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GeoBioScience: Red Wood Ants as Bioindicators for Active Tectonic Fault Systems in the West Eifel (Germany).

Berberich G, Schreiber U - Animals (Basel) (2013)

Bottom Line: The results showed linear alignments and clusters of approx. 3,000 RWA mounds.A possible cause can be found in occasionally occurring H₂S in the fault systems, which is toxic at miniscule concentrations to the ants.Viewed overall, there is a strong relationship between RWA mounds and active tectonics in the West Eifel.

View Article: PubMed Central - PubMed

Affiliation: Department of Geology, Faculty of Biology, University of Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany. gabriele.berberich@uni-due.de.

ABSTRACT
In a 1.140 km² study area of the volcanic West Eifel, a comprehensive investigation established the correlation between red wood ant mound (RWA; Formica rufa-group) sites and active tectonic faults. The current stress field with a NW-SE-trending main stress direction opens pathways for geogenic gases and potential magmas following the same orientation. At the same time, Variscan and Mesozoic fault zones are reactivated. The results showed linear alignments and clusters of approx. 3,000 RWA mounds. While linear mound distribution correlate with strike-slip fault systems documented by quartz and ore veins and fault planes with slickensides, the clusters represent crosscut zones of dominant fault systems. Latter can be correlated with voids caused by crustal block rotation. Gas analyses from soil air, mineral springs and mofettes (CO₂, Helium, Radon and H₂S) reveal limiting concentrations for the spatial distribution of mounds and colonization. Striking is further the almost complete absence of RWA mounds in the core area of the Quaternary volcanic field. A possible cause can be found in occasionally occurring H₂S in the fault systems, which is toxic at miniscule concentrations to the ants. Viewed overall, there is a strong relationship between RWA mounds and active tectonics in the West Eifel.

No MeSH data available.


Related in: MedlinePlus

GeoBioScience: Relationship between RWA mound sites and gaspermeable tectonic fault systems showing gas anomalies: Along the open systems geogenic gas concentrations exceed atmospheric standards (He > 5,220 ppb) and background values (CO2 > 2 Vol%; Rn, CH4 and H2S depending on the geological setting). Linear alignment of RWA mounds occurs if the gaspermeable fault is running open for a very long distance, e.g., 3 km at the Oberehe site (West Eifel, cf.Figure 5(b)). At crosscut zones of tectonic fault systems clusters of RWA mounds occur. Solitary mounds can be found mostly at unusual locations with spotty degassing [28].
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animals-03-00475-f003: GeoBioScience: Relationship between RWA mound sites and gaspermeable tectonic fault systems showing gas anomalies: Along the open systems geogenic gas concentrations exceed atmospheric standards (He > 5,220 ppb) and background values (CO2 > 2 Vol%; Rn, CH4 and H2S depending on the geological setting). Linear alignment of RWA mounds occurs if the gaspermeable fault is running open for a very long distance, e.g., 3 km at the Oberehe site (West Eifel, cf.Figure 5(b)). At crosscut zones of tectonic fault systems clusters of RWA mounds occur. Solitary mounds can be found mostly at unusual locations with spotty degassing [28].

Mentions: Red wood ants (RWA; Formica rufa-group (Hymenoptera: Formicidae)) are useful bioindicators for the identification of active tectonic fault systems (cf.Figure 3) [28,36]. A particular advantage of the RWA is their high sensitivity to environmental changes. Forced by some million years of evolutionary selection they developed anticipatory mechanisms. Besides an extremely strong temperature sensitivity (0.25 K), they have chemo-receptors for the detection of CO2-concentrations and an electromagnetic field sensitivity [37,38,39,40,41,42]. As early as the beginning of the last century, entomologists presumed a dependency of spatial RWA mound distributions on geological formations [43,44,45]. Work [46] already stated in 1929 that there are no preferred locations of RWA mounds within a forest stand. Typical in-line alignments of RWA mounds regardless of any preferred direction, i.e., edge effects of forest stands and/or roads, were described for the nature reserve Rudolfshagen [47]. Consequently, an integrated GeoBioScience-approach requires the consideration of the interaction between the abiotic (e.g., tectonic processes) and biotic (e.g., preferred settlement sites by RWA) environment.


GeoBioScience: Red Wood Ants as Bioindicators for Active Tectonic Fault Systems in the West Eifel (Germany).

Berberich G, Schreiber U - Animals (Basel) (2013)

GeoBioScience: Relationship between RWA mound sites and gaspermeable tectonic fault systems showing gas anomalies: Along the open systems geogenic gas concentrations exceed atmospheric standards (He > 5,220 ppb) and background values (CO2 > 2 Vol%; Rn, CH4 and H2S depending on the geological setting). Linear alignment of RWA mounds occurs if the gaspermeable fault is running open for a very long distance, e.g., 3 km at the Oberehe site (West Eifel, cf.Figure 5(b)). At crosscut zones of tectonic fault systems clusters of RWA mounds occur. Solitary mounds can be found mostly at unusual locations with spotty degassing [28].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494391&req=5

animals-03-00475-f003: GeoBioScience: Relationship between RWA mound sites and gaspermeable tectonic fault systems showing gas anomalies: Along the open systems geogenic gas concentrations exceed atmospheric standards (He > 5,220 ppb) and background values (CO2 > 2 Vol%; Rn, CH4 and H2S depending on the geological setting). Linear alignment of RWA mounds occurs if the gaspermeable fault is running open for a very long distance, e.g., 3 km at the Oberehe site (West Eifel, cf.Figure 5(b)). At crosscut zones of tectonic fault systems clusters of RWA mounds occur. Solitary mounds can be found mostly at unusual locations with spotty degassing [28].
Mentions: Red wood ants (RWA; Formica rufa-group (Hymenoptera: Formicidae)) are useful bioindicators for the identification of active tectonic fault systems (cf.Figure 3) [28,36]. A particular advantage of the RWA is their high sensitivity to environmental changes. Forced by some million years of evolutionary selection they developed anticipatory mechanisms. Besides an extremely strong temperature sensitivity (0.25 K), they have chemo-receptors for the detection of CO2-concentrations and an electromagnetic field sensitivity [37,38,39,40,41,42]. As early as the beginning of the last century, entomologists presumed a dependency of spatial RWA mound distributions on geological formations [43,44,45]. Work [46] already stated in 1929 that there are no preferred locations of RWA mounds within a forest stand. Typical in-line alignments of RWA mounds regardless of any preferred direction, i.e., edge effects of forest stands and/or roads, were described for the nature reserve Rudolfshagen [47]. Consequently, an integrated GeoBioScience-approach requires the consideration of the interaction between the abiotic (e.g., tectonic processes) and biotic (e.g., preferred settlement sites by RWA) environment.

Bottom Line: The results showed linear alignments and clusters of approx. 3,000 RWA mounds.A possible cause can be found in occasionally occurring H₂S in the fault systems, which is toxic at miniscule concentrations to the ants.Viewed overall, there is a strong relationship between RWA mounds and active tectonics in the West Eifel.

View Article: PubMed Central - PubMed

Affiliation: Department of Geology, Faculty of Biology, University of Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany. gabriele.berberich@uni-due.de.

ABSTRACT
In a 1.140 km² study area of the volcanic West Eifel, a comprehensive investigation established the correlation between red wood ant mound (RWA; Formica rufa-group) sites and active tectonic faults. The current stress field with a NW-SE-trending main stress direction opens pathways for geogenic gases and potential magmas following the same orientation. At the same time, Variscan and Mesozoic fault zones are reactivated. The results showed linear alignments and clusters of approx. 3,000 RWA mounds. While linear mound distribution correlate with strike-slip fault systems documented by quartz and ore veins and fault planes with slickensides, the clusters represent crosscut zones of dominant fault systems. Latter can be correlated with voids caused by crustal block rotation. Gas analyses from soil air, mineral springs and mofettes (CO₂, Helium, Radon and H₂S) reveal limiting concentrations for the spatial distribution of mounds and colonization. Striking is further the almost complete absence of RWA mounds in the core area of the Quaternary volcanic field. A possible cause can be found in occasionally occurring H₂S in the fault systems, which is toxic at miniscule concentrations to the ants. Viewed overall, there is a strong relationship between RWA mounds and active tectonics in the West Eifel.

No MeSH data available.


Related in: MedlinePlus