"Geological" might not be the correct term here. Who really cares about the geology of earth here on earth if a gigantic sunspot explodes and creates a gigantic solar mass ejection that wipes out life here on earth?
A full description of how sun spots are formed is given elsewhere. If the sun has undergone cyclic variations in its gravitational field, then it also has undergone cyclic variations in its stability. As the sun becomes less stable, it would create more sunspots, and consequently more solar eruptions that could have negatively affected earth. (Of course, this will eventually happen again.)
The Ball-of-Light Particle Model predicts that a star is more stable when it is being accelerated, and thus is inducing higher gravitational forces. When a star is decelerating, it will induce less gravitational forces, become less stable and decay more rapidly. When a star decays more rapidly, then the radiation given off of course will have a negative impact of on any nearby planets with life.