Climate-driven cyclicity in an Early Cretaceous synrift lacustrine series (Aguilón sub-basin, NE Spain)

Terra Nova, 24, 407–416, 2012 Lacustrine sedimentation is very sensitive to climate changes and its cyclicity analysis allows a better quantitation of the time of sedimentation than other methods. Climate and tectonic influence on sedimentation in a synrift basin is interpreted from the spectral analysis of a 49‐m‐thick series, which includes 88 deepening–shallowing lacustrine cycles. The interpreted position of the different facies with respect to the palaeolake shoreline and the depth of deposition are used as input for spectral analysis. To recognise a clear climate signal, it was necessary to eliminate the thicker cycles from the analysis. Results show power spectrum maxima (confidence level >99%) at 199, 47 and 15 cm. The first two are interpreted as representing short eccentricity and precession cycles respectively. The 88 deepening–shallowing cycles thus would reflect the influence of precession. Thicker cycles reflect short episodes with a significant increase of accommodation space due to synsedimentary tectonics.