Coastal lowland and floodplain evolution along the lower reaches of the Supsa River (western Georgia)
<p>In the southernmost part of the Colchian plain (Georgia), the Supsa and Rioni rivers represent important catchments for reconstructing Holocene landscape changes. Using granulometric methods, geochemical analyses and radiocarbon dating, we demonstrate that significant palaeoenvironmental ch...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | deu |
| Published: |
Copernicus Publications
2019-07-01
|
| Series: | Eiszeitalter und Gegenwart |
| Online Access: | https://www.eg-quaternary-sci-j.net/68/119/2019/egqsj-68-119-2019.pdf |
| Summary: | <p>In the southernmost part of the Colchian plain (Georgia), the Supsa and
Rioni rivers represent important catchments for reconstructing Holocene
landscape changes. Using granulometric methods, geochemical analyses and
radiocarbon dating, we demonstrate that significant palaeoenvironmental
changes have taken place in the surroundings of the Supsa fan since at least
4000 BCE. The initial foothill fan accumulation was prolonged by delta plain
progradation. Due to continued fluvial sediment supply, mainly from
the Rioni, the lagoon silted up and extended peat bogs formed east of the
beach ridge complex. The Supsa fan first prograded northwards (since the
third millennium BCE) and later shifted westwards, eventually following
an avulsion of the Rioni. While Supsa deposits remain limited to the area of
the fan and the modern estuary, the alluvial fines of the Rioni dominate the
surrounding areas. The relative sea-level (RSL) index points of the region
suggest a gradual RSL rise from <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>∼</mo><mo>-</mo><mn mathvariant="normal">9</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="26pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="9e7984693a9677c424a0f8a3cd0658c9"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="egqsj-68-119-2019-ie00001.svg" width="26pt" height="10pt" src="egqsj-68-119-2019-ie00001.png"/></svg:svg></span></span> <span class="inline-formula">m</span> between 4000 and 3500 BCE to <span class="inline-formula">−3</span>/<span class="inline-formula">−2</span> <span class="inline-formula">m</span> below the modern sea level in the second half of the
first millennium BCE, the period during which Greek colonization and
Colchian settlements are attested by archaeological remains.</p> |
|---|---|
| ISSN: | 0424-7116 2199-9090 |