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Geochronological Implications Of 210Pb And 137Cs Mobility In Cave Guano Deposits, Donald A. Mcfarlane, Joyce Lundberg
Geochronological Implications Of 210Pb And 137Cs Mobility In Cave Guano Deposits, Donald A. Mcfarlane, Joyce Lundberg
International Journal of Speleology
Some recent publications on the paleo- and historical environmental interpretation of bat guano sequences have relied on 210Pb and 137Cs distribution to establish age-depth models, even when these are at odds with radiocarbon models in the lower parts of the sequence. Here, we present both field and laboratory evidence for the unpredictable mobility of lead and cesium in decomposing bat guano deposits. We suggest that 210Pb- and 137Cs-based chronologies of bat guano deposits should only be used when independently supported, for example, by a robust radiocarbon age-depth model.
The Impact Of Burning On The Structure And Mineral Composition Of Bat Guano, Joyce Lundberg, Donald A. Mcfarlane
The Impact Of Burning On The Structure And Mineral Composition Of Bat Guano, Joyce Lundberg, Donald A. Mcfarlane
International Journal of Speleology
Here we addressed the question of whether burning of guano produces a characteristic suite of morphological changes and/or unique mineralogical products. The changes observed in our experimental burning of guano (both fresh and decayed) included colour change (blackening), grain size and morphological change (grain size generally reduced, morphology rendered generally less distinct), alteration of minerals by dehydration (e.g., gypsum to anhydrite, brushite to whitlockite), and production of new minerals or compounds (e.g., augelite, bayerite, giniite, graphite, oldhamite, strontium apatite, tridymite). The key morphological feature we found that may be diagnostic of burning was severe damage to crystals from rapid dehydration …
New Records Of Guano-Associated Minerals From Caves In Northwestern Borneo, Donald A. Mcfarlane, Joyce Lundberg
New Records Of Guano-Associated Minerals From Caves In Northwestern Borneo, Donald A. Mcfarlane, Joyce Lundberg
International Journal of Speleology
Recent studies of ancient bat guano deposits in the caves of Gunung Mulu National Park and Niah National Park, Sarawak, Malaysia, have resulted in noteworthy records of phosphate minerals from these environments, including variscite, nano-particulate silica, fluorapatite, and niter.