The Area around Meldon Quarries is a wealth of both geology and industrial archaeology, both of which are passions of mine. The area boasts three distinct large scale disused quarry zones, with some evidence for other smaller ones, including some of the dump areas that may have been infilled quarries. To highlight this wonderful area I have placed three EarthCaches to highlight this, as well as a Puzzle Cache on a wider geological theme.
Geology is an incredibly interesting, and important field of study that has grown over the centuries, since its simple beginnings. During the 17th centuries there was a great leap forward with it becoming its own science. During this period there was still an incredibly strong influence from Christianity, and this led to much of the new geological evidence during this period being married with the preconceived idea of the Christian creation of Earth. A good example of this is William Whitson, who published "A New Theory of the Earth" in ``1696. In this publication William Whitson concluded that he could 'prove' that the Great Flood had formed the rock strata of Earth. Despite the general tendency to align geological thinking with the longstanding ideas of the church, there were the beginnings for the separation of geology and the church. A pioneer of this was Nicolas Steno. He was trained in the classical texts on science, however by 1659 he seriously questioned the accepted knowledge on the natural world, in particular geology. Importantly he questioned the belief that the fossils discovered in rocks actually grew in the ground, in the position they were later found. His later laws became the basis of modern day stratigraphy and are still used today. For more information on this see Ramsley Mine - Man Made Stratigraphy.
The increase in knowledge and interest in geology during the 17th century continued into the 18th century. This was happening in conjunction with an increase in economic importance of mining in Europe. As a result of the importance of mining, there was a drive, not for intellectual knowledge, but for profit. This, as has occurred throughout history, pushed the study of geology forward at an accelerated rate. The work by Abraham Gottlob Werner in `1774 "Von den äusserlichen Kennzeichen der Fossilien" is a good example of this. It was a detailed catalogue of specific minerals and metals based on their external characteristics, an ideal guide for determining the economic potential of land. During this period we also see the first meaningful departure from the Christian chronology of Earth's creation, towards a solely geological chronology. This first occurred in 1749 when Georges-Louis Leclerc published his "Histoire Naturelle" in which he attacked the popular Biblical accounts for the history of the Earth given by Whitson, amongst others. With the departure of the science of geology from external influences, it paved the way for other scientific methods, most significantly chemistry, to be used to transform geology to a hard science. A fine example of this is William Smith. During the 1780's William Smith, working as a surveyor for mining companies and canal builders, in southern England. He developed a systematic, and scientific, method of describing and recording rock types to test the theory for identifying the relative ages of the rocks.
Engraving from William Smith's 1815 monograph on identifying strata by fossil types
During the 19th century Smith's ideas, and scientific methodology, was built upon and the knowledge of the stratigraphic relationships of the rocks creating the Earth grew. Darwin actually used fossil evidence to support his theory of evolution. Throughout this century the geological periods were started to be formed, categorised and subdivided to create a greater, and more defined, geological timeline. Once again economic driving factors pushed the science of geology. Large scale surveys were undertaken allowing geologists to map the bedrocks of a large number of countries. A great leap forward in the understanding of the geological chronology was the development of radiometric dating, which enabled absolute dating, rather than the simply relative dating. In `1911 Arthur Holmes dated a sample from Ceylon at 1.6 billion years using lead isotope. This led the British Association for the Advancement of Science to conclude, in 1921, that the Earth was a few billion years old. Subsequently Holmes published "The Age of the Earth", in which he presented an age range of 1.6 to 3 billion years.
The 20th century saw an exponential increase in the scientific methods at the disposal of geologists in increasing the knowledge of geological processes and chronology. Holmes continued his work dating the history of the Earth's creation, and in 1927 revised his estimate for the age of the Earth to 3 billion years. Thanks to his work he is known as the father of modern geochronology. During this period interest was growing in the processes that formed the land, both the movement of land (continental drift) and the formation of mountains.
Modern geology has grown upon these solid foundations and is turning geology into a multidiscipline study, using as many techniques as required to better understand both the chronology and processes that have gone into creating the geology and geological features we see today. As a result we now understand the age of the Earth to be 4.55 billion years old.
The study of geology has dramatically changed from its beginnings, where well to do amateurs were the geologists of their day. Now there is a science, with professionals studying every aspect. However, there is still much interest and activity from the interested amateurs and given internet resources, such as the REALLY useful British Geological Survey those interested can easily immerse themselves in the fascinating world of geology. Indeed the hobby we all enjoy has its own way of doing this, the EarthCache, which is my favourite cache type.
Here are a list of some of my favourite ones
Tolmen Stone
Cleopatra's Needle - London
Culpepper's Dish Earthcache
Tintagel: Lanterdan Pinnacle
Towerhouse Woods Bubbling Pond
Towerhouse Woods Lime Kiln
Reigate Heath Tumulus
Piggle Dene Earthcache
I myself have placed a good number of EarthCaches, including three nearby the posted coordinates, focusing on two quarries of the historic complex for exploiting the geology of the Meldon area. This cache is a puzzle cache, but regardless is based on geology and rock types.
The Key to the Puzzle
Sand = 1
Granite = 6
Sandstone = 8
Chalk = 3
Clay = 5
Limestone = 7
N 50 42.XXX W 004 01.XXX
Fieldpuzzle
At the solved puzzle coordinates you will find a field puzzle which will require you to identify different rock types in the container. Below I have done a brief description of all of them to help you. I would suggest that if you are unsure in recognising your rock types that you make sure you have these descriptions with you.
Chalk is a soft pure white calcareous form of limestone composed of the shells of millions of tiny sea creatures. When used as a building material Chalk is very susceptible to weathering, both physical and chemical weathering. Chalk is easily identified by its pure white colour and fine grained smooth powdery texture.
Mudstone, as its name suggests, is stone that is formed on material that used to be mud. They form when fine, clay like, particles are deposited in water. It is a very fine grained rock that is usually black or dark grey-brown in colour. It is often relatively soft and crumbly for a stone. The clay particles that form these rocks are smaller than 0.05 mm and cannot be seen by the naked eye. This gives mudstone the appearance of being smooth, as rocks go, both in appearance and feel.
Flint is a hard, often black, and commonly has a smooth, almost shiny appearance. It is very easy to recognise as its smooth to the touch and look crystalline.
Aplite is a dark igneous rock that looks very similar in appearance to mudstone in the Meldon area. The best indicator to be able to tell the two apart is the additional impurities that aplite has in it. These add different colours to the dark colour, commonly almost a red shimmer.
Limestone, is a very fine grained sedimentary rock that has a similar texture to that of mudstone. Unlike mudstone the colour is normally very light, ranging from pure white to a light browning yellow. As a result of the sedimentary formation it commonly contains odd inclusions, ranging from fossils to bands of crystalline material.
Quartz is a crystalline rock that ranges in colour from clear to brilliant pinks, reds and others. It is a very easy rock to recognise as unlike most others it is semi transparent, allowing you to see through it.
The final can be found at N 50 42."mudstone" "chalk" "aplite W 004 01."Flint" "quartz" "Limestone"