3.1. Paleomagnetic Results
Sedimentary samples were demagnetized generally up to 20 mT (for details
see Table S2) which removed the viscous remanent magnetization component
causing change in the direction of remanent magnetization during such
demagnetization for most of the samples. Intensity of the natural
remanent magnetization (NRM) of the samples varies between 8.5-34.1e-3
A/m. Median destructive field (MDF) values where samples lost half of
its magnetization range between 5-8 mT for the samples. NRM intensity
and MDF values of the samples are shown in supplementary figures (Table
S3). Maximum angular deviation (MAD) values for Matuyama and Brunhes
sections are between 0.3o-5.4o(Figure 5). These values for transition section are between
0.7o-5.3o which is relatively
reliable for detection of the migration of the paleomagnetic vector from
a reversed to normal polarity (Figure 5). Comparisons of MAD values with
previous studies (Okada et al., 2017; Sagnotti et al., 2014) shows the
relative magnitude of fluctuations.
In this study, paleomagnetic data showed inclination values changing by
approximately 90o when measuring the sediment from
12.8 to 7.1 cm depth (Figure 6). This revealed the transition nature of
the Matuyama-Brunhes magnetic reversal in Za Hajovnou cave. Below this
depth, there is a Matuyama section which has inclination fluctuations
between -6.3o-88.7o (Figure 6).
Inclination angle changes between
33o-65.9o for Brunhes section above
transition (Figure 6). Also, transition from reversed to normal polarity
can be seen in declination data with similar depth (Figure 6). Despite
the fluctuations, magnetic intensity values which can depend on the
concentration variation of magnetic carriers of every individual sample,
were decreasing for the Matuyama section from the bottom to the
transition (Figure 6). After the transition from reversed to normal
polarity, these values kept increasing which can be seen in Brunhes
section between 7.1-0 cm depth (Figure 6). Figure 6 shows the data in
comparison with other studies that consisted of various sediment types
and locations around the world. Depth of the data sets was normalized
considering the transition zone amd differences of sedimentation rate
for each study and is not given in Figure 5, 6. Even though, there are
some differencies in absolute values, comparisons of this data set with
other studies showed that fluctuations and frequency of fluctuations in
our data is consistent with other data sets and serves as a supporting
argument for Matuyama-Brunhes magnetic reversal in Za Hajovnou cave
(Figure 6).