Chronostratigraphy of eastern Mediterranen Sea sediment cores

An Accelerator Mass Spectrometry (AMS) 14C dated multiparameter event stratigraphy is developed for the Aegean Sea on the basis of highly resolved (centimeter to subcentimeter) multiproxy data collected from four late glacial to Holocene sediment cores. We quantify the degree of proportionality and synchroneity of sediment accumulation in these cores and use this framework to optimize the confidence levels in regional marine, radiocarbon-based chronostratigraphies. The applicability of the framework to published, lower-resolution records from the Aegean Sea is assessed. Next this is extended into the wider eastern Mediterranean, using new and previously published high-resolution data from the northern Levantine and Adriatic cores. We determine that the magnitude of uncertainties in the intercore comparison of AMS 14C datings based on planktonic foraminifera in the eastern Mediterranean is of the order of ±240 years (2 SE). These uncertainties are attributed to synsedimentary and postsedimentary processes that affect the materials dated. This study also offers a background age control that allows for vital refinements to radiocarbon-based chronostratigraphy in the eastern Mediterranean, with the potential for similar frameworks to be developed for any other well-studied region.

(Table 1) Compositional variation with depth in a nodule of sediment sample RVG-10D

A detailed study of a nodule from the Somali Basin dated by 230Thexcess was correlated with the paleoceanographic events recorded in Site 236 (Leg 24) Deep Sea Drilling Project (DSDP) cores. Tentative indications are that the phase of nodule accretion starting with the development of pillar structure at a depth of 20 mm in the nodule around 13 Ma coincides with increased Antarctic Bottom Water (AABW) flow and an elevated calciumcarbonate compensation depth (CCD). The Late Miocene lowering of the CCD is represented by the mottled zones between 8 and 18 mm in the nodule is characterised by an abundant silicate component (>20%) of aeolian origin. The Miocene/Pliocene boundary (5 Ma) occurs at a depth of about 8 mm and is represented by the development of pillar structure and a minimum of aeolian dust (10.3%). The increased biological productivity of the Somali surface water since the Middle Miocene is demonstrated by the increasing Corg content of the nodule (from 0.11 to 0.19%) towards its surface.

Rapid methods for the chemical analysis of special steels, steel-making alloys, their ores and graphites,

Table on lining-paper.

Summary report :

"December 22, 1959."

The true stress-strain properties of brittle materials to 5000° F : final report.

"5081-1190-XIV ; July 28, 1961."

The Arcades at the Palais Royal

Louis Léopold Boilly; 1 ft. 2 3/8 in. x 1 ft. 5 63/64 in.; pen and black ink with black and grey wash over traces of graphite on paper

Édouard Manet, Seated, Holding His Hat

Edgar Degas; 1 ft. 1 1/32 in.x 9 1/16 in.; graphite and black chalk on wove (China) paper