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The Arch - D_Leslie_A #97 EarthCache

Hidden : 11/28/2017
2 out of 5
1.5 out of 5

Size: Size:   other (other)

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Geocache Description:


The Arch is a six-metre high Roman travertine sculpture positioned on the north bank of the Long Water. It was presented by the artist Henry Moore to the nation for siting in Kensington Gardens in 1980



Opening time: The park is open from 6am to dusk all year round.

(More information further down. BUT first the earth lesson.)




Sedimentary rocks are rocks formed from sediments. They are deposited over time, and often show layers which can be seen in cliffs. Sediments are usually formed from matter which falls to the bottom of oceans and lakes. The matter includes tiny pieces of other rocks, and dead animals, plants and microorganisms. Also, inorganic chemicals may be precipitated from solution in the water. Sedimentary rocks cover 75–80% of the Earth's land area, but they make up only 5% of the Earth's crust.


Travertine is a type of limestone rock, but, unlike limestone it is naturally deposited and created by *geothermally heated hot springs and geysers. Similar (but extremely porous) deposits formed from ambient-temperature water are known as **tufa. It is considered to be a type of limestone which forms due to rapid precipitation of ***calcium carbonate, hence, it is found around mineral spring deposits. Some people would rather call it limestone; yet, it would be a really narrow-minded approach to call this stone only limestone. If we are being technical and extremely specific then we can refer to travertine by its mineral name which is calcium carbonate. When minerals dissolve in the groundwater and get moved by natural springs and rise above the ground, travertine is created. It forms in large blocks, and is taken from quarries and cut down into smaller blocks for more practical loading and unloading processes.



* A hot spring is a spring produced by the emergence of geothermally heated groundwater from the Earth's crust. There are hot springs all over the crust of the earth.

** Tufa is a porous variety of limestone. It is formed by the precipitation of carbonate minerals from water at normal temperatures. Geothermally heated hot springs sometimes produce similar (but less porous) carbonate deposits known as travertine.

*** Calcium carbonate is a chemical compound, with the chemical formula CaCO3. The elements involved are calcium (Ca), carbon (C) and oxygen (O). It is a common substance found as rock in all parts of the world, and is the main component of seashells, snails, and eggshell.


The coloring of the travertine is caused by impurities that are deposited in the bedrock, such as iron, together with the sediments in mineral-rich bodies of water.

As iron is one of the elements which cause travertine to form in many different colors, you get such as brown, beige, tan, reddish, gold, ivory, and other white shaded colors.



Travertine is characterized by holes, also known as pores, created from carbon dioxide evasion. Exposure to air and moisture can cause these holes to tear after a while. The pitted holes and troughs in its surface means that it has a concentric texture and porous surface. Although these troughs occur naturally, they suggest signs of considerable wear and tear over time.

The primary purpose of the travertine stone is in building. It has been used in construction for a very long time. Temples, bath complexes and various monuments have been built from travertine. It is one of the several natural stones that are used for paving patios, courtyards and garden paths.

Travertine stone was discovered and begun to be used in Italy, in the times of the Roman Empire, and it is also incredibly prolific in Turkey, where we own several travertine quarries ourselves. One of the most famous structures in existence that employs travertine is the ancient Coliseum in Rome, Italy. Italy is renowned for travertine so it doesn’t come as a shock that the word itself is derived from the Italian word ‘travertino’, which is a derivation of the Latin tiburtinus ‘of Tibur’. Its namesake is also the origin of Tivoli, a district near Rome.



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To get to log this cache you will have to read the cache text and visit the coordinates given. After that you will have to answer the questions which are related to the text and the coordinates given.


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1. Answer the questions under by visiting the Coordinates.


A. Travertine is a form of what stone?


B. How do we know what type of stone we got here? What are the characteristics of it and what is this caused off??


C. Sedimentary rocks are often deposited in layers. By having a look at the “feet”, can you see any marks or traces from layers? What would you say is the approx distance between the layers if there is any? Please describe!


D. What color do the stone at the GZ have, and what typical impurity is its color caused by? If the stone was more pure white, what reason would that be for?


E. Can any fossils be seen in the stone?


2.  (It’s voluntary to post a photo in your online log)



The Arch



The Arch is a six-metre high Roman travertine sculpture positioned on the north bank of the Long Water. It was presented by the artist Henry Moore to the nation for sitting in Kensington Gardens in 1980 - two years after his eightieth-birthday exhibition at the Serpentine Gallery, London.

The Arch is made from seven travertine stones weighing a total of 37 tonnes. The stones were sourced from a quarry in northern Italy.

The Arch was inspired by life – in this instance, a fragment of bone – and epitomises for me Moore’s artistic philosophy, drawing inspiration from natural objects.  It also evokes comparisons with other monumental structures such as Stonehenge. Originally created especially for Kensington Gardens following a major retrospective at the Serpentine Gallery in 1978, the artwork was restored in 1996 after being disassembled due to structural instability, then repositioned in its original location in Kensington Gardens by The Royal Parks and The Henry Moore Foundation.


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