• Title/Summary/Keyword: basin evolution

Search Result 119, Processing Time 0.023 seconds

Analysis on the evolution of water resources situation in Qiandao Lake Basin from 1960 to 2020

  • DU Junkai;Qiu Yaqin
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2023.05a
    • /
    • pp.27-27
    • /
    • 2023
  • To analyze the evolution of water resources in Qiandao Lake Basin under the condition of climate change, a WEP-L distributed hydrological model was established to simulate the water cycle process in the basin during 1960-2020. The Mann-Kendall non-parametric test method and Hurst index method were used to analyze the inter-annual variation and annual distribution characteristics of the total water resources in the basin. The multi-scale temporal and spatial distribution and evolution trend of water resources in Qiandao Lake Basin were evaluated. The results show that: (1) The WEP-L model has good simulation results in the Qiandao Lake basin, and the Nash coefficient rate is above 0.83 in the periodic period and above 0.85 in the verification period. (2) The water yield coefficient of the whole basin ranges from 0.436 to 0.630. The annual average total water resource is 12.25 billion m3, equivalent to 1176.4mm of water depth. The annual distribution process shows a unimodal structure, and the water depth of each sub-basin ranges from 742 mm to 1266 mm, and the spatial distribution is higher in the west and lower in the east. (3) The annual water resources series in the basin showed an insignificant upward trend, and the Hurst index was 0.86, indicating a continuous upward trend. From the perspective of monthly water resources, January and February increased significantly, the other months were not significant changes.

  • PDF

Tectonics, sedimentation, and magmatism of the Cretaceous Gyeongsang (Kyongsang) Basin, Korea: Integrated approach to defining basin history and event mineralization

  • Chang, Ryu-In;Park, Seon-Gyu;Meen, Wee-Soo;Lee, Sang-Yeol
    • Proceedings of the KSEEG Conference
    • /
    • 2003.04a
    • /
    • pp.27-31
    • /
    • 2003
  • During the past decade, integrated stratigraphy has been effectively applied to many sedimentary basins to analyze stratigraphic response to tectonic evolution. This application has been beneficial to hydrocarbon exploration in the basins because it provides a better understanding of temporal and spatial relationships of hydrocarbon source and reservoir rocks as a function of basin evolution. Like the maturation, migration, and trapping of hydrocarbons, ore-forming processes in hydrothermal deposits may be causally linked to particular phases of basin evolution. Consequently, applying integrated stratigraphy to mineral exploration may be a logical and helpful approach to understanding ore-forming processes and predicting their occurrence, location, and origin. (omitted)

  • PDF

Additional Records of the Hydrothermal Vent Scale Worm Branchinotogluma segonzaci (Polynoidae: Lepidonotopodinae) from the North Fiji Basin and Tonga Arc

  • Lee, Won-Kyung;Lee, Geon Hyeok;Ju, Se-Jong;Kim, Se-Joo
    • Animal Systematics, Evolution and Diversity
    • /
    • v.37 no.4
    • /
    • pp.273-279
    • /
    • 2021
  • Branchinotogluma segonzaci (Miura and Desbruyères, 1995) occurs in hydrothermal vent fields of the southwestern Pacific Ocean. We morphologically compared B. segonzaci from the North Fiji Basin with the original description from the Lau Basin and a subsequent study of specimens from the Manus Basin. The main characteristics of all B. segonzaci populations were similar having 21 segments, 10 pairs of elytra, cylindrical-shaped anterior lobes, and ventral papillae on segment 12 and ventral lamellae on segments 13-17 in males. However, the specimens from the North Fiji Basin had rounded to sub-renifrom elytra rather than oval in the original description. Additionally, we newly obtained 11 cytochrome oxidase subunit I (COI) DNA barcodes from the North Fiji Basin and Tonga Arc populations and compared them with known COI DNA barcodes of Branchinotogluma species. Thirteen sequences of B. segonzaci showed 0.0-1.07% intraspecific variation and formed two clades in the COI neighbor-joining tree, whereas the interspecific variation among Branchinotogluma species was 8.19-22.4%. The results of this study contribute to biogeographic studies of B. segonzaci and the evolution of polynoid scale worms in chemosynthesis-based ecosystems.

Basin modelling with a MATLAB-based program, BasinVis 2.0: A case study on the southern Vienna Basin, Austria (MATLAB 기반의 프로그램 BasinVis 2.0을 이용한 분지 모델링: 오스트리아 비엔나 분지의 남부 지역에 대한 사례 연구)

  • Lee, Eun Young;Wagreich, Michael
    • Journal of the Geological Society of Korea
    • /
    • v.54 no.6
    • /
    • pp.615-630
    • /
    • 2018
  • Basin analysis is a research field to understand the formation and evolution of sedimentary basins. This task requires various geoscientific datasets as well as numerical and graphical modelling techniques to synthesize results dimensionally in time and space. For basin analysis and modelling in a comprehensive workflow, BasinVis 1.0 was released as a MATLAB-based program in 2016, and recently the software has been extended to BasinVis 2.0, with new functions and revised user-interface. As a case study, this work analyses the southern Vienna Basin and visualizes the sedimentation setting and subsidence evolution to introduce the basin modelling functions of BasinVis 2.0. This is a preliminary study for a basin-scale modelling of the Vienna Basin, together with our previous studies using BasinVis 1.0. In the study area, during the late Early Miocene, sedimentation and subsidence are significant along strike-slip and en-echelon listric normal faults. From the Middle Miocene onwards, however, subsidence decreases abruptly over the area and this situation continues until the Late Miocene. This is related to the development of the pull-apart system and corresponds to the episodic tectonic subsidence in strike-slip basins. The subsidence of the Middle Miocene is confined mainly to areas along the strike-slip faults, while, from the late Middle Miocene, the depocenter shifts to a depression along the N-S trending listric normal faults. This corresponds to the regional paleostress regime transitioning from NE-SW trending transtension to E-W trending extension. This study applies various functions and techniques to this case study, and the modelled results demonstrate that BasinVis 2.0 is effective and applicable to the basin modelling.

Revised Geology and Geological Structures of the Northeastern Chungnam Basin in the Southwestern Korean Peninsula

  • Yujung Kwak;Seung-Ik Park;Jeong-Yeong Park;Taejin Choi;Eun Hye Jeong
    • Economic and Environmental Geology
    • /
    • v.55 no.6
    • /
    • pp.597-616
    • /
    • 2022
  • The Chungnam basin is a crucial area for studying the Mesozoic crustal evolutionary history of the Korean Peninsula. This study reports the revised geology and new isotopic ages from the northeastern Chungnam Basin based on detailed geological mapping and LA-ICP-MS zircon U-Pb analysis. Our renewed geologic map defines intra-basin, basin-bounding, and basement fault systems closely related to hydrothermal gold-bearing quartz vein injections. Here, we propose the directions of (micro)structural and geochronological future work to address issues on the relationship between the tectonic process, basin evolution, and hydrothermal fluid migration in the southwestern Korean Peninsula.

Feasibility Test for Hydraulic Conductivity Characterization of Small Basin-Scale Aquifers Based on Geostatistical Evolution Strategy Using Naturally Imposed Hydraulic Stress (자연 수리자극을 이용한 소유역 규모 대수층 수리전도도 특성화: 지구통계 진화전략 역산해석 기법의 적용 가능성 시험)

  • Park, Eungyu
    • Journal of Soil and Groundwater Environment
    • /
    • v.25 no.4
    • /
    • pp.87-97
    • /
    • 2020
  • In this study, the applicability of the geostatistical evolution strategy as an inverse analysis method of estimating hydraulic properties of small-scale basin was tested. The geostatistical evolution strategy is a type of data assimilation method that can effectively estimate aquifer hydraulic conductivity by combining a global optimization model of the evolution strategy and a local optimization model of the ensemble Kalman filtering. In the applicability test, the geometry, hydraulic boundary conditions, and the distribution of groundwater monitoring wells of Hanlim-Eup were employed. On the other hand, a synthetic hydraulic conductivity distribution was generated and used as the reference property for ease of estimation quality assessment. In the estimations, two different cases were tested where, in Case I, both groundwater levels and hydraulic conductivity measurements were assumed to be available, and only the groundwater levels were available, in Case II. In both cases, the reference and estimated hydraulic conductivity fields were found to show reasonable similarity, even though the prior information for estimation was not accurate. The ability to estimate hydraulic conductivity without accurate prior information suggests that this method can be used effectively to estimate mathematical properties in real-world cases, many of which little prior information is available for the aquifer conditions.

Tectonics and Evolutionary History of the Cretaceous Intra-arc Yongdong Basin, Korea

  • Lee, Dong-Woo
    • Journal of the Korean earth science society
    • /
    • v.30 no.5
    • /
    • pp.565-580
    • /
    • 2009
  • The Yongdong basin developed during Early Cretaceous in the central part of the Korean Peninsula and bounded on the northwest and southeast by northeast trending mega-scale strike-slip Yongdong Fault. An 8 km thick succession of exclusively terrigeneous sediments can be grouped into two mega-sequences. In concert with the migration of depocenter, the upper sequence overlaps the lower and occupies northern part of the basin during basin evolution. Alluvial and lacustrine environments were predominantly formed from early to late stage of the basin formation. Several lines of evidence support that the basin was formed within intra-arc tectonic environments and destroyed by polyphase tectonic force. Schematic evolutionary diagram of the basin is proposed.

An Understanding the Opening Style of the West Philippine Basin Through Multibeam High-Resolution Bathymetry (고해상도 다중빔음향측심 지형자료 분석을 통한 서필리핀분지의 진화 연구)

  • Hanjin Choe;Hyeonuk Shin
    • Journal of the Korean earth science society
    • /
    • v.44 no.6
    • /
    • pp.643-654
    • /
    • 2023
  • The West Philippine Basin, an oceanic basin half the size of the Philippine Sea Plate, lies in the western part of the plate and south of the Korean Peninsula on the Eurasian Plate. It subducts beneath the Eurasian Plate and the Philippine Islands bordering the Ryukyu Trench and the Philippine Trench with 25-50% of this basin already consumed. However, the history of the opening of the basin's southern region has been a topic of debate. The non-transform discontinuity formed during the seafloor spreading is similar to the transform fault boundaries normally perpendicular to mid-ocean ridge axes; however, it was created irregularly due to ridge propagations caused by variations of mantle convection attributable to magma supply changes. By analyzing high-resolution multi-beam echo-sounding data, we confirmed that the non-transform discontinuity due to the propagating rift evolved in the entire basin and that the abyssal hill strike direction changed from E-W to NNW-SSE from the fossil spreading center. In the early stage of basin extension, the Amami-Sankaku Basin was rotated 90 degrees clockwise from its current orientation, and it bordered the Palau Basin along the Mindanao Fracture Zone. The Amami-Sankaku Basin separated from the Palau Basin while the spreading of the West Philippine Basin began with a counter-clockwise rotation. This indicates that the non-transform discontinuities formed by a sudden change in magma supply due to the drift of the Philippine Sea Plate and simultaneously with the rapid changes in the spreading direction from ENE-WSW to N-S. The Palau Basin was considered to be the sub-south of the West Philippine Basin, but recent studies have shown that it extends into an independent system. Evidence from sediment layers and crustal thickness hints at the possibility of its existence before the West Philippine Basin opened, although its evolution continues to be debated. We performed a combined analysis using high-resolution multi-beam bathymetry and satellite gravity data to uncover new insights into the evolution of the West Philippine Basin. This information illuminates the complex plate interactions and provides a crucial contribution toward understanding the opening history of the basin and the Philippine Sea Plate.

Geological Structures and Evolution of the Tertiary Chŏngja Basin, Southeastern Margin of the Korean Peninsula (울산군 강동면 제 3기 정자분지(亭子盆地)의 지질구조와 분지발달)

  • Son, Moon;Kim, In-Soo
    • Economic and Environmental Geology
    • /
    • v.27 no.1
    • /
    • pp.65-80
    • /
    • 1994
  • The Tertiary $Ch{\check{o}}ngja$ basin is located in the southeastern coastal area of the Korean Peninsula. It is a lozenge shaped fault-bounded basin with circa $5{\times}5km$ areal extent, isolated from other Tertiary basins by the Cretaceous Ulsan Formation in-between. The northwestern boundary of the basin is a domino/listric type normal fault trending $N30^{\circ}E$, whereas its southwestern boundary is a dextral strike-slip fault (trending $N20^{\circ}W$) with a lateral offset of more than 1 km. The basin is bounded by the East Sea on the eastern margin. Basin-fills consist of extrusive volcanic rock (Tangsa Andesites) of Early Miocene (16~22 Ma in radiometric age), unconsolidated fluviatile conglomerate (Kangdong Formation) and shallow brackish-water sandstone ($Sinhy{\check{o}}n$ Formation). The latter yields abundant Vicarya-Anadara molluscan fossils of early Middle Miocene age. The Tertiary strata become younger toward the northwestern boundary-fault of the basin, showing a zonal distribution pattern parallel to the fault: the younger sedimentary formations occupy a narrow zone of 2 km width along the northwestern boundary-fault, whereas the older Tangsa Andesites underlie them unconformably in the eastern and southeastern portions of the basin. The strata in the basin, including the Tangsa Andesites, are tilted (about $20^{\circ}$) toward the northwestern boundary-fault Sedimentary strata thicken toward the boundary-fault, forming a wedge shaped half-graben structure. A number of small-scale syndepositional normal growth faults and graben structures are observed in the sedimentary strata. These extensional structures have the same trend as the normal northwestern boundary-fault which we interpret as a pull-apart detachment fault. These characteristics imply persistent extension during the basin evolution, caused by a NW-SE directed tensional force. The $Ch{\check{o}}ngja$ basin is, thus, a kind of syndepositional tectonic basin evolved in a strike-slip (pull-apart) regime. The latter was caused by a dextral simple shear associated with the NNW-SSE opening of the East Sea. In view of the fact that the normal growth faults do not cut through the uppermost portion of the youngest $Sinhy{\check{o}}n$ Formation, it is inferred that the tensional force came to be inactive in the early Middle Miocene. This is coincident in timing with the termination of the East Sea opening (15 Ma).

  • PDF

A Review on the Stratigraphy, Depositional Period, and Basin Evolution of the Bansong Group (반송층군의 층서, 퇴적시기, 분지 진화에 관한 고찰)

  • Younggi Choi;Seung-Ik Park;Taejin Choi
    • Economic and Environmental Geology
    • /
    • v.56 no.4
    • /
    • pp.385-396
    • /
    • 2023
  • The Mesozoic Bansong Group, distributed along the NE-SW thrust fault zone of the Okcheon Fold Belt in the Danyang-Yeongwol-Jeongseon areas, contains important information on the two Mosozoic orogenic cycles in the Koran Peninsula, the Permian-Triassic Songrim Orogeny and the Jurassic Daebo Orogeny. This study aims to review previous studies on the stratigraphy, depositional period, and basin evolution of the Bansong Group and to suggest future research directions. The perspective on the implication of the Bansong Group in the context of the tectonic evolution of the Korean Peninsula is largely divided into two points of view. The traditional view assumes that it was deposited as a product of the post-collisional Songrim Orogeny and then subsequently deformed by the Daebo Orogeny. This interpretation is based on the stratigraphic, paleontologic, and structural geologic research carried out in the Danyang Coalfield area. On the other hand, recent research regards the Bansong Group as a product of syn-orogenic sedimentation during the Daebo Orogeny. This alternative view is based on the zircon U-Pb ages of pyroclastic rocks distributed in the Yeongwol area and their structural position. However, both models cannot comprehensively explain the paleontological and geochronological data derived from Bansong Group sediments. This suggests the need for a new basin evolution model integrated from multidisciplinary data obtained through sedimentology, structural geology, geochronology, petrology, and geochemistry studies.