Complex sentence: As the southern supercontinent Gondwana drifted over the South Pole, ice caps formed on it, which have been detected in late Ordovician rock strata of North Africa and then-adjacent northeastern South America, which were south-polar locations at the time.
Split into simpler sentences: As the southern supercontinent Gondwana drifted over the South Pole, ice caps formed on it. The strata have been detected in late Ordovician rock strata of North Africa and then-adjacent northeastern South America, which were south-polar locations at the time.