https://repository.kopri.re.kr/handle/201206/5274 2026-04-07T05:39:35Z 2026-04-07T05:39:35Z S.K. Chough Jason Howell Woo, Jusun https://repository.kopri.re.kr/handle/201206/6291 2022-03-24T07:11:27Z 2011-01-01T00:00:00Z

Title: Dendroid morphology and growth patterns: 3-D computed tomographic reconstruction Authors: S.K. Chough; Jason Howell; Woo, Jusun Abstract: This paper analyzes the growth patterns of dendrolite in the Zhangxia Formation (Middle Cambrian), Shandong Province, China, using the technique of 3-D computed tomographic reconstruction. Dendroids are classified into V-dendroids, columnar dendroids, and arborescent dendroids, based on morphological characteristics. The means of interconnection between dendroids are classified into trunks, nodules, shoots, and fingers. Stacking and tiering control the gross morphology and structural framework of dendrolite. Stacking is a process of vertical growth, in which V-dendroids create a staircase-like structure. Tiering occurs when a layer of dendroids is covered by sediment, and then partially eroded, allowing a new layer of dendroids to form. A comprehensive blueprint of the structural divisions of dendrolite is presented, according to scale, being divided into micro-, meso-, macro-, and megastructures. The mesostructure, which includes individual dendroids and their combined structures, is subsequently divided into primary (V-dendroid), secondary (columnar and arborescent dendroid), and tertiary (stair and tier) structures and a basic growth model is provided for V-dendroids. The stages of V-dendroid growth are: 1) trunk extension and base expansion, 2) divergence, 3) expansion and convergence, followed by repetition of stages 2 and 3, until 4) growth completion, followed by the subsequent emergence of a new dendroid by either stacking or tiering. This development of systematically ordered structures is suggestive of the reaction of microbial colonies to external environmental conditions.

2011-01-01T00:00:00Z Lee, Joohan Hong, Jong Kuk Kim, Ki Young Shon, Howoong Hong, Myung Ho https://repository.kopri.re.kr/handle/201206/5988 2022-03-24T07:11:22Z 2010-01-01T00:00:00Z

Title: Helicopter-borne and ground-towed radar surveys of the Fourcade Glacier on King George Island, Antarctica Authors: Lee, Joohan; Hong, Jong Kuk; Kim, Ki Young; Shon, Howoong; Hong, Myung Ho Abstract: To determine subglacial topography and internal features of the Fourcade Glacier on King George Island in Antarctica, helicopter-borne and ground-towed ground-penetrating radar (GPR) data were recorded along four profiles in November 2006. Signature deconvolution, f-k migration velocity analysis, and finite-difference depth migration applied to the mixed-phase, single-channel, ground-towed data, were effective in increasing vertical resolution, obtaining the velocity function, and yielding clear depth images, respectively. For the helicopter-borne GPR, migration velocities were obtained as root-mean-squared velocities in a two-layer model of air and ice. The radar sections show rugged subglacial topography, englacial sliding surfaces, and localised scattering noise. The maximum depth to the basement is over 79 m in the subglacial valley adjacent to the south-eastern slope of the divide ridge between Fourcade and Moczydlowski Glaciers. In the ground- towed profile, we interpret a complicated conduit above possible basal water and other isolated cavities, which are a few metres wide. Near the terminus, the GPR profiles image sliding surfaces, fractures, and faults that will contribute to the tidewater calving mechanism forming icebergs in Potter Cove.

2010-01-01T00:00:00Z Lee, Joohan Jin, Young Keun Kim, Ki Young Hong, Jong Kuk https://repository.kopri.re.kr/handle/201206/6009 2022-03-24T07:11:17Z 2010-01-01T00:00:00Z

Title: An englacial image and water pathways of the Fourcade glacier on King George Island, Antarctic Peninsula, inferred from ground-penetrating radar Authors: Lee, Joohan; Jin, Young Keun; Kim, Ki Young; Hong, Jong Kuk Abstract: The distribution of small fractures and water content of the Fourcade glacier on King George Island, Antarctica, was investi- gated in November 2006 and December 2007 by two ground-based (470- and 490-m-long profiles) and one helicopter-borne (470-m-long profile) ground-penetrating radar (GPR) surveys using 50-, 100-, and 500-MHz antennas. Radar images in the pre-migrated GPR sections are characterized by a smooth ice surface and irregular bed topography, numerous diffraction hy- perbolas in the ice and at the glacier bed, strong scattering noise, and near-surface folded layers. Scattering noise above a mound in the center of the profiles is associated with an area of dense fractures extending down from the ice surface that has relatively low reflection strength. Near the northeast ends of the profiles where few englacial fractures occur, scattering noise may result from the presence of warmer ice. A water-filled conduit and an air-filled cavity are interpreted as the source of two distinct hyperbolas in sub-glacial valleys based on the polarity of the reflections. Through migration velocity analysis on 106 hyperbolas, radar velocities were obtained for the 100-MHz ground-based profile. Using the velocities and Paren's mixture formula, we calculated the water content of the ice to have been in the range of 0.00？0.09. High water content occurs near the glacier margin, in sub-glacial valleys, and in zones of scattering noise.

2010-01-01T00:00:00Z G.D. Kamenov Lee, Sang-Mook Park, Sung Hyun Lee, Kyeong-Yong Kwon, Sung-Tack https://repository.kopri.re.kr/handle/201206/6234 2022-03-24T07:12:19Z 2010-01-01T00:00:00Z

Title: Tracing the origin of subduction components beneath the South East rift in the Manus Basin, Papua New Guinea Authors: G.D. Kamenov; Lee, Sang-Mook; Park, Sung Hyun; Lee, Kyeong-Yong; Kwon, Sung-Tack Abstract: The Manus Basin to the northeast of Papua New Guinea is an actively spreading/rifting back-arc basin in the Bismarck Sea located between the inactive Manus-Kilinailau trench on the Pacific-plate side and the activeNew Britain trench on the Solomon-plate side. Spreading/rifting in the Manus Basin takes place in the last 0.78Myr or so. We present major and trace elements, and Sr？Nd？Pb isotope compositions of rock samples taken from the South East Rift (SER) at the eastern end of the Manus Basin. The strong enrichment of Pb and LILE (large ion lithophile elements) relative toHFSE (high field strength elements) and REE (rare earth elements) in the SER lava is also quite similar to other island arc lavas, suggesting that substantial amount of subduction componentswere present in its sourcemantle. To investigate the origin of the subduction components in SER lavas,we compare the geochemical data of SER lavas to published data fromNewBritain Arc (NBA) and Tabar？Lihir？Tanga？Feni (TLTF) island chain. The volcanisminNBAis related to presently active subduction of the Solomon slab,whereas the TLTF volcanism is located in the forearc area of New Ireland arc which was formed during a former subduction of the Pacific slab. In otherwords, the NBA and TLTF lavaswere influenced by subduction components fromthe present and former subduction, respectively.We argue that the subduction components in SER lava were incorporated in the mantle lithosphere during the active arc volcanism on New Ireland because the amount of the subduction component in SER decreases with increasing in distance from New Ireland. On the other hand, no relationships are found with respect to New Britain. The Sr？Nd？Pb isotopes indicate that SER lavas contain little sediment component and less amount of fluid component derived from altered oceanic crust compared to the TLTF lavas. This is probably due to the fact that SER is located in backarc settings in

2010-01-01T00:00:00Z