Highly weathered basaltic rock was exposed at PSK profile of Kuantan, Segamat Highway. The weathering profile from fresh rock soil can be observed at PKJ profile at Kg. Jabi Quarry. Twelve rock and soil samples from PSK profile and thirteen samples from PKJ profile have been collected for geochemical analysis. The objective of the analysis is to establish the behaviour of several major and trace elements in the weathering profile of the basaltic rock. The samples were analysed by XRF and XRD techniques. Petrographic study was done on fresh rock samples and concretions. The concentration of major elements (TiO2, Al2O3 and Fe2O3) appear to be increased with the increasing of the degree of weathering whereas the concentration of SiO2 and CaO are decreased. There is a clear correlation between Fe2O3 + Al2O3 with L.O.I as well as between Fe2O3 with Al2O3. Behaviour of the trace elements (Ni, Co, Cr and Zn) against the weathering process are totally different. The secondary minerals (kaolinite, nactire, geothite, hematite and gibbsite) appear to control the behaviour of the major and trace elements.
Batuan basalt yang terluluhawa sepenuhnya telah dicerap di lokaliti PSK Lebuhraya Segamat-Kuantan. Profil luluhawa yang boleh dilihat perubahan daripada batuan segar hingga tanih didapati di lokaliti PKJ Kuari Kg. Jabi. Dua contoh profil dengan masing-masing 12 sampel dan 13 sample tanih telah dikaji untuk menentukan perlakuan beberapa unsur major dan unsur surih batuan basalt yang terluluhawa. Kaedah analisis yang digunakan ialah pendarflour sinar-X (XRF) dan pembelauan sinar-X (XRF). Kajian petrografi pula dibuat pada sampel batuan segar dan sampel konkresi. Nilai unsur major TiO2, Al2O3 dan Fe2O3 bertambah dengan bertambahnya darjah luluhawa manakala SiO2 dan CaO menyusut. Hubungan korelasi Fe2O3 + Al2O3 dengan L.O.I dan Fe2O3 denagn Al2O3 adalah jelas. Unsur surih nikel (Ni) kobalt (Co), kromium (Cr) dan zink (Zn) mempunyai perlakuan yang berbeza-beza dengan luluhawa. Perlakuan yang ditunjukkan oleh unsur major dan surih tersebut dikawal oleh mineral sekunder (koalinit, nakrit, geotit, hematit dan gibsit).
Terdapat dua jenis permineralan bijih besi di kawasan Ladang Toh Pawang, Kedah iaitu bijih besi primer dan sekunder. Kepekatan Pb dan Cr yang amat rendah ditemui dalam bijih besi primer (bdl) manakala Cu ditemui sebagai bendasing (60-93 μg/g). Kepekatan Cr dan Cu meningkat di persentuhan antara jasad rejahan bijih besi dengan batuan sekitar. Kepekatannya masing-masing ialah sebanyak 27-30 μg/g and 242-294 μg/g. Pengayaan logam-logam tersebut disebabkan oleh penggantian metasomatik apabila magma likat yang panas berinteraksi dengan batuan syal Formasi Mahang yang kaya besi. Secara umum, kepekatan Pb dan Cr dalam bijih besi sekunder lebih tinggi berbanding dengan pemineralan bijih besi primer yang mana masing-masing berjulat 3-7 μg/g and 121-151 μg/g. Kepekatan Cu di dalam bijih besi primer dan sekunder hampir sama. Taburan Pb, Cr dan Cu di dalam bijih besi sekunder berpunca daripada luluhawa batuan syal Formasi Mahang yang kaya besi. Ketika proses permukaan berlaku, logam-logam berat tersebut telah dijerap daripada air bawah tanah lalu turut terenap bersama-sama dengan bijih besi sekunder.
Eleven marine sediment samples from Sg. Tengi Estuary, Tanjung Karang were analysed for their major elements in the oxides form (SiO2, Al2O3, Fe2O3, Na2O3, MgO, CaO, K2O, TiO2, P2O5 and MnO) and trace elements (Ba, Co, Cr, Cu, Ni, Pb, Rb, Sr, V, Zn, and Zr) contents. The muddy marine sediment was collected at the left and right side of the river mouth as far as one kilometre away and about 25-30 meters from the edge of existing growth. Some of the mud sample appears to have cockleshell flakes in them. The mean of major elemental content (oxides form) in the sediment in decreasing order were dominated by SiO2 (56.3%), followed by Al2O3, (15.5%), Fe2O3 (4.1%), Na2O (2.7%), CaO (2.6%), MgO (2.3%), K2O (1.8%), TiO2 (0.5%), P2O5 (0.14%) and MnO (0.06%). Volatile substances represented by loss on ignition (LOI) (13.9%) occupied substantial amounts of the sediment volume. The most abundant trace elements displayed as mean was Zr (222 mgkg-1), followed by Ba (200 mgkg-1), Sr (172 mgkg-1), Rb (131 mgkg-1), Zn (103 mgkg-1), V (l02mgkg-1), Cr (84 mgkg-1), Pb (40 mgkg-1), Ni (34 mgkg-1), Cu (31 mgkg-1) and Co (22 mgkg-1). Correlation analysis showed that Cr, Pb and Zn were positively related to the Fe203 and Al2O3 content whereas increase in pH immobilised Cr and Zn in the sediment. The mean of Cr (84 mgkg-1) and Zn (103 mgkg-1) content in sediment were higher than the lower limit of their respective threshold concentration.
Sebanyak 11 sampel sedimen marin daripada muara Sg. Tengi, Tanjung Karang telah dianalisis untuk menentukan kandungan unsur major dalam bentuk oksida (SiO2, Al2O3 Fe2O3, Na2O3, MgO, CaO, K2O, TiO2, P2O5 and MnO) dan unsur surih (Ba, Co, Cr, Cu, Ni, Pb, Rb, Sr, V, Zn, and Zr). Sedimen marin berlumpur dikutip daripada bahagian kiri dan kanan muara sungai dalam jarak sejauh kira-kira 1 km dan 25-30 meter ke arah laut daripada kawasan pertumbuhan yang sedia ada. Sebahagian daripada sampel lumpur tersebut mempunyai kandungan serpihan kulit kerang. Purata kandungan unsur major di dalam sedimen mengikut urutan menurun adalah didominasi oleh SiO2 (56.27%) diikuti oleh Al2O3 (15.5%), Fe2O3 (4.1 %), Na2O (2.7%), CaO. (2.6%), MgO (2.3%), K2O (1.8%), TiO2 (0.5%), P2O5 (0.14%)dan MnO. (0.06%). Sebatian mudah meruap diwakili oleh kehilangan menerusi pembakaran (LOI) (13.9%) mengisi isipadu yang agak besar di dalam komposisi sedimen. Purata kandungan unsur surih yang terbanyak ditunjukkan. oleh Zr (222 mgkg-1), diikuti oleh Ba (200 mgkg-1), Sr (172 mgkgÂ-1), Rb (131 mgkg-1), Zn (103 mgkg-1), V (l02 mgkg-1), Cr (84 mgkg-1), Pb (40 mgkg-1), Ni (34 mgkg-1), Cu (31 mgkg-1) dan Co (22 mgkg-1). Analisis korelasi menunjukkan Cr, Pb dan Zn mempunyai hubungan positij yang signijikan dengan Fe2O3 dan Al2O3, manakala peningkatan pH memegunkan Cr dan Zn dalam sedimen. Purata kandungan Cr (84 mgkg-1) dan Zn (103 mgkg-1) di dalam sedimen lebih tinggi daripada paras yang dikira berpotensi toksik di dalam sedimen.
Sixteen topsoil samples from Bukit Jernih, Gua Kelam and Bukit Merah were analysed for their major elements and heavy metal composition, together with several physico-chemical parameters. Major elements determined were SiO2, TiO2, Al2O3, Fe2O3, MnO, MgO, CaO, Na2O, K2O, P2O5, whereas heavy metals determined were As, Co, Cu, Cr, Ni, Pb and Zn. Physico-chemical parameters determined were percentage of organic matter, clay, silt and sand composition, pH and electrical conductivity. The results showed that the average soil pH in limestone soil was between 6.38 to 6.93, whereas average soil pH in quartzite soil was 6.23. The average soil electrical conductivity for all sampling stations was below 1.7 mScm-1. High organic matter content average was shown in soil samples from Bukit Jernih (7.45%), followed by Gua Kelam (5.21%) and Bukit Merah (3.31%). Soil samples from Bukit Jernih and Gua Kelam showed a clayey texture with more than 35% clay content, whereas soil from Bukit Merah was sandy in texture with more than 67% sand content. In general, soil samples from limestone area of Bukit Jernih and Gua Kelam recorded higher content of heavy metals compared to quartzite soil from Bukit Merah. The average concentration of Cr and Co at Bukit Jernih at 413 µg/g and 88 µg/g, respectively, whereas the concentration at Gua Kelam was 152 µg/g dan 76 µg/g. These concentrations exceeded the potential toxic concentration in soil. The main major elements were SiO2 followed by Al2O3 and Fe2O3. SiO2 content in quartzite soil from Bukit Merah(89.45%) was higher compared to limestone soil from Bukit Jernih (59.74%) and Gua Kelam (53.16%). Nevertheless, Al2O3 and Fe2O3 content in limestone soil was higher compared to quartzite soil. The percentage of easily ignited content in limestone soil was two fold higher than quartzite soil. Other major elements were less than 2.5%. The study showed that enrichment of Cr, Zn, Pb, Ni and Cu in soil was influenced by the presence of SiO2, Al2O3 and Fe2O3.
Keywords: Enrichment; heavy metals; limestones hill; major elements; toxicity