Detrital Mica : Abundance Distribution and Grain Surface Textures in Continental Margin Sediments off the Mid-Atlantic U.S.

Yong Ahn Park(朴龍安),Orrin H. Pilkey 대한지질학회 1982 지질학회지 Vol.18 No.2

Petrology of Silica Cementation in Some Sandstones of the Dongjeom Quartzite, Joseon Supergroup, Sangdong Region, Kwangweondo, Korea

Yong Ahn Park(박용안) 대한지질학회 1992 지질학회지 Vol.28 No.3

Petrography and Depositional Environments of the Triassic Border Conglomerates in New Jersey

YONG AHN PARK(朴龍安) 대한지질학회 1967 지질학회지 Vol.3 No.1

Size Distribution of Suspended Particulate Materials in the Southern East Sea of Korea

박용안,김경렬,최진용,박수철,Park, Yong Ahn,Kim, Kyung-Ryul,Choi, Jin Yong,Park, Soo Chul The Korean Society of Oceanography 1988 韓國海洋學會誌 Vol.23 No.2

Size distribution of suspended particulate materials (SPM) in the coastal waters of eastern Korea was studied using a laser particle size analyzer. Mean particle size (MPS) ranges from 3.69 to 8.40 ${\mu}m$ in surface waters, from 3.38 to 6.43 ${\mu}m$ in mid-depth waters, and from 3.88 to 8.30 ${\mu}m$ in near-bottom waters. For smaller MPS, the size distribution is unimodal, whereas it becomes polymodal as the MPS increases. Particle concentrations increased with the increases in MPS, suggesting that processes of adding larger particles in the waters such as resuspension of bottom sediments are more important in controlling MPS in the area than processes of removing smaller particles such as flocculation of fine particles. Observations of higher MPS near the coast in mid-depth waters, and at the continental slope in near-bottom waters appear to support the above idea. For surface waters with high MPS, mean particle density was noticably low, indicating the importance of biological activities in the formation of suspended particles.

한국 서남해 함평만 조간대 퇴적층의 제4기 후기 층서 연구

박용안,임동일,최진용,이영길,Park, Yong-Ahn,Lim, Dhong-Il,Choi, Jin-Yong,Lee, Young-Gil 한국해양학회 1997 바다 Vol.2 No.2

한반도 서남 해역에 위치한 함평만(전라남도 함평군) 조간대 퇴적층의 제 4기 후기 층서와 퇴적학적 연구를 위하여 총 37 지점에서 평균 3 m 깊이(최대 5.2 m)의 시추가 실시되었다. 채취된 퇴적물 시료의 입자 조직(grain texture), 퇴적 구조(sedimentary structure), 색(color) 및 광물 조성(mineral composition) 등을 토대로 10개의 퇴적상(sedimentary facies)이 분류되었다. 분석 결과에 의하면, 함평만 조간대 퇴적분지의 층서는 상위로부터 순차적으로 층서단위 Unit I, Unit II 및 Unit III로 구성된다. 최상위의 층서단위 Unit I은 조립질 퇴적상인 비조직 사질역 퇴적상(Facies SGd)과 괴상 역질 이토 퇴적상(Facies GMm) 또는 세립질 퇴적상인 엽층리 실트 퇴적상(Facies Zp), 괴상 이토 퇴적상(Facies Mm) 및 평행 엽층리 이토 퇴적상(Facies Mp)으로 구성되며, 상향 조립화의 특정을 나타낸다. 이 퇴적층은 해수면이 거의 현재의 위치에 도달된 지난 약 4.000년 동안 형성된 후기 현세(late Holocene) 해침 퇴적층으로 해석된다. Unit I에 의하여 부정합적으로 피복되는 층서단위 Unit II는 준 고화된 황색 이토 퇴적상 (Facies Mym)과 회색의 미고결된 니질 퇴적상(Facies Mgm)으로 구성되며, 수평적 연속성이 양호하고, 함평만 전체에 광역적으로 분포한다. Unit II는 서해의 여러 조간대에서 보고된 간월도층과 대비되는 것으로 여겨지며, 후기 플라이스토세(late Pleistocene)의 조간대 퇴적환경에서 집적된 퇴적층으로 해석된다. 이러한 Unit II에는 지난 최대 빙하기 동안 대기중에 노출된 다양한 증거(황갈색, 고화상태, 동토구조, 점토광물의 함량 변화등) 들을 함유한다. Unit II에 의하여 부정합적으로 피복되는 Unit III는 역질의 층리를 갖는 조립의 퇴적물(Facies SGb와 Facies Sx)로 구성되며 내만역의 한정된 지역(후동과 시목동 해역)에 분포한다. 퇴적학적 특성과 지역적인 분포 양상을 고려할 때, Unit III는 육성 환경(nonmarine deposits)의 하천 퇴적물(fluvial sediment)로 해석된다. 결과적으로 함평만 조간대 퇴적분지의 층서(최고기로부터 최신기)는 기반암 지층(중생대 화강암)${\rightarrow}$육성 퇴적층(Unit III)${\rightarrow}$후기 플라이스토세의 니질 조간대 퇴적층(Unit II)${\rightarrow}$후기 현세의 조간대 퇴적층(Unit I)의 층서이며, 각각의 층서단위의 경계는 부정합적이다. The late Quaternary stratigraphy of the tidal deposits in the Hampyung Bay, southwestern coast of Korea comprises 1) Unit III (nonmarine fluvial coarse-grained sediments), 2) Unit II (late Pleistocene tidal deposits), and 3) Unit I (late Holocene fine-grained tidal deposits) in ascending order. The basements of the Hampyung Bay is composed of granitic rocks and basic dyke rocks. These three units are of unconformally bounded sedimentary sequences. The sequence boundary between Unit I and Unit II, in particular, seems to be significant suggesting erosional surface and exposed to the air under the cold climate during the LGM. The uppermost stratigraphic sequence (Unit I) is a common tidal deposit formed under the transgression to highstand sea-level during the middle to late Holocene.

韓半島 南東海域 大陸棚 海底에서의 第四期 後期의 推積作用

박용안,Park, Yong-Ahn The Korean Society of Oceanography 1985 韓國海洋學會誌 Vol.20 No.3

Two hundred suspended-matter samples were collected from the continental shelf off the southeast coast of Korea during September, 1981, March, 1982 and April 1983. Superficial bottom sediments on the shelf were also taken. Based on the alalyses of TSM distribution and concentration patterns, it is considered that finegrained suspended matters are restricted to nearshore-inner shelf showing a band or zone paralleling with coastal morphology. This fact suggests a limitation of "modern" fine grained sediments to a nearshore and inner shelf band. The sand deposits with the lower value of mud content (<5%) adjacent to the shelf break and on the outer shelf would probably be "relict" sediments (old beach sediments) deposited in response to a lower stand of sea level during the Pleistocene ice age. The transgression did little to alter the distribution of sand on the outer shelf in this particular study area. The progress of shore line was so rapid that a given locality was in the beach zone and subject to rapid longshore drift and extensive reworking only for a few years. Probably the most pronounced effect of the transgression was sorting of the sand, and at least partial winnowing out of the finer fractions.

光陽灣의 堆積環境에 관한 硏究

박용안,이창복,최진혁,Park, Yong Ahn,Lee, Chang-Bok,Choi, Jin Hyuk 한국해양학회 1984 韓國海洋學會誌 Vol.19 No.1

The Gwangyang Bay, southern coast of Korea, is characterized by its semi-enclosed basin morphology and mesotidal regime. The Seomjin River, in particular, has a complex delta depositional system at its mouth, which has approximately 44$\textrm{km}^2$ in the total surface area. Various sedimentary environments, such as delta, intertidal flat, subtidal zone and major tidal channels are recognized based on sediment facies and depositional regime. However, the essential intertidal flat environments are developed mainly in the western parts of the bay which is generally low in energy, i, e. tidal current and wave action.

Sea Level Fluctuation in the Yellow Sea Basin

박용안,김부근,자오송링,PARK, YONG AHN,KHIM, BOO KEUN,ZHAO, SONGLING The Korean Society of Oceanography 1994 韓國海洋學會誌 Vol.29 No.1

A series of radiocarbon dating from intertidal, subtidal, and inner continental shelf deposits investigated along the west coast of Korea as well as from its offshore sea floor (namely, the eastern Yellow Sea Basin) how (1) the Holocene sea level rise, i.e., the ecstatic sea-level history during the oxygen isotope stage 1, and (2) pre-Holocene sea-level fluctuations during the oxygen isotope stages 2 and 3. Marine geophysical investigations in the Yellow Sea reported a possible development of desert and loses deposits due to dieselization under the cold and dry climate during the Last Glacial Maximum. The Kanweoldo deposit overlain unconformably by the Holocene intertidal deposits, which is mainly exposed along the tidal channels and intertidal flats in the Cheonsu Bay, the west coast of Korea, shows the characteristic cryogenic structure (cryoturbation). Such cryoturbation structure of the Kanweoldo deposit appears to indicate the cold and dry climate under the ecstatic sea-level paleoshoreline standing before and after of the pre-Holocene interstitial period (about 30000 y BP is suggested and its shoreline curve is constructed.

한반도 동남해역 대륙붕 표층퇴적물의 요인분석과 그 퇴적역사

박용안,최진용,Park, Yong-Ahn,Choi, Jin-Yong 한국해양학회 1986 韓國海洋學會誌 Vol.21 No.1

A Q-mode factor analysis for 115 surficial bottom sediments on the continental shelf off the southeast coast of Korean Peninsula(the Korea Strait) has been carried out to determine the depositional environments. The first four factors are taken as the "principal" factors, and the results are considered to represent the depositional history and sedimentary processes in relation to the Holocene sea-level changes. The fact implies that the sediments are grouped as outer-shelf relict sand sediments, inner-shelf modern muddy sediments, and finally the palimpsest sediments that are mainly distributed within and around the Korea Trough.

韓國 西海岸 서산만에 發達한 一部 潮間帶 堆積層에 대한 堆積學的 硏究와 第四紀 海洋地質學的 考察

박용안,이일상,Park Yong-Ahn,Lee Il-Sang 한국제4기학회 1987 제사기학회지 Vol.1 No.1

干潮線 부근에 發達한 堆積層과 砂質堆積相은 특징적 퇴적입자 조직특성을 나타내며 堆積메카니즘에 따른 干潮堆積環境의 지시적 퇴적구조를 포함하고 있다. 또한 滿潮堆積層과 堆積相이 干潮堆積環境의 특징과는 다르며 滿潮堆積層特有의 퇴적구조가 발달함을 규명하였다. 混合潮間帶 堆積相이 干潮線과 滿潮線사이의 部分에 해당하는 潮水環境에 발달하녀 이에따른 특유의 퇴적구조가 발달한다는 사실이 규명되었다. 現世 海水面上昇의 過程中 約 9000~8500 y B.P.의 시기는 西海岸의 다른 여러 潮間帶環境 發達 初期에 해당하는 것과 마찬가지이며 本 硏究地域의 潮間帶堆積層의 主된 堆積時間은 約 8000年 동안으로 해석된다. In the present study area, a part of intertidal flat in the Seosan Bay, west coast of Korea, characteristic three dominant tidal sedimentary facies and their related several typical sedimentary structures are described, Furthermore, a possible interpretation about the time stratigraphic developments of these intertidal deposits is suggested by introducing very late Quaternary (Holocene) sea-level rise in Korean Seas.