Memorial Cross
I was recently walking along the lough shore when I stumbled upon a memorial cross to a disaster near Mount Stewart, the cross was erected by the Marquis and Marchioness of Londonderry in “affectionate remembrance” of Eliza Taunt, Elizabeth Dougal, Joseph Grainge, William Rowe, William and Robert Hagan, who drowned in Strangford Lough on the April 11, 1895.
The four servants from Mount Stewart and two local boatmen (the Hagans), together with two servants visiting from Florence Court House in Fermanagh – Jane Cheshire and William Start – had perished together in the lough. The party had set off on a picnic outing on the lough aboard the ‘Mountstewart’, which was Lady Londonderry’s yacht, and never returned.
There is no parking close to this earthcache it requires a walk, either along the shore or along the pavement on the road from the preferred parking. If you choose to walk along the shore, please check the tide times.
Alternatively if you are a National Trust member you could park at Mount Stewart.
Logging Requirements (Questions to Answer)
Compulsory tasks in order to log a find against this EarthCache, you will need to visit GZ and make some observations and then answer some questions and send answers to me via my Geocaching profile or through the Messenger Centre.
I'VE BEEN INFORMED THE CROSS HAS FALLEN OVER, THOUGH THE INFORMATION NEEDED IS STILL VISIBLE.
We are here to look at different features within the granite memorial cross at GZ.
1) Please describe characteristics of the feature found within the word MARCHIONESS, in particular its shape, size and colour
2) Using the information below, what type of feature can be observed?
3) Please describe characteristics of the feature found within the word DROWNED, in particular its shape, size and colour
4) Given your answer to Q3. (A) Is the feldspar within the feature Orthoclase or Plagioclase, (B) What may be present in the feldspar to give it that colour.
5) Also nclude in your log a photograph of you, your GPS or another identifiable item near GZ, taking care not to include anything in the photo that may give away your answers.
Granite.
Igneous and sedimentary rocks differ significantly in their formation processes and hardness. Igneous rocks originate from the cooling and solidification of molten magma or lava. This process, either deep within the Earth's crust (intrusive) or on its surface (extrusive), results in the formation of crystals, giving igneous rocks a generally hard and crystalline structure. On the other hand, sedimentary rocks are formed through the accumulation and cementation of sediments, such as mineral and organic particles, over time. These sediments are often derived from the weathering and erosion of pre-existing rocks. Due to their formation from loosely compacted materials, sedimentary rocks are typically softer compared to igneous rocks. The contrasting processes of solidification from molten material versus sediment compaction contribute to the distinct textures and hardness levels observed in these two major rock types.
Granite's unique composition makes it ideal for memorials, it is a very robust stone that will last for hundreds of years to come. It has the ability to withstand extreme temperatures as well as general weathering over time.
The quartz is typically transparent or translucent - not unlike glass. The mica is often black or brown but sometimes silvery in nature.The pink colour of feldspar in granite is primarily caused by the presence of a mineral called orthoclase feldspar. Orthoclase feldspar contains small amounts of impurities, such as iron or manganese, which can give it a pink hue. The gray colour of plagioclase feldspar is mainly a result of its mineral composition, which includes a mix of sodium, calcium, and aluminum ions within its structure.
Features that can occur in Granite.
1. Enclaves. Enclaves are fragments of the host rock or magmatic material that are enclosed within a larger rock body, showcasing mingling and mixing of different magmas during crystallization. Enclaves typically exhibit evidence of physical interaction and hybridization between different magmas at various scales, while xenoliths can originate from different depths and environments, such as deep magma chambers or crustal partial melting processes, reflecting diverse geological processes and histories.
2. Aplite Veins. Aplite veins are thin, tabular, or sheet-like intrusive bodies that cut across the host granite. These veins consist of fine-grained, light-colored minerals such as quartz, feldspar, and mica. Aplite veins are formed when late-stage, residual magma with a high silica content intrudes into pre-existing fractures or weaknesses in the granite. The rapid cooling of this silica-rich magma results in the formation of aplite veins, which often form parallel to the foliation of the granite.
3. Phenocrysts. Phenocrysts in granite are large, visible crystals that are embedded within the finer-grained groundmass. Phenocrysts form when certain minerals, such as feldspar, quartz, or mica, crystallize early during the cooling of the granite magma. These early-forming minerals have sufficient time to grow larger in size compared to the surrounding minerals, resulting in the formation of phenocrysts. The presence of phenocrysts can add visual interest and variation to the granite's appearance.
4. Foliation. Granite typically lacks foliation, which refers to a layering or alignment of minerals within a rock due to pressure during its formation. However, in rare cases, foliation can develop in granites that have been subjected to significant tectonic forces or deformation. When pressure causes the minerals within the granite to align in a preferred orientation, foliation may develop, giving the granite a layered or banded appearance.
5. Xenoliths. Xenoliths are rock fragments that are foreign to the granite and become incorporated during its formation. Xenoliths can originate from the country rock that the granite intrudes or from previous magmatic events. When the magma that eventually solidifies into granite assimilates these xenoliths, they are surrounded by the host granite. Xenoliths can introduce different mineral compositions, textures, or colors to the granite, creating localized areas of contrast within the rock.