Return to search

Foraminifera and tidal notches: dating neotectonic events at Korphos, Greece

<p> Foraminiferal and thecamoebian biofacies were documented in the modem
Korphos marsh located on the western coast of the Saronikos Gulf, Greece in order to
define the general ecological features (such as salinity and proximity to marine
influence) of the environments they occupied. These constraints were later used to
identify fossil biofacies in subsurface marsh sediments at Korphos. </p> <p> Positive marine tendencies identified in fossil biofacies distributions were used
for the first time to radiocarbon date relative changes in sea-level implied by a series of
discrete, submerged tidal notches and beach rock adjacent to the marsh along the coast.
Magnitude of subsidence events based on notch and beach rock data were measured to
2.9m, 0.5m, 1.3m, 0.39m, 0.47m, and 0.34m. The relatively unaltered v-shape of each
notch profile suggested that sea-level rise was rapid and episodic. </p> <p> A comparison between the tidal notches and beach rock and an isostatically corrected
model of sea-level for this area isolated the tectonic contribution to sea-level
change and revealed that at least four of the six sea-level indicators plotted well-below
predicted sea-level during subsidence. Therefore, the gradual sea-level rise of the late
Holocene was interrupted by at least four sub-meter to meter-scale, step-wise increases in
relative sea-level during coseismic subsidence of the Korphos marsh. The results of this
study show how the combination of geomorphological and salt-marsh records have the
potential to remove errors stemming from a lack of datable material for notches and
autocompaction of marsh sediments when reconstructing local sea-level change. </p> / Thesis / Master of Science (MSc)

Identiferoai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/19256
Date10 1900
CreatorsNixon, Chantel
ContributorsReinhardt, E. G., Geography and Geology
Source SetsMcMaster University
LanguageEnglish
Detected LanguageEnglish

Page generated in 0.0022 seconds