• Title/Summary/Keyword: 현세

Search Result 150, Processing Time 0.027 seconds

Late Holocene Sedimentation Rates from Core Sediments of the Western Part of the East Sea, Korea (한국 동해 서측해역에서 채취한 시추 퇴적물의 후기 현세 퇴적률 연구)

  • 박병권;한상준
    • 한국해양학회지
    • /
    • v.30 no.5
    • /
    • pp.382-389
    • /
    • 1995

  • This study intended to investigate the sedimentation rates of core sediments of the western part of the East Sea using Accelerator Mass Spectrometer (AMS) C-age on the planktonic foraminifera or acid-ex-tracted residue, base-soluble and base-extracted residue fractions. On the basis of the depth-age correlations, the sedimentation rates during the late Holocene period of Cores HP-10, HP-3, 94-9 and 92-3 were 30 cm/kyr, 10 cm/kyr, 11 cm/kyr and 112 cm/kyr, respectively. The sedimentation rates of the westem part of the East Sea, however, seems to be ranged from 11 cm/kyr to 30 cm/kyr, because the rates of the only two cores (Cores HP-10 and 94-9) which were dated at more than three depths are considered to be more reliable. The rates in each core sediment showed good linear relationship with the sample depth, suggesting that the sea-level rise had been finished nearly during the early Holocene period and the general depositional environments had been lasted rather constant during the late Holocene period.

  • PDF

Sediment Distributions and Depositional Processes on the Inner Continental Shelf Off the West Coast (Middle Part) of Korea (한국 서해 중부해역 대륙붕 퇴적물의 분포와 퇴적작용)

  • 박용안;최진용
    • 한국해양학회지
    • /
    • v.29 no.4
    • /
    • pp.357-365
    • /
    • 1994

  • The sediments on the continental shelf off the west coast (middle part) of Korea are divided into northern sandy deposits and southern muddy sediments, respectively. The sandy sediments consist dominantly of quartz and feldspar grains, representing mature-stage sediment in composition. Further-more, the presence of iron-stained quartz grain and glauconite does indicate that the sediments are similar to the relict sediments on the outer shelf of Yellow Sea and East China Sea. These sandy sediments are interpreted as a basal sands that were deposited during the transgression period due to sea-level rise after to last glacial maximum (LGM). The tidal deposits in the Namyang Bay, the west coast of Korea are divided vertically into the upper layer of muddy sediments and the lower layer of sandy sediments. the upper layer sediments contain abundant rock fragments, and are interpreted as the modern tetragenous sediments. The lower layer sediments, on the other hand, are rich in quartz and feldspar grains, representing high index of sediment maturity ratio. the lower layer sandy deposits show the presence of iron-stained.

  • PDF