Author:
De Vleeschouwer D.,Da Silva A. C.,Boulvain F.,Crucifix M.,Claeys P.
Abstract
Abstract. A Devonian magnetic susceptibility (MS) record obtained on limestones ranging from the Uppermost-Eifelian to the Lower-Givetian and located on the southern border of the Dinant Synclinorium in Belgium was selected for time-series analysis. In these carbonate ramp and platform deposits, spectral analyses highlight persistent, high-frequency cycles in both the MS-signal and the microfacies curve, reflecting environmental and climate changes. These metre-scale variations in the MS-signal are interpreted as changes in the flux of magnetic minerals towards the marine system, most likely controlled by monsoon rainfall-intensity. By combining chrono- and biostratigraphic information with theoretical knowledge of sedimentation rates in different depositional environments, these cycles are interpreted as astronomically driven and dominated by precession. It is hypothesized that during precession minima (longitude of the perihelion ≈270°) the trans-equatorial pressure gradient reaches a maximum and intensifies the northeasterly monsoonal circulation. The consequent increase in moisture transport towards the continent leads to enhanced precipitation and runoff, which, in turn, induces a higher flux of detrital material – including magnetic minerals responsible for the MS-signal – towards the marine system. Moreover, this unique high-resolution climate signal reveals half-precessional cycles. These cycles suggest that during precession maxima (longitude of the perihelion ≈90°) southeasterly monsoonal circulation strengthened due to an increased inter-hemispheric pressure gradient.
Subject
Paleontology,Stratigraphy,Global and Planetary Change
Reference65 articles.
1. Algeo, T. J., Scheckler, S. E., and Maynard, J. B.: Effects of the Middle to Late Devonian spread of vascular land plants on weathering regimes, marine biota, and global climate, in: Plants Invade the Land: Evolutionary and Environmental Approaches, edited by: Gensel, P. G. and Edwards, D., Columbia Univ. Press, New York, 213–236, 2001.
2. Barrell, J.: Dominantly Fluviatile Origin Under Seasonal Rainfall of the Old Red Sandstone, Proc. Natl. Acad. Sci. USA., 2, 498–499, 1916.
3. Beauchamp, K. G.: Applications of Walsh and Related Functions, with an Introduction to Sequency Theory, Academic Press, New York, 1975.
4. Beaufort, L., van der Kaars, S., Bassinot, F. C., and Moron, V.: Past dynamics of the Australian monsoon: precession, phase and links to the global monsoon concept, Clim. Past, 6, 695–706, https://doi.org/10.5194/cp-6-695-2010, 2010.
5. Berger, A. and Loutre, M. F.: Pre-Quaternary Milankovitch frequencies, Nature, 342, 133, https://doi.org/10.1038/342133b0, 1989.
Cited by
33 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献