 |
| Titel |
Wetter and cooler: pronounced temperate climate conditions in western Anatolia during the Middle Miocene Climatic Optimum |
| VerfasserIn |
Tuncay H. Güner, Johannes M. Bouchal, Nesibe Köse, Thomas Denk |
| Konferenz |
EGU General Assembly 2017
|
| Medientyp |
Artikel
|
| Sprache |
en
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250141257
|
| Publikation (Nr.) |
 EGU/EGU2017-4744.pdf |
|
|
|
|
|
| Zusammenfassung |
| During the course of an ongoing palaeobotanical investigation of the lignite mines
of the Yatağan Basin, Muğla province, Turkey, the fossil leaves of the Eskihisar
lignite mine were analysed using the Climate Leaf Analysis Multivariate Program
(CLAMP).
The investigated fossil leaves derive from the marls and clayey limestones (Sekköy Member)
overlying the exploited lignite seam (uppermost Turgut Member). The age of the studied
sedimentary rocks is well constrained by vertebrate fossils occuring in the main lignite seam
(MN6 → Gomphoterium angustidens Cuvier, 1817; Percrocuta miocenica Pavlov &
Thenius, 1965) and at the Yenieskihisar Mammal locality (MN7/8, uppermost Sekköy
Member).
719 specimens were measured and assigned to 65 leaf morphotypes. Using this data, CLAMP
reconstructed the following climate parameters: mean annual temperature (MAT) 12.58
(+/-1.5)∘C, warm month mean temperature (WMMT) 23.72 (+/-2.5)∘C, cold month mean
temperature (WMMT) 2.29 (+/-2)∘C, length of growing season (LGS) 7.52 (+/-0.75) month,
mean growing season precipitation (GSP) 130.1 (+/-40) cm, precipitation during the three
wettest months (3-WET) 67 (+/-25) cm, precipitation during the three driest months (3-DRY)
20.4 (+/-7.5) cm.
The reconstructed parameters are too cool for tropical climates (the 18˚ C winter isotherm
being a threshold for tropical climates) and indicate temperate conditions; climates fitting
these parameters (Cfb according to the Köppen-Geiger climate classification) can be found
today in regions known as “Tertiary relict areas” (e.g. Black sea coast of Northeast Turkey,
eastern China, Japan).
Based on a substantial amount of rainfall during the three driest months, it is further possible
to exclude markedly seasonal climates such as a summer-dry and winter-wet Mediterranean
climate and a summer-wet and winter-dry monsoon climate as commonly found along the
southern foothills of the Himalayas and in southwestern China. Instead, a fully humid Cf
climate is proposed that has only a weak seasonality in precipitation (lower precipitation in
winter).
The findings of our study provide valuable information for inferring palaeoenvironments of
middle Miocene rich ungulate faunas in western Turkey (e.g. Paşalar), for which
seasonal tropical and subtropical forest communities have been proposed (Andrews,
1990).
The fossil floras of the Tınaz and Salihpaşalar lignite mines, representing the Tınaz sub-basin
and the main basin of the wider Yatağan Basin, are investigated at the moment, and a
synthesis paper combining and comparing evidence from the macro floral and palynological
data is soon to be submitted.
Andrews. (1990) Palaeoecology of the Miocene fauna from Paşalar, Turkey. Journal of
Human evolution 19:569–582. |
|
|
|
|
|
|