Assuming an Earthlike planet orbiting a halo star and passing through the galactic disk, let's look at the case for geological evidence of supernovae. Because the planet is Earthlike we can assume the geological evidence will be effectively the same for the Earth. If its passage through the galactic disk takes it close to more supernovae than the Earth has experienced in its past, then that evidence will give a stronger geological signal.
Past supernovae might be detectable on Earth in the form of metal isotope signatures in rock strata. Subsequently, iron-60 enrichment has been reported in deep-sea rock of the Pacific Ocean by researchers from the Technical University of Munich. Twenty-three atoms of this iron isotope were found in the top 2 cm of crust (this layer corresponds to times from 13.4 million years ago to the present). It is estimated that the supernova must have occurred in the last 5 million years or else it would have had to happen very close to the solar system to account for so much iron-60 still being here. A supernova occurring so close would have probably caused a mass extinction, which did not happen in that time frame. The quantity of iron seems to indicate that the supernova was less than 30 parsecs away. On the other hand, the authors estimate the frequency of supernovae at a distance less than D (for reasonably small D) as around (D/10 pc)3 per billion years, which gives a probability of only around 5% for a supernova within 30 pc in the last 5 million years. They point out that the probability may be higher because the Solar System is entering the Orion Arm of the Milky Way. In 2019, the group in Munich found interstellar dust in Antarctic surface snow not older than 20 years which they relate to the Local Interstellar Cloud. The detection of interstellar dust in Antarctica was done by the measurement of the radionuclides Fe-60 and Mn-53 by highly sensitive Accelerator mass spectrometry, where Fe-60 is again the clear signature for a recent near-Earth supernova origin.
This suggests the amount of Fe-60 present in geological strata may be taken as evidence of close supernovae events.
However, there are more extreme possibilities for the impact of supernovae on Earthlike planets. These will occur when the supernovae are a bit too close for comfort.
Gamma ray bursts from "dangerously close" supernova explosions occur two or more times per billion years, and this has been proposed as the cause of the end Ordovician extinction, which resulted in the death of nearly 60% of the oceanic life on Earth.
The good thing is dangerous close supernovae will be, in general, rare. Unless, of course, the galactic disk is rich in stars undergoing supernova. Then passage through the galactic disk will be somewhat fraught.
In conclusion, the impact of supernovae will appear in geological evidence both in terms of the isotopic abundance of Fe-60 and, possibly, in mass extinction events.
Please note: This has confined itself to considering the evidence for supernovae on the hypothetical Earthlike planet orbiting a halo star.