New york state bedrock of which age contains
salt, gypsum, and hematite?
(1) cambrian (3) mississippian
(2) devonian (4) silurian

The New York State bedrock contained salt, gypsum and hematite during the Silurian age. The Silurian age started around 443.8 million years ago.  The bedrock gives scientists a clear indication of when each age started and ended. The Silurian age is also an important period in the evolution of life on the earth. During this age, life began to appear on the land in the form of small, moss-like, vascular plants. They started growing next to lakes, coastlines and streams. Small terrestrial arthropods also starting appearing during the Silurian age. 

Mantle convection is the process that drives plate tectonics. the theory of plate tectonics states that the crust is divided into plates that float on the semi molten mantle below. the circular motion of the magma as it slowly rises and falls or move though convection cells drags the plates along causing them to move. the heat source in the lamp would represent the earth's core. the core is the source of energy that drives convection in the mantle. the lava represents molten magma under the earth's surface. if the lava lamp had floating pieces they would move as the circular motion of the lava in the lamp as it rises and falls would move them along the surface. these floating pieces would represent pieces of the earth's crust.