Complex sentence: Some of the departed at Herjolfsnes had been laid to rest in wooden coffins, but, perhaps owing to the scarcity of wood, it increasingly became the practice to wrap the deceased in layers of wool clothing.
Split into simpler sentences: Some of the departed at Herjolfsnes had been laid to rest in wooden coffins. However, perhaps owing to the scarcity of wood, it increasingly became the practice to wrap the deceased in layers of wool clothing.