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Long-term summer temperature variations in the Pyrenees from detrended stable carbon isotopes

Esper J., Konter O., Krusic P. J., Saurer M., Holzkämper S., Büntgen U.

Geochronometria

2015

Vol. 42, no.1

53--59

Substantial effort has recently been put into the development of climate reconstructions from tree-ring stable carbon isotopes, though the interpretation of long-term trends retained in such timeseries remains challenging. Here we use detrended δ13C measurements in Pinus uncinata treerings, from the Spanish Pyrenees, to reconstruct decadal variations in summer temperature back to the 13th century. The June-August temperature signal of this reconstruction is attributed using decadally as well as annually resolved, 20th century δ13C data. Results indicate that late 20th century warming has not been unique within the context of the past 750 years. Our reconstruction contains greater amplitude than previous reconstructions derived from traditional tree-ring density data, and describes particularly cool conditions during the late 19th century. Some of these differences, including early warm periods in the 14th and 17th centuries, have been retained via δ13C timeseries detrending — a novel approach in tree-ring stable isotope chronology development. The overall reduced variance in earlier studies points to an underestimation of pre-instrumental summer temperature variability derived from traditional tree-ring parameters.

Black "marble" in the Polish architecture - characteristics and possibility of its provenance determination: the case of the Dębnik limestone

Marszałek M.

Geology, Geophysics and Environment

2014

Vol. 40, no. 2

189--205

Black limestone, also known as black "marble", was widely used in the Polish small-scale architecture and art of the 17th and 18th centuries. Besides the Devonian limestone from Dębnik near Krakow, also popular were the Netherlandish (Wallonian), Devonian to Carboniferous limestones from the Meuse River and Schelde River valleys. This paper deals with the possibility of identifying the rocks imported to Poland. Macroscopic similarities between the Netherlandish rocks and some Dębnik limestones have been highlighted for the oldest Carmelite quarry in Dębnik, exploiting the best stones. The analyses include: optical microscopy, scanning electron microscopy with EDS, X-ray diffraction, X-ray fluorescence and isotope ratio mass spectrometry (13 C and 18 O stable isotopes). Carboniferous limestones from Netherlands can be identified within and distinguished from the Dębnik limestone in the macroscopic observations. Differences, depending on the varieties, are associated primarily with the presence of white calcite fragments of fossils, calcite veins intersecting the rock in all directions or hardness of the limestones. Deeply black Devonian limestones from Wallonia and Dębnik without macrofossils and calcite veins differ in microscopic observations considering their texture, type of microfossils and inventory of non-carbonate components. The characteristic graying and whitening of the black limestones has also been discussed as a possible feature of rock provenance.