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| Titel |
Stable Carbon (δ13C) and oxygen (δ18O) isotopic compositions of the evaporate mineral associated recent and shallow core sediments of hypersaline Lake Acı göl Denizli, Turkey |
| VerfasserIn |
Murat Budakoğlu, Muhittin Karaman |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250132654
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| Publikation (Nr.) |
 EGU/EGU2016-13181.pdf |
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| Zusammenfassung |
| Carbon ($\delta ^{13}$C$_{VPDB})$ and oxygen ($\delta ^{18}$O$_{VPDB})$
isotopic ratios of recent lake sediments (n=33) and lithological samples
(n=6) were obtained to investigate of carbon source and hydro climate
changes in Lake Ac{\i{ }}g\"{o}l Basin. Recent lake samples were collected
as surface (n=15), core (n=13) and shallow core samples (n=5). Discrete
samples, totally 13 samples, were collected every 5cm of core from recent
lake sediments. The $\delta ^{18}$O$_{VPDB }$values of 33 samples from
different sediments and lithology (n=6) varied between
-9.7\permil\ and 6.2\permil\. $\delta
^{13}$C$_{VPDB}$ values of all samples ranged between
-5.1\permil\ and 2.1\permil\. Lithology samples have
negative oxygen isotope values changing between -9.7 \permil\
and -1.3\permil\, and carbon isotope values varying between -5.1
\permil\ ile 2.1\permil\. $\delta ^{13}$C$_{VPDB}$
and $\delta ^{18}$O$_{VPDB}$ isotope core data are positive ranging
between 0.9\permil\ and 0.8\permil\, and
2.8\permil\ and 6.2\permil\, respectively. Lithology
samples have negative $\delta ^{18}$O$_{VPDB}$ isotope values due to the
their calcite contents. Recent surface lake sediments samples collected
different location of lakes and classified as covered always (CAbLW) or
covered seasonally (CSbLW) by lake waters. The $\delta ^{18}$O$_{VPDB
}$and $\delta ^{13}$C$_{VPDB}$ values of CSbLW sediments vary between -1.9
\permil\ and 4.9\permil\, -2.0 \permil\
and 0.6 \permil\, respectively. In contrast to, CAbLW sediments
have negative $\delta ^{13}$C$_{VPDB }$values ranged between
-3.7\permil\ and -0.9\permil\ and positive $\delta
^{18}$O$_{VPDB }$values changed between 1.3\permil\ and
2.8\permil\. The positive $\delta ^{18}$O$_{VPDB }$values of
CAbLW sediments indicate that carbonate precipitation occurs under
evaporation effect. The strong positive correlation identified between
$\delta ^{18}$O$_{VPDB }$and $\delta ^{13}$C$_{VPDB }$for each distinct
group of sediment sample. The correlation coefficient between the $\delta
^{18}$O$_{VPDB }$and $\delta ^{13}$C$_{VPDB }$is 0.67, 0.87, and 0.78
for CSbLW, CAbLW and core samples, respectively. The strong correlation for
each sediment group indicates that lake basin has a closed basin system and
carbonate precipitation occurred from saturated lake water. The extreme
$\delta ^{18}$O$_{VPDB }$and $\delta ^{13}$C$_{VPDB }$anomaly were
obtained at 4-6cm and 30-32 cm, and 18-22cm and 22-26cm range of the core
samples, respectively. The positive $\delta ^{18}$O$_{VPDB }$anomaly along
the core samples indicates that lake basin has always semi arid-arid
climate. However, the extreme anomaly of $\delta ^{18}$O$_{VPDB }$in core
samples reveals that in this sedimentation range lake basin has a severe
drought climate and high saline environment.
Keywords: Hypersaline Lakes, Stable Carbon ($\delta ^{13}$C) and oxygen
($\delta ^{18}$O) isotope |
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