Orbital forcing in Pliocene–Pleistocene Mediterranean lacustrine deposits: dominant expression of eccentricity versus precession

Abstract

Milankovitch forcing of climate is expressed in the sedimentary record as lithological cycles that can have one or more of four typical periods related to precession (21 kyr), obliquity (41 kyr) and eccentricity (100 and 400 kyr). In several Mediterranean continental successions, striking differences in the expression of particularly precession and eccentricity appear. We present the results of an additional lower Pliocene lacustrine succession from Lupoaia (southern Romania), and compare the cyclic expression in this lignite±siliciclastic basin in detail with the time-equivalent lignite±carbonate basin of Ptolemais (northern Greece), the middle Pleistocene lignite±siliciclastic basin of Megalopolis (southern Greece) and the Miocene carbonate±clay basin of Orera (north eastern Spain). It appears that carbonate basins dominantly express precession, while siliciclastic basins dominantly express eccentricity in their lithological cycles. This can be explained by a more linear response to insolation forcing in carbonate basins than in siliciclastic basins. Alternatively, it can be explained by the low amplitude of 100-kyr eccentricity at the times the carbonate sections were deposited. This reduced 100-kyr amplitude was caused by minima in the 2.35 Myr eccentricity cycle, that co-occurred with the deposition in both carbonate basins. Finally, the expression of 100-kyr eccentricity appears to be independent of glacial cyclicity. q

20 Myr of eccentricity paced lacustrine cycles in the Cenozoic Ebro Basin

“…These results are in agreement with earlier studies in the Mediterranean region and other perimediterranean Neogene records (van Vugt et al, 2001;Abdul Aziz et al, 2003;Abels et al, 2009) which concluded that the 100-kyr and 400-kyr eccentricity minima and maxima were related to periods of low-and high-average precipitation respectively. Since the contribution of the 2.4-Myr cycle to the insolation spectra is very low , it is inferred that long-period orbital forcing is transmitted through modulation of the shorter eccentricity cycles of 400-kyr and (specially) 100-kyr and, consequently, by the amplitude of the precession cycle.…”

Climatic control on palaeohydrology and cyclical sediment distribution in the Plio-Quaternary deposits of the Guadix Basin (Betic Cordillera, Spain)

“…Although there are documented astronomically-forced cycles in continental sediments (Agustí et al, 2001;van Vugt et al, 2001;Kruiver et al, 2002;Steenbrink et al, 2006;Amorosi et al, 2008;García-García et al, 2009;Abels et al, 2010), most of them are focused on lacustrine settings with a recording of precessional cycles (e.g. van Vugt et al, 2001) or cyclicity corresponding to changes in obliquity and/or eccentricity (e.g.…”

“…van Vugt et al, 2001) or cyclicity corresponding to changes in obliquity and/or eccentricity (e.g. Steenbrink et al, 2006;Jiménez-Moreno et al, 2013).…”

Miocene siliciclastic deposits of Naxos Island: Geodynamic and environmental implications for the evolution of the southern Aegean Sea (Greece)

“…The pebble size in the channels reflects the intensity of runoff which may be controlled by Milankovitch-type climatic cycles. The dominance of the 41 ka obliquity and the precession cycles as found in this region in the Pliocene (Cramp and O'Sullivan, 1999) may also be applicable to the Miocene (e.g., Juhasz et al, 1997;Hilgen et al, 2000;van Vugt et al, 2001). A cyclic variation of precipitation and runoff may be related to an early precursor of the African monsoon, which is dominantly forced by insolation and responds both to the 41 ka obliquity cycle and the 19/23 ka precession cycle (Rossignol-Strick, 1983).…”