This is an EarthCache, there is no physical container to search for. The posted co-ordinates bring you to an interesting feature of Carrickfergus Pier.
SEDIMENTARY ROCK
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles to settle in place.
SANDSTONE
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Old Red Sandstone, is a thick sequence of Devonian rocks (formed from 416 million to 359.2 million years ago) that are continental rather than marine in origin and occur in northwestern Europe, Scandinavia, Greenland, and northeastern Canada. Most sandstone is composed of quartz or feldspar (both silicates) because they are the most resistant minerals to weathering processes at the Earth's surface. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are whites & yellows from quartz & calcite, black, grey, tan or brown from pyroxene or biotite and reds or pinks from iron oxides.
STRATIFICATION
Stratification is the layering that occurs in most sedimentary rocks and in those igneous rocks formed at the Earth's surface The layers range from several millimetres to many metres in thickness and vary greatly in shape. The 'strata' may appear as alternate layers of course or fine particles, the colour may change due to different mineral compsition in that layer. The most common cause of stratification is the transporing ability of the depositing agent. The wind or water sort and settle the layers.
Now we know a bit about the rock we are going to look at, let's take a look! There is an interesting piece of rock at GZ - it caught my eye anyway. I have obscured the stone - under the green block is where the focus is.
To log this Earthcache Please contact me through my profile with the answer to questions 1-4. Please send the answers before logging your find, you don't have to wait for a reply to log it, if there is a problem I will contact you.
Questions:
1. Observe & measure the interesting stone at GZ. Describe the colour, texture and the angle of stratification.
2. In your opinion what caused the differences in this stone compared to the stone below.
3. What do you think is the predominant mineral within these stones, why do you think so.
4. How old is the stone you are looking at?
5. Upload a photo of yourself or personal item in the area.