weathering

Most trace elements, including manganese and arsenic, get into the water through the natural process of rock weathering.

Now, the bits of rock, the inorganic input to soil, uh...they come from the breakdown of rocks on Earth's surface through a process called weathering.

Weathering can be either physical or chemical.

Physical weathering, uh...that's when exposure to the elements over time causes a rock to break up and eventually disintegrate.

Groundwater is stored in the pore spaces and joints of rocks and unconsolidated (unsolidified) sediments or in the openings widened through fractures and weathering.

During this epoch, sediment was made by the kind of erosion and weathering that happens when the climate was colder.

Now, just as rocks are broken down by weathering, the animal and plant residues are broken down, too.

The clay minerals you find in soil are the result of chemical weathering.

It differs from physical weathering in that the chemical properties of the minerals are actually changed.

Now, chemical weathering, uh... that's the chemical breakup of rocks.

If you think of the sand particles in soil, those are the result of physical weathering, and they have the same chemical composition as the original rock.

Uh... of course, some rocks are more resistant to physical weathering than others. 

His team suggests that at least the smaller Buddha might be partially rebuilt with existing fragments injected with a synthetic material designed to halt weathering.