Bulletin of the Geological Society of Malaysia, Volume 40, July 1997, pp. 37 – 45
Jabatan Sains Bumi, UKM Kampus Sabah, Beg Berkunci No. 62, 88996 Kota Kinabalu, Sabah
Abstrak: Hasil kajian analisis struktur geologi dan geokimia bagi kawasan Telupid, Sabah, didapati bahawa kawasan kajian telah dipengaruhi oleh beberapa kali pergerakan tektonik yang telah menyebabkan batuan ultrabes wujud dan tersingkap sebagai suatu jasad igneus yang padat tetapi rapuh.
Terdapat sekurang-kurangnya dua jenis pergerakan sesar dan pembentukan satah-satah kekar hasil daripada canggaan yang telah berlaku, iaitu 2 sesar mendatar ke kanan, 6 sesar naik dan 8 pasang kekar ricih, yang menunjukkan perkaitan struktur yang sama di antara satu dengan yang lain.
Empat arah daya mampatan yang telah bertindak ke atas batuan di kawasan kajian telah dikenal pasti berdasarkan kepada kedudukan satah-satah sesar dan kekar, yang didapati dengan menggunakan kaedah roset dan jaringan samaluas, adalah seperti berikut:
• daya PI dan P2 pada arah Baratlaut-Tenggara
• daya P3 pada arah Utara-Selatan
• daya P4 pada arah Timurlaut-Baratdaya
Keputusan analisis geokimia menunjukkan unsur major yang melimpah dalam tanah ialah Fe2O3 (59.76%-70.18%), manakala kepekatan Al2O3, SiO2 dan L.O.I. masing-masing ialah 7.79%-11.8%, 1.77%-7.70% dan 16.88%-18.7%. Secara perbandingan antara kepekatan dalam batuan segar dan tanah didapati Fe2O3 dan L.O.I. masing-masing ialah 10 kali dan 14 kali sebaliknya SiO2 berkurang 30 kali.
Kepekatan Cr dalam tanah ialah 16,460 ppm-18,279 ppm, Co pula ialah 608 ppm-665 ppm dan Nd ialah 68 ppm-69 ppm. Perbandingan dengan kandungan kepekatan unsur surih dalam batuan segar pula menunjukkan Cr dalam tanah bertambah sebanyak 8 kali, Co 6 kali dan Nd juga 6 kali. Korelasi (Fe2O3 + Al2O3) lawan L.O.I. dan Fe2O3 lawan Al2O3 adalah linear positif. Kedua-dua korelasi tersebut mencadangkan penguraian mineral pembentuk batuan dan diikuti dengan pembentukan mineral sekunder terutama Fe-oksida dan Al-oksida. Korelasi linear negatif yang ditunjukkan antara SiO2 lawan Al2O3 mencadangkan mineral lempung tidak cenderung terbentuk dalam tanah. Fe2O3 lawan Cr dan Fe2O3 lawan Nd menunjukkan korelasi linear positif. Begitu juga dengan Al2O3 lawan Co. Korelasi tersebut boleh dijelaskan melalui proses jerapan Cr dan Nd oleh mineral Fe-oksida manakala jerapan Co oleh AI-oksida.
Abstract: Based on geological structure and geochemistry study in the Telupid area, Sabah, it was found that the study area has been influenced by several tectonic movements, which caused the formation of the ultrabasic rock which is exposed as a solid but brittle igneous body.
There are at least two kinds of fault and joint developments due to the above deformations, such as 2 of right strike-slips, 6 reverse faults and 8 complementary shears, which showed that geological structure relation between one to another.
Four compression force directions have been identified in the study area based on the position of the fault and joint planes, according to the study of rosette and stereonet methods, are as follows:
• PI and P2 forces at Northwest-Southeast directions
• P3 force at North-South directions.
• P4 force at Northeast-Southwest direction.
The geochemical analysis result show that the major elements abundance in the soils of Fe2O3, Al2O3, SiO2, L.O.I. are 59.76%-70.18%, 7.79%-11.80%, 1.77%-7.70% and 16.88%-18.70% respectively. The comparison between abundance of fresh rock and soil, indicated that Fe2O increased 60 times in soil, whereas the increasing abundance of Al2O3 and L.O.I. are 10 times and 14 times respectively, but SiO2 decrease 30 times.
The Cr content in the soil is 16,469 ppm-18,279 ppm, Co is 608 ppm-665 ppm and, Nd is 68 ppm- 69 ppm. The comparison of trace elements contents in fresh rock show that Cr in the soil increase 8 times, Co 6 times and, Nd 6 times. The correlation of (Fe2O3 + Al2O3) versus L.O.I. and Fe2O3 versus Al2O3 are positive linear. Both correlation suggested the decomposition of rock forming minerals was followed by secondary minerals formation mainly Fe-oxide and Al-oxide. The negative linear correlation between SiO2 versus Al2O3 suggested that the clay mineral had no tendency to form in the soil. The Fe2O3 versus Cr and Fe2O3 versus Nd show positive linear correlations. Similarly with Al2O3 versus Co. Such correlation could be explained through adsorption of Cr and Nd by Fe-oxide minerals, and Co adsorption by Al-oxide minerals.
https://doi.org/10.7186/bgsm40199704
