A spectral natural gamma-ray log in a 190 m borehole in Faxe chalk
quarry confirms that Danish bryozoan and corallic limestones
contain very low levels of natural radioactivity. Due to the low
content of natural radioactivity it has been possible to observe
the influence from cosmic radiation. The upper 20 m of the SNG-log
shows a peak at 2.2 MeV caused by neutrons captured in hydrogen.
As no neutron source is present, the neutrons originate from
interactions beteen energetic cosmic radiation and the atoms of
the chalk. Below 20 m no 2.2 MeV signal is observed.
| Number of pages | 15 |
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| Publication status | Published - 1996 |
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