By counting the varves
they are now able to travel back in time to about 52,000 years ago.
1977a, Paleoecology of Eocene lacustrine varves
at Horsefly, British Columbia: Canadian Journal of Earth Sciences, v.
The basal reddish-brown till and varved clay (core depth 760-708 cm) did not contain terrestrial macrofossils and therefore AMS dates are absent, but annual varves
were rather clear, forming 29 couplets, in the central part of the lake obviously more.
Interpretations of the turbidite varves
suggest there were fluctuations in precipitation showing peaks of monsoon intensity and decreasing force after 4000-3500 yr BP, calibrated to c.
A long sequence of varves
, in turn, records cycles in the earth's climate.
Evidence of the final drainage of the Baltic Ice Lake and the brackish phase of the Yoldia Sea in glacial varves
from the Baltic Sea.
In principle, these records suffer some of the same problems as varved lakes (for one discussion of problems in the chronology of the well-known GISP2 ice core, see Southon 2004) but due to the concentration of effort in these records and the degree of duplication they are, at their best, considerably better than varves
(presentation of J.
Clearly, in the buried Clermont lacustrine unit at CECOS and in the Backbone Creek paleosol "till balls," the pathway for water and contaminant migration is through fractures, between the varves
, and around the "till balls.
1965) showed that time series of river discharges, lake levels, but also thickness of tree rings and varves
give Hurst exponents of around H [approximately equal to] 0.
It was time to take a step forward and therefore the Varves
Working Group (VWG), a new community of scientists, was established under the frame of the IGBP-PAGES Cross Cutting Theme 1 'Chronology'.
The concept of "double porosity" recognizes both primary porosity (flow through the glacial till matrix of silt and/or clay) and secondary porosity (flow through fractures, worm holes, root holes, and along preferential pathways such as varves
or other depositional features).
The detailed record of climatic change was derived from annual varves
in Greenland ice-cores while archaeological sites provided proxies for human responses to climate changes that were largely [sup.