Architectural Development of Inclined Heterolithic Stratification (IHS) and Relevant Hydrodynamics in a Macrotidal Channel, Gomso Bay, West Coast of Korea

Abstract

Morphodynamics and hydrodynamics of tidal channels in macrotidal Gomso Bay were investigated to understand the architecture of inclined heterolithic stratification (IHS) formed in tide-dominated environment with meager fluvial influence. A series of high-precision profilings revealed that tidal channels migrated in response to rain-induced runoff discharge and to lesser degree strong tidal currents. Abrupt morphologic changes such as meander-bend cutoff, chute channels, and rill channels were linked mostly with high precipitation events during summertime rainy season. Tidal currents are mutually evasive, forming flood or ebb chute channels and barbs. Overall ebb-dominance in the channels produces ebbwardly dipping IHS. Sinuous channel planform and mutually evasive tidal current facilitate preferential preservation of subordinate-current generated bedforms within dominant currentwardly dipping IHS. During fairweather condition, seaward and landward portions of meander bend are flood and ebb-dominated, respectively. During rainy season, however, entire channel become ebb-dominated except flood barb area due to increased runoff discharge. Present study highlights the fact that IHS architecture of macrotidal channel is controlled mainly by climate-driven high-discharge events and is less compartmentalized compared to counterparts of fluvially dominated channel.

AAPG Datapages/Search and Discovery Article #90194 © 2014 International Conference & Exhibition, Istanbul, Turkey, September 14-17, 2014