169 research outputs found
Neogene Uplift and Magmatism of Anatolia: Insights from Drainage Analysis and Basaltic Geochemistry
It is generally agreed that mantle dynamics have played a significant role in generating and maintaining the elevated topography of Anatolia during Neogene times. However, there is much debate about the relative importance of subduction zone and asthenospheric processes. Key issues concern onset and cause of regional uplift, thickness of the lithospheric plate, and the presence or absence of temperature and/or compositional anomalies within the convecting mantle. Here, we tackle these interlinked issues by analyzing and modeling two disparate suites of observations. First, a drainage inventory of 1,844 longitudinal river profiles is assembled. This geomorphic database is inverted to calculate the variation of Neogene regional uplift through time and space by minimizing the misfit between observed and calculated river profiles subject to independent calibration. Our results suggest that regional uplift commenced in the east at 20 Ma and propagated westward. Secondly, we have assembled a database of geochemical analyses of basaltic rocks. Two different approaches have been used to quantitatively model this database with a view to determining the depth and degree of asthenospheric melting across Anatolia. Our results suggest that melting occurs at depths as shallow as 60 km in the presence of mantle potential temperatures as high as 1400°C. There is evidence that potential temperatures are higher in the east, consistent with the pattern of sub-plate shear wave velocity anomalies. Our combined results are consistent with isostatic and admittance analyses and suggest that elevated asthenospheric temperatures beneath thinned Anatolian lithosphere have played a first order role in generating and maintaining regional dynamic topography and basaltic magmatism
The Early Messinian Velona basin (Siena, central Italy): paleoenvironmental and paleobiogeographical reconstructions
Reconciling the stratigraphy and depositional history of the Lycian orogen-top basins, SW Anatolia
Terrestrial fossil records from the SWAnatolian basins are crucial both for regional correlations and palaeoenvironmental reconstructions.
By reassessing biostratigraphic constraints and incorporating new fossil data, we calibrated and reconstructed the late Neogene
andQuaternary palaeoenvironments within a regional palaeogeographical framework. The culmination of the Taurides inSWAnatolia
was followed by a regional crustal extension from the late Tortonian onwards that created a broad array of NE-trending orogen-top
basins with synchronic associations of alluvial fan, fluvial and lacustrine deposits. The terrestrial basins are superimposed on the upper
Burdigalian marine units with a c. 7 myr of hiatus that corresponds to a shift from regional shortening to extension. The initial infill of
these basins is documented by a transition from marginal alluvial fans and axial fluvial systems into central shallow-perennial lakes
coinciding with a climatic shift from warm/humid to arid conditions. The basal alluvial fan deposits abound in fossil macro-mammals
of an early Turolian (MN11–12; late Tortonian) age. The Pliocene epoch in the region was punctuated by subhumid/humid conditions
resulting in a rise of local base levels and expansion of lakes as evidenced by marsh-swamp deposits containing diverse fossilmammal
assemblages indicating late Ruscinian (lateMN15; late Zanclean) ageWe are grateful for the support of the international
bilateral project between The Scientific and Technological Research
Council of Turkey (TUBITAK) and The Russian Scientific Foundation
(RFBR) with grant a number of 111Y192. M.C.A. is grateful to the
Turkish Academy of Sciences (TUBA) for a GEBIP (Young Scientist
Award) grant. T.K. and S.M. are grateful to the Ege University
Scientific Research Center for the TTM/002/2016 and TTM/001/2016
projects. M.C.A., H.A., S.M. and M.B. have obtained Martin and
Temmick Fellowships at Naturalis Biodiversity Center (Leiden). F.A.D.
is supported by a Mehmet Akif Ersoy University Scientific Research
Grant. T.A.N. is supported by an Alexander-von-Humboldt
Scholarship. L.H.O. received support from TUBITAK under the 2221
program for visiting scientists
Considerazioni sulla strutturazione della catena dei Monti Aurunci: vincoli stratigrafici
Miocene tectono-sedimentary events and geodynamic evolution of the central Apennines (Italy)
Il bacino di Belvedere-Vallocchia (Monti di Spoleto): un thrust-top basin dell'Appennino serravalliano
Il sistema Tirreno-Appennino: segmentazione litosferica e propagazione del fronte compressivo
La paleogeografia neogenica del Mediterraneo centrale: vincoli geologici dall’Appennino centro-settentrionale
La linea Olevano-Antrodoco: contributo della biostratigrafia alla sua caratterizzazione cinematica
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