Complex sentence: The Manquez agglutinate above the Tumbres deposits was formed either by the Tumbres eruption or by a subsequent stage; a pyroclastic cone in the western crater may be associated with this agglutinate.
Split into simpler sentences: The Manquez agglutinate above the Tumbres deposits was formed either by the Tumbres eruption or by the next stage. A pyroclastic cone in the western crater may be associated with this agglutinate.