Bulletin of the Geological Society of Malaysia, Volume 48, June 2004, pp. 7-11
Pusat Pengajian Sains Sekitaran dan Sumber Alam, Fakulti Sains dan Teknologi, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan
Abstrak: Plumbum dalam sedimen muara terbahagi kepada dua fraksi utama iaitu Pb baki atau litogenik (residual) dan Pb bukan baki (non-residual). Pengaruh jenis batuan terhadap kepekatan Pb bukan baki dalam sedimen muara penting bagi mengenalpasti sama ada kepekatan Pb bukan baki dalam sedimen muara berpunca secara tabii ataupun disumbangkan oleh kegiatan manusia. Kajian ini bertujuan untuk mengenalpasti pengaruh jenis batuan sekitar iaitu granit-pegmatit, syis, syal dan bijih besi terhadap pekatan Pb baki dan bukan baki dalam sedimen muara Sungai Merbok. Sebanyak 80 sampel sedimen berkedalaman 5-50 cm di sepanjang Sungai Merbok dan Sungai Petani telah diambil. Kandungan Pb pukal dalam batuan granit-pegmatit, syis, syal dan bijih besi masing-masing sebanyak 91 ppm, 6.3 ppm, 59 ppm dan di bawah had pengesanan. Sebahagian besar daripada Pb baki dan bukan baki dalam sedimen muara dipengaruhi oleh batuan syal Formasi Mahang. Pengaruh batuan granit-pegmatit terhadap Pb baki di kesan dalam sedimen muara di selatan Gunung Jerai. Walau bagaimanapun, kesannya terhadap Pb bukan baki tidak begitu ketara. Batuan syis dan bijih besi mempunyai kepekatan Pb yang rendah dan tidak menunjukkan pengaruh yang besar terhadap kepekatan Pb dalam sedimen muara Sungai Merbok. Secara kesimpulan, pengaruh jenis batuan didapati lebih jelas dalam fraksi Pb baki atau litogenik berbanding dengan Pb bukan baki.
Abstract: Lead in estuarine sediments can be divided into two fractions i.e. residual or lithogenic Pb and non-residual Pb. The influence of country rocks on non-residual Pb in estuarine sediments is important to differentiate natural or anthropogenic sources of Pb. The purpose of this study is to determine the influence of the country rocks i.e. granite-pegmatite, schist, shale and iron ore on the total, residual and non-residual Pb concentrations in the Sungai Merbok estuarine sediments. Eighty sediment samples were collected representing 5-50 cm depths along Sungai Merbok and Sungai Petani. Total Pb concentrations in granite-pegmatite, schist, shale and iron ore were 91 ppm, 6.3 ppm, 59 ppm and below the detection limit respectively. Most of the residual and non-residual Pb in the estuarine sediments show the influence of shale from the Mahang Formation. The influence of granite-pegmatite on residual Pb were detected in estuarine sediments south of Gunung Jerai. However, their influence on non-residual Pb was not significant. Schist and iron ore contain low Pb concentrations and did not show any significant influence on Pb concentrations in the estuarine sediments in Sungai Merbok. It is concluded that the influence of rock types are clearer in residual or lithogenic Pb compared to the non-residual fraction.
https://doi.org/10.7186/bgsm48200402
