Holocene climate change, vegetation history and human impact in the Central Mediterranean: evidence from the Maltese Islands

Holocene climates and human impact in the Mediterranean basin have received much attention, but the Maltese Islands in the Central Mediterranean, although a pivotal area, have been little researched. Here, sedimentary and palynological data are presented for three cores from the Holocene coastal and shallowmarine
deposits of the Maltese Islands. These show deforestation from Pinus-Cupressaceae woodland in the early Neolithic, and then a long, but relatively stable history of agriculturally degraded environments to the present day. The major climate events which have affected the Italian and Balkan peninsulas to the
north, and Tunisia to the south, are not reflected in the pollen diagrams from the Maltese Islands because of the strong anthropogenic imprint on the Maltese vegetation from early in the Neolithic. Previous suggestions of environmentally-driven agricultural collapse at the end of the Neolithic appear, however,
to be substantiated and may be linked to regional aridification around 4300 cal. BP. Depopulation in early Medieval times is not supported by the current palynological evidence.

Pristine Early Eocene Wood Buried Deeply in Kimberlite from Northern Canada

We report exceptional preservation of fossil wood buried deeply in a kimberlite pipe that intruded northwestern Canada's Slave Province 53.3±0.6 million years ago (Ma), revealed during excavation of diamond source rock. The wood originated from forest surrounding the eruption zone and collapsed into the diatreme before resettling in volcaniclastic kimberlite to depths >300 m, where it was mummified in a sterile environment. Anatomy of the unpermineralized wood permits conclusive identification to the genus Metasequoia (Cupressaceae). The wood yields genuine cellulose and occluded amber, both of which have been characterized spectroscopically and isotopically. From cellulose d O and d H measurements, we infer that Early Eocene paleoclimates in the western Canadian subarctic were 12-17°C warmer and four times wetter than present. Canadian kimberlites offer Lagerstätte-quality preservation of wood from a region with limited alternate sources of paleobotanical information. © 2012 Wolfe et al.