Earthcaches are there for us to learn and see, but many of them are off the beaten track, where not all can get to, this is an attempt to try and meet the need of others who are not as able as others.
Bury, is one of those Lancashire towns that many just associate with black pudding and the market, but spend you time looking and there is geology to be had. This earthcahe takes you to just off Silver Street in Bury, which is an easy walk / wheelchair push / mobile ride from the town centre. I have brought you to see the Bury Unitarians' War Memorial, which records the names of those from three congregations (Chesham, Heywood and Bank Street, Bury), who died in the two world wars. Take your time to pay your respect, and read some of the names, which are not just men.
The majority of war memorials are made from stone of some kind, and now stand sentinal to the slaughter of the world wars, but we can also look their geology when we pay our respects.
There are three main types of stone.
Igneous rock is formed through the cooling and solidification of magman or lava. Igneous rock may form with or without crystallisation. An example is granite.
Sedimentary rocks are types of rock that are formed by the deposition and subsequent cementation of that material at the surface and within bodies of water. Sedimentation is the collective name for processes that cause particles to settle in place. The particles that form a sedimetary rock by accumulating are called sediment. Before being deposited, the sediment was formed by weathering and erosion from the source area, and then transported to the place of deposition. An example of this is sandstone. Sedimentation may also occur as minerals precipitate from water solution or shells of aquatic creatures settle out of suspension, an example of this is limestone.
Metamorphic rocks arise from the transformation of existing rock types, in a process called metamorphism, which means change in form.The original rock is subjected to heat (temperatures greater than 150 to 200 °C) and pressure (1500 bars ),causing profound physical and/or chemical change. The original may be a Sedimentary rock, an igneous rock or another older metamorphic rock. Examples include slate and marble.
What we have here is a sedimentary rock known as limestone, and a metamorphic rock known as slate.
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate. Most limestone is composed of skeletal fragments of marine organisms. Most limestones form in shallow, calm, warm marine waters. That type of environment is where organisms capable of forming calcium carbonate shells and skeletons can easily extract the needed ingredients from ocean water. When these animals die their shell and skeletal debris accumulate as a sediment that might be lithified into limestone. Their waste products can also contribute to the sediment mass. Limestones formed from this type of sediment are biological sedimentary rocks. Their biological origin is often revealed in the rock by the presence of fossils. Limestone tends to be white, or grey colour.
Slate is a fine-grained metamorphic rock derived from an original shale type sedimentary rocks composed of clay or volcanic ash through low-grade regional metamorphism. It can be found in many shades of grey, including some which has a greenish tinge.
So this is an earthcache, in order for you to log your find, I ask that you complete a series of questions and send them to me, please do not include them in your log. However, please do log when you send your questions.
1. Using the information provided, what part of the memorial is made of limestone, and which part made from slate?
2. Please feel both types and describe their texture to touch, and how they are different from each other.
3. What colour is the limestone and the slate?
4. Can you see any fossils, if so please describe them.
5. Now there is a bit of history to this memorial, please name the only female on it.