Complex sentence: The northern quadrant of Trawscoed Fort showed up easily on the greyscale plot of the results, and sections of the ramparts showed evidence of burning, evidenced by stronger magnetic reactions at points along the rampart.
Split into simpler sentences: The northern quadrant of Trawscoed Fort showed up easily on the greyscale plot of the results, and sections of the ramparts showed evidence of burning. Burning is evidenced by stronger magnetic reactions at points along the rampart.