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.
The Caddo made stone tools such as these axe heads or celts and attached them to wooden handles for many wood-working tasks. A dome-shaped grass house. For hundreds of years, the Caddo Indians built huge dome-shaped houses, temples, and other structures without using modern equipment or tools!They had no chainsaws or metal axes to cut down the tall pine trees from the forests.They had no metal hammers and nails to join the pieces of their houses together.he Caddo made stone tools such as these axe heads or celts and attached them to wooden handles for many wood-working tasks. A dome-shaped grass house. For hundreds of years, the Caddo Indians built huge dome-shaped houses, temples, and other structures without using modern equipment or tools!