Driving Questions? Rock Cycle Webquest
How does the rock cycle help create these large stones?What kind of stones are the Sarsens and the Bluestones?
What are the elements that make up these stones?
How can this help scientist learn where they came from?
Can studying elements help you find out where someone lived?
Geologist and Archeologist work together to analyze and hypothesize about the rocks of Stonehenge.How does the rock cycle help create these large stones?What kind of stones are the Sarsens and the Bluestones?
What are the elements that make up these stones?
How can this help scientist learn where they came from?
Can studying elements help you find out where someone lived?
How can an understanding of elements help you understand Stonehenge?
There are many types of that make up the Bluestones and the Sarsens stones at Stonehenge.
Advanced information on the rocks of Stonehenge
The 2 main stones are the large Sarsens that make up the large Trilithons in the center and the Bluestones (dolerite) that encircle the site. It is hypothesized that the Bluestones come from Wales because of the chemical make up. They are igneous stones and by studying their elements geologist can infer their origination.
The Sarsen Stones
Sarsen stones, are blocks of hard sandstone – a sedimentary rock, which consists of quartz grains bonded together by a naturally formed siliceous cement. They were formed some 60-50 million years ago, when layers of silt and sand (mainly quartz), laid down as river or marine sediment, were saturated with silica-rich groundwater.
Later on, possibly due to either acidification, or evaporation, of the groundwater, the silica precipitated out and filled the gaps between the grains of sand. This eventually acted liked a mineral glue (siliceous cement), sticking enormous numbers of sand grains together to form a layer of solid rock just below the water table.
Subsequent ice and water action, broke this rock layer up into the boulders (Sarsen Stones) that we see today. The stones vary in texture and colour, depending upon grain size, surface erosion, and mineral impurities, e.g. small amounts of iron oxide can make them look darker, especially when wet. They are found across much of the United Kingdom, and vary widely in size and shape, the most famous Sarsen stones being those found at Stonehenge (together with Bluestones).
How dis the rock cycle help create these stones?
There are several theories now... though.Later on, possibly due to either acidification, or evaporation, of the groundwater, the silica precipitated out and filled the gaps between the grains of sand. This eventually acted liked a mineral glue (siliceous cement), sticking enormous numbers of sand grains together to form a layer of solid rock just below the water table.
Subsequent ice and water action, broke this rock layer up into the boulders (Sarsen Stones) that we see today. The stones vary in texture and colour, depending upon grain size, surface erosion, and mineral impurities, e.g. small amounts of iron oxide can make them look darker, especially when wet. They are found across much of the United Kingdom, and vary widely in size and shape, the most famous Sarsen stones being those found at Stonehenge (together with Bluestones).
How dis the rock cycle help create these stones?
Wales
Archaeologists have long debated how it came to be built,
given that the distinctive bluestones used in Stonehenge’s construction
are native to southeast Wales, some 100-150 miles away from Salisbury.
The (Bluestones) spotted dolerites have distinctive markings as a result of elements within the bluestones
cooling at different rates after an underwater volcano ejected the stones some
450 million years ago.
What kind of are formed by heating a cooling magma? Is there a volcano nearly?
What kind of are formed by heating a cooling magma? Is there a volcano nearly?
The Glacier Theory
Other geologists theorise that they were carried east on an ice-age glacier 20,000 years ago. Dr Bevins's team are able to say so categorically that they have discovered the source of the spotted dolerites thanks to a range of laser mass spectrometry techniques which analyse both the chemical composition of the rock and the microbiology present when it was formed.
Other geologists theorise that they were carried east on an ice-age glacier 20,000 years ago. Dr Bevins's team are able to say so categorically that they have discovered the source of the spotted dolerites thanks to a range of laser mass spectrometry techniques which analyse both the chemical composition of the rock and the microbiology present when it was formed.
In 2011, Dr Bevins's team located the source of another of Stonehenge's Pembrokeshire Bluestones - the rhyolites - 3km away from the spotted dolerites at Craig Rhos y Felin.
The Glacier theory implies they came from Carn GoedogThe team used a new method of identifying the chemical makeup of the rocks, to match the
rocks with their origin. They believe that they have now identified Carn Goedog as the
source of at least 55 per cent of the spotted dolerite bluestones at Stonehenge.
rocks with their origin. They believe that they have now identified Carn Goedog as the
source of at least 55 per cent of the spotted dolerite bluestones at Stonehenge.
This alternative strategy in this study re-examines the data set of
Thorpe's team but investigates the concentration of elements which are
compatible in such basaltic systems (that is elements which do enter into the
crystallizing mineral phases), namely MgO, Ni, Cr and Fe2O3.
But Dr Bevins said: “By x-raying dolerites from Stonehenge and comparing them with dolerites from Carn Goedog, we know with some degree of certainty that’s where the blue stones originated.
Can using elements help Scientist find out where someone lived?Mysterious Man found near Stonehenge
But forensic archaeology has revealed some telling details. One of the most sensational came straight from the archer’s mouth. To scientists, a person’s tooth enamel is like a GPS for pinpointing his childhood home. The main ingredient of tooth enamel, apatite, is composed of calcium, phosphorous, oxygen and other elements. The composition of the oxygen molecules in apatite depends on the water a person drank as a child, and that, in turn, can reveal a great deal about where he grew up—from the temperature of rain or snow to the distance from a coast and the area’s altitude. Using a laser scan to determine the makeup of the oxygen in the archer’s tooth enamel, a team at the British Geological Survey led by geoscientist Carolyn Chenery concluded that he grew up in a cool region of Central Europe, most likely somewhere close to the Alps or present-day southern Germany.
Additional Research Links for your reading pleasure:)
Stages of Stonehenge
Stonehenge and the Ice Age
The Glacier Theory
Blue Stone not from Wales
Chronology of Stonehenge Construction Materials
Bluestones from Carn Goedog Science Direct Abstract
Carn Goeg Bluestone origin
More Research on stone origins
Mediterranean Monolith
But forensic archaeology has revealed some telling details. One of the most sensational came straight from the archer’s mouth. To scientists, a person’s tooth enamel is like a GPS for pinpointing his childhood home. The main ingredient of tooth enamel, apatite, is composed of calcium, phosphorous, oxygen and other elements. The composition of the oxygen molecules in apatite depends on the water a person drank as a child, and that, in turn, can reveal a great deal about where he grew up—from the temperature of rain or snow to the distance from a coast and the area’s altitude. Using a laser scan to determine the makeup of the oxygen in the archer’s tooth enamel, a team at the British Geological Survey led by geoscientist Carolyn Chenery concluded that he grew up in a cool region of Central Europe, most likely somewhere close to the Alps or present-day southern Germany.
Additional Research Links for your reading pleasure:)
Stages of Stonehenge
Stonehenge and the Ice Age
The Glacier Theory
Blue Stone not from Wales
Chronology of Stonehenge Construction Materials
Bluestones from Carn Goedog Science Direct Abstract
Carn Goeg Bluestone origin
More Research on stone origins
Mediterranean Monolith
No comments:
Post a Comment