Bluestone

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Carn Menyn bluestones. These dolerite slabs, split by frost action, seem to be stacked ready for the taking, and many have been removed over the centuries for local use. Research favors the theory that humans also transported stones from Carn Menyn to Stonehenge, about 250 kilometers away. Carn Menyn bluestones - geograph.org.uk - 1451509.jpg
Carn Menyn bluestones. These dolerite slabs, split by frost action, seem to be stacked ready for the taking, and many have been removed over the centuries for local use. Research favors the theory that humans also transported stones from Carn Menyn to Stonehenge, about 250 kilometers away.

Bluestone is a cultural or commercial name for a number of dimension or building stone varieties, including:

Contents

Stonehenge

Bluestone monument and Carn Menyn, Preseli Hills Carnmenyn Monument H1a.jpg
Bluestone monument and Carn Menyn, Preseli Hills

The term "bluestone" in Britain is used in a loose sense to cover all of the "foreign," not intrinsic, stones and rock debris at Stonehenge. It is a "convenience" label rather than a geological term, since at least 46 different rock types are represented. One of the most common rocks in the assemblage is known as Preseli Spotted Dolerite—a chemically altered igneous rock containing spots or clusters of secondary minerals replacing plagioclase feldspar. It is a medium grained dark and heavy rock, harder than granite.

Preseli bluestone tools, such as axes, have been discovered elsewhere within the British Isles. Many of them appear to have been made in or near Stonehenge, since there are petrographic similarities with some of the spotted dolerites there. The bluestones at Stonehenge were first used there during the third phase of construction at Stonehenge around 2300 BC. [1] It is assumed that there were about 80 monoliths originally, but this has never been proven since only 43 remain. The stones are estimated to weigh between 2 and 4 tons each. The majority of them are believed to have come from the Preseli Hills, about 250 kilometres (150 miles) away in Wales, either through glaciation (glacial erratic theory) or through humans organizing their transportation.

Glacial erratic theory

A summary of the major aspects of the Stonehenge "bluestone conundrum" was published in 2008. [2] In 2018 a book devoted specifically to the problem of bluestone provenance and transport concluded that the Stonehenge bluestones are essentially an ill-sorted assemblage of glacial erratics. [3] Much further research into the origin of the bluestones has been published between 2012 and 2022 particularly by geologists Richard Bevins and Rob Ixer. [4] If a glacier transported the stones, then it must have been the Irish Sea Glacier. [5] In support of the glacial erratic theory, researchers reporting in 2015 found no firm evidence of quarrying at Rhosyfelin in the Preselis. [6] However, in such event, one might expect to find other bluestone boulders or slabs near the Stonehenge site, but no such bluestones (apart from fragments) have been found. [7]

Human transport theory

The archaeological find of the Boscombe Bowmen has been cited in support of the human transport theory. Preseli Bluestone dolerite axe heads have been found around the Preseli Hills as well, indicating that there was a population who knew how to work with the stones, [8] In 2015, researchers claimed that some of the stones at Stonehenge came from Neolithic quarries at Carn Goedog and Craig Rhos-y-felin in the Preseli Hills. [9] The quarrying hypothesis has been hotly disputed by Brian John, Dyfed Elis-Gruffydd and John Downes, whose own detailed research led to the conclusion that the so-called quarrying features were all natural, created over a long period of glacial and periglacial landscape change. [10] Further, no independent evidence has ever been found to support the thesis of long overland or sea transport of Preseli bluestones from Wales to Salisbury Plain.

Australia

HM Prison Pentridge was one of the many buildings constructed of local bluestone in Melbourne in the 19th century Pentridge.jpg
HM Prison Pentridge was one of the many buildings constructed of local bluestone in Melbourne in the 19th century

There are three distinct building materials called "bluestone" in Australia.

Victoria

In Victoria, what is known as bluestone is a basalt or olivine basalt. It was one of the favoured building materials during the Victorian Gold Rush period of the 1850s. In Melbourne, it was extracted from quarries throughout the inner northern suburbs, such as Clifton Hill, Brunswick and Coburg, where the quarry used to source the stone for Pentridge Prison is now Coburg Lake. [11] [12] Bluestone was also sourced in many other regions of the Victorian volcanic plains, and used in towns and cities in the state's central and western regions, including Ballarat, Geelong, Kyneton, Port Fairy and Portland. It is still quarried at a number of places around the state.

Bluestone is a very hard material and therefore difficult to work, so it was predominantly used for warehouses, miscellaneous walls, and the foundations of buildings. However, a number of significant bluestone buildings exist, including the Old Melbourne Gaol, Pentridge Prison, St Patrick's Cathedral, Victoria Barracks, Melbourne Grammar School, Deaf Children Australia and Victorian College for the Deaf, Vision Australia, the Goldsbrough Mort warehouses (Bourke Street) and the Timeball Tower at Williamstown, as well as St Mary's Basilica in Geelong. Some examples of other major structures that use bluestone include Princes Bridge, the adjacent Federation Wharf, and Hawthorn Bridge. Because of its distinctive qualities, post-modern Melbourne buildings have also made use of bluestone for nostalgic reasons. They include the Southgate complex and the promenade in Southbank, Victoria.

Bluestone was used extensively as cobblestone, and for kerbs and gutters, many examples of which still exist in Melbourne's smaller city lanes, and 19th-century inner-suburban streets and lanes. Crushed bluestone aggregate, known as "blue metal" (or "bluemetal"), is used extensively in Victoria as railway ballast, as road base, and in making concrete. Combined with bitumen, it is used as a road surfacing material.

South Australia

Typical colouring caused by mineralisation in Adelaide bluestone Bluestone33.jpg
Typical colouring caused by mineralisation in Adelaide bluestone

In South Australia, the name bluestone is given to a form of slate which is much less durable than Victorian bluestone, but was valued for its decorative appearance. The interior of the stone is usually pale grey or beige in colour, but is given attractively coloured surfaces by ferric oxide and other minerals deposited in joints and bedding planes. The slate is laid in masonry with the mineralised surfaces exposed. Bluestone was most popular from about the 1850s to the 1920s, quarried in the Adelaide Hills at Dry Creek, O'Halloran Hill (formerly Tapley's Hill) and Glen Osmond, as well as a number of other places in rural areas. [13]

Tasmania

In Tasmania, the name bluestone is given to dolerite (diabase), which is a dominant stone variety in the landscape, and used in a variety of building roles. [14]

New Zealand

Dunedin Railway Station and Law Courts, New Zealand, showing dark bluestone and creamy Oamaru stone construction Dunedin Railway Station and Dunedin Law Courts.jpg
Dunedin Railway Station and Law Courts, New Zealand, showing dark bluestone and creamy Oamaru stone construction

Timaru bluestone (also known as Port Chalmers bluestone) is an attractive building material, used both historically and to the present. It is a grey basalt similar to Victorian bluestone, quarried near Timaru in the South Island. Bluestone from near Kokonga in Central Otago is also widely used, and is the main construction material (often with facing of Oamaru stone, a local compact limestone) in many of the notable historic buildings in the southern South Island, most of which were constructed during the financial boom following the Central Otago gold rush. Prominent structures to use this combination include Otago University Registry Building, Dunedin Law Courts, and Dunedin Railway Station. Similar construction using Timaru bluestone was used for Christchurch Arts Centre.

United States and Canada

Starrucca Viaduct, Pennsylvania Starrucca Viaduct, Oct 2014.jpg
Starrucca Viaduct, Pennsylvania

There are two distinct building materials called "bluestone" in the United States, one of which is also found in Canada.

Bluestone from Pennsylvania and New York is a sandstone defined as feldspathic greywacke. The sand-sized grains from which bluestone is constituted were deposited in the Catskill Delta during the Middle to Upper Devonian Period of the Paleozoic Era, approximately 370 to 345 million years ago. The Catskill Delta was created from runoff from the Acadian Mountains ("Ancestral Appalachians"). [15] This delta ran in a narrow band from southwest to northeast and today provides the bluestone quarried from the Catskill Mountains and Northeastern Pennsylvania. The term "bluestone" is derived from a deep-blue-colored sandstone first found in Ulster County, New York. [16] It can, however, appear in many other hues, mostly shades of grays and browns. Bluestone quarrying is of particular value to the economy of Susquehanna County, Pennsylvania. The Starrucca Viaduct, finished in 1848, is an example of Pennsylvania bluestone as a building material. [17] Bluestone is quarried in western New Jersey, Pennsylvania, and eastern New York. [18] It is also quarried in the Canadian Appalachians near Deer Lake in Western Newfoundland. [19] The Pennsylvania Bluestone Association has 105 members, the vast majority of them quarriers. [17]

The other, lesser known, type of American "bluestone" is a blue-tinted limestone abundant in the Shenandoah Valley of Virginia. It is a limestone formed during the Ordovician Period approximately 450 to 500 million years ago, at the bottom of a relatively shallow ocean that covered what is today Rockingham County, Virginia. The limestone that accumulated there was darker in color than most other limestone deposits because it was in deeper waters exposed to less light. The darker blue color resulted in limestone from this region being dubbed "bluestone" and with two sequences measuring about 10,000 feet (3,000 m) thick, it gives the area one of the largest limestone deposits in the world. [20] The stone eventually fades from a deep blue to a light grey after prolonged exposure to sun and rain. Given the abundance of the stone in the Rockingham County area, the first settlers used it as foundations and chimneys for their houses. When James Madison University was built, the local bluestone was used to construct the buildings because of its high quality and cultural heritage. [21]

See also

Related Research Articles

<span class="mw-page-title-main">Stonehenge</span> Ancient monument in England

Stonehenge is a prehistoric megalithic structure on Salisbury Plain in Wiltshire, England, two miles (3 km) west of Amesbury. It consists of an outer ring of vertical sarsen standing stones, each around 13 feet (4.0 m) high, seven feet (2.1 m) wide, and weighing around 25 tons, topped by connecting horizontal lintel stones. Inside is a ring of smaller bluestones. Inside these are free-standing trilithons, two bulkier vertical sarsens joined by one lintel. The whole monument, now ruinous, is aligned towards the sunrise on the summer solstice and sunset on the winter solstice. The stones are set within earthworks in the middle of the densest complex of Neolithic and Bronze Age monuments in England, including several hundred tumuli.

<span class="mw-page-title-main">Preseli Mountains</span> Hill range in Wales

The Preseli Mountains, also known as the Preseli Hills, or just the Preselis, is a range of hills in western Wales, mostly within the Pembrokeshire Coast National Park and entirely within the county of Pembrokeshire.

<span class="mw-page-title-main">Bedd Arthur</span> Standing stones

Bedd Arthur is a possibly Neolithic hengiform monument megalithic site in the Preseli Hills in the Welsh county of Pembrokeshire. Thirteen upright stones and at least 2 fallen ones, each around 0.6 metres (2.0 ft) high form an oval horseshoe with similarities to the earliest form of Stonehenge.

<span class="mw-page-title-main">Diabase</span> Type of igneous rock

Diabase, also called dolerite or microgabbro, is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine-grained to aphanitic chilled margins which may contain tachylite.

<span class="mw-page-title-main">Oamaru stone</span>

Oamaru stone, sometimes called whitestone, is a hard, compact limestone, quarried at Weston, near Oamaru in Otago, New Zealand.

<span class="mw-page-title-main">Mynachlog-ddu</span> Human settlement in Wales

Mynachlog-ddu is a village, parish and community in the Preseli Hills, Pembrokeshire, Wales. The community includes the parish of Llangolman.

Michael Parker Pearson, is an English archaeologist specialising in the study of the Neolithic British Isles, Madagascar and the archaeology of death and burial. A professor at the UCL Institute of Archaeology, he previously worked for 25 years as a professor at the University of Sheffield in England, and was the director of the Stonehenge Riverside Project. A prolific author, he has also written a variety of books on the subject.

<span class="mw-page-title-main">Carn Menyn</span>

Carn Menyn is a grouping of craggy rock outcrops or tors in the Preseli Hills in the Welsh county of Pembrokeshire.

<span class="mw-page-title-main">Hamstone</span> Building stone from Somerset

Hamstone is a honey-coloured building stone from Ham Hill, Somerset, England. It is a well-cemented medium to coarse grained limestone characterised by marked bedding planes of clay inclusions and less well-cemented material which weather differentially to give exposed blocks a characteristic furrowed appearance. In origin, Hamstone is a Jurassic limestone from the Toarcian, or Upper Lias, stage.

In Arthurian legend, Mount Killaraus is a legendary place in Ireland where Stonehenge originally stood. According to the narrative presented in Geoffrey of Monmouth's Historia Regum Britanniae, King Ambrosius Aurelianus embarks on a quest to construct a memorial for the Celtic Britons who were treacherously slain by Anglo-Saxons. When conventional methods fail to produce an awe-inspiring monument, Ambrosius turns to the renowned wizard Merlin for guidance. In response, Merlin advises the king to transport a stone circle known as the Giant's Ring from Mount Killaraus in Ireland, attributing magical and healing properties to these stones, which were believed to have been brought from Africa by giants.

<span class="mw-page-title-main">Geology of Wales</span> Overview of the geology of Wales

The geology of Wales is complex and varied; its study has been of considerable historical significance in the development of geology as a science. All geological periods from the Cryogenian to the Jurassic are represented at outcrop, whilst younger sedimentary rocks occur beneath the seas immediately off the Welsh coast. The effects of two mountain-building episodes have left their mark in the faulting and folding of much of the Palaeozoic rock sequence. Superficial deposits and landforms created during the present Quaternary period by water and ice are also plentiful and contribute to a remarkably diverse landscape of mountains, hills and coastal plains.

<span class="mw-page-title-main">Stone quarries of ancient Egypt</span> Aspect of Egyptian economy

The stone quarries of ancient Egypt once produced quality stone for the building of tombs and temples and for decorative monuments such as sarcophagi, stelae, and statues. These quarries are now recognised archaeological sites. Ancient quarry sites in the Nile valley accounted for much of the limestone and sandstone used as building stone for temples, monuments, and pyramids. Eighty percent of the ancient sites are located in the Nile valley; some of them have disappeared under the waters of Lake Nasser and some others were lost due to modern mining activity.

<span class="mw-page-title-main">Theories about Stonehenge</span> Theories on the origin and purpose of Stonehenge

Stonehenge has been the subject of many theories about its origin, ranging from the academic worlds of archaeology to explanations from mythology and the paranormal.

The building stones of Wales are many and varied reflecting the diverse geology of the country. Some of the earliest known use of natural stone for building purposes was the sourcing of Ordovician dolerite in the Preseli Hills for the 'bluestone' lintels of Stonehenge. Other early use was in the construction of dolmens, burial cairns and stone circles in the late Stone Age and Bronze Age. The tradition of building in stone was continued into Iron Age with the establishment of such hill forts as those at Tre'r Ceiri in North Wales and Garn Goch in the south.

Craig Rhos-y-felin is a rocky outcrop on the north side of the Preseli Mountains in Wales, which is designated as a RIGS site on the basis of its geological and geomorphological interest. It is accepted by some in the archaeological community that it is the site of a quarry, used together with one at Carn Goedog, for gathering stones used at Stonehenge, most notably as the source of some of the foliated rhyolite found in the Stonehenge "debitage". This is disputed by others, who believe that all of the features at the site, apart from evidence of intermittent occupation over a long period, are of natural origin. Some believe that the site was used as a quarry in both the Neolithic and Bronze Ages, around 4000 to 5000 years ago, and the rock's shape, like a pillar, allowed the stones to be quarried with relative ease compared to stones taken from other places. Others argue that if prehistoric men had wanted to obtain monoliths for use as standing stones, all they had to do was collect them from the abundant glacial erratics littering the landscape.

<span class="mw-page-title-main">Derbyshire Dome</span> Geological formation of the Derbyshire Peak District

The Derbyshire Dome is a geological formation across mid-Derbyshire in England.

<span class="mw-page-title-main">Waun Mawn</span> Dismantled neolithic stone circle in Pembrokeshire,

Waun Mawn is the site of a possible dismantled Neolithic stone circle in the Preseli Mountains of Pembrokeshire, Wales. The diameter of the postulated circle is estimated to be 110 m (360 ft), the third largest diameter for a British stone circle.

The geology of Pembrokeshire in Wales inevitably includes the geology of the Pembrokeshire Coast National Park which extends around the larger part of the county's coastline and where the majority of rock outcrops are to be seen. Pembrokeshire's bedrock geology is largely formed from a sequence of sedimentary and igneous rocks originating during the late Precambrian and the Palaeozoic era, namely the Ediacaran, Cambrian, Ordovician, Silurian, Devonian and Carboniferous periods, i.e. between 635 and 299 Ma. The older rocks in the north of the county display patterns of faulting and folding associated with the Caledonian Orogeny. On the other hand, the late Palaeozoic rocks to the south owe their fold patterns and deformation to the later Variscan Orogeny.

References

  1. ↑ Swaine, Jon (2008-09-22). "Stonehenge birthdate discovered by archaeologists". The Daily Telegraph . Retrieved 2008-09-22.
  2. ↑ Anthony Johnson "Solving Stonehenge: The New Key to an Ancient Enigma" (fig.89.P165.) (Thames and Hudson 2008) ISBN   978-0-500-05155-9
  3. ↑ Brian John, "The Stonehenge Bluestones" (Greencroft Books, 2018) page 157. ISBN   978-0-905559-94-0
  4. ↑ Bevins, Richard E., Ixer, Rob A., Webb, Peter C., Watson, John S. 2012. Provenancing the rhyolitic and dacitic components of the stonehenge landscape bluestone lithology: New petrographical and geochemical evidence. Journal of Archaeological Science, Volume 39, Issue 4, April 2012, pages 1005–1019
  5. ↑ Chiverrekk RC, Thrasher I, Thomas GS, Lang A, et al (2013). Bayesian modelling the retreat of the Irish Sea Ice Stream. Journal of Quaternary Science 28, 200-209.
  6. ↑ "New research undermines Welsh bluestone quarry theory". Western Telegraph. 13 November 2015. Retrieved 13 November 2015.
  7. ↑ "National Geographic Channel, Naked Science: Who Built Stonehenge?". Archived from the original on May 2, 2013.
  8. ↑ N. P. Figgis, "Prehistoric Preseli" (Atelier Productions, 2001). ISBN   1-899793-06-2 [ page needed ]
  9. ↑ "Stonehenge 'bluestone' quarries confirmed 140 miles away in Wales". University College London. 7 December 2015. Retrieved 3 August 2018.
  10. ↑ Brian John, Dyfed Elis-Gruffydd and John Downes. 2015. OBSERVATIONS ON THE SUPPOSED “NEOLITHIC BLUESTONE QUARRY” AT CRAIG RHOSYFELIN, PEMBROKESHIRE". Archaeology in Wales 54, pp 139-148.
  11. ↑ History of Brunswick, City of Moreland, http://moreland.vic.gov.au/moreland-libraries/services/local-history/history-brunswick.html Archived 2011-03-28 at the Wayback Machine , accessed 11 September 2012
  12. ↑ Encyclopedia of Melbourne: Quarries and Brickmaking, http://www.emelbourne.net.au/biogs/EM01213b.htm, accessed 11 September 2012
  13. ↑ R. Lockhart Jack, "The Building Stones of South Australia" (Adelaide 1923) pp. 18-28.
  14. ↑ "Building Stone". Companion to Tasmanian History. Retrieved 18 May 2017.
  15. ↑ Ettensohn, F (1985). "The Catskill Delta complex and the Acadian Orogeny". The Catskill Delta. Geological Society of America. 39-49. doi:10.1130/SPE201-p39.
  16. ↑ Mahayes. "Bluestone Quarries | Welcome to the Hudson Valley: A Guidebook of Topics in Local Environmental History" . Retrieved 2019-10-23.
  17. 1 2 "Susquehanna County: The Heart of Pennsylvania Bluestone". Susquehanna County, Pennsylvania. Retrieved 25 January 2019.
  18. ↑ Chacon, Mark A. (1999-10-11). Architectural Stone: Fabrication, Installation, and Selection. John Wiley & Sons. ISBN   9780471246596 . Retrieved 2019-01-31.
  19. ↑ Evans, DT; Dickson, WL (2004). "Dimension Stone in Newfoundland and Labrador" (PDF). Government of Newfoundland and Labrador. Retrieved 25 January 2019.
  20. ↑ Sherwood, WC. "A Brief Geologic History of Rockingham County". James Madison University. Retrieved 25 January 2019.
  21. ↑ "JMU Centennial Celebration - The History of Bluestone". James Madison University. 2007. Retrieved 26 January 2019.

Bibliography

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