• Journal of the Korean earth science society
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• v.29 no.3
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• pp.246-254
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• 2008

This study has been performed to evaluate the possibility of utilizing feldspar porphyry as an adsorbent for heavy metals in natural water. The research sample rock 'Maekbansuk' was altered feldspar porphyry which included chlorite, epidote and calcite formed by a prophylitic alteration process. In extraction tests, the majority of extracted elements were Ca and Na, which were extracted in much greater abundance from the groundmass than from the feldspar phenocryst. In adsorption tests, the adsorption capacities of Pb, Fe and Cu within an hour of reaction time were 99, 98 and 97%, respectively, but that of As remained 25% for a full 24 hours. The high adsorption capacities of altered feldspar porphyry for Pb, Fe and Cu suggest its potential utilization as a heavy metal adsorbent fur water purification.

• The Journal of the Petrological Society of Korea
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• v.26 no.2
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• pp.143-152
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• 2017

As weathering processes, micro-cavities are formed on the surface of rocks, and in particular, the porous structure is increased in feldspar. Adsorption and antibacterial tests were carried out to clarify the environmental function of porous feldspar porphyry. Almost all the heavy metals were adsorbed in the feldspar filter and the adsorption rate could be controlled by changing the filter length. The shake flask method of fabric coated with 5% and 7% feldspar powder showed very high antibacterial activity of 98% and 99.9%, respectively. The cation exchange capacity at a particle size of $10{\mu}m$ was 114.63 meq/100g probably due to the porous structure. The potential value of porous feldspar porphyry as a resource is sufficient based on the results of the experiment.

• Economic and Environmental Geology
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• v.44 no.4
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• pp.321-327
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• 2011

As a product of geological mapping of the Changamjeom Sheet (1:50,000) located around Misiryeong at a distance towards the west from Sokcho city, a small laccolith of hypabyssal rocks has been geometrically reconstructed to understand the original laccolith shape using structural contour lines of random spot sediments laid on the quartz feldspar porphyry and a schematic cross section. The laccolith age is constrained to ca. $84.4{\pm}1.8$ Ma (SHRIMP). The originated Baekdam sedimentary basin with the lost size has been yielded to 6 km wide and 16 km long.

• Journal of the Mineralogical Society of Korea
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• v.19 no.2 s.48
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• pp.99-109
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• 2006

Igneous rocks occurring in the northwesern part of Keumsan area, Chungcheongnam-do were studied petrogeochemically. The geology of this area is composed mainly of the Precambrian biotite gneiss, age-unknown Ogchon supergroup, Jurassic biotite granite, and Cretaceous volcanic rocks, pink feldspar granite and quartz porphyry. The biotite granite is gradually changes to leucocratic nature by going from center to periphery of the rock mass. It shows variation, with distance from the center, in chemical components: $SiO_2,\;Na_2O\;and\;K_2O$ increase, whereas $Fe_2O_3,\;CaO,\;P_2O_5,\;MgO,\;and\;TiO_2$ decrease. Based on geochemical data, the biotite granite and quartz porphyry belong to subalkaline series and I-type. They show calc-alkaline differentiation trend. The biotite granite shows little negative Eu-anomaly pattern, whereas quartz porphyry show marked negative Eu-anomaly pattern, indicating that quartz porphyry was evolved further, when compared with biotite granite.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.291-293
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• 2003

감포남서부 효동리일대는 효동리 화산암류(다데이와, 1924)로 보고된 바 있으나, 야외조사결과 경상계 퇴적암, 화산쇄설암류, 안산암류, 데사이트류, 석영장석반암류, 유문암류 그리고 염기성 암맥류로 구분될 수 있다. 경상계 퇴적암은 최하부층으로서 대체로 완만한 경사를 이루며 주로 셰일로 구성되며 일부 사암이 발달한다 화산쇄설암류는 가장 넓게 분포되며, 쇄설물의 크기에 따라 부분적으로 분대되기도 하나, 대부분 연속성이 빈약한 편이다. (중략)

• Journal of the Mineralogical Society of Korea
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• v.26 no.3
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• pp.161-174
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• 2013

The geology of the weondong deposit area consists mainly of Cambro-Ordovician and Carboniferous-Triassic formations, and intruded quartz porphyry and dyke. The skarn mineralized zone in the weondong deposit is the most prospective region for the useful W-mineral deposits. To determine the skarn-mineralization age, U-Pb SHRIMP and K-Ar age dating methods were employed. The U-Pb zircon ages of quartz porphyry intrusion (WD-A) and feldspar porphyry dyke (WD-B) are 79.37 Ma and 50.64 Ma. The K-Ar ages of coarse-grained crystalline phlogopite (WD-1), massive phlogopite (WDR-1), phlogopite coexisted with skarn minerals (WD-M), and vein type illite (WD-2) were determined as $49.1{\pm}1.1$ Ma, $49.2{\pm}1.2$ Ma, $49.9{\pm}3.6$ Ma, and $48.3{\pm}1.1$ Ma, respectively. And the ages of the high uranium zircon of hydrothermally altered quartz porphyry (WD-C) range from 59.7 to 38.7 Ma, which dependson zircon's textures affected by hydrothermal fluids. It is regarded as the effect of some hydrothermal events, which may precipitate and overgrow the high-U zircons, and happen the zircon's metamictization and dissolution-reprecipitation reactions. Based on the K-Ar age datings for the skarn minerals and field evidences, we suggest that the timing of W-skarn mineralization in weondong deposit may be about 50 Ma. However, for the accurate timing of skarn mineralization in this area, the additional researches about the sequence of superposition at the skarn minerals and geological relationship between skarn deposits and dyke should be needed in the future.

• The Journal of the Petrological Society of Korea
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• v.17 no.3
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• pp.166-178
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• 2008

The modal analyses on the phenocryst phases and the normative mineralogies from the bulk chemical analyses record that the volcanic rocks related to the Yangsan caldera might been derived from compositionally zoned magma. The volcanic rocks show linearly continuous mineralogical gradients, not only totally in the relations between $SiO_2$ and proportion of phenocryst content, but also within each rock unit in the relations between total phenocryst content and the proportion, Q-Ab-Or and Q-An(Ab-Or) diagrams. The roughly gradational modal variations of the phenocryst phases are shown upward within each rock unit. However, the contents and proportion of the phenocrysts in the Yangsan Tuff and the Hwajeri Formation represent the zigzaggedly undulatory variations. The continuous mineralogical gradients without large gaps define a large zoned magma system in the pre-eruptive, later precollapse and postcollapse magma chambers respectively. The zigzagged variations reflect the intermittent eruptive pulses representing any time gaps.

• Journal of the Korea Concrete Institute
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• v.20 no.6
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• pp.689-696
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• 2008

The purpose of this study was to evaluate the alkali-silica reactivity for aggregates in Korea according to test methods: accelerated mortar bar test (AMBT) by ASTM C 1260; chemical test by KS F 2545 (ASTM C 289). The results are as follows: The AMBT (ASTM C 1260) results showed that two (2) igneous rocks (two mica granite and felsite), three (3) sedimentary rocks (arkose, red sandstone and shale), two (2) metamorphic rock (slate and vitric tuff), one (1) mineral (quartz) showed more expansion than 0.1% at 14 days. But, some sedimentary rocks and metamorphic rocks expanded more than 0.1% at 28 days even though they were less than 0.1% at 14 days. Therefore, it is necessary to extend the experimental dates more than 14 days to evaluate the possibility of alkali-aggregate reactivity. The chemical test (KS F 2545) results showed that five (5) igneous rocks (andesite, diabase, granite porphyry, muscovite granite and diorite) were indicative of potentially deleterious expansion, while two (2) igneous rocks (diorite porphyry and quartz porphyry) were possible indicative of expansion, and three (3) igneous rocks (biotite granite, two mica granite and felsite) were indicative of innocuous reactivity. The above results showed that the results from chemical method (KS F 2545) and AMBT (ASTM C 1260) had little relationship.

• Korean Journal of Heritage: History & Science
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• v.43 no.3
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• pp.122-143
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• 2010

The Shilla Stone Monument in Jungseongri was found during the road-construction in Pohang. It has approximately two hundreds of letters inscribed on the surface of one side, and it is estimated to be older than Shilla Stone Monument in Naengsuri which had been known for the oldest stele in Shilla Period. This monument is made of fine to medium-grained biotite granite, while the Shilla Stone Monument in Naengsuri is made of fine-grained granodioritic porphyry bearing feldspar and amphibole phenocrysts. Both rock types of the monuments are interpreted to be cognate with biotite granite in Shinkwangmyeon, and with granodioritic porphyry in Gigyemyeon. They are characterized by xenolith and miarolitic cavity. Damage aspects in both monuments are discoloring, cracking and breaking. These damages do not cause structural instability of the monuments, but attenuate aesthetic value. Black and brown discoloring contaminants on the surface of the Jungseongri Monument contain a high amount of manganese and iron. As a result of ultrasonic test, both monuments were evaluated to be medium-weathered (MW), although the velocity of the Shilla Monument in Jungseongri was slightly lower than the Shilla Monument in Naengsuri. This is because the Monument in Juengseongri had been exposed to outdoor environment for long time until the discovery. It is necessary for Shilla Monuments to be protected by appropriately environmental control and management.

• Economic and Environmental Geology
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• v.30 no.6
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• pp.603-612
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• 1997

Cretaceous sedimentary-volcanoclastic formations of the Kyeongsang Supergroup were intruded by granitic rocks in the late Cretaceous and early Tertiary. In the Euiseong and Shinryeong area, these intrusives have various compositions including gabbro, diorite，biotite granite and feldspar porphyry. Associated volcanic rocks consist of two chemically distinct types: the bimodal suite of basalt and rhyolite in the Keumseongsan caldera, and the felsic suite of andesite and rhyolite in the Sunamsan-Hwasan calderas. Most rocks are subalkaline, and follow a typical differentiation path of the calc-alkaline magma. The granitic rocks can be distinguished chemically from the volcanics by high Zr/Y ratios. Differences in Zr/Y and K/Y ratios between the two volcanic suites can be accounted for by mantle source and fractionation. Chondrite-normalized trace element abundances of granitic rocks are depleted in Th and K, whereas those of the Keumseongsan rhyolites are depleted in Sr and Ti. Rb, La and Ce is enriched in rhyolites of the Sunamsan-Hwasan calderas. $Rb-SiO_2$ and Rb-Y+Nb discrimination diagrams suggest that the intrusives and volcanics have a volcanic arc setting. K-Ar ages indicate four plutonic episodes : diorite (89 Ma), granite (66~62 Ma), granite and porphyry (55~52 Ma) and gabbro (52~45 Ma), and two volcanisms : bimodal basaltic and rhyolitic volcanism (71~66 Ma) in the Keumseongsan caldera, and felsic andesitic and rhyolitic volcanism (61~54 Ma) in the Sunamsan-Hwasan calderas. Geochemical and age data thus suggest that the igneous rocks are related to several geologic episodes during the late Cretaceous to early Tertiary.