1 For subsidence caused by sudden collapse of the ground to form sinkholes, several measures can be taken. 2  First, geologists can make maps of areas known to be underlain by rocks like limestone, gypsum, or salt, that are susceptible to dissolution by fluids.
The Navajos used bows and arrows, spears, clubs, tomahawks, knives and sticks among their tools and weapons. Beyond these, they also used bolas and... The Navajos used bows and arrows, spears, clubs, tomahawks, knives and sticks among their tools and weapons. Beyond these, they also used bolas and blowguns. The Navajos employed the use of several tools and weapons:Bows and arrows were used by Native Americans to defend themselves, and sometimes for fishing. They also used them for hunting animals like bison.When fighting against European explorers, Native Americans used spears.
Mayan Construction: Tools The ancient Mayas did not use metal tools because metals were not common to the area that they inhabited. The tools that they had to work with were very simple. They used tools such as fire and basalt axes on wood. Fire was very unpredictable so they switched to basalt axes for a little more precision. On stone they used tools made of flint, obsidian, granite, limestone, and quartzite(Stierlin 132).