Guano means "the droppings of sea birds" in Quechua language (Perú)
The US passed the Guano Islands Act in 1856 giving citizens discovering a source of guano the right to take possession of unclaimed land and entitlement to exclusive rights to the deposits. However, the guano could only be removed for the use of citizens of the United States. This enabled US citizens to take possession of unoccupied islands containing guano.
Control over guano played an important role in the War (1864-1866) between Spain and a Peruvian-Chilean alliance since Spain occupied with its navy the Chincha Islands depriving Peru of lucrative income.
Large Xerox copies of tinfoil / like natural guano accumulations/ simple making process/ highly uncontrolled result composition/ mountain drawings/