At the listed coordinates you will arrive to one of the entrances to the 5 Star, The Merchant Hotel.
Formerly known as the Ulster Bank's head office, the building dates from 1858. It comprises a two-storey Italianate sandstone façade, paired windows, and a three-bay pediment with elaborate sculptures and urns.
The building was designed by James Hamilton with carving by the Fitzpatrick Brothers, and the main contractors were Messrs D & J Fulton. The stone was originally to be quarried in France, but Hamilton feared that the French stone would erode too quickly, and thus an alternative stone was used, despite its being considerably more expensive.
Rocks are classified according to characteristics such as mineral and composition, permeability, texture of the constituent particles, and particle size. These physical properties are the result of the processes that formed the rocks. Over the course of time, rocks can be transformed from one type into another, as described by a geological model called the rock cycle.
This transformation produces three general classes of rock: igneous, sedimentary, and metamorphic.
Igneous
Igneous rock is formed through the cooling and solidification of magma or lava. This magma may be derived from partial melts of pre-existing rocks in either a planet's mantle or crust. Typically, the melting of rocks is caused by one or more of three processes: an increase in temperature, a decrease in pressure, or a change in composition.
Igneous rocks are divided into two main categories:
- Plutonic or intrusive rocks result when magma cools and crystallizes slowly within the Earth's crust. A common example of this type is granite.
- Volcanic or extrusive rocks result from magma reaching the surface either as lava or fragmental ejecta, forming minerals such as pumice or basalt.
Sedimentary
Sedimentary rocks are formed at the Earth's surface by the accumulation and cementation of fragments of earlier rocks, minerals, and organisms or as chemical precipitates and organic growths in water (sedimentation). This process causes clastic sediments (pieces of rock) or organic particles (detritus) to settle and accumulate or for minerals to chemically precipitate from a solution. The particulate matter then undergoes compaction and cementation at moderate temperatures and pressures.
Metamorphic
Metamorphic rocks are formed by subjecting any rock type (sedimentary rock, igneous rock or another older metamorphic rock) to different temperature and pressure conditions than those in which the original rock was formed. This process is called metamorphism, meaning to "change in form". The result is a profound change in physical properties and chemistry of the stone. The original rock, known as the protolith, transforms into other mineral types or other forms of the same minerals, by recrystallization. The temperatures and pressures required for this process are always higher than those found at the Earth's surface: temperatures greater than 150 to 200 °C and pressures greater than 1500 bars. This occurs, for example, when continental plates collide.
Granite
Granite is a coarse-grained intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground. It is common in the continental crust of Earth, where it is found in igneous intrusions. These range in size from dikes only a few centimetres across to batholiths exposed over hundreds of square kilometres. Granite is nearly always massive (lacking any internal structures), hard, and tough. These properties have made granite a widespread construction stone throughout human history.
Granitic rocks mainly consist of feldspar, quartz, mica, and amphibole minerals, which form an interlocking, somewhat equigranular matrix of feldspar and quartz with scattered darker biotite mica and amphibole (often hornblende) peppering the lighter colour minerals. Occasionally some individual crystals (phenocrysts) are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic texture is known as a granite porphyry. Granitoid is a general, descriptive field term for lighter-coloured, coarse-grained igneous rocks. Granites can be predominantly white, pink, or grey in colour, depending on their mineralogy.
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. 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 colour due to impurities within the minerals, but the most common colours are tan, brown, yellow, red, grey, pink, white, and black.
Giffnock Sandstone
Giffnock Sandstone is a Carboniferous sandstone from the Glasgow area. During the Carboniferous Period, Scotland was located close to the equator and experienced tropical conditions. In the Midland Valley Region sands, silts and muds were deposited under deltaic conditions and it was from these that Giffnock Sandstone eventually formed. Giffnock is described as a 'freestone' because of its textural uniformity and as such is often seen as dressings and carved detail on buildings.
Giffnock is fine to medium-grained and when fresh is buff coloured with specks of darker mineral grains visible. Exposure results in oxidation of the vast iron minerals in the stone surface forming a hardened rust-brown outer layer. If this layer is breached, decay of the underlying sandstone may proceed rapidly.
Scrabo Sandstone
Scrabo Sandstone is a Triassic sandstone which outcrops Dundonald and Newtownards is a variety of colours from warm, rich yellow, orange and deep red to paler grey and pink hues, but has been modified during the eruption of the Antrim lavas 60 million years ago and gave rise to the more predominant paler grey varieties.
Geological evidence shows that these desert sandstones were disturbed by explosions and intrusions of hot, molten magma. In fact, this is why the sandstone at the Scrabo Quarries is so well preserved, as a sill of black dolerite emplaced 60 million years ago caps the sandstone and has protected it from weathering and erosion. At microscopic level, the stone shows quartz and feldspar grains cemented together with weak iron cements and calcite. This is reflected in the accessory mineral assemblage of the stone that includes soft and fibrous needles of talc and actinolite visible in the pore spaces.
The range of colours, pre and post alternation, and its relative ease of working made Scrabo sandstone attractive for stonemasons. The stone was found to split relatively easily along bedding planes due to its sedimentary nature.
How to log this Earthcache
Please send your answers to me over the messaging service. Do not wait for a response from me to log your find, I will contact you if there are any issues. Logged finds with no answers sent will be deleted.
Questions
- Describe the texture and colour of the façade at Stage 1.
- What type of rock is the façade at Stage 1 made from?
Look at the steps at Stage 1.
- What type of rock is this?
- Why do you think it has been inserted here and the steps are not entirely the same as the surrounding steps and façade?
Look at the building at Stage 2. The stone belongs to the same family of rock as the Stage 1 façade, but there is a big difference in the appearance.
- What is the main difference and why do you think this is?
Optional
- Take a photo of yourself, your geocaching name or a personal object at the GZ.
Best wishes, warmest regards
!!Congratulations sgtzara on their FTF!!
