They shall grow not old, as we that are left grow old:
Age shall not weary them, nor the years condemn.
At the going down of the sun and in the morning,
We will remember them.
This EarthCache will take you to the highest point in Scarborough. The war memorial here can be seen on the horizon at a great distance from many parts of Scarborough. It was unveiled on 26 September 1923, where it commemorated civilians and servicemen who died in the first world war. After the second world war and then again after the Korean war, more names were added. It stands as a great monument to those, willingly or otherwise, who made the ultimate sacrifice in service of their country, as well as those who kept the home fires burning.
Now for your geology lesson.
Oxidisation is a process that occurs when oxygen reacts with the material, occurring faster in humid air. It involves a loss of electrons in the material being oxidised. Some elements lose electrons more easily than others, making these elements more susceptible to oxidisation. Many metals, particularly iron, oxidises easily.
Lichen is a composite organism, meaning that it forms by symbiosis of multiple organisms. The mutual symbiosis of lichen is between a fungus and either an algae, cyanobacteria or both. The fungus benefits from this symbiosis because it obtains carbon, a food source, from the other organism(s), that feed themselves through photosynthesis. The algae and/or cyanobacteria benefit because the filaments of the fungi protects them from the environment, as well as gathering moisture and nutrients.
There are three rock types: Igneous, metamorphic and sedimentary.
Igneous rock is formed through the cooling and solidification of magma, located in the mantle and crust of Earth, or lava.
Granite is a common example of igneous rock, which forms after magma crystalises before reaching Earth’s surface. Granite can be found deep underground in nearly every continent, especially in the continental crust of Earth. It is particularly common in mountainous regions. To our knowledge, Earth is the only planet in our solar system that has granite. Because of the high pressure involved in the formation and the slowness of the cooling process, granite has coarse grain-sized crystals and is very strong. Granite has a melting point of around 1240°C, although this varies. When water is present, however, this can reduce to around 650°C.
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 and pressure, causing profound physical and/or chemical change.
Slate is an example of metamorphic rock. It is formed under relatively low temperature and pressure. Slate forms from what is originally a fine clay, sometimes with sand or volcanic dust. Slate can be black, grey, red, green, blue or purple. Dark slate typically have their colour because of carbonaceous material or finely divided iron sulfide. Important minerals in slate include flakes of chlorite, small amounts of mica and lens-shaped grains of quartz. Slate is split from quarried blocks, by lightly tapping with a mallet, with a chisel positioned against the edge of a block of slate. The mallet causes cracks that appear in the direction of cleavage, which can then be split into two with the chisel. These slate slabs have a high tensile strength and are smooth and even. This process can be repeated to obtain more pieces.
Sedimentary rocks are formed by the deposition and subsequent cementation of material at Earth's surface. Sedimentation is the collective name for processes that cause mineral and/or organic particles to settle in place. The particles that form a sedimentary rock by accumulation are called sediment.
Sandstone is a common example of sedimentary rock. It forms over time as fragmented rocks, sand, and similarly-sized minerals deposit. Rocks that are a source of sandstone are weathered by water and wind, causing them to erode and be carried away. They can be continually recycled over millions of years. The grains tend to be smaller as the distance the rock travels increases. The sand sediments often mix with other minerals, such as calcites, feldspars and quartz. The resulting grains are turned into sandstone from the pressure of the sediments above and the water that passes through. The gaps are filled in and cemented together by the mixture of the finer grains and the new mineral growth of natural silica or carbonate.
To log this EarthCache, you must do two things.
The first is to send me, via message centre or email, your answers to the following questions:
1a. Describe the colour, texture and general appearance of the obelisk.
1b. What rock is it made from?
1c. Is the rock igneous, sedimentary or metamorphic?
2. There are some faint areas of red discolouration. One example is the vertical-facing surface on the south-facing side. What causes this?
3. There are some whitish patches. The east-facing side is a good place to look at. What is this?
4a. Observe the vertical-facing corners of the obelisk. How does the texture and colour pattern differ compared to the adjacent horizontal surface?
4b. Along with your observations for 4a, also note that the corners are rougher. What causes this?
The second thing to do is to upload a photograph of yourself at GZ. If you don't want yourself in the photograph, you can instead take a photograph of an item with your Geocaching name written on it. Either way, the photograph should prove that you were at GZ.
Also be warned that there is some misinformation on the internet regarding this obelisk, particularly pertaining to its rock type, so I would advise against relying on internet searches specific to this monument to answer the questions.
Thanks to Wandafree for sharing her geological expertise with me as I was setting these questions.