When geologists want to study an active earthquake fault, they often rely on a trenching study. ... They brace the walls, if needed, to prevent cave-ins, then they climb down into the trench and carefully map its walls, looking for signs of past earthquakes and ground movement.
The sequence of events that can lead to magma becoming soil is C. crystallization followed by exposure and weathering. Under these circumstances it may happen that magma actually turns to soil - it cools off so much that it becomes the ground we walk upon.
The answer is C. Rubber. Iquitos profited greatly from the boom of the rubber industry, beginning in the 1900s.
Prior to the existence of the nation-state, Europe was comprised of several multi ethnic empires, the largest and most powerful of which was the Holy Roman Empire. Territory changed hands often. Many times, this took place because of marriage or as a result of war.
