scholarly journals Petrology and Geochemistry of The Volcanic Arc Tarusan Pluton in Comparison to Lolo Pluton, West Sumatra

2019 ◽  
Vol 20 (4) ◽  
pp. 199
Author(s):  
Ronaldo Irzon ◽  
Ildrem Syafri ◽  
Irfani Agustiany ◽  
Arief Prabowo ◽  
Purnama Sendjaja
Keyword(s):  
Microscopic Analysis ◽  
Calc Alkaline ◽  
Magma Evolution ◽  
Peraluminous Granite ◽  
Volcanic Arc ◽  
Eu Anomaly ◽  
Icp Ms ◽  
West Sumatra ◽  
Petrology And Geochemistry ◽  
Geochemistry Characteristics

The Volcanic Arc Suite is the group of batholiths in the range of the Barisan Mountains and mostly denotes I-type affinity. Previous investigations of the intrusions in West Sumatra emphasized the crystallization age without completing geochemistry characteristics. No former study discussed a pluton which mapped in the Kota XI Tarusan District. This study explains the geochemistry and petrology of the Tarusan Pluton using polarized microscope, XRF, and ICP-MS at the Center for Geology Survey of Indonesia. The microscopic analysis confirms the granite character of the samples. Although both plutons are identified as I-type calc-alkaline series, the Tarusan Pluton is peraluminous granite whilst the Lolo Pluton denotes wider range from metaluminous to peraluminous of granodiorite to granite. Both the plutons are clearly classified as volcanic arc granitoid in the correlation to Volcanic Arc Suite of Sumatra. Negative Ba, Nb, and P anomalies together with positive K, Nd, and Y anomalies are pronounced on the two felsic intrusions. Negative Eu anomaly on the Tarusan Pluton but the positive one at the Lolo Pluton might explain different magma evolution process.Keywords: volcanic arc granite, geochemistry, Tarusan Pluton, Lolo Pluton.

Petrology and Geochemistry of The Volcanic Arc Tarusan Pluton in Comparison to Lolo Pluton, West Sumatra

2019 ◽  
Vol 20 (4) ◽  
pp. 199
Author(s):  
Ronaldo Irzon ◽  
Ildrem Syafri ◽  
Irfani Agustiany ◽  
Arief Prabowo ◽  
Purnama Sendjaja
Keyword(s):  
Microscopic Analysis ◽  
Calc Alkaline ◽  
Magma Evolution ◽  
Peraluminous Granite ◽  
Volcanic Arc ◽  
Eu Anomaly ◽  
Icp Ms ◽  
West Sumatra ◽  
Petrology And Geochemistry ◽  
Geochemistry Characteristics

The Volcanic Arc Suite is the group of batholiths in the range of the Barisan Mountains and mostly denotes I-type affinity. Previous investigations of the intrusions in West Sumatra emphasized the crystallization age without completing geochemistry characteristics. No former study discussed a pluton which mapped in the Kota XI Tarusan District. This study explains the geochemistry and petrology of the Tarusan Pluton using polarized microscope, XRF, and ICP-MS at the Center for Geology Survey of Indonesia. The microscopic analysis confirms the granite character of the samples. Although both plutons are identified as I-type calc-alkaline series, the Tarusan Pluton is peraluminous granite whilst the Lolo Pluton denotes wider range from metaluminous to peraluminous of granodiorite to granite. Both the plutons are clearly classified as volcanic arc granitoid in the correlation to Volcanic Arc Suite of Sumatra. Negative Ba, Nb, and P anomalies together with positive K, Nd, and Y anomalies are pronounced on the two felsic intrusions. Negative Eu anomaly on the Tarusan Pluton but the positive one at the Lolo Pluton might explain different magma evolution process.Keywords: volcanic arc granite, geochemistry, Tarusan Pluton, Lolo Pluton.

scholarly journals Komparasi Geokimia Batuan Gunung Api Kuarter dan Tersier di Tepian Selatan Lampung

EKSPLORIUM ◽  
2020 ◽  
Vol 41 (2) ◽  
pp. 101
Author(s):  
Ronaldo Irzon
Keyword(s):  
Volcanic Rocks ◽  
Crustal Contamination ◽  
Silica Content ◽  
Formation Processes ◽  
Calc Alkaline ◽  
Geochemical Composition ◽  
Eu Anomaly ◽  
Icp Ms ◽  
West Sumatra ◽  
Quaternary Volcanic Rock

ABSTRAK Keterdapatan batuan gunung api di Sumatra diakibatkan oleh penunjaman Lempeng Samudra India-Australia ke bawah Lempeng West Sumatra sejak Eosen. Tanggamus adalah kabupaten di ujung selatan Lampung dengan keterdapatan beberapa unit batuan gunung api berumur Tersier maupun Kuarter. Studi ini bertujuan untuk membandingkan komposisi geokimia batuan gunung api Tersier Formasi Hulusimpang dengan batuan gunung api Kuarter Gunung Tanggamus. Perangkat XRF dan ICP-MS dimanfaatkan untuk mengetahui kadar oksida utama, unsur jejak, dan unsur tanah jarang pada penelitian ini. Berdasarkan karakter geokimia, sampel dari Formasi Hulusimpang adalah batuan gunung api kalk-alkali, metalumina hingga peralumina, dan dalam rentang trakiandesit basaltik hingga riolit. Sampel batuan gunung api berumur Kuarter berada pada rentang kadar silika yang lebih sempit dan cenderung metalumina. Studi ini membuktikan bahwa kedua kelompok batuan berasal dari magma yang sama, tetapi dengan kontaminasi kerak selama diferensiasi. Proses pembentukan yang berbeda pada kedua kelompok batuan diperjelas oleh derajat kemiringan kurva diagram laba-laba UTJ dan jenis anomali Eu.ABSTRACT The presence of volcanic rocks in Sumatra is due to the subduction of the Indian-Australian Ocean Plate under the West Sumatra Plate since the Eocene. Tanggamus Regency situated at the southern edge of Lampung with the occurrence of several Tertiary and Quaternary volcanic rock units. The aim of this study is to compare the geochemical composition of Tertiary volcanic rocks from the Hulusimpang Formation and Quaternary volcanic rocks from Mount Tanggamus in the Tanggamus Regency. XRF and ICP-MS devices were used to determine the compositions of major oxides, trace elements, and rare earth elements in this study. Based on geochemical characters, samples from the Hulusimpang Formation are calc-alkaline volcanic rocks, metaluminous to peraluminous, and in the basaltic trachyandesite to rhyolite ranges. Quaternary samples are in a narrower range of silica content and tend to be metaluminous. This study proves that the two rock groups originate from the same magma but with crustal contamination during differentiation. The two volcanic should experience through different formation processes based on the slope of the heavy-REE and the type of Eu anomaly.

scholarly journals Geochemistry of Granitoids in Central Sumatra: An Identification of Plate Extension during Triassic

2021 ◽  
Vol 19 ◽  
Author(s):  
Ronaldo Irzon ◽  
Ildrem Syafri ◽  
Nana Suwarna ◽  
Johanes Hutabarat ◽  
Purnama Sendjaja ◽  
...  
Keyword(s):  
Age Dating ◽  
Composition Analysis ◽  
Volcanic Arc ◽  
Granite Intrusion ◽  
Icp Ms ◽  
West Sumatra ◽  
Type Granite ◽  
Almost All ◽  
Central Sumatra

Previous investigations of granitoids in Sumatra were focused on age dating with minimum geochemistry composition analysis. The purpose of this study is to define the geochemistry classification of the intrusions in central Sumatra and to explain the rocks' correlation to Southeast Asia tectonic activities. A polarizing microscope was used for petrography description while XRF and ICP-MS were applied for geochemistry measurements. According to the geochemistry, almost all of the intrusions are the I-type volcanic arc granitoids. The oldest studied rock is the Late Permian Ombilin Granite that should have been formed before West Sumatra and West Burma move away from the Cathaysia. Sulit Air Granite and Tanjung Gadang Granite intrusion were triggered by the subduction of Meso-Tethys beneath West Sumatra while Lassi Pluton and Lolo Pluton due to Indo-Australia and West Sumatra convergency. The Triassic Sijunjung Granite depicts A-type granite natures to suggest an extension in the West Sumatra plate.

scholarly journals Petrogenesis of a late-stage calc-alkaline granite in a giant S-type batholith: geochronology and Sr–Nd–Pb isotopes from the Nomatsaus granite (Donkerhoek batholith), Namibia

2021 ◽  
Author(s):  
S. Aspiotis ◽  
S. Jung ◽  
F. Hauff ◽  
R. L. Romer
Keyword(s):  
Partial Melting ◽  
Mineral Assemblage ◽  
Central Zone ◽  
Calc Alkaline ◽  
Pb Isotope ◽  
Alkaline Granite ◽  
Ti Oxides ◽  
Eu Anomaly ◽  
Environment Characteristic ◽  
Southern Central

AbstractThe late-tectonic 511.4 ± 0.6 Ma-old Nomatsaus intrusion (Donkerhoek batholith, Damara orogen, Namibia) consists of moderately peraluminous, magnesian, calc-alkalic to calcic granites similar to I-type granites worldwide. Major and trace-element variations and LREE and HREE concentrations in evolved rocks imply that the fractionated mineral assemblage includes biotite, Fe–Ti oxides, zircon, plagioclase and monazite. Increasing K2O abundance with increasing SiO2 suggests accumulation of K-feldspar; compatible with a small positive Eu anomaly in the most evolved rocks. In comparison with experimental data, the Nomatsaus granite was likely generated from meta-igneous sources of possibly dacitic composition that melted under water-undersaturated conditions (X H2O: 0.25–0.50) and at temperatures between 800 and 850 °C, compatible with the zircon and monazite saturation temperatures of 812 and 852 °C, respectively. The Nomatsaus granite has moderately radiogenic initial 87Sr/86Sr ratios (0.7067–0.7082), relatively radiogenic initial εNd values (− 2.9 to − 4.8) and moderately evolved Pb isotope ratios. Although initial Sr and Nd isotopic compositions of the granite do not vary with SiO2 or MgO contents, fSm/Nd and initial εNd values are negatively correlated indicating limited assimilation of crustal components during monazite-dominated fractional crystallization. The preferred petrogenetic model for the generation of the Nomatsaus granite involves a continent–continent collisional setting with stacking of crustal slices that in combination with high radioactive heat production rates heated the thickened crust, leading to the medium-P/high-T environment characteristic of the southern Central Zone of the Damara orogen. Such a setting promoted partial melting of metasedimentary sources during the initial stages of crustal heating, followed by the partial melting of meta-igneous rocks at mid-crustal levels at higher P–T conditions and relatively late in the orogenic evolution.

scholarly journals Lower Permian basaltic agglomerate from the Tsengel River valley, Mongolian Altai

2020 ◽  
Vol 51 ◽  
pp. 1-11
Author(s):  
Kristýna Hrdličková ◽  
Altanbaatar Battushig ◽  
Pavel Hanžl ◽  
Alice Zavřelová ◽  
Jitka Míková
Keyword(s):  
River Valley ◽  
Lower Permian ◽  
Basalt Lava ◽  
Volcanic Arc ◽  
Lower Carboniferous ◽  
Upper Carboniferous ◽  
Mongolian Altai ◽  
Icp Ms ◽  
Volcaniclastic Rocks ◽  
Data Yield

A new occurrence of Permian volcanic and volcaniclastic rocks in the Mongolian Altai south of the Main Mongolian Lineament was described between soums of Tugrug and Tseel in Gobi-Altai aimag. Studied vitrophyric pyroxene basalt lies in a layer of agglomerate and amygdaloidal lavas, which is a part of NE–SW trending subvertical sequence of varicolored siltstones and volcaniclastic rocks in the Tsengel River valley. This high-Mg basalt is enriched in large ion lithophile elements, Pb and Sr and depleted in Nb and Ta. LA-ICP-MS dating on 44 spots reveals several concordia clusters. The whole rock geochemistry of sample fits volcanic arc characteristic in the geotectonic discrimination diagrams. Dominant zircon data yield Upper Carboniferous and Permian magmatic ages 304.4 ± 2.3 and 288.6 ± 1.9 Ma. Two smaller clusters of Upper Devonian (376 ± 4.7 Ma) to Lower Carboniferous ages (351.9 ± 3.5 Ma) indicate probably contamination of ascending magmatic material. Youngest Triassic age found in three morphologically differing grains reflects probably lead loss. Described high-Mg basalt lava represents sub-aerial volcanism in volcanic arc environment developed over the N dipping subduction zone in the southwestern Mongolia in the time span from Uppermost Carboniferous to Permian during terminal stage of its activity.

Petrology and geochemistry of calc-alkaline volcanic and subvolcanic rocks, Dalli porphyry copper–gold deposit, Markazi Province, Iran

2012 ◽  
Vol 55 (2) ◽  
pp. 158-184 ◽  
Author(s):  
Farimah Ayati ◽  
Fuat Yavuz ◽  
Hooshang H. Asadi ◽  
Jeremy P. Richards ◽  
Fred Jourdan
Keyword(s):  
Gold Deposit ◽  
Porphyry Copper ◽  
Calc Alkaline ◽  
Copper Gold ◽  
Petrology And Geochemistry

A geochronological framework for sedimentation and Mesoproterozoic tectono-magmatic activity in lower Belt–Purcell rocks exposed west of Kimberley, British Columbia

2015 ◽  
Vol 52 (7) ◽  
pp. 444-465 ◽  
Author(s):  
Christopher R.M. McFarlane
Keyword(s):  
British Columbia ◽  
Minor Component ◽  
Structural Level ◽  
Peraluminous Granite ◽  
Icp Ms ◽  
Ductile Shearing ◽  
History Of ◽  
Metamorphic Zone ◽  
A Minor ◽  
Plate Reconstruction

The Matthew Creek Metamorphic Zone (MCMZ) exposes what is inferred to be the lowest structural level of the lower Aldridge Formation in the Canadian portion of the Belt–Purcell Supergroup. Zircon, monazite, and titanite were dated using the U–Pb system by LA–ICP–MS. The detrital zircon populations of quartzite layers in these rocks define a provenance dominated by sources of Laurentian affinity with a minor component of non-North American ages between 1600 and 1490 Ma. Special attention was paid to monazite in sillimanite-grade metapelitic schists that was analyzed using in situ LA–ICP–MS techniques guided by BSE imaging and compositional mapping. Textural and geochronological evidence indicate that coupled dissolution–reprecipitation affected detrital monazite at 1413 ± 10 Ma. This was followed by prograde monazite growth at 1365 ± 10 Ma, synchronous with crystallization of the nearby Hellroaring Creek peraluminous granite at 1365 ± 5 Ma. Late-stage pegmatite emplacement and ductile shearing along the contact of the MCMZ and overlying rocks occurred at 1335 ± 5 Ma, interpreted as a period of post-collisional extension, core complex formation, exhumation, and decompression melting. The entire package was subsequently affected by a pervasive ∼1050 Ma hydrothermal overprint that partially reset U–Pb dates in monazite, zircon, and titanite contained in all lithologies examined. The lowermost Belt–Purcell stratigraphy in southeast British Columbia preserves a detailed record of sedimentary provenance and a long history of episodic collision and extension that must be reconciled with plate reconstruction models for the break-up of the Nuna supercontinent and assembly of Rodinia.

Dating polymetamorphism using titanite: Linking trace elements, textures, and ages

2021 ◽  
Author(s):  
Jesse Walters ◽  
Alicia Cruz-Uribe ◽  
Won Joon Song ◽  
Joshua Stone ◽  
Hanna Brooks ◽  
...  
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Bulk Composition ◽  
Granulite Facies ◽  
Compositional Variation ◽  
Excimer Laser Ablation ◽  
Eu Anomaly ◽  
Fluid Infiltration ◽  
Icp Ms ◽  
The University

<p>Here we present titanite U-Pb dates from two banded calc silicate gneisses (SSP18-1A and 1B) from western Maine. Mineral textures and compositions display multiple phases of metamorphism. The peak lower granulite facies assemblage is Di + Kfs + Pl + Ttn, with little to no calcite present. Late Czo + Tr replaces Di + Pl, suggesting an influx of X<sub>H2O</sub> > 0.90 fluids. Nearby metapelites show the transition from sillimanite-bearing to muscovite-bearing assemblages, indicating that fluid infiltration may be widespread. Compositional maps of clinopyroxene in SSP18-1B show fracturing and rehealing of early Fe-rich diopside with late Mg-rich diopside. Both samples exhibit overprinting of An-rich plagioclase by increasingly Ab-rich plagioclase. Titanite grains in both samples exhibit BSE textures and compositional variation consistent with multiple phases of growth and dissolution-reprecipitation reactions.</p><p>Titanite trace element and U-Pb data were collected by LA-ICP-MS at the University of Maine using an ESI NWR193<sup>UC</sup> excimer laser ablation system coupled to an Agilent 8900 ICP-MS. Single spot ages range from 280 to 400 Ma with 12-20 Ma propagated 2SE. Four composition-date domains are identified in SSP18-1B: A. 400 ± 8 Ma (dark BSE cores), B. 372 ± 4 Ma (bright BSE cores), C. 342 ± 6 Ma (bright BSE cores, no Eu anomaly), and D. 302 ± 3 Ma (dark BSE rims, low LREE). Titanite Fe and Y concentrations increase with decreasing date, whereas Sr concentrations decrease. In clinopyroxene, Fe and Y decrease between high Fe-diopside and late Mg-diopside, placing the fracturing and rehealing events between 400 and 372 Ma. Strontium concentrations in titanite decrease between subsequent generations of plagioclase, diopside, and titanite, suggesting a continual fractionation of Sr from the reactive bulk composition. Low LREE in ca. 300 Ma titanite domains in both samples are consistent with the formation of texturally late allanite and clinozoisite, thus constraining the timing of the high X<sub>H2O</sub> fluid infiltration event. Zr-in-titanite temperatures for rims in the quartz-bearing SSP18-1B give a weighted mean T of 764 °C at 4.5 GPa, consistent with the muscovite-absent sillimanite-bearing assemblage in garnet cores from metapelite samples. However, the 100-150 °C lower Grt-Bt temperatures for metapelites are not consistent with peak metamorphic phase equilibria. Our data demonstrate the utility of linking titanite textures and trace element concentrations with those of other minerals to reveal past metamorphic and deformational events. Additionally, we show that titanite may reliably preserve U and Pb isotopic ratios, trace elements, and textures over subsequent high-T metamorphic events.</p>

scholarly journals Widespread Permian granite magmatism in Lower Austroalpine units: significance for Permian rifting in the Eastern Alps

2020 ◽  
Vol 113 (1) ◽  
Author(s):  
Sihua Yuan ◽  
Franz Neubauer ◽  
Yongjiang Liu ◽  
Johann Genser ◽  
Boran Liu ◽  
...  
Keyword(s):  
Tectonic Setting ◽  
Eastern Alps ◽  
Geochemical Data ◽  
Calc Alkaline ◽  
Three Samples ◽  
High K ◽  
Icp Ms ◽  
Granite Magmatism ◽  
Austroalpine Unit ◽  
Granite Suite

Abstract The Grobgneis complex, located in the eastern Austroalpine unit of the Eastern Alps, exposes large volumes of pre-Alpine porphyric metagranites, sometimes associated with small gabbroic bodies. To better understand tectonic setting of the metagranites, we carried out detailed geochronological and geochemical investigations on the major part of the porphyric metagranites. LA–ICP–MS zircon U–Pb dating of three metagranites sampled from the Grobgneis complex provides the first reliable evidence for large volumes of Permian plutonism within the pre-Alpine basement of the Lower Austroalpine units. Concordant zircons from three samples yield ages at 272.2 ± 1.2 Ma, 268.6 ± 2.3 Ma and 267.6 ± 2.9 Ma interpreted to date the emplacement of the granite suite. In combination with published ages for other Permian Alpine magmatic bodies, the new U–Pb ages provide evidence of a temporally restricted period of plutonism (“Grobgneis”) in the Raabalpen basement Complex during the Middle Permian. Comparing the investigated basement with that of the West Carpathian basement, we argue that widespread Permian granite magmatism occurred in the Lower Austroalpine units. They belong to the high-K calc-alkaline to shoshonitic S-type series on the base of geochemical data. Zircon Hf isotopic compositions of the Grobgneis metagranites show εHf(t) values of − 4.37 to − 0.6, with TDM2 model ages of 1.31–1.55 Ga, indicating that their protoliths were derived by the recycling of older continental crust. We suggest that the Permian granitic and gabbroic rocks are considered as rifted-related rocks in the Lower Austroalpine units and are contemporaneous with cover sediments.

scholarly journals Geochemistry of the Um Had Plutonites, Central Eastern Desert, Egypt: Implications for Magma Evolution, and Tectonic Setting

2014 ◽  
Vol 6 (2) ◽  
pp. 36 ◽  
Author(s):  
Nedal Qaoud
Keyword(s):  
Tectonic Setting ◽  
Active Continental Margin ◽  
Eastern Desert ◽  
Island Arc ◽  
Water Vapour Pressure ◽  
Calc Alkaline ◽  
Magma Evolution ◽  
Basement Complex ◽  
Central Eastern Desert ◽  
Pan African

Geochemistry of gabbroid and granitoid plutonites from the Um Had area indicates island arc subalkaline basic magma with tholeiitic affinity and calc-alkaline, metaluminous and slightly peraluminous magma, respectively. Although different in age both plutonite types were emplaced under compressional regime, where subduction-related environment was dominant. They were formed under relatively low to moderate water-vapour pressure (1–5 k-bars) at moderate depths (20–30 km). Biotite granites were formed at a relatively high temperature range (800–840 °C), while biotite-muscovite granites were formed under relatively moderate temperature conditions (760–800 °C). These two units may represent evolution from island arc to active continental margin. It is suggested that island arc gabbros might have sourced the late subduction-related calc-alkaline granitoids during the waning stages of the pan-African orogeny. The I-type nature of the investigated plutonites in the study area and elsewhere suggests the juvenile character of the basement complex of the Eastern Desert of Egypt.

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