Isotope signature of the Younger Dryas and two minor oscillations at Gerzensee (Switzerland): palaeoclimatic and palaeolimnologic interpretation based on bulk and biogenic carbonates

Oxygen- and carbon-isotope ratios in the carbonate of benthic ostracodes (Pseudocandona marchica) and molluscs (Pisidium ssp.) were measured across the transitions bordering the Younger Dryas chronozone in littoral lacustrine cores from Gerzensee (Switzerland). The specific biogenic carbonate records confirm the major shifts already visible in the continuous bulk-carbonate oxygen-isotope record (δ18OCc). If corrected for their vital offsets, oxygen-isotope ratios of Pisidium and juvenile P. marchica, both formed in summer, are almost identical to δ18OCc. This bulk carbonate is mainly composed of encrustations of benthic macrophythes (Chara ssp.), also mainly produced during summer. Adult P. marchica, which calcify in winter, show consistently higher δ18O, larger shifts across both transitions, and short positive excursions compared with the summer forms, especially during early Preboreal. Despite such complexity, the δ18O of adult P. marchica probably reflects more accurately the variations of the δ18O of former lake water because, during winter, calcification temperatures are less variable and the water column isotopically uniform. The difference between normalised δ18O of calcite precipitated in winter to that formed in summer can be used to estimate the minimum difference between summer and winter water temperatures. In general, the results indicate warmer summers during the late Allerød and early Preboreal compared with the Younger Dryas. Altogether, the isotopic composition of lake water (δ18OL) and of the dissolved inorganic carbonate (δ13CDIC) reconstructed from adult Pseudocandona marchica, as well as the seasonal water temperature contrasts, indicate that the major shifts in the δ18O of local precipitation at Gerzensee were augmented by changes of the lake's water balance, with relatively higher evaporative loss occurring during the Allerød compared with the Younger Dryas. It is possible that during the early Preboreal the lake might even have been hydrologically closed for a short period. We speculate that such hydrologic changes reflect a combination of varying evapotranspiration and a rearrangement of groundwater recharge during those climatic shifts.

Hydrogen isotope data of aquatic and terrestrial lipid biomarkers from Lake Meerfelder Maar during the Younger Dryas

Here we use compound-specific hydrogen isotope data of aquatic and terrestrial lipid biomarkers from precisely dated annually laminated sediments from Lake Meerfelder Maar (MFM) in Western Germany to reconstruct decadal resolved hydroclimatic changes during the Younger Dryas. We show that cooling at MFM begun synchronous to the onset of cooling in Greenland at 12.850 years BP. Major environmental changes at MFM however took place 170 years later as a result of substantially drier conditions.

Eliot the younger; a fiction in freehand.

Mode of access: Internet.

Selected letters of Pliny /

Mode of access: Internet.

Selected letters of Pliny;

Latin text, English editorial matter.

Familiar letters on various subjects of business and amusement : written in a natural, easy manner, with a view, chiefly, to form the style of the younger part of both sexes ... /

Mode of access: Internet.

Abridgement of Murray's English grammar, with an appendix, containing exercises in orthography, in parsing, in syntax, and in punctuation. Designed for the younger classes of learners. To which questions are added--punctuation, and the notes under rules in syntax, supplied from the author's large grammar. Being his own abridgement entire, rev., prepared, and adapted to the use of the "English exercises."

Mode of access: Internet.

Sermons preached to a country congregation : to which are added, a few hints for sermons, intended chiefly for the use of the younger clergy /

Pie de imp. v. 2-4: Printed by Strahan and Preston

Princetoniana. Charles & A. A. Hodge: with class and table talk of Hodge the younger.

Mode of access: Internet.

Travels of Anacharsis the younger in Greece, during the middle of the fourth century before the Christian era.

Atlas has imprint: Dublin, M. Mills, 1795.

The Drawings of Holbein the younger.

Bibliography: p. 40.

Botany for beginners: an introduction to Mrs. Lincoln's Lectures on botany. For the use of common schools and the younger pupils of higher schools and academies.

Mode of access: Internet.