold mine located in northwest Pahang, Peninsular Malaysia. Lithology of the area consists of low-grade metamorphosed sedimentary and volcanic rocks of Gua Musang Formation of Late Permo-Triassic age. The gold mineralisation occurs in quartz veins that cut host rocks and are related to the N-S and NE-SW lateral faults and shear zones in the area. Minerals associated with gold are pyrite, arsenopyrite and traces of chalcopyrite, tetrahedrite and sphalerite. Wall rock alteration in Selinsing Gold Mine shows a direct relation with hydrothermal solution, structures, formation of quartz veins and gold mineralisation. Wall rock alterations related to mineralization are recognized from combined data from field observations, mineral alteration and trend of chemical compositions. They are silicification, sericitization and argilitization. Silicification is marked by the presence of secondary quartz and sericite, are is characterized by a decrease in K2O, Al2O3, LOI, Fe2O3 and increase of SiO2, Na2O. Argillic alteration is indicated by the development of clay minerals such as kaolinite, muscovite and quartz, accompanied by an increase in K2O, Al2O3, LOI, and a decrease in SiO2. Sericitization is characterized by the formation of sericite, clay minerals, quartz, chlorite, carbon, sulphides and minute traces of gold. This alteration is characterized by an increase of K2O, Al2O3, LOI, Fe2O3 and Mg, loss of Na2O and abrupt losses of SiO2.
Keywords: wall rock alteration, Selinsing Gold Mine, silicification, argilitization, sericitization
https://doi.org/10.7186/bgsm54200813
