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Here at GZ you will find the Bradbourne Obelisk it sits here, 5 meters high, on the former site of Bradbourne House.
Bradbourne House (or Hall) in Sevenoaks was originally a timber-framed manor house, surrounded by a moat in the early days. This was replaced by a stone mansion in 1689. The Bosville family came to Bradbourne in 1555 and stayed there until 1761. Later residents included the Betenson family, Francis Crawshay, and the Lambardes. After standing empty for over a decade, the Hall was eventually demolished in 1937. Modern houses were later built on the site, but the lakes beyond the former mansion still exist.
The Obelisk is made of Solid Granite so I thought this would be a good start for a Earth Cache, so here goes and hope you enjoy, Happy Caching.
"Granite" is a common type of Igneous rock that has large granular structure, the crystals were formed over a long time as the rock slowly cooled. The word "granite" comes from the Latin granum, a grain, in reference to the coarse-grained structure.
The term 'Granite' also applies to a group of intrusive igneous rocks with similar textures and slight variations on composition and origin. These rocks mainly consist of feldspar, quartz, mica, and amphibole minerals, which form interlocking, somewhat irregular matrix of feldspar and quartz with scattered darker biotite mica and amphibole peppering the lighter color minerals.
Granites can be mainly white, pink, or gray in color, depending on their mineral make up. By definition, granite is an igneous rock with at least 20% quartz and up to 65% alkali feldspar by volume.
The pinker Granites would contain a higher percentage of Feldspar where as the Lighter ones have more Quartz and the Darker Granites have biotite, mica and amphibole as the main mineral present.
Granite is nearly always massive (lacking any internal structures), hard and tough, and has been used widely throughout human history, and more recently as a construction stone. The average density of granite is between 2.65 and 2.75 g/cm3, Melting temperature of dry granite is 1215–1260 °C or (2219–2300 °F).
Granite has poor primary permeability (allowing water to pass through the rock), but strong secondary permeability (The permeability developed in a rock after its deposition, through such processes as weathering and fracturing).
Granite is usually found in the continental plates of the Earth's crust, Outcrops of granite tend to form tors and rounded massifs. Granites sometimes occur in circular depressions surrounded by a range of hills.
Granite has been intruded into the crust of the Earth during all geologic periods, although much of it is of Precambrian age (4.6 billion years ago). Granitic rock is widely distributed throughout the continental crust and is the most abundant basement rock that underlies the relatively thin sedimentary veneer of the continents, therefore, granitic rocks form the basement of all land continents.
In some areas, granite is used for gravestones and memorials. Granite is a hard stone and requires skill to carve by hand. Until the early 18th century, in the Western world, granite could only be carved by hand tools with generally poor results.
A key breakthrough was the invention of steam-powered cutting and dressing tools by Alexander MacDonald of Aberdeen, inspired by seeing ancient Egyptian granite carvings. In 1832, the first polished tombstone of Aberdeen granite to be erected in an English cemetery. Granite memorials became a major status symbol in Victorian Britain.
Modern methods of carving include using computer-controlled rotary bits and sandblasting over a rubber stencil. Leaving the letters, numbers and emblems exposed on the stone, the blaster can create virtually any kind of artwork.
Granite is also widely used in the building industry, not only for strong building blocks but also decorative polished floor and wall surfaces, also granite chippings are used on railways a a strong base for the Sleepers holding the tracks, to sit upon.
Now you know a little bit about Granite here is the "Nitty Gritty" Bit you need for My Earth Cache
IN ORDER TO CLAIM A FIND ON THIS EARTH CACHE,YOU NEED TO EMAIL ME (through my geocaching Profile). THE ANSWERS TO THE FOLLOWING QUESTIONS.
1, --- The Bradbourne Obelisk is 5 meters high, How long is the Largest Horizontal rock at the base ???
2, --- At the Base of the Obelisk are 4 large rocks, one of which is not Granite but is another type of rock,
a -- Which one of the rock is this ??? (i.e. Largest, Medium or smallest) ???
b -- What do you think this rock is ??
3, --- Now looking closely at the at the rocks at the base of the Obelisk, you will see that the Granite contains many different color's in its make up
a -- Please can you name the Lightest color mineral ?
b -- Name the Hexagonal shaped crystals that are opaque and light brown in color ?
NOTE : "The two different Mineral names, not just the colors are needed !!"
4, --- How does the grains in the granite rocks compare to those in the "odd one out", type of rock at the Obelisk Base ???
Please describe the difference in texture and feel between the two ??
5, --- This is not compulsory but would be nice, that is to take a photo of yourself or GPSr at GZ and post it along with your log, its always nice to see folk enjoying an Earth Cache. !!
Thank-you for coming and finding my Earth Cache, Please Email me, Through my profile, Your Earth Cache answers, Then feel free to Log Your Find, !!
Any logs received without the answer in an email will be delete (sorry but that's the Rules).
Additional Hints
(Decrypt)
Vgf svir zrgref uvtu, lbh pnag zvff vg !!