scholarly journals Mineral, petrography and petro-geochemical characteristics of diabasic dykes at the Trai Mat quarry, Da Lat City

2016 ◽  
Vol 19 (1) ◽  
pp. 94-100
Author(s):  
Phuc Duc Le
Keyword(s):  
Biotite Granite ◽  
Geochemical Characteristics ◽  
Coarse Grained ◽  
Chemical Components ◽  
Upright Orientation ◽  
Mineral Components

The diabasic dykes exposed at the Trai Mat quarry, Da Lat city intrude the granitoids of Ankroet complex (such as middle – coarse grained biotite granite and leucogranites. As can be seen in the field the thickess of these dykes vary from 0.5m to nearly 1.5 m extended north-south-east slope angles ranging from ~50 0 to being upright (Orientation of lying 31<50 ÷ 90 o). Petographical components consist of diabaz porphyrite. The main mineral components are plagioclase, pyroxene?, quartz, carbonate, chloride. Chemical components of rocks are: SiO2: 54.34 %, K2O: 2.43 %,Na2O: 2,50 %. The content of W, Pb, U, Th, Hf, Rb, Au is higher

scholarly journals Petrographical petrochemical characteristics of Xa Yu granitoid massif, Binh Thuan province

2016 ◽  
Vol 19 (3) ◽  
pp. 85-98
Author(s):  
Phuc Duc Le ◽  
Huong Thi Thu Ha
Keyword(s):  
Biotite Granite ◽  
Chemical Components ◽  
Accessory Mineral ◽  
Type I ◽  
Mineral Components ◽  
The Common ◽  
Granitoid Massif

Xa Yu granitoid is isometric shape, with the exposure of 7.5 km2 area. The petrographical component consists of medium – coarse to small grained biotite granite. The vein rocks are incusive of aplite, pegmatoid,…The main mineral components are plagioclase, potassium felspate, quartz, biotite, and little horblende. The common accessory mineral components are zircon, orthite and apatite. Chemical components of rocks are: SiO2: 65.96 –76.50, Na2O: 1.85 –3.30, K2O: 3.60 – 5.27, K2O+Na2O: 5.45 –7.18; K2O/Na2O: 1.23 – 1,95. The content of Ba, Sr is low but Rb is higher, variability Rb/Sr: 0.552 –10.526; Ba/Sr: 0.379 – 1.816, Ba/Rb: 0.055 – 3.092; K/Rb: 235.3 – 246.9, Type I-S-granite.

scholarly journals MINERAL - PETROGRAPHICAL, PETROCHEMICAL CHARACTERISTICS OF XUAN THU GRANITOID MASSIF, QUANG NGAI PROVINCE

2009 ◽  
Vol 12 (10) ◽  
pp. 119-131
Author(s):  
Phuc Duc Le ◽  
Hung Phu Tran ◽  
Thang Dai Tran
Keyword(s):  
Biotite Granite ◽  
Geological Mapping ◽  
Geochemical Characteristics ◽  
Material Component ◽  
First Time ◽  
Granitoid Massif

The first time, Xuanthu granitoid massif was researched and arranged into component of Bana complex in project of 1/50,000 scale geological mapping and minerals prediction of Quangngai sheets (Than Duc Duyen et al, 1999). The investigations carried out within area of Nuocnhieu stream, SE corner of Xuanthu massif which has displayed mainly plutonic formations, such as biotite granite, medium - coarse granular 2 mica granite, fine granular granite and fine granular 2 mica granite. Vein phases are commonly aplite, pegmatoid, porphyry granite.... This paper is mainly to research on mineral - petrography and petro - geochemical characteristics as well as to make more clearly about material component, mineral forming order, forming original explaining and related mineralizations of Xuanthu granitoid massif.

scholarly journals Mineralogical and geochemical characteristics of graphite-bearing rocks at Chenjere Area, south-eastern Tanzania: Implications for the nature and quality of graphite mineralization

2021 ◽  
Vol 47 (2) ◽  
pp. 535-551
Author(s):  
Charles D Moye ◽  
Michael M Msabi
Keyword(s):  
Industrial Applications ◽  
Geological Mapping ◽  
Geochemical Characteristics ◽  
Coarse Grained ◽  
Field Observations ◽  
Conducting Surface ◽  
Advanced Technologies ◽  
Size Grade ◽  
Petrographic Study

This study focused on the mineralogical and geochemical characteristics of graphite-bearing rocks at Chenjere area by conducting surface geological mapping, geochemical and petrographical analyses with the intention of characterizing the nature of graphite occurrence in these lithological units. This paper presents results of the flake size, grade and mineralization extension of graphite in the graphitic gneiss. Field observations, petrographic investigation and comparison with other studies indicate that graphite occurrence at the Chenjere area is of sedimentary origin which fall under syngenetic type. The petrographic study revealed that nature of metamorphism of rocks in the Chenjere area is of high grade (amphibolite facies). Both field observations and petrographic studies indicate that minerals in the rock associated with graphite include quartz, feldspar (mostly K-feldspar) and biotite. Further, the mineralized zones are concordant to the rest of the lithologies of the area and biotite gneiss is forming the hangingwall and footwall. The rocks’ foliation is generally NE striking and dipping SE with the dip amount ranging from 30 to 60 degrees. The graphite mineralization at the study area occurs as medium to coarse grained crystalline, flake type graphite with long axis of up to 1000 micrometres in size. Graphite flakes are disseminated and oriented in the host rock that represents a normal metamorphic fabric. Geochemical results indicate that graphite contents in the host graphitic gneiss range from 3.03 wt.% to 16.00 wt.%. Mineralogy and texture of the graphite at Chenjere area meet the standards required for industrial applications in various advanced technologies. Keywords: Graphite Mineralization, Flake Graphite, Chenjere Area

Early Mesozoic granitoids from SW Vietnam and SE Cambodia – an example of the southeastern extension of the Southeast Asian granite belt

2020 ◽  
Author(s):  
Anh Nong ◽  
Christoph Hauzenberger ◽  
Daniela Gallhofer ◽  
Sang Dinh
Keyword(s):  
Large Scale ◽  
Early Stage ◽  
Tectonic Setting ◽  
Biotite Granite ◽  
Coarse Grained ◽  
Late Triassic ◽  
Late Paleozoic ◽  
Western Boundary ◽  
Early Mesozoic ◽  
Granite Belt

&lt;p&gt;Early Mesozoic magmatism in Indochina and its vicinities in Sundaland (SE Asia) has been usually ascribed to be in connection with one of three approximately coeval tectonic regimes: 1) the Indochina-Sibumasu amalgamation leading to the closure of the Paleotethys during the Late Paleozoic &amp;#8211; Early Mesozoic forming the Thai-Malaysia tin-bearing granite belt, 2) the Indochina-South China amalgamation along the northern boundary of Indochina closing another branch of the Paleotethys during Late Paleozoic &amp;#8211; Triassic times, and 3) the early stage of an active margin with subduction of the Paleo-Pacific plate during Triassic-Jurassic times.&lt;/p&gt;&lt;p&gt;Scattered granitic plutons (185&amp;#8211;210 Ma) located in southern Cambodia and some islands in southernmost Vietnam are distributed along the N-S Rach Gia-Nam Can fault which is a large-scale fault active during the Early Mesozoic. The studied rocks can be distinguished based on petrological features: weakly foliated biotite-rich granite (Hon Khoai Island, SW Vietnam), biotite-tourmaline-bearing granite (Hon Da Bac Island, SW Vietnam), and coarse-grained biotite granite (Tamao, SE Cambodia). The Honkhoai granites are a range of dark to light coloured granites due to a variation in biotite content and display a foliation. They usually contain amphibole, ilmenite, and monazite. The Hondabac granites comprise dark-colored granodiorites and granites with biotite, tourmaline, ilmenite, apatite, fluorite, epidote, and subordinate titanite. The Tamao granites are mainly composed of biotite aggregates with sporadic&amp;#160;muscovite and accessory phases such as ilmenite, apatite, and fluorite.&lt;/p&gt;&lt;p&gt;Zircon U-Pb ages yield 189 &amp;#177; 1 to 206 &amp;#177; 2 Ma for the Honkhoai rocks, 192 &amp;#177; 1 to 202 &amp;#177; 1 Ma for the Hondabac rocks, and 189 &amp;#177; 2 Ma for the Tamao rocks. Apparently, these Late Triassic - Early Jurassic granitoids are chronologically consistent with all three tectonic events. However, geographical and geochemical arguments favor a connection to the Thai-Malaysia tin-bearing granites. Similarities include high silica content and predominantly high-K to calc-alkaline affinities. Trace element composition is characterized by enrichments in Cs, Rb, Th, U, and Pb, and depletion in Ba, Sr, Nb, P, and Ti. All analyzed rock samples show (La/Yb)n values of 4.05&amp;#8211;17.27 and negative Eu anomalies (Eu/Eu*=0.15&amp;#8211;0.65). The whole-rock and biotite chemistry point to an arc-related tectonic setting for the Hondabac rock, while the Honkhoai and Tamao rocks are ambiguous in the tectonic regime but likely close to syn-collision and within-plate field, respectively. Geobarometry of the Honkhoai rocks using the Al-in-amphibole geobarometer yields crystallization pressure up to 3 kbar.&lt;/p&gt;&lt;p&gt;We conclude that the studied rocks formed during the closure of the Palaeotethys along the western boundary of the Indochina block, particularly similar to the Thai-Malaysia granite belt. Hence, the Sukhothai-Chantaburi Terrane may be extended southeastward as far as to the Hon Khoai Island (Southernmost Vietnam).&lt;/p&gt;

scholarly journals U-Pb zircon and Hf composition of granite Song Ma block

2019 ◽  
Vol 2 (4) ◽  
pp. 167-175
Author(s):  
Tai Minh Nguyen ◽  
Hoa Xuan Tran ◽  
Giang Thi Truong Nguyen ◽  
Cuong Chi Truong ◽  
Minh Pham
Keyword(s):  
Isotope Composition ◽  
Biotite Granite ◽  
Hf Isotope ◽  
Geochemical Characteristics ◽  
Composition Analysis ◽  
Viet Nam ◽  
Early Triassic ◽  
Late Permian ◽  
Weighted Mean ◽  
Mineral Assemblages

The granite of the Song Ma block mainly consists of two types of granite: biotite granite and hornblende-biotite granite. Biotite granites have the percent of plagioclase (35– 45%), K-feldspar (25–35%), quartz (~20%) and biotite (~10%). Biotite-hornblende granite with the content of plagioclase (40–50%), Kfeldspar (10–15%), hornblende (5–10%) and biotite (5%). Zircon crystals were selected from the granite of Song Ma block are V0741, V0856 and V1006 samples with the LA-ICPMS U-Pb analyses gave concordant ages concentrated at 257±4Ma, 262±3Ma and 241±6Ma (weighted mean). Those ages are older than the results of the previous research. The mineral assemblages and geochemical characteristics show the typical of I-type granites. The results of Hf isotope composition analysis give the value of εHf(t) from +7.3 to +13.9, which is proven the sources of the granite Song Ma block similar to the granite of Phan Si Pan zone, NW Viet Nam during the period from late Permian to early Triassic.

scholarly journals Subsurface radon gradient in parts of tremor-prone, north-central Nigeria

2021 ◽  
Author(s):  
Arabi Suleiman ◽  
Zainab Tukur ◽  
Idris I. Isa Funtua ◽  
Ali A. M. ◽  
Ewa Kurowska ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Radon Concentration ◽  
Activity Concentration ◽  
Ground Level ◽  
The United States ◽  
Biotite Granite ◽  
Coarse Grained ◽  
Radon Activity ◽  
Below Ground ◽  
Natural Decay

Abstract Radon is a natural gas that originates from geogenic and cosmic material as a part of the natural decay process of uranium and thorium. Radon is reported to have been the second leading cause of lung cancer in the United States. The US-EPA estimates that about 21,000 people die each year from radon-related (inhaled/ingested) lung cancer. Radon can escape from basement and soils where they are formed and build up indoors where they are eventually inhaled. In this study, radon activity concentration was measured from subsurface at a depth of 0.33m, 0.66m and 0.99m below ground level from 130 locations that covered the entire Federal Capital territory, Abuja-Nigeria and reported. The results obtained showed that the minimum, maximum and mean radon activity concentration (Bq/m3) from soil at 0.33, 0.66 and 0.99m below ground level are 15.20, 48,500.00 and 4,257.47 at 0.33m, 15.20, 59,600.00 and 5,061.19 at 0.66m and 10.02, 81,200.00 and 9,993.15 at 0.99m, respectively. Minimum, maximum and mean radon diffusion length (m) recorded at 0.003m are 0.05, 159.63 and 14.01m. At 0.66 and 0.99m, the values calculated are 0.005,19.62 and 1.67, and 0.003, 26.73 and 0.32, respectively. These results indicate that radon concentration increases with depth and characterized by “high” radon concentration in areas covered by biotite granite, undifferentiated schist, undifferentiated gneiss and porphyroblastic gneiss, “medium” in areas covered by coarse porphyritic biotite and medium to coarse grained biotite and “low” in areas covered by migmatite and marble. Most of the values obtained suggest health burden especially in the study areas where massive excavations for construction of housing units is going on and the likelihood of radon entering homes through opening and cracks created as building/structure settles with time.

scholarly journals GRANITOID PETROLOGY OF HAI VAN MASSIF

2009 ◽  
Vol 12 (5) ◽  
pp. 46-54
Author(s):  
Phuc Duc Le
Keyword(s):  
Mantle Source ◽  
Source Region ◽  
Biotite Granite ◽  
Chemical Components ◽  
Isotopic Age ◽  
Mantle Source Region

The granitoid formations of Hai Van massif with petrographical components consist of biotite granite, two mica granite. Chemical components of rocks are: SiO2: 69,34=73,92%, Na2O+KO: 6,11-8,11%, K2O/Na20>1. Content of Ba, Sr is low but Rb is higher. From results of Nd-Sm isotopic analysic shows that they are nearly same with stable crust material. Age of source region formation is 1,33 billion years (model of homogeneous chondrite source region), or 1,95 billion years (model of poor mantle source region). U-Pb isotopic age: 241,9+ 2 and 241,4+2.1 million years.

scholarly journals PETROGRAPHIC, MINERAL, GEOCHEMICAL CHARACTERISTICS OF BA NA GRANITOID

2009 ◽  
Vol 12 (7) ◽  
pp. 58-71
Author(s):  
Phuc Duc Le
Keyword(s):  
Mantle Source ◽  
Source Region ◽  
Isotopic Analysis ◽  
Biotite Granite ◽  
Geochemical Characteristics ◽  
Second Phase ◽  
Granite Sample ◽  
Petrographic Composition ◽  
Fine Grained ◽  
Mantle Source Region

Ba Na granitoid is isometric shape, with exposure of 30 sqa km area. Petrographic composition is mainly coarse - medium grained biotite granite, included in the first phase. The fine grained leuco rock of the second phase is small massif in shape, distributed along fault in NE-SW direction. SiO, content of Bana granitoid is variation from 73.74% to 76.24%. Total of K2O +Na2O is from 7.32% to 8.33%. Ratio of K2O/Na2O: 1.66 - 2.07. This is S-Granite. Value of 147Sm/144Nd = 0,1249 is nearly stable crust material. Ratio of Sm/Nd is low. ena has negative value and very small proved that Ba Na granitoid must derive from crust source or mantle source which rich (EM). The age of source regional forming calculated from isotopic of Sm, Nd is 1.06 Ba (according to model of chondrite mantle source region) or 1.74 Ba (according to model of poor mantle source). The prospects of related mineralization of Ba Na granitoid is Sn (W, Nb, Ta) with amsemblage of topaz - cassiterite - tourmaline - quartz (sometime is Ta - Nb). The result of isotopic analysis of U Pb in zircon of Ba Na biotite granite sample at lab of Tasmania University, Australia, age of Ba Na is 242.9 +1.5 Ma and 240.6 2.2 Ma.

Lithostratigraphy of the Naros Granite (Komsberg Suite), South Africa and Namibia

2021 ◽  
Author(s):  
P.H. Macey ◽  
R.J. Thomas ◽  
H.P. Smith ◽  
D. Frei ◽  
PJ. le Roux
Keyword(s):  
South Africa ◽  
Partial Melting ◽  
Mineral Assemblage ◽  
Chemical Weathering ◽  
Biotite Granite ◽  
Igneous Rocks ◽  
Coarse Grained ◽  
Southern Margin ◽  
A Minor ◽  
Significant Chemical

Abstract The Naros Granite occurs as a large, northwest-trending ovoid batholith roughly 30 km long and 15 km wide straddling the Orange River border between South Africa and Namibia, 25 km northeast of Onseepkans. It consists mainly of a leucocratic to mesocratic grey, coarse-grained equigranular hornblende-biotite granite-granodiorite that is locally mildly feldspar porphyritic. Small, ovoid mafic autoliths are common and characteristic of the Naros Granite. The composition of the unit varies from granite to granodiorite with a minor leucogranitic phase observed along the southern margin of the batholith. Hornblende and biotite are ubiquitous mafic minerals but small amounts of orthopyroxene occur locally. The Naros Granite has yielded tightly-constrained U-Pb zircon ages between 1 114 Ma and 1 101 Ma. The Naros Granite is generally unfoliated to weakly deformed with only localised shearing along contacts with the surrounding country rocks giving rise to orthogneissic fabrics. It has an intermediate to felsic composition (mean SiO2: 63.9 ± 2.2 wt.%) and is strongly metaluminous. This, together with its biotite-hornblende ± orthopyroxene mineral assemblage and the abundance of mafic autoliths, suggests it is an I-type granitoid, with the source magma produced by partial melting of older igneous rocks that had not undergone any significant chemical weathering. The Naros Granite is the youngest and most evolved member of the ~1.11 Ga Komsberg Suite, a collection of late- to post-tectonic I-type metaluminous, intermediate to felsic, biotite ± hornblende granitoids and their charnockitic equivalents that have intruded the older pre-tectonic gneisses of the Kakamas Domain of the Namaqua Metamorphic Sector.

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