Physics
Scientific paper
Feb 2003
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003e%26psl.207...13h&link_type=abstract
Earth and Planetary Science Letters, Volume 207, Issue 1-4, p. 13-22.
Physics
Varves, Paleoclimate, Gowganda Formation, Spectral Analysis
Scientific paper
Rhythmically deposited argillites of the Gowganda Formation (ca. 2.0-2.5 Ga) probably formed in a glacial setting. Drop stones and layered sedimentary couplets in the rock presumably indicate formation in a lacustrine environment with repeating freeze-thaw cycles. It is plausible that temporal variations in the thickness of sedimentary layers are related to interannual climatic variability, e.g. average seasonal temperature could have influenced melting and the amount of sediment source material carried to the lake. A sequence of layer couplet thickness measurements was made from high-resolution digitized photographs taken at an outcrop in southern Ontario, Canada. The frequency spectrum of thickness measurements displays patterns that resemble some aspects of modern climate. Coherent periodic modes in the thickness spectrum appear at 9.9-10.7 layer couplets and at 14.3 layer couplets. It is unlikely that these coherent modes result from random processes. Modern instrument records of regional temperature and rainfall display similar spectral patterns, with some datasets showing significant modes near 14 yr in both parameters. Rainfall and temperature could have affected sedimentary layering in the Gowganda argillite sequence, and climate modulation of couplet thickness emerges as the most likely explanation of the observed layering pattern. If this interpretation is correct, the layer couplets represent predominantly annual accumulations of sediment (i.e. they are varves), and the thickness spectrum provides a glimpse of Early Proterozoic climatic variability. The presence of interannual climate patterns is not unanticipated, but field evidence presented here may be of some value in developing a climate theory for the Early Proterozoic.
Giegengack Robert
Hughes Gary B.
Kritikos Haralambos N.
No associations
LandOfFree
Modern spectral climate patterns in rhythmically deposited argillites of the Gowganda Formation (Early Proterozoic), southern Ontario, Canada does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Modern spectral climate patterns in rhythmically deposited argillites of the Gowganda Formation (Early Proterozoic), southern Ontario, Canada, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Modern spectral climate patterns in rhythmically deposited argillites of the Gowganda Formation (Early Proterozoic), southern Ontario, Canada will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-920888