• 자원환경지질
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• 제15권3호
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• pp.123-154
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• 1982

Petrochemical, K-Ar dating, Sand Rb/Sr isotopes, metallogenic zoning, paleomagnetic and geotectonic studies of the Gyongsang basin were carried out to examine applicability of plate tectonics to the post-late Cretaceous igneous activity and metallogeny in the southeastern part of Korean Peninsula. The results obtained are as follows: 1. Bulgugsa granitic rocks range from granite to adamellite, whose Q-Ab-Or triangular diagram indicates that the depth and pressure at which the magma consolidated increase from coast to inland varying from 6 km, 0.5-3.3 kb in the coastal area to 17 km, 0.5-10 kb in the inland area. 2. The volcanic rocks in Gyongsang basin range from andesitic to basaltic rocks, and the basaltic rocks are generally tholeiitic in the coastal area and alkali basalt in the inland area. 3. The volcanic rocks of the area have the initial ratio of Sr^{87}/Sr^{86} varying from 0.706 to 0.707 which suggests a continental origin; the ratio of Rb/Sr changing from 0.079-0.157 in the coastal area to 0.021-0.034 in the inland area suggests that the volcanism is getting younger toward coastal side, which may indicate a retreat in stage of differentiation if they were derived from a same magma. The K_2O/SiO_2 (60%) increases from about 1.0 in the coastal area to about 3.0 in the inland area, which may suggest an increase indepth of the Benioff zone, if existed, toward inland side. 4. The K-Ar ages of volcanic rocks were measured to be 79.4 m.y. near Daegu, and 61.7 m.y. near Busan indicating a southeastward decrease in age. The ages of plutonic rocks also decrease toward the same direction with 73 m.y. near Daegu, and 58 m.y. near Busan, so that the volcanism predated the plutonism by 6 m.y. in the continental interior and 4 m.y. along the coast. Such igneous activities provide a positive evidence for an applicability of plate tectonics to this area. 5. Sulfur isotope analyses of sulfide minerals from 8 mines revealed that these deposits were genetically connected with the spacially associated ingeous rocks showing relatively narrow range of ${\delta}^{34}S$ values (-0.9‰ to +7.5‰ except for +13.3 from Mulgum Mine). A sequence of metallogenic zones from the coast to the inland is delineated to be in the order of Fe-Cu zone, Cu-Pb-Zn zone, and W-Mo zone. A few porphyry type copper deposits are found in the Fe-Cu zone. These two facts enable the sequence to be comparable with that of Andean type in South America. 6. The VGP's of Cretaceous and post Cretaceous rocks from Korea are located near the ones($71^{\circ}N$, $180^{\circ}E$ and $90^{\circ}N$, $110^{\circ}E$) obtained from continents of northern hemisphere. This suggests that the Korean peninsula has been stable tectonically since Cretaceous, belonging to the Eurasian continent. 7. Different polar wandering path between Korean peninsula and Japanese islands delineates that there has been some relative movement between them. 8. The variational feature of declination of NRM toward northwestern inland side from southeastern extremity of Korean peninsula suggests that the age of rocks becomes older toward inland side. 9. The geological structure(mainly faults) and trends of lineaments interpreted from the Landsat imagery reveal that NNE-, NWW- and NEE-trends are predominant in the decreasing order of intensity. 10. The NNE-trending structures were originated by tensional and/or compressional forces, the directions of which were parallel and perpendicular respectively to the subduction boundary of the Kula plate during about 90 m.y. B.P. The NWW-trending structures were originated as shear fractures by the same compressional forces. The NEE-trending structures are considered to be priginated as tension fractures parallel to the subduction boundary of the Kula plate during about 70 m.y. B.P. when Japanese islands had drifted toward southeast leaving the Sea of Japan behind. It was clearly demonstrated by many authors that the drifting of Japanese islands was accompanied with a rotational movement of a clock-wise direction, so that it is inferred that subduction boundary had changed from NNE- to NEE-direction. A number of facts and features mentioned above provide a suite of positive evidences enabling application of plate tectonics to the late Cretaceous-early Tertiary igneous activity and metallogeny in the area. Synthesizing these facts, an arc-trench system of continental margin-type is adopted by reconstructing paleogeographic models for the evolution of Korean peninsula and Japan islands. The models involve an extention mechanism behind the are(proto-Japan), by which proto-Japan as of northeastern continuation of Gyongsang zone has been drifted rotationally toward southeast. The zone of igneous activity has also been migrated from the inland in late-Cretaceous to the peninsula margin and southwestern Japan in Tertiary.

• 자원환경지질
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• 제30권4호
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• pp.279-289
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• 1997

Dark to pale green-colored, Cr-bearing sericites from hydrothermal alteration zone of the Narim gold deposit were investigated mineralogically and geochemically. The alteration zone is composed mineralogically of quartz, carbonate minerals and green sericite with minor amounts of chlorite, barite and sulfide minerals (pyrite, sphalerite, galena). The zone is enriched in As (967 to 1520 ppm), Cu (31 to 289 ppm), Ni (1027 to 1205 ppm), Pb (0.20 to 1.24 wt.%) and Zn (1.03 to 1.07 wt. %) compared with fresh rocks such as granitic gneiss, porphyritic biotite granite and basic dyke. The Cr, probably the chromophore element, is highly enriched in the alteration zone (1140 to 1500 ppm), host granitic gneiss (1200 ppm) and porphyritic biotite granite (1200 ppm). Occurrence and grain size of sericite are diverse, but most of the Cr-bearing sericites (150 to $200{\mu}m$ long and 20 to $30{\mu}m$ wide) occur along the boundaries between ore veins and host rocks (especially basic dyke and granitic gneiss). X-ray diffraction data of the sericite show its monoclinic form with unit-cell parameters of $a=5.202{\AA}$, $b=8.994{\AA}$, $c=20.103{\AA}$, ${\beta}=95.746^{\circ}$ and $V=935.83{\AA}^3$, which are similar with the normal 2M1-type muscovite. Representative chemical formula of the sericite is ($K_{1.54}Ca_{0.03}Na_{0.01}$)($Al_{3.42}Mg_{0.38}Cr_{0.14}Fe_{0.06}V_{0.02}$)($Si_{6.69}Al_{1.31}$)$O_{20}(OH)_4$. The Cr content increases with decrease of the octahedral Al content, and ranges from 0.36 to 2.58 wt.%. DTA and TG curves of the sericite show endothermic peaks at $342^{\circ}$ to $510^{\circ}$, $716^{\circ}$ to $853^{\circ}$ and $1021^{\circ}C$, which are due to the expulsion of hydroxyl group. The total weight loss by heating is measured to be about 8.8 wt. %, especially at $730^{\circ}C$. Infrared absorption experiments of the sericite show broad absorption band due to the O-H bond stretching vibration near the $3625cm^{-1}$, coupled with the 825 and $750cm^{-1}$ doublet. The vibration bands related with the H-O-Al and Si-O-Al bonds occur at $1030cm^{-1}$ and 500 to $700cm^{-1}$, respectively. Based on paragonite content of the sericite, the formation temperature of the Narim gold deposit is calculated to be $220{\pm}10^{\circ}C$.

• 한국환경보건학회지
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• 제49권5호
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• pp.251-261
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• 2023

Background: This paper deals with the study of natural radioactivity in rocks from Ogun State in Southwestern Nigeria. The aim is to determine radiation emissions from rocks in order to estimate radiation hazard indices. Objectives: The following objectives were targeted: 1. To determine radiation emissions from each type of rocks; 2. To estimate radiation hazard indices based on the rocks; 3. To correlate the activity concentrations of radionuclides with major oxides. Methods: The samples were analyzed using a NaI (Tl) gamma ray spectrometric detector and PerkinElmer AAnalyst 400 AAS spectrometer. Results: The activity of ⁴⁰K, ²²⁶Ra, and ²³²Th were found in order of decreasing magnitude from pegmatite>granite>migmatite. In contrast, lower concentrations were found in shale, phosphate, clay stone, sandstone and limestone. The mean absorbed doses were 125±23 nGyh^-1 (migmatite), 74±13 nGy/h (granite), 72±13 nGyh^-1 (pegmatite), 64±09 nGyh^-1 (quartzite), 45±16 nGyh^-1 (shale), 41±09 nGyh^-1 (limestone), 41±11 nGyh^-1 (clay stone), 24±03 nGyh^-1 (phosphate), and 21±10 nGyh^-1 (sandstone). The outdoor effective dose rates in all rock samples were slightly higher than the world average dose value of 0.34 mSvy^-1. The percentage composition of SiO₂ in the rock samples was above 50 wt% except for in the limestone, shale and phosphate. Al₂O₃ ranged from 4.10~21.24 wt%, Fe₂O₃ from 0.39~7.5 wt%, and CaO from 0.09-46.6 wt%. In addition, Na₂O and K₂O were present in at least 5 wt%. Other major oxides, including TiO₂, P₂O₅, K₂O, MnO, MgO and Na₂O were depleted. Conclusions: The findings suggest that Ogun State may be described as a region with elevated background radiation. It is recommended that houses should be constructed with good cross ventilation and residences should use home radiation monitoring instruments to monitor radon emanating from walls.

• 한국대기환경학회지
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• 제24권4호
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• pp.439-454
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• 2008

The purpose of this study was to extensively identify $PM_{10}$ sources and to estimate their contributions to the study area, based on the analysis of the $PM_{10}$ mass concentration and the associated inorganic elements, ions, and total carbon. The contribution of $PM_{10}$ sources was estimated by applying a receptor method because identifying air emission sources were effective way to control the ambient air quality. $PM_{10}$ particles were collected from May to November 2007 in the Yongin-Suwon bordering area. $PM_{10}$ samples were collected on quartz filters by a $PM_{10}$ high-volume air sampler. The inorganic elements (Al, Mn, V, Cr, Fe, Ni, Cu, Zn, Cd, Pb, Si, Ba, Ti and Ag) were analyzed by an ICP-AES after proper pre-treatments of each sample. The ionic components of these $PM_{10}$ samples ($Cl^_$, $NO_3^-$, $SO_4^{2-}$, $Na^+$, $NH_4^+$, $K^+$, $Ca^{2+}$, and $Mg^{2+}$) were analyzed by an IC. The carbon components (OC1, OC2, OC3, OC4, OP, EC1, EC2 and EC3) were also analyzed by DRI/OGC analyzer. Source apportionment of $PM_{10}$ was performed using a positive matrix factorization (PMF) model. After performing PMF modeling, a total of 8 sources were identified and their contribution were estimated. Contributions from each emission source were as follows: 13.8% from oil combustion and industrial related source, 25.4% from soil source, 22.1% from secondary sulfate, 12.3% from secondary nitrate, 17.7% from auto emission including diesel (12.1%) and gasoline (5.6%), 3.1% from waste incineration and 5.6% from Na-rich source. This study provides information on the major sources affecting air quality in the receptor site, and therefore it will help us maintain and manage the ambient air quality in the Yongin-Suwon bordering area by establishing reliable control strategies for the related sources.

• 한국토양비료학회지
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• 제11권2호
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• pp.75-80
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• 1979

암모니움 탈착(脫着)을 16개(個) 토양에 대하여 $(NH_4)_2HPO_4$를 처리하여 0.01M $CaCl_2$로 7회(回) 연속침출(連續浸出)하여 검토하였다. 1. 탈착(脫着)은 2~4개의 속탈(速脫) 또는 완탈단계(緩脫段階)의 반복(反復)으로 진행(進行)된다. 2. 탈착단계(脫着段階)는 탈착량(脫着量)(y)과 침출회수(浸出回數)(x)간(間)에 log y=b-ax의 관계식(關係式)이 성립(成立)된다. 3. 탈착율(脫着率)(100${\times}$탈착량(脫着量)/흡착량(吸着量))은 15개(個) 토양평균이 65%였고 최고(最高)는 김천통(金泉統)의 87% 최소(最小)는 삼각통(三角統)의 32%였으며 이탄토(泥炭土)인 용호통(龍湖統)은 156%로 토양 ammonium 이 다량방출(多量放出)되었다. 4. 탈착률(脫着率)은 흡착량(吸着量)과 부(否)의 상관을 보이며 이 관계에서 토양은 세개의 계열(系列)로 분류(分類)되었다. 5. 탈착누적곡선(脫着累積曲線)은 최대치(最大値)에 접근(接近)하고 있으며 7회탈착(回脫着)으로 모든 토양이 최대치(最大値)에 접근(接近)하였다. 이때의 흡착량(吸着量)은 CEC의 502%(삼각통(三角統))에서 25%(김해통(金海統))의 범위(範圍)에 있었다. 6. 탈착량(脫着量) 또는 탈착률(脫着率)은 LAMA, (암모니움 Langmuir 최대흡착) CEC, 점토함량(粘土含量), 유효인산, 유기물함량등(有機物含量等)과 아무런 관계가 없었다. 7. 이상(以上)의 결과(結果)들은 ammonium의 흡착(吸着)과 탈착(脫着)에 있어 Fe, Al Si 등(等)의 관련성과 동반음(同伴陰) ion 흡탈착(吸脫着)이 관여함을 강하게 암시하는 것 같다.

• 한국전기전자재료학회논문지
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• 제32권3호
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• pp.201-206
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• 2019

This report constitutes the first demonstration in Korea of single-crystal lateral gallium oxide ($Ga_2O_3$) as a metal-oxide-semiconductor field-effect-transistor (MOSFET), with a breakdown voltage in excess of 480 V. A Si-doped channel layer was grown on a Fe-doped semi-insulating ${\beta}-Ga_2O_3$ (010) substrate by molecular beam epitaxy. The single-crystal substrate was grown by the edge-defined film-fed growth method and wafered to a size of $10{\times}15mm^2$. Although we fabricated several types of power devices using the same process, we only report the characterization of a finger-type MOSFET with a gate length ($L_g$) of $2{\mu}m$ and a gate-drain spacing ($L_{gd}$) of $5{\mu}m$. The MOSFET showed a favorable drain current modulation according to the gate voltage swing. A complete drain current pinch-off feature was also obtained for $V_{gs}<-6V$, and the three-terminal off-state breakdown voltage was over 482 V in a $L_{gd}=5{\mu}m$ device measured in Fluorinert ambient at $V_{gs}=-10V$. A low drain leakage current of 4.7 nA at the off-state led to a high on/off drain current ratio of approximately $5.3{\times}10^5$. These device characteristics indicate the promising potential of $Ga_2O_3$-based electrical devices for next-generation high-power device applications, such as electrical autonomous vehicles, railroads, photovoltaics, renewable energy, and industry.

• 한국지구과학회지
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• 제18권6호
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• pp.500-514
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• 1997

옥천습곡대 중앙부에 해당하는 문경지역예 분포하는 각섬암에 대하여 정밀한 산상, 조직 및 지화학적 성질을 조사하고, 지구조적 환경을 추적했다. 본역의 상내리층(옥천층군)과 석회암층(조선누층군)에 분포하는 각섬암은 변성된 조립현무암질 암상이며 주변암과 조화적로 분포함을 확인했다. 본 연구를 통하여 본 암석의 분포를 이전의 그것에 비해 크게 대선하였다. 상내리 지역을 중심으로 관찰한 암상을 최소한 4매 이상이다. 그 하나는 석회암층 내에 분포하며(Ls Sill, 두께 약 3 m), 나머지는 상내리층 내에 분포한다. 상내리층 내에 분포한 암상들을 하부로부터 각각 First Sill(두께 약 40 m), Second Sill(두께 약 100 m), Third Sill(두께 약 40 m)로 명명했다. 두꺼운 암상은 후기에 관입한 소규모의 암상을 포함하며, Third Sill은 2매의 주 암상과 2매의 소규모 암상으로 구성된다. 각 암상은 주변암과의 접촉부에서 세립질의 냉각대를 가지며, 내측으로 갈수록 입자의 크기가 증가한다. 두꺼운 암상은 다양한 암맥과 중심부에서 힌색의 단편을 가지며, 접촉부에서 중앙부로 감에 따라 화학적 성질도 규칙적으로 변한다. $SiO_2,\;Na_2O,\;K_2O,\;P_2O_5$는 증가하며, $TiO_2,\;FeO^*,\;Al_2O_3,\;CaO$는 감소하는 경향을 보인다. 각섬암의 산상과 화학적 특징을 고려하여, 초기에 관입한 마그마로 생각되는 대표적인 10개의 화학조성을 선택하여 그들의 주성분 및 부성분 변화를 조사하였다. 그들이 보여주는 조성변화는 단일 마그마의 분별결정작용으로 설명할 수 없다. 본 역의 각섬암에 관한 지질분포, 지화학적 특성 및 과거 연구자들의 자료는 각섬암의 원암(현무암질마그마)이 intracontinental rift 환경에서 암상형태로 관입하였음을 지시한다.

• 자원환경지질
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• 제31권4호
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• pp.297-310
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• 1998

Geochemical characteristics of environmental toxic elements at the Narim mine area were investigated on the basis of major, minor, rare earth element geochemistry and mineralogy. Ratios of $Al_2O_3/Na_2O$ and $K_2O/Na_2O$ in soils and sediments range from 11.57 to 22.21 and from 1.86 to 3.93, and are partly negative and positive correlation against $SiO_2/Al_2O_3$ (3.41 to 4.78), respectively. These suggested that sediment source of host granitic gneiss could be due to rocks of high grade metamorphism originated by sedimentary rocks. Characteristics of some trace and rare earth elements of V/Ni (0.33 to 1.95), Ni/Co (2.00 to 6.50), Zr/Hf (11.27 to 53.10), La/Ce (0.44 to 0.55), Th/Yb (4.07 to 7.14), La/Th (2.35 to 3.93), $La_N/Yb_N$ (6.58 to 13.67), Co/Th (0.63 to 2.68), La/Sc (3.29 to 5.94) and Sc/Th (0.49 to 1.00) are revealed a narrow range and homogeneous compositions may be explained by simple source lithology. Major elements in all samples are enriched $Al_2O_3$, MgO, $TiO_2$ and LOI, especially $Fe_2O_3$ (mean=7.36 wt.%) in sediments than the composition of host granitic gneiss. The average enrichment indices of major and rare earth elements from the mining drainage are 2.05 and 2.91 of the sediments and are 2.02 and 2.60 of the soils, normalizing by composition of host granitic gneiss, respectively. Average composition (ppm) of minor and/or environmental toxic elements in sediments and soils are Ag=14 and 1, As=199 and 14, Cd=22 and 1, Cu=215 and 42, Pb=1770 and 65, Sb=18 and 3, Zn=3333 and 170, respectively, and extremely high concentrations are found in the subsurface sediments near the ore dump. Environmental toxic elements were strongly enriched in all samples, especially As, Cd, Cu, Pb, Sb and Zn. The level of enrichment was very severe in mining drainage sediments, while it was not so great in the soils. Based on the EPA value, enrichment index of toxic elements is 8.63 of mining drainage sediments and 0.54 of soils on the mining drainage. Mineral composition of soils and sediments near the mining area were partly variable being composed of quartz, mica, feldspar, amphibole, chlorite and clay minerals. From the gravity separated mineralogy, soils and sediments are composed of some pyrite, arsenopyrite, chalcopyrite, sphalerite, galena, goethite and various hydroxide minerals.

• 한국토양비료학회지
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• 제33권3호
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• pp.205-211
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• 2000

제강슬래그 시용 1년 후 논토양의 토양화학성분 함량, 벼의 생육, 그리고 수량에 대한 제강슬래그의 잔류효과를 밝히려 1997년에 Lim등 (2000)이 설치한 포장 중유정리와 남평의 포장을 그대로 보존하였다가 1998년에 동일품종과 동일재배 방법을 이용하여 벼를 재배하였다. 이앙 후 2주 간격으로 4~6회에 걸쳐 초장과 주당분얼수를 조사하였으며 생육중기와 수확기에 토양 표본을 채취하여 토양의 주요 무기화학성분함량을 조사하였고 수확시 수량 및 수량 구성요소를 조사하였다. 유정리논이나 남평논 모두 비슷한 토양화학성분 함량에서의 변이를 보였다. 제강슬래그 처리구의 토양 pH와 Ca 함량은 7월까지 무처리구에 비하여 유의적으로 높은 값을 보인 후 점차 감소하였으며 제강슬래그 시용 수준이 높을수록 그 지속 기간이 길어지는 경향이어서 토양 Ca의 공급원이나 산성토양개량제로서 제강슬래그의 효과는 2년정도 지속되는 것으로 생각된다. 제강슬래그 $4Mg\;ha^{-1}$ 시용수준의 pH 상승효과는 석회 $2Mg\;ha^{-1}$ 처리보다 다소 높거나 비슷한 경향이었다. $SiO_2$ 함량은 슬래그 시용구에서 무처리구보다 유의하지는 않지만 높은 경향을 보였다. Fe나 Mg 함량은 제강슬래그 시용 1년차에는 무처리구에 비하여 유의적으로 높았으나 2년차에는 점차 무처리구와 비슷한 수준으로 안정되었다. 유정리논 벼의 정조수량은 슬래그 시용수준이 높을수록 증가하는 경향이었다. 석회 $2Mg\;ha^{-1}$ 처리구의 정조수량은 제강슬래그 $4Mg\;ha^{-1}$ 시용수준과 비슷하였다. 최대치를 보인 제강슬래그 $12Mg\;ha^{-1}$ 처리구의 정조수량은 $5,400kg\;ha^{-1}$로 무처리구의 $4,720kg\;ha^{-1}$에 비하여 14%의 증수효과가 있었다. 제강슬래그 $12Mg\;ha^{-1}$ 처리구는 생육초기의 초장생장이 빠르고 생육중기 이후 적정수의 주당 분얼수가 비교적 일정하게 유지되며 수화기의 주당수수는 적은 반면 천립중이 높은 경향이었다. 남평논 벼의 정조수량은 석회 $2Mg\;ha^{-1}$, 제강슬래그 12, 8, $4Mg\;ha^{-1}$, 무처리구의 순으로 많았다. 제강슬래그 처리중 정조수량이 가장 많은 제강슬래그 $12Mg\;ha^{-1}$ 처리의 정조수량은 $7,170kg\;ha^{-1}$로 무처리구의 $6,670kg\;ha^{-1}$에 비하여 8%의 유의적인 증수효과가 있었다. 제강슬래그 $12Mg\;ha^{-1}$ 처리구는 무처리구에 비하여 생육초기의 초장생장은 느린 반면 생육중기 이후의 초장생장이 양호한 생장특성을 보였고 수당립수와 천립중이 유의적으로 많았다.

• 한국토양비료학회지
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• 제19권2호
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• pp.89-97
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• 1986

영남지역(嶺南地域)에 분포(分布)된 단구지토양(段丘地土壤)의 특성(特性)과 생성(生成)을 구명(究明)하기 위하여 영천(永川)(내륙(內陸)) 및 영일(迎日) (해안(海岸))지역(地域)에서 대표적(代表的)인 단구군(段丘群)을 선정(選定)하여 1, 2차광물(次鑛物)의 조성(助成)과 특성(特性)을 토양생성(土壤生成)과 연관시켜 분석(分析)하여 본 결과(結果)는 다음과 같다. 1. 단구퇴적물(段丘堆積物)의 중세사(中細砂)에 함유(含有)된 중광물(重鑛物)은 5% 이하(以下)이었으나 모재(母材)의 불연속성(不連續性)이 예상되는 토층(土層)에서는 9.8~16.2%로 높았고 경험물(輕驗物) 중(中) 장석류(長石類)의 함량(含量)은 영천지역(永川地域)에서 높은 반면(反面)에 석영(石英)은 영일지역(迎日地域)에서 높았으며 석영(石英)/장석비(長石比)도 모재(母材)의 불연속예상토층(不連續豫想土層)은 단구퇴적물(段丘堆積物)과 구분(區分)되었다. 2. 풍화잔사물(風化殘渣物)의 성숙도지수는 영천지역(永川地域)이 76.7~29.9이었으며 영일지역(迎日地域)은 85.6~67.2로서 고위단구(高位段丘) 일수록 높은 경향이었다. 3. 점토(粘土)의 규반비(珪礬比)는 1.93~2.65로서 낮았고, $Al_2O_2/TiO_2$비(比)와 $Fe_2O_3/Al_2O_3$비(比)를 기준(基準)한 모재(母材)는 산성암류(酸性岩類)에 속하였고 모재(母材)의 불연속성(不連續性)도 구별(區別)되었다. 4. X-선회절분석(線回折分析) 및 시차열분석(示差熱分析)에 의한 점토광물(粘土鑛物)은 Kaolin 및 Illite가 주광물(主鑛物)이었고 일부(一部)는 Vermiculite 및 Vermiculite-Illite중간형광물(中間型鑛物) 등(等)이었으며 모재(母材)의 불연속성(不連續性)이 예상(豫想)되는 영천(永川)의 반천통기층(盤泉統基層)에서는 Kaolin함량(含量)이 증가(增加)되었고 영일(迎日)의 우평통기층(牛坪統基層)에서는 Montmorin계광물(系鑛物)이 다량(多量) 검출(檢出)되는 등(等)으로 단구퇴적물(段丘堆績物)과 구별(區別)되었다.