• The Korean Journal of Petroleum Geology
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• v.13 no.1
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• pp.1-16
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• 2007

The southeastern Korean Peninsula has experienced crustal multi-deformations according to changes of global tectonic setting during the Cenozoic. Characteristic features of the crustal deformations in relation to major Cenozoic tectonic events are summarized as follows. (1) Collision of Indian and Eurasian continents and abrupt change of movement direction of the Pacific plate (50${\sim}$43 Ma): The collision of Indian and Eurasian continents caused the eastward extrusion of East Asia block as a trench-rollback, and then the movement direction of the Pacific plate was abruptly changed from NNW to WNW. As a result, the strong suction-force along the plate boundary produced a tensional stress field trending EW or WNW-ESE in southeastern Korea, which resultantly induced the passive intrusion of NS or NNE trending mafic dike swarm. (2) Opening of the East Sea (25${\sim}$16 Ma): The NS or NNW-SSE trending opening of the East Sea generated a dextral shear stress regime trending NNW-SSE along the eastern coast line of the Korean Peninsula. As a result, pull-apart basins were developed in right bending and overstepping parts along major dextral strike slip faults trending NNW-SSE in southeastern Korea. The basins can be divided into two types on the basis of geometry and kinematics: Parallelogram-shaped basin (rhombochasm) and wedged-shaped basin (sphenochasm), respectively. In those times, the basins and adjacent basement blocks experienced clockwise rotation and northwestward tilting contemporaneously, and the basins often experienced a kind of propagating rifting from NE toward SE. At about 17Ma, the Yonil Tectonic Line, which is the westernmost border fault of the Miocene crustal deformation in southeastern Korea, began to move as a major dextral strike slip fault. (3) Clockwise rotation of southeastern Japan Island (about 15 Ma): The collision of the Izu-Bonin Arc and southeastern Japan Island, as a result of northward movement of the Philippine sea-plate, induced the clockwise rotation of southeastern Japan Island. The event caused the NW-SE compression in the Korea Strait as a tectonic inversion, which resultantly tenninated the basin extension and caused local counterclockwise rotation of blocks in southeastern Korea. (4) E-W compression in the East Asia (after about 5 Ma): Decreasing subduction angle of the Pacific plate and eastward movement of the Amurian plate have constructed the-top-to-west thrusts and become a major cause for earthquakes in southeastern Korea until the present time.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.3
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• pp.431-438
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• 2003

This study investigates pulp chamber temperature rise during composite resin polymerization by plasma arc(Group III : Flipo 3 sec, Group IV : Flipo 5 sec) and LED curing units(Group V : Lux-O-Max, 40 sec) as well as conventional halogen lamp curing units(Group I : VIP mode3, 20 sec, Group II : VIP mode6, 20 sec). The results are as follows : 1. All of the investigated pulp chamber temperature rises are lower than the boundary temperature could result in irreversible damage to the pulpal tissue ($5.5^{\circ}C$). 2. In the group II, it is found the significantly higher pulp chamber temperature rise than any other groups(p<0.05). 3. In the group of composite resin light-cured with VIP, it is found the significantly higher pulp chamber temperature rise in the group II than group I(p<0.05). 4. In the group of composite resin light-cured with Flipo, it is found the significantly higher pulp chamber temperature rise in the group IV than group III (p<0.05). 5. In the case of comparing VIP and Flipo, group II is significantly higher pulp chamber temperature rise than group III, IV(p<0.05), and group IV is significantly higher pulp chamber temperature rise than group I(p<0.05), and it does not significantly differ between group I and III. 6. In the group of composite resin light-cured with Lux-O-Max, it is found the significantly lower pulp chamber temperature rise than any other groups (p<0.05).