Spatial variability in modern tropical peat deposits from Sarawak, Malaysia and Sumatra, Indonesia: analogues for coal

1994 ◽  
Vol 26 (1-2) ◽  
pp. 1-41 ◽  
Author(s):  
J.S. Esterle ◽  
J.C. Ferm
Radiocarbon ◽  
2008 ◽  
Vol 50 (3) ◽  
pp. 359-372 ◽  
Author(s):  
Raphael A J Wüst ◽  
Geraldine E Jacobsen ◽  
Haitse von der Gaast ◽  
Andrew M Smith

Various organic fractions of an Indonesian tropical peat deposit were dated using radiocarbon accelerator mass spectrometry (AMS). Four different depth layers, deposited during the last 28,000 14C yr, were analyzed and the data compared to bulk sample analyses. The pollen extracts consistently produced the oldest dates. The bulk samples (<250 μm and <100 μm) often yielded the youngest dates. The age difference between the individual fractions depended on the layer depth and hence the true age of the sampled peats. The age discrepancy was highest (∼16,000 14C yr) in the oldest peat material. We interpret this to be a consequence of the input of organic matter over a long period of time, with peat oxidation and/or no peat accumulation during the last glacial maximum (LGM). The age discrepancies were smaller (between 10 and 900 14C yr) for the Holocene peat samples. It was concluded that the pollen extract fraction might be the most reliable fraction for dating tropical peat deposits that are covered by deeply rooting vegetation.


Geologos ◽  
2014 ◽  
Vol 20 (4) ◽  
pp. 269-288 ◽  
Author(s):  
Dominik Pawłowski ◽  
Daniel Okupny ◽  
Wojciech Włodarski ◽  
Tomasz Zieliński

Abstract Geostatistical methods for 2D and 3D modelling spatial variability of selected physicochemical properties of biogenic sediments were applied to a small valley mire in order to identify the processes that lead to the formation of various types of peat. A sequential Gaussian simulation was performed to reproduce the statistical distribution of the input data (pH and organic matter) and their semivariances, as well as to honouring of data values, yielding more ‘realistic’ models that show microscale spatial variability, despite the fact that the input sample cores were sparsely distributed in the X-Y space of the study area. The stratigraphy of peat deposits in the Ldzań mire shows a record of long-term evolution of water conditions, which is associated with the variability in water supply over time. Ldzań is a fen (a rheotrophic mire) with a through-flow of groundwater. Additionally, the vicinity of the Grabia River is marked by seasonal inundations of the southwest part of the mire and increased participation of mineral matter in the peat. In turn, the upper peat layers of some of the central part of Ldzań mire are rather spongy, and these peat-forming phytocoenoses probably formed during permanent waterlogging.


2008 ◽  
Vol 7 (1) ◽  
pp. 1-5
Author(s):  
S. K. Balasundram ◽  
M. H. A. Husni ◽  
O. H. Ahmed

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