Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Geomagnetic field intensity in the middle jurassic - oligocene   The present paper summarizes results of the studies on the intensity of
geomagnetic field in the (167 - 23) Ma interval by sedimentary rocks of the
Russian Plate and adjacent territories. The joint analysis of the data
paleointensity obtained by sedimentary and thermomagnetized (from PINT12) rocks
within this temporal interval is conducted. It is shown that the changes of the
paleointensity were occurred chaotically. Alternating bursts and periods of
quiet regime of the geomagnetic field are typical for intermittent processes
and is a characteristic of the geological interval Jurassic-beginning of
Paleogene. The distributions of the paleointensity corresponding to different
intervals of geologic time were investigated. It is revealed that the
cumulative distribution function (CDF) of the paleointensity values is best
approximated by a power function. The indices of the power functions varied
depending on geologic time intervals.The analysis of the paleomagnetic data
suggests that the medium in which the geomagnetic field is generated is
turbulent. Turbulence in the Earth's liquid core is enhanced in the Cretaceous
compared with Jurassic and Paleogene.

4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio