Petrology of granitic rocks along new Pos Selim to Kampung Raja highway (km 0 to km 22): identification of different granitic bodies, its field and petrographic characteristics

Abstract: Four granitic bodies have been identified along the Pos Selim-Kampung Raja Highway (0 to km 18). They are Selim granite (km 0 to km 5), Suku granite (from km 6 to km II), Semerengol aplopegmatite (occur as granitic dykes intruded the metamorphic rocks at km 14 to km 15) and Regul granite (km 17 to km 18). The Selim granite consists of outer coarse grained porphyritic biotite granite and medium to fine grained granite. The Suku granite is characterized by the presence of xenoliths and other enclaves. Among the enclaves are biotite rich, quartz tourmaline pods and various types of xenoliths (metamorphic). The Regul granite at km 17 and 18 contains primary muscovite. The Semerengol aplopegmatite consists of tourmaline muscovite garnet granite and their aplopegmatite dykes found at km 14 and 15. Geochemical evidence showed that three granitic bodies (Selim, Suku and Regul granites) are different in term of their Ti0 2 , Fep3 and pps contents. This supports our field observation and division of the granites along Pos SelimKampung Raja Highway. Abstrak: Empat badan granitik telah dikenalpasti di sepanjang jalan Pos Selim-Kampung Raja (km 0 ke 18). Mereka adalah Granit Selim (km 0 ke km 5), Granit Suku (km 6 ke km 11), Semerengol aplopegmatite (wujud sebagai daik-daik granite yang menerobos batuan metamorftk di km 14 ke 15) dan Granit Regul (km 17 ke km 18). Granit Selim mengandungi granit biotit porfIritik berbutir kasar dan granite berbutur halus ke sederhana. Granit Suku di cirikan oleh kehadiran berbagai jenis xenolit dan 'enclave'. Di antara 'enclave' yang hadir ialah enclave kaya biotite, pod kuarza tourmaline dan berbagai jenis xenolit metamof. Granite Regul dijumpai antara km 17 dan 18 mengandungi muskovit primer. Semerengol aplopegmatit pula mengandungi granite tourmaline muskovit garnet dan daik-daik aplopegmatit dijumpai di km 14 dan 15. Bukti geokimia menunjukkan ketiga-tiga badan granit (Granit Selim, Suku and Regul) adalah dari magma yang berlainan berdasarkan kandungan Ti0 2 , Fep3 and Pps' Ini menyokong pemerhatian lapangan dan pembahagian granit di sepanjang Jalanraya Pos Selim-Kampung Raja

Ce anomaly in I‒type granitic soil from Kuantan, Peninsular Malaysia: retention of zircon in the weathering product

This paper describes the Ce anomaly observed in granitic soil from the humid, tropical area of Kuantan, Pahang, Peninsular Malaysia. Three granite rock soil profiles from Kuantan, were sampled and all samples were analysed for rare earth elements. All the profiles of the granitic soil samples show prominent positive Ce anomalies, with the Ce/Ce* ratio values (Ce/Ce*= CeN/√LaN.PrN) ranging from 1.2 to 125. l. Ce4+ is compatible in zircon because it has also the same charge and a similar ionic radius as to Zr4+ (Ce4+ = 0.97 Å; Zr4+ = 0.84 Å). The retention of zircon in the weathering product of the granitic rocks will increase the Ce content in the soil. Thus it is likely that the positive Ce anomaly in the REE profile of the Kuantan Granites may also have resulted from retention of zircon in the weathering product

Potential alkali-reactivity of granite aggregates in the Bukit Lagong area, Selangor, Peninsular Malaysia

The Bukit Lagong area is the most important aggregate supply centre in Selangor. Geological studies were carried out in four quarries in the Bukit Lagong area and samples were subjected to petrographic examination and accelerated expansion tests to assess the potential alkali-aggregate reactivity of granite aggregates. The granitic rocks comprise mainly of coarse grained megacrystic granite, minor medium grained megacrystic granite and microgranite. Petrographic examination showed that the primary minerals in these undeformed granitic rocks are not alkali reactive. Faulting and related alteration and mineralization have produced potentially alkali reactive minerals including microcrystalline and strained quartz and fine phyllosilicates. Marginally deleterious and deleterious expansion is shown by the accelerated mortar bar tests. Although alkali reactive rocks are present in some quarries in Bukit Lagong, their volume is small. When blended with the undeformed granitic rocks, the aggregates produced are not expected to cause alkali-aggregate reaction in concrete

Petrography and geochemical characterization of a granite batholith in Idanre, southwestern Nigeria

Idanre granite batholith in southwestern Nigeria contain three rock types, namely, Older granite undifferentiated (OGu), Older granite porphyritic (OGp) and Older granite fine-grained (OGf). The granitoids intruded into a basement rock of primarily migmatite gneiss. Petrography indicates that quartz, orthoclase, hornblende, and biotite are common to all members while microcline is more prominent in OGp and plagioclase is poorly represented in OGf. Despite minor differences in petrographic features, the granite units generally have similar geochemical relationships. The average SiO2 contents in OGp (70.49%), OGu (68.7%) and OGf (65.8%) are comparable to similar Pan-African suites located in eastern and northern Nigeria. Na2O+K2O-CaO versus SiO2 diagram shows all the granite members are calcic, K2O vs SiO2 plot classify the granites as high-K calcic alkali to shoshonitic. ANK vs ACNK plot indicates they are peraluminous. Plot of A/CNK vs SiO2 and K2O vs Na2O diagrams classified the rock as S-type granite. The granitoids are calc-alkaline with elevated Na2O (>2.6%) and Al/(Na2O+CaO) contents (OGu, 2.1-3.4; OGp, 2.4-3.1 and OGf, 2.2-2.9). The tectonic diagram (Rb vs (Y+Nb) indicates that the batholith is Within Plate Granite (WPG)

Rare earth elements and fractionation of Zr-Hf and Y-Ho: implication to petrogenesis of idanre granite, Nigeria

Idanre area which is situated within the Nigerian shield is affected by orogenic activities accompanied by emplacement of Pan-African granitoids. This paper presents a new information on geochemical behaviour of Rare Earth Elements (REEs) and High Field Strength Elements (HFSEs) Zr-Hf and Y-Ho that can explain post magmatic processes relating to the origin and evolution of the Idanre granite. Zr-Hf, Hf-(Zr/Hf) and Y-Ho, (Y/Ho)-Ho variation diagrams depicted similar mobility and migration patterns for Zr, Hf, Y and Ho. Binary plots of Log Zr/Hf vs Log Hf, Log Y/Ho vs Log Ho; high LREE/HREE and negative Eu anomaly shows extensive plagioclase and calcic amphibole fractionation. High Ce/Yb values 113.49, 134.97, and 123.6 reflects low partial melting in the source rocks. Similar Zr/Hf ratios 39.16; 39.3 and 43.26 for members of the granite suite suggest a common source for the minimally differentiated magmatic fluid. Y/ Ho ratios of 27.15, 27.12 and 25.91 indicate that the rock units are comagmatic. Mean Zr/Hf (41.69) and Y/Ho (27.18) ratios indicate the host migmatite may be the source rock for the Idanre granite complex

Rare-earth elements modelling of the Langkawi granites

Based on the REE patterns the Langkawi granites can be divided into two groups i.e. the Gunung Raya-Dayang Bunting granite and Kuah-Pulau Tuba granite. The Gunung Raya-Dayang Bunting granite has weak negative Eu anomalies whereas the Kuah-Pulau Tuba granite has moderately strong negative Eu anomalies. Rb/Sr ratios also show similar differences with Rb/Sr ratios in Kuah-Pulau Tuba granites being much higher than those of the Gunung Raya-Dayang Bunting granite. Examination of the REE patterns shows that they have the usual 'bird-wing' shape with weak to moderately strong negative Eu anomalies. This pattern is similar to the West coast S-type granites and is different from the I-type granites of the East coast. A possible source material for the Langkawi granite is the Cambrian sediments of the Machinchang Formation. Modelling of the REE pattern has been carried out in two stages namely batch melting and fractional crystallisation. Results show that the Gunung Raya-Dayang Bunting magma requires a slightly higher degree of partial melting fraction (0.15-0.25%) compared to the Kuah-Pulau Tuba magma (0.25-0.3%). On the other hand the Gunung Raya­/Dayang Bunting magma has undergone a higher degree of fractionation (16%) compared to the Kuah-Pulau Tuba magma (9%)

Peranan subduksi terhadap batuan volkanik berusia neogen di Semenanjung Semporna: perspektif petrologi dan geokimia

Batuan volkanik Semenanjung Semporna yang berusia Neogen terkenal dengan ciri-ciri geokimia subduksi dan menyerupai-OIB. Proses subduksi yang berlaku semasa usia Miosen menyebabkan magmatisme kaitan-subduksi diganti dengan magmatisme menyerupai-OIB. Batuan volkanik berusia Neogen di Semenanjung Semporna boleh dibahagi kepada basalt, andesit basalt, andesit dan riolit. Corak yang ditunjukkan oleh unsur major dan unsur surih mencadangkan magma batuan volkanik di Semenanjung Semporna telah mengalami penghabluran berperingkat. Berdasarkan kepada tren daripada mantel primitif dan REE, 3 jenis tren dapat dikenal pasti: Kaitan-subduksi; susutan Nb, Ta, P dan Ti, pengayaan pada LILE dan LREE dan susutan terhadap HFSE, menyerupai-OIB; pengayaan Nb, Ta and Ti, dan MORB; mantel primitif dan REE hampir rata. Pola REE turut menunjukkan batuan volkanik mempunyai nilai anomali Eu negatif dan positif, yang menjelaskan pengfraksian plagioklas dan pengumpulan plagioklas berlaku di dalam magma. Berdasarkan kepada sekitaran tektonik untuk Semenanjung Semporna, batuan volkanik kaitan-subduksi mempunyai sekitaran lava arka kepulauan dan basalt pinggir kepingan. Segitiga FeOT-MgO-Al2O3 pula menunjukkan batuan volkanik kaitan-subduksi tersebar pada kawasan orogeni dan pemuaian pusat kepulauan. Sekitaran tektonik untuk batuan volkanik menyerupai-OIB (basalt, 18L5; andesit basalt, 18L9) dan MORB (andesit basalt, 11L5) ialah basalt dalam-kepingan dan lava dalam-kepingan yang terbentuk di sekitaran benua (Segitiga FeOT-MgO-Al2O3)

Low voltage DC power supply with spike-blocking features

RFID tags, sensors embedded with buried devices and biomedical implants all operate at low voltage levels due to power limitations. The ever increasing use these embedded devices has also created a demand in the industry for lowvoltage power supplies. Since many of these circuits are mobile in nature and so are bound to operate in many different environments, the power supply must also be capable of ensuring a stable voltage output even under adverse conditions. This paper analyzes and simulates a power supply circuit that promises a low ripple factor with an element of spike-blocking capability. It centers on a phase-modulation technique that effectively cancels out 99.6% of ripples when operating with a 100 mV ac input at a frequency of 10 kHz. This active noise-cancellation technique allows for a more stable voltage output. It also has a limited inbuilt capability to block spikes. A 100 mV injected spike is brought down to only 6 mV without the use of other damping circuits. This work is therefore capable of damping a large part of the variations in the input voltage, even at low voltages