Soil organic matter as an important contributor to Late Quaternary sediments of the tropical West African continental margin

2005 ◽  
Vol 69 (8) ◽  
pp. 2031-2041 ◽  
Author(s):  
Jens Holtvoeth ◽  
Sadat Kolonic ◽  
Thomas Wagner
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Continental Margin ◽  
Late Quaternary ◽  
West African ◽  
Quaternary Sediments ◽  
Important Contributor

scholarly journals Combination of Numerical Dating Techniques Using 10Be in Rock Boulders and 14C of Resilient Soil Organic Matter for Reconstructing the Chronology of Glacial and Periglacial Processes in a High Alpine Catchment during the Late Pleistocene and Early Holocene

Radiocarbon ◽  
2009 ◽  
Vol 51 (2) ◽  
pp. 537-552 ◽  
Author(s):  
Filippo Favilli ◽  
Markus Egli ◽  
Dagmar Brandova ◽  
Susan Ivy-Ochs ◽  
Peter W Kubik ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Late Quaternary ◽  
Chemical Characterization ◽  
Soil Formation ◽  
Parent Material ◽  
Surface Dynamics ◽  
Exposure Dating ◽  
Minimum Age ◽  
Absolute Dating

Glacier fluctuations and paleoclimatic oscillations during the Late Quaternary in Val di Rabbi (Trentino, northern Italy) were reconstructed using a combination of absolute dating techniques (14C and 10Be) and soil chemical characterization. Extraction and dating of the stable fraction of soil organic matter (SOM) gave valuable information about the minimum age of soil formation and contributed to the deciphering of geomorphic surface dynamics. The comparison of 10Be surface exposure dating (SED) of rock surfaces with the 14C ages of resilient (resistant to H2O2 oxidation) soil organic matter gave a fairly good agreement, but with some questionable aspects. It is concluded that, applied with adequate carefulness, dating of SOM with 14C might be a useful tool in reconstructing landscape history in high Alpine areas with siliceous parent material. The combination of 14C dating of SOM with SED with cosmogenic 10Be (on moraines and erratic boulders) indicated that deglaciation processes in Val di Rabbi were already ongoing by around 14,000 cal BP at an altitude of 2300 m asl and that glacier oscillations might have affected the higher part of the region until about 9000 cal BP. 10Be and 14C ages correlate well with the altitude of the sampling sites and with the established Lateglacial chronology.

Late Quaternary Vegetation Dynamics in the Southern Amazon Basin Inferred from Carbon Isotopes in Soil Organic Matter

2001 ◽  
Vol 55 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Hermes Augusto de Freitas ◽  
Luiz Carlos Ruiz Pessenda ◽  
Ramon Aravena ◽  
Susy Ely Marques Gouveia ◽  
Adauto de Souza Ribeiro ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Carbon Isotopes ◽  
Vegetation Dynamics ◽  
Amazon Basin ◽  
Late Quaternary ◽  
Savanna Vegetation ◽  
Forest Regions ◽  
Dry Conditions ◽  
Forested Areas

AbstractCarbon isotopes of soil organic matter (SOM) were used to evaluate and establish the chronology of the vegetation dynamics of an ecosystem presently composed of savannas surrounded by forests. The study was carried out on a 200-km transect along highway BR 319, on the border of Amazonas and Rondônia states, in southern Amazon, Brazil. Large ranges in δ13C values were observed in SOM collected from profiles in the savanna (−27 to −14‰) and forest regions (−26 to −19‰), reflecting changing distribution of 13C-depleted C3 forest and 13C-enriched C4 savanna vegetation in response to climate change. These results indicate that from about 17,000 to 9000 14C yr B.P., the study area was covered by forest vegetation. Between approximately 9000 and 3000 14C yr B.P., savanna vegetation expanded at the expense of the forest. Although the expansion of savanna did not occur with the same intensity along the study transect, this process was very clearly registered by 13C-enrichment in the SOM. Since 3000 14C yr B.P., the carbon isotope data suggest that forested regions have expanded. This study adds to the mounting evidence that extensive forested areas existed in the Amazon during the last glaciation and that savanna vegetation expanded in response to warm and dry conditions during the early to middle Holocene.

Variation in Radiocarbon Ages of Soil Organic Matter Fractions from Late Quaternary Buried Soils

1995 ◽  
Vol 43 (2) ◽  
pp. 232-237 ◽  
Author(s):  
Charles W. Martin ◽  
William C. Johnson
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Great Plains ◽  
Radiocarbon Dating ◽  
Late Holocene ◽  
Late Quaternary ◽  
Buried Soils ◽  
Contamination Of Soils ◽  
Total Fraction ◽  
Organic Matter Fractions

AbstractRadiocarbon dating of three organic matter fractions (total, humic acid, and residue) isolated from late Quaternary buried soils of the central Great Plains reveals that there often are considerable differences among, but no consistent order to, the ages of fractions. For late Holocene soils, the residue fraction or the total fraction generally produces the oldest age; for late Pleistocene soils, however, no fraction was consistently the oldest. The absence of a consistent sequence of fraction ages is attributed to postburial contamination of soils. When bulk samples from the same soil were split and sent to two laboratories, different radiocarbon ages were usually obtained. The variability in radiocarbon ages of soil organic matter confirms that caution should be taken when using radiocarbon ages obtained from different laboratories to make regional stratigraphic correlations.

scholarly journals Origin of the organic matter in the Late Quaternary sediments of the eastern margin of Japan Sea

2009 ◽  
Vol 68 (2) ◽  
pp. 117-128 ◽  
Author(s):  
Antonio Fernando Menezes Freire ◽  
Taissa Rego Menezes ◽  
Ryo Matsumoto ◽  
Toshihiko Sugai ◽  
Dennis James Miller
Keyword(s):  
Organic Matter ◽  
Late Quaternary ◽  
Japan Sea ◽  
Quaternary Sediments ◽  
Eastern Margin
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