If someone is buried after death, it is customary to place some sort of grave marker to honor and remember that person. Although grave markers have come a long way with modern material compositions, visit almost any cemetery and you will see signs of deterioration. Some grave markers are so deteriorated that the inscriptions on them are either impossible or extremely difficult to read. This is because of a process called weathering. Weathering is the decomposition of rocks, soils, and minerals through direct contact with the Earth's atmosphere and it is often a very slow process.
Weathering is often confused with erosion, but the word erosion implies that the rock has been subjected to transport processes which has worn it down. Rocks are transported by water in rivers or by waves. They can be moved by glaciers or rock falls or landslides. Small particles of rock can be blown by wind. All of these transport processes make rocks smaller, but only weathering will break down rock which stays in one place.
WEATHERING PROCESS (TYPE)
Weathering falls into three types of processes - Physical, Chemical and Biological. It is common to see more than one type of process on a grave stone.
Physical
Physical Weathering breaks apart rocks without changing their chemical composition. Each fragment and particle weathered away by a mechanical process retains the same characteristics as the original rock.
TEMPERATURE - Different minerals expand and contract at varying rates. Temperature changes occur in both day-night and seasonal cycles. Frost shattering or ice wedging is due to the expansion of ice.
WIND - The abrasive action of wind causes separation of rock particles from the parent rock.
WATER - The abrasive action of water also causes separation of rock particles from the parent rock.
GRAVITY - As rocks tumble downward, abrasion causes separation of rock particles from parent rock.
Chemical
Chemical weathering occurs when water, air, and other substances react with the minerals in rock. In chemical weathering, the composition of the rock changes.
WATER - Water dissolves minerals in rocks, producing new compounds.
OXYGEN - Oxygen reacts with rocks, changing the color of rocks.
ACIDS - Produced when water reacts with the atmosphere.
LIGHTNING STRIKES - The immense energy completely changes the rock.
Biological
Living organisms contribute to mechanical weathering through the growth of roots or the burrowing of animals.
VASCULAR PLANTS (larger and grow out from the rocks) - Plant roots and seedlings sprouting in a crevice exert physical pressure as well as providing a pathway for water and chemical infiltration. The evidence that some soil is present is found in the plants which appear to be growing "out" of the rock. In reality, these plants have roots that are growing in soil that is located in the cracks of the rock.
NONVASCULAR PLANTS (smaller and cover surface of rocks) - Lichens and mosses grow on essentially bare rock surfaces and create a more humid chemical microenvironment. The attachment of these organisms to the rock surface enhances physical as well as chemical breakdown of the surface microlayer of the rock.
ANIMALS - There are many animals that break apart rocks, or consume rocks, for a variety of purposes, most of which ends up changing the rock in some way.
LOGGING REQUIREMENTS
In order to log this EarthCache, send me your answers to the following questions. Please follow all cemetery rules, CITO, replace fallen flags, and respect the area. Cemetery hours are SUNRISE to SUNSET. Allow yourself 20-30 minutes to finish this Earthcache.
Find each of the following headstones to make your observations. (Several coordinate readings have been taken and averaged.) Additional descriptions for the stone markers you need to evaluate are located in the waypoints.
Stage 1: Illegible
This old cylindrical monument shows a good example of physical weathering. What do you see that supports that weathering type?
Stage 2: M Gilgen
What types of weathering are present at this location? Which is the most prominent?
Stage 3: Stotzer / MacDonald
What area of this mausoleum is showing chemical weathering? Describe what you see.
Stage 4: Greenleaf
What type of weathering is present here? Give some descriptions of what you are seeing.