scholarly journals Bacteria, guano and soot: Source assessment of organic matter preserved in black laminae in stalagmites from caves of the Sierra de Atapuerca (N Spain)

2021 ◽  
Vol 50 (2) ◽  
pp. 121-135
Author(s):  
Joeri Kaal ◽  
Virginia Martínez-Pillado ◽  
Antonio Martínez Cortizas ◽  
Jorge Sanjurjo Sánchez ◽  
Arantza Aranburu ◽  
...  
Keyword(s):  
Organic Matter ◽  
Human Activities ◽  
Ex Situ ◽  
Formation Processes ◽  
Karst System ◽  
Northern Spain ◽  
Human Fossil ◽  
Soot Deposition

Speleothems are a recognized source of paleoclimatic information, but their value as a source of signals from human activities in caves with an archaeological record has rarely been explored. Previous studies of speleothems in the Sierra de Atapuerca karst system (Burgos, northern Spain) revealed an important human fossil record, provided information about human activities in and around these caves, and the impacts on their natural environment. The present study reports the results of molecular characterization of dark-colored laminae from the stalagmites Ilargi (Galería de las Estatuas) and GS1, GS2, and GS3 (Galería del Silo), by pyrolysis-GC-MS (Py-GC-MS) and thermally assisted hydrolysis and methylation (THM-GC-MS). The features of the organic matter demonstrate the presence of (1) a dominant aliphatic fraction probably from in situ bacterial and ex situ plant-derived lipids, (2) black carbon (from soot and/or charcoal), (3) polysaccharides and N-rich moieties (probably from bat guano and microbial sources), and (4) a signal of terpenoid derivatives that may originate from the overlying limestone (kerogen) and extant gymnosperm resin (soils) or cyanobacteria (cave). Some plant-derived lignin may be present as well but was not identified unambiguously. It is concluded that this approach allows identifying multiple general sources of organic matter which can help understand speleothem formation processes, and evidence of soot deposition could be clearly linked to human activities.

Design and comparison of ex situ and in situ devices for Raman characterization of lithium titanate anode material

Ionics ◽  
2011 ◽  
Vol 17 (6) ◽  
pp. 503-509 ◽  
Author(s):  
Jie Shu ◽  
Miao Shui ◽  
Dan Xu ◽  
Shan Gao ◽  
Tingfeng Yi ◽  
...  
Keyword(s):  
Anode Material ◽  
Lithium Titanate ◽  
Ex Situ ◽  
Raman Characterization

In-situ and ex-situ characterization of surface oxide films on AB5-type metal hydride electrodes

1999 ◽  
Vol 293-295 ◽  
pp. 747-750 ◽  
Author(s):  
J.M Nan ◽  
Y Yang ◽  
J.K You ◽  
X.Q Li ◽  
Z.G Lin
Keyword(s):  
Metal Hydride ◽  
Oxide Films ◽  
Surface Oxide ◽  
Ex Situ ◽  
Metal Hydride Electrodes

scholarly journals In-Situ and Ex-Situ Characterization of Evolution of Defects in AlGaN/GaN HEMTs under Bias

2013 ◽  
Vol 19 (S2) ◽  
pp. 452-453
Author(s):  
H. Ghassemi ◽  
A. Lang ◽  
C. Johnson ◽  
R. Wang ◽  
B. Song ◽  
...  
Keyword(s):  
Ex Situ ◽  
Gan Hemts

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

scholarly journals Hydrogen isotopic anomalies in extraterrestrial organic matter: role of cosmic ray irradiation and implications for UCAMMs

2019 ◽  
Vol 627 ◽  
pp. A122 ◽  
Author(s):  
B. Augé ◽  
E. Dartois ◽  
J. Duprat ◽  
C. Engrand ◽  
G. Slodzian ◽  
...  
Keyword(s):  
Organic Matter ◽  
Infrared Spectroscopy ◽  
Spatial Scale ◽  
Secondary Ion Mass Spectrometry ◽  
Isotopic Fractionation ◽  
Cosmic Ray ◽  
High Energy ◽  
Galactic Cosmic Rays ◽  
Ex Situ

Context. Micrometeorites represent, at timescales shorter than a few million years, the dominant source of extraterrestrial matter at the surface of the Earth. Analyses of ultracarbonaceous micrometeorites recovered from Antarctica, known as UCAMMs reveal an exceptionally N-rich organic matter associated with spatially extended high D enrichments. Experiments show that this specific organic matter might have been formed in the outer solar system by energetic irradiation of N-rich icy surfaces. Aims. We experimentally investigate the hydrogen isotopic fractionation resulting from irradiation of normal and D-rich N2-CH4 ices by high energy ions, simulating the exposition to Galactic cosmic rays of icy bodies surfaces orbiting at large heliocentric distances. Methods. Films of N2-CH4 ices and a N2-CH4/CD4/N2-CH4 “sandwich” ice were exposed to 129Xe13+ ion beams at 92 and 88 MeV. The chemical evolution of the samples was monitored using in situ Fourier transform infrared spectroscopy. After irradiation, targets were annealed to room temperature. The solid residues of the whole process left after ice sublimation were characterized in situ by infrared spectroscopy, and the hydrogen isotopic composition measured ex situ by imaging secondary ion mass spectrometry at the sub-micron scale (NanoSIMS). Results. Irradiation leads to the formation of new molecules and radicals. After annealing, the resulting poly-HCN-like macro-molecular residue exhibits an infrared spectrum close to that of UCAMMs. The residue resulting from irradiation of N2-CH4 ices does not exhibit a significant deuterium enrichment comparable to that found in extraterrestrial organic matter. The residue formed by irradiation of D-rich ices shows the formation of isotopic heterogeneities with localised hotspots and an extended contribution likely due to the diffusion of the radiolytic products from the D-rich layer. Conclusions. These results show that high-energy cosmic ray irradiation does not induce the large hydrogen isotopic fractionation observed at small spatial scale in interplanetary organics. By contrast, large D/H ratio heterogeneities at the sub-micron spatial scale in extraterrestrial organic matter can result from isotopically heterogeneous ices mixtures (i.e. condensed with different D/H ratios), which were transformed into refractory organic matter upon irradiation.

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