The posted coordinates are a good place to park and start.
WEATHERING
Weathering is defined as the breakdown of rock, that is without being moved. Weathering processes depend upon the presence of water, the temperature, the mineral composition of the rock and its chemical composition.
WHY HERE?
Headstones are subjected to weathering simply by standing in a cemetery. Headstones provide a useful means of observing and measuring the weathering of different types of rock over relatively long and easily measurable periods of time. The markers in this cemetery contain all three types of rocks: Sedimentary (sandstone), Igneous (granite) and Metamorphic (marble) making it valuable for comparison of headstone weathering.
WEATHERING FACTORS
The weathering on headstones is a product of four interconnected factors.
The four factors are:
Material the headstone is made from
Environment the headstone is in
Form of the weathering on the headstone
Process by which the headstone is weathered
WEATHERING PROCESS (TYPE)
Weathering falls into three types of processes - Physical, Chemical and Biological.
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 either through email or messaging from my profile page.
Find each of the following headstones to make your observations.
Reference point 1: E C Bartlett - N 42° 43.654' W 83° 25.689'
Describe two processes of weathering present.
Reference point 2: Fred - N 42° 43.619' W 83° 25.636'
What kind of Biological processes is present?
Reference point 3: David & Myrtle Miller - N 42° 43.644' W 83° 25.642'
What kind of Physical processes is present?
Reference point 4: Cross - N 42° 43.669' W 83° 25.663'
All three processes are present here. Give one example of each.
* Pictures are not required but are appreciated. Please post a pic of you or your GPS with anything you find interesting around the cemetery.
Resources
https://spadeandthegrave.com/2019/05/05/the-geologic-composition-weathering-of-gravestones/
https://www.ucl.ac.uk/earth-sciences/impact/public-engagement/londons-geology/londons-geology-fieldwork/st-pancras-gardens/gravestone#:~:text=In%20simple%20terms%2C%20weathering%20is,to%20300%20years%20or%20more).
https://www.wyorksgeologytrust.org/misc/Teaching%20weathering%20in%20West%20Yorkshire.pdf
https://www.livescience.com/18681-cemetery-gravestones-weathering-acid-rain.html