Other
Scientific paper
Mar 2005
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005e%26psl.232..109p&link_type=abstract
Earth and Planetary Science Letters, Volume 232, Issue 1-2, p. 109-123.
Other
12
Scientific paper
The sediments of Lake Chiemsee, located in the Alpine foreland in Southern Germany, host a variety of magnetotactic bacteria (MTB), which contain intracellular crystals of magnetite arranged in linear chains. To detect bacterial magnetite in the carbonate-dominated surface sediments and further quantify its contribution to the magnetic signal of the sediments, we conducted detailed rock magnetic measurements as well as complimentary non-magnetic analyses (electron microscopy, powder X-ray diffraction, and sediment pore-water analysis). Our results demonstrate that biogenic single-domain magnetite (characterized by bullet- and truncated hexagonal prismatic shapes) is the dominant ferrimagnetic component in the topmost few centimetres of the sediment. The changes of magnetic properties with depth are due to the occurrence of live MTB and the downward increasing dissolution of biogenic magnetite. Moreover, the ratios of remanence loss on warming through the Verwey transition after field cooling and zero-field cooling of saturation isothermal remanence (δFC/δZFC) were determined as 1.47 and 1.25 for freeze-dried and air-dried sediment samples containing MTB, respectively. These low ratios suggest that the bacterial magnetite chains were disrupted to a large extent and/or that the bacterial magnetosomes might have undergone partial low-temperature oxidation. It is proposed that although rock magnetic measurements are suitable for quantifying the contribution of fine-grained particles to the overall magnetic signal of sediments, complementary non-magnetic methods are essential to unambiguously identify its bacterial origin.
Davila Alfonso F.
Hanzlik Marianne
Liu Qingsong
Pan Yongxin
Petersen Nikolai
No associations
LandOfFree
The detection of bacterial magnetite in recent sediments of Lake Chiemsee (southern Germany) does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The detection of bacterial magnetite in recent sediments of Lake Chiemsee (southern Germany), we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The detection of bacterial magnetite in recent sediments of Lake Chiemsee (southern Germany) will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1214911