Once you arrive at GZ you will notice many old gravesones in various states of decay. This is because of the materials used to create them and the weathering process. Hopefully you have read this EC cache page prior to walking around .
This EC has been approved by the local HOA Board.
What is Weathering
There are two basic classifications of weathering processes – physical and chemical weathering; and each can involve biological or non-biological components.
Physical weathering, also called mechanical weathering, is the class of processes that causes the weathering of rocks without chemical change. The primary process in physical weathering is abrasion. Thermal stress weathering occurs when temperature changes cause the expansion and contraction of rock. Frost weathering occurs when water seeps into cracks in the rock, and then expands as the water freezes, exerting pressure on the surrounding rock. Wind can carry sand and other sediments, which over time can wear away the surface of rocks. Plant roots sometimes get into cracks in rocks and pry them apart, resulting in disintegration.
Chemical weathering changes the chemical composition of rocks, often when water interacts with minerals to create various chemical reactions. One of the most common chemical weathering processes is carbonation, where atmospheric carbon dioxide reacts with chemicals in the rock. Carbonation occurs on rocks which contain calcium carbonate, such as limestone and chalk. Acid rain also causes chemical weathering. A number of plants and animals may create chemical weathering through release of acidic compounds. Lichens, algae, and moss all produce various chemical compounds that can react with chemicals in some rocks.
Biological weathering
This is a type of weathering caused by plants and animals. Plants and animals release acid forming chemicals that cause weathering and also contribute to the breaking down of rocks and landforms. I've included this type because there is a nice example of it here in this cemetery.
The Properties of Different Rocks and Materials Used for Gravestones
The most common materials used for gravestones in this cemetery include granite, marble, limestone, slate, and sandstone. Granite and marble are not native to the area; these stones were imported from elsewhere. Limestone, slate, and sandstone are quarried locally, although gravestones made from these materials can be from local or imported stone. Additionally for a short period headstones were also made of zinc Granite is an igneous rock which consists mainly of quartz, mica, and feldspar. It is granular in texture, and can be pink to gray in color, depending on their chemistry and mineralogy. Granite is hard and tough, and therefore it has gained widespread use as a construction stone.
Marble is a metamorphic rock composed of recrystallized limestone. Marble is commonly used for sculpture and as a building material. Marble has been used in sculptures, buildings, and gravestones since classical times. This is due to its softness, which makes it easy to carve, its relatively homogenous consistency, and a resistance to shattering.
an example
Slate is a fine-grained, foliated metamorphic rock that comes from an original shale-type sedimentary rock composed of clay or volcanic ash. Slate is foliated, or layered. It commonly is formed in layers that can be split or broken apart. Because of this foliation, slate is commonly used to make roofing tiles. Due to its resistance to heat and its chemical inertness, slate has been used for laboratory bench tops. In areas where it is available, high-quality slate is often used for tombstones.
an example
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite. Many limestones are made from the skeletal fragments of marine organisms such as coral or foraminifera. Like most other sedimentary rocks, most limestone is composed of grains, making it somewhat porous. Limestone was a popular building material in the late 19th and early 20th centuries. The Bloomington, Indiana area has long been a source of high quality quarried limestone, and much of the limestone used in the Cincinnati area came from Bloomington. Limestone and marble react with acid solutions, making acid rain a significant problem to the preservation of gravestones made from them. Limestone was also quarried in an open pit and tunnel mine just north of Lewisburg.
an example
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains. Sandstone is usually very porous, which allows percolation of water and other fluids. Sandstone was commonly used for headstones because it was inexpensive, available locally, and easy to carve. Unfortunately, because of its porous nature, sandstone headstones are especially prone to damage due to weathering.
an example
I have used these resourses in creation of this Earth Cache:
1) https://www.bioexplorer.net/biological-weathering.html/
2) https://sciencing.com/biological-weathering-5633317.html
3) https://socratic.org/questions/how-do-plants-cause-weathering
To Log this EC and recieve the smiley please forward your answers to me using the messaging system on geocaching.com
1) What type stone is the primary one used at this Cemetery?
2) Which type of weathering is causing the the most problems here?
3) Very near GZ there is a headstone that is a prime example of Biological Weathering , What name appears on that stone, and what type of material is it made of?
4) At the Biological Weathering site, do you see any other weathering process occuring ?
