TY - JOUR
T1 - Age and paleoenvironmental reconstruction of partially remagnetized lacustrine sedimentary rocks (Oligocene Aktoprak basin, central Anatolia, Turkey)
AU - Meijers, Maud J.M.
AU - Strauss, Becky E.
AU - Özkaptan, Murat
AU - Feinberg, Joshua M.
AU - Mulch, Andreas
AU - Whitney, Donna L.
AU - Kaymakçi, Nuretdin
N1 - Publisher Copyright:
© 2016. American Geophysical Union. All Rights Reserved.
PY - 2016/3
Y1 - 2016/3
N2 - The age and paleoenvironmental record of lacustrine deposits in the Aktoprak basin of south-central Turkey provides information about the evolution of topography, including the timing of development of an orographic rain shadow caused by uplift of the mountain ranges fringing the Central Anatolian Plateau. New magnetostratigraphy-based age estimates, in combination with existing biostratigraphic ages, suggest that the partially remagnetized Kurtulmuş Tepe section of the basin is Chattian (Upper Oligocene). The mean carbon and oxygen stable isotope ratios (δ18O = 24.6 ± 2.0 ‰, δ13C = -4.9 ± 1.1‰) are largely constant through the section and indicative of a subtropical, open freshwater lake. These isotopic values are also similar to those of the Chattian Mut basin to the south, on the Mediterranean side of the modern orographic barrier (Tauride Mountains), and indicate absence of an orographic barrier during Late Oligocene basin deposition. Post-depositional partial remagnetization occurred after tilting of the basin sequence and was mineralogically controlled, affecting grey, carbonate-rich rocks (average %CaCO3 = 82), whereas interlayered pink carbonate-poor rocks (average %CaCO3 = 38) carry a primary, pretilt magnetization. The pink rocks are rich in clay minerals that may have reduced the permeability of these rocks that carry a primary magnetization, concentrating basinal fluid flow in the carbonate-rich grey layers and leading to the removal and reprecipitation of magnetic minerals. The normal and reverse polarities recorded by the remagnetized rocks suggest that remagnetization occurred over a protracted period of time.
AB - The age and paleoenvironmental record of lacustrine deposits in the Aktoprak basin of south-central Turkey provides information about the evolution of topography, including the timing of development of an orographic rain shadow caused by uplift of the mountain ranges fringing the Central Anatolian Plateau. New magnetostratigraphy-based age estimates, in combination with existing biostratigraphic ages, suggest that the partially remagnetized Kurtulmuş Tepe section of the basin is Chattian (Upper Oligocene). The mean carbon and oxygen stable isotope ratios (δ18O = 24.6 ± 2.0 ‰, δ13C = -4.9 ± 1.1‰) are largely constant through the section and indicative of a subtropical, open freshwater lake. These isotopic values are also similar to those of the Chattian Mut basin to the south, on the Mediterranean side of the modern orographic barrier (Tauride Mountains), and indicate absence of an orographic barrier during Late Oligocene basin deposition. Post-depositional partial remagnetization occurred after tilting of the basin sequence and was mineralogically controlled, affecting grey, carbonate-rich rocks (average %CaCO3 = 82), whereas interlayered pink carbonate-poor rocks (average %CaCO3 = 38) carry a primary, pretilt magnetization. The pink rocks are rich in clay minerals that may have reduced the permeability of these rocks that carry a primary magnetization, concentrating basinal fluid flow in the carbonate-rich grey layers and leading to the removal and reprecipitation of magnetic minerals. The normal and reverse polarities recorded by the remagnetized rocks suggest that remagnetization occurred over a protracted period of time.
KW - continental basin
KW - magnetostratigraphy
KW - paleoenvironment
KW - partial remagnetization
KW - stable isotope geochemistry
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U2 - 10.1002/2015GC006209
DO - 10.1002/2015GC006209
M3 - Article
AN - SCOPUS:84977930106
SN - 1525-2027
VL - 17
SP - 914
EP - 939
JO - Geochemistry, Geophysics, Geosystems
JF - Geochemistry, Geophysics, Geosystems
IS - 3
ER -