• 지질공학
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• 제25권4호
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• pp.499-510
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• 2015

이 연구에서는 울릉도에 분포하는 현무암질 각력암과 조면암, 화산각력암의 풍화특성을 울릉도의 기후조건을 고려하여 설계한 인공풍화가속실험을 이용하여 고찰하였다. 암석 시료는 XRF 결과를 이용하여 도시한 TAS diagram에 따라 화산암 종류를 판별하고 XRD 분석으로 조성광물을 확인한 후, 시료를 일차적으로 구분하였으며, 이차적으로 흡수율에 의해 시료의 풍화정도에 따라 구분하였다. 인공풍화가속실험 결과, 흡수율 증가는 대부분의 시료에서 발생하였으나, 화산각력암을 제외한 대부분의 시료에서는 강도 저감이 발생하지 않았다. 특히, 조면암의 초기 흡수율이 크면 인공풍화가속실험에 따른 흡수율 증가률이 더욱 증대되었으며, 화산각력암은 기타 암석보다 높은 흡수율 증가와 점하중강도 감소를 보여주고 있다. 이러한 실험 결과로 조면암의 화학적 풍화속도가 시간에 따라 가속될 수 있다는 것을 예측할 수 있고, 화학 및 물리적 풍화에 대한 저항성이 약한 화산각력암은 짧은 시간에서도 감소가 발생할 수 있다는 것을 파악할 수 있었다. 따라서, 이러한 암석들이 분포하고 있는 일주도로에서는 낙석 및 산사태와 같은 자연재해에 대한 대책이 필요한 것으로 판단된다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.667-672
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• 2005

The uncemented breccia consisted of conglomerate and breccia, which are not originated from volcanic clastics, shows wide variation of engineering properties depending on the characteristics of matrix of the uncemented breccia. These uncemented breccia have breccia and matrix irregularly distributed according to their depth and position. Clay minerals are also included in the matrix of these uncemented breccia, so they are expected to show expansive behavior and weakness against weathering process. In this study, the volumetric ratio of breccia on the cores had been calculated using digital image processing technique (performed on recovered core box and their sections). The 3-axial compressional strength test had been done with a shaping of rapid cooling method, and the shear strength (c, ${\phi}$) of uncemented breccia due to the breccia content had been calculated by applying BIMROCK model curve suggested by Goodman. A reliable analysis on the engineering properties of uncemented breccia had been also possible by using borehole density logging and borehole loading test for the accurate determination of the unit weight and the deformation constants deformation modulus.

• 암석학회지
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• 제16권2호
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• pp.73-81
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• 2007

경상북도 포항시 장기지역의 제3기 장기분지에는 제 3기 장기층군의 상부현무암질응회암이 넓게 분포하고 있으며, 그 가운데에 연일현무암이 단속적으로 산출되고 있다. 본 연구의 목적은 이들 현무암질암의 산상과 암상의 조사를 통하여 그 형성과정을 밝히는데 있다. 야외조사 결과 본역의 현무암질암은 다음과 같이 크게 4가지 특징적인 암상으로 구분된다: (1) sideromelane shard hyaloclastite, (2) pillow breccia, (3) entablature-jointed basalt, 그리고 (4) in situ breccia. 본역에서 관찰되는 현무암질암의 여러 특징에 의하면 장기지역의 장기분지에 분포하는 상부현무암질응회암은 hyaloclastite에 해당하며. 현무암질 용암의 수저분출 후 일어난 비폭발성 급랭 파쇄작용에 의해서 형성된 것으로 추론된다.

• 자원환경지질
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• 제21권4호
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• pp.335-348
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• 1988

The author aimed to describe the volcano-stratigraphy and petrology of the volcanic mass in the Koheung peninsula, South Cheolla province. The volcanic mass is composed of the volcanics and intrusives of late Cretaceous which extruded the Pre-cambrian metamorphic(Jirisan gneiss complex) and the early Cretaceous sedimentary(Duwon Formation) basement. The volcanic pile consists of, in ascending order, Bibongsan andesite, Koheung tuff and breccia, and Palyeongsan welded tuff, and are intruded by ring intrusives( intrusive breccia, andesite porphyry, intrusive rhyolite and fine-grained quartz-diorite) and central pluton(diorite, quartz monzodiorite, biotite granite and micrographic granite). Bibongsan andesite mainly consists of andesite tuff and lava. Koheung tuff consists of alternation of fine tuff, coarse tuff and lapilli tuff, and Palyeongsan welded tuff which overlies Koheung tuff, comprises K-feldspar and quartz phenocrysts, elongated brown fiamme, lithic fragments in matrix of devitrified brown glass shards, and mainly consists of rhyodacite to rhyolite vitric ash-flow tuff. The results of petrochemical studies of the igneous rocks suggest that the rocks were a serial differentiational products of fractional crystallization of calc-alkaline magma series. This study reveals that the volcanic mass in this area is inferred to the remnant of the resurgent cauldron, measuring 30 by 25 km in diameter. The cauldron block was lowered at least 1,000 m by ring fault displacement.

• 암석학회지
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• 제2권2호
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• pp.156-166
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• 1993

부산시 남부일원에 분포하는 백악기 화산암류에 대한 화산층서 및 각 암층별 화학성분 변화 그리고 화산활동의 양상을 고찰한 결과, 본역에 분포하는 중성화산암류는 안산암질 화성쇄설암 (pyroclastic rocks)과 안산암으로 구분되며, 이들은 서로 호층을 이루며 두터운 층후의 화산암누층을 형성하는 다윤회 성층화산체의 구성물이다. 안산암류는 반정광물로 휘석(augite), 사장석 및 각섬석이 나타나며 석기는 휘석, 자철석, 각섬석, 인회석 그리고 유색광물의 변질광물인 녹니석, 녹염석, 견운모, 철광립 등으로 구성되어있다. 국부적으로 안산암질 화산암누층의 상부에는 데이사이트질 화산각력암과 유문암질 용결회류응회암(welded ash-flow tuff) 등이 분출 피복하고 있다. 선행연구(부산·가덕도폭)에서 안산암질 각력암 또는 안산암으로 기재한 화산암류들은 화학성분에 따라 구분해 보면 현무암에서 현무암질 안산암, 안산암, 데이사이트 및 유문암의 성분영역에 해당된다. 본역의 화산암류는 칼크-알칼리 계열의 성분변화를 나타내며, 본역에 가장 광범위하게 분포하는 안산암류는 조산대 안산암(Oroge-nic andesite)에 속한다.

• 자원환경지질
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• 제26권4호
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• pp.445-454
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• 1993

The Keumseongsan caldera is composed of the Cretaceous sedimentary rocks of the Gyeonesang Supergroup, volcanic rocks of the Yucheon Group and basic dykes. The Keumseongsan caldera is formed by subsidence of volcanic rocks, and arc fault developed late. Also, synistral strike-slip fault ($N60^{\circ}W$) developed. Volcanic rocks belong to subalkaline rocks and calcalkaline magma series. First tuffaceous breccia erupted before 71.4 Ma and cavity of magma chamber caused subsidence, which formed arc fault. Basaltic lava erupted at 71.4 Ma and residual fluids containing Fe, As, Pb, Zn and Cu metal elements built the Ohto deposits, which are dated to be 70.5 Ma based on K-Ar age for sericite. Tuffaceous breccia and tuff erupted between 70.5 and 67 Ma. When volcanic eruption became weakened, cavity in site of magma chamber brought subsidence. Rhyolite intruded and erupted at 67 Ma, and intrusive rhyolite intruded according to arc faults, also. Hydrothermal fluids containing Fe, As, Pb, Zn, Cu, Sb, Bi, Au and Ag formed the Tohyeon deposits. K-Ar age for sericite from the Tohyeon mine gives 66.0 Ma. Results of field exploration, geochemical analyses of volcanic rocks support mineralization possibility by volcanism. Especially, age of volcanism and mineralization are well in coincidence with results of K-Ar age dating. By these results, Ohto Cu mineralization is regarded to be associcated with basaltic rocks, while Tohyeon Cu mineralization with rhyolitic rocks.

• 광물과 암석
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• 제34권4호
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• pp.293-311
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• 2021

부산광역시 남해안에 위치한 행정자치구 영도(Yeongdo island) 봉래산 일원을 구성하는 화산암류는 안산암질~유문암질암으로 구성된다. 안산암질암은 주로 화산각력암으로 구성되며, 반정으로 사장석을 가지며 다량의 암편(岩片)을 함유하고 있다. 유문암질암은 산출형태에 따라 봉래산 기저부는 화산각력암으로 구성되며, 용결응회암이 봉래산 주산체를 이룬다. 육안으로 피아메 구조를 관찰할 수 있고, 고도가 높아질수록 용결구조는 약하게 발달하고 응회암을 구성하는 암편 및 결정 함량은 적어진다. 본 연구지역을 형성한 마그마는 섭입작용과 관련된 대륙연변부의 조구조 환경과 관련 있으며, 약간의 대륙지각의 혼염과 동시에 분별결정작용을 겪은 뒤 분출하였음을 지시한다. 고도별 주원소를 분석한 결과, 최소 4회 이상의 마그마 배취(magma batches)가 주입되어 혼합이 일어난 결과로 생각된다.

• 자원환경지질
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• 제14권1호
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• pp.35-49
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• 1981

The studied area is largely occupied by thick piles of the late Cretaceous volcanic rocks of the Yucheon group, which is northeastern border part of the vast volcanic region in the Yucheon basin. The Yucheon group overlies the Geoncheonri Formation and is intruded by granitic and dioritic stocks and dykes. The group can be devided into two parts; the lower is Jusasan andesitic rocks which was called as Jusasan Porphyrite Formation by Tadeiwa in 1929, and the upper is Unmunsa rhyolitic rocks. The volcanic pile consists mainly of various tuffs such as tuff breccia, lapilli tuff, coarse to fine tuff and tuffaceous sediments, and interlayered flows, which range from basaltic andesite to rhyolite in their lithology. The results of petrochemical and volcanostratigraphic studies on the Jusasan andesitic socks suggest that the volcanic rocks were derived from two cyclic evolutions of magmatic fractionation. Systematic study of 5226 joints from the area reveals two sets of steep joints striking $N20^{\circ}-40^{\circ}E$ and $N40^{\circ}-70^{\circ}W$, are dominant and coincide with the fault pattern developed in the area. Three defferent maximum principal stress axes were recognized from conjugate shear joints, which are trending east-west, north-northwest, and north-northeast.

• 자원환경지질
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• 제32권6호
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• pp.645-651
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• 1999

The gravity and magnetic measurements have been obtained from 34 stations with 50m intervals along the survey line positioned between Jangtanri and sindapri for studying subsurface geology and structures of the volcanic rocks in Yeoncheon area. The Bouguer gravity and magnetic anomaly values were evaluated from the reduction of the field observation, and then interpreted by Nettleton's method and maximum-pepth rules, are approximately 160m based on magnetic data and 135m based on gravity data. High Bouguer gravity anomaly zone between 0m in Jangtanri and 900m along the survery line, is caused by thick and high density, older dasalt which is positioned beneath jijangbong tuff breccia, and this result corresponds to the interpretation result based on magnetic anomly. Lower gravity and magnetic anomaly zones ariund 900m are caused by between 1300m and 1550m are caused by high density of Quarternary basalt exposed in the surface, and lower gravity and magnetic anomalies at 200m and 1250m are caused by faults.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.135-137
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• 2003

The purpose of this preliminary study is the applied to geology using the Landsat TM satellite image of the Tanggung area of southern part of the Bandung, Indonesia to provide basic information for geological survey. For this, topography, geology and satellite image were constructed to spatial database. Digital elevation, slope, aspect, curvature, hill shade of topography were calculated from the topographic database and lithology was imported from the geological database. Lineament, lineament density, and NDVI were extracted the Landsat TM satellite image. The results showed the close relationship between geology and terrain and satellite image. Each sedimentary rock seldom corresponds with geology and analyses of topography but as a whole for sedimentary rocks coincide with them. Tuff and volcanic breccia in the volcanic rocks correspond with the result of terrain analyses. Talus deposits is well matched with the analyses of opography/satellite image.