tvrigs.org.uk » Cenozoic

September – Whinstone

admin — Thu, 10 Sep 2009 17:53:12 +0000

Whinstone is a quarryman’s term for a variety of hard, dark-coloured, rocks including basalt and chert. Here, in the Tees Valley and Cleveland, the name refers to a hard rock that is very different from the soft sedimentary strata which make up the majority of the area’s underlying geology.

Around 58 million years ago, as the Atlantic oceanic basin formed, adjacent areas of crust became stretched and weaknesses could be exploited by molten material (magma) being forced into the crust by pressure from below. This magma cooled very quickly surrounded by local rocks and became the Cleveland Dyke.

Stretching for c.350 miles between Mull in Western Scotland and the Tees Valley and North Yorkshire the hot magma cooled to form a dark blue-grey, finely crystalline rock referred to by geologists, more correctly, as dolerite. Dolerite is chemically similar to basalt, the major difference being that basalt is erupted at the Earth’s surface, whereas dolerite solidifies within the Earth’s crust.

Following removal of the overlying strata by erosion, primarily through glaciation, the dyke was exposed at the Earth’s surface. In the west of our region it can be traced crossing the river at Preston-on-Tees, but perhaps its most notable feature occurs near Great Ayton where the more durable rock making up the dyke, and softer Jurassic strata into which it is intruded, exhibit a phenomenon known as differential erosion. The softer sedimentary rock is preferentially removed by erosion leaving the harder whinstone to form a bold ridge called Langbaurgh Ridge.

The geater hardness of whinstone relative to sedimentary rock makes it ideal for use road-stone and cobbles, and it was for this purpose that Leeds City Council leased land around Great Ayton, where the ridge is best developed, in 1869. Large quantities of the rock were quarried at Cliff Rigg, as well as elsewhere along the length of the dyke, for example at Preston-on-Tees, Ingleby Barwick, and at a variety of locations on the North York Moors. The now-abandoned workings today form an unmistakeable scar on the landscape, though the former quarry’s remains allow geologists to study the effects of metamorphism, i.e. the baking of the surrounding sedimentary rock when the hot magma was injected.

February – Woolly Mammoth Tooth.

admin — Tue, 03 Feb 2009 11:38:07 +0000

Mammoth lived on most of the continents in the Northern Hemisphere during the last big ice age 70-10,000 years ago. Woolly Mammoths were about the same size as Indian elephants are today and covered in a layer of coarse hair. They are a good indicator of a cold climate and tundra or Steppe conditions. They are well known about and understood as whole frozen carcasses have been found in several places in Siberia. Mammoths are the symbols of the last ice age and many stories have evolved about them. The Siberian tribes believed that they lived in the centre of the earth and died when they came into contact with air. This explained to them why they never found one alive before the theory of extinction had been developed. Mammoths became extinct due to rapid climate change and large-scale human predation.

Mammoths have six sets of teeth throughout their lifetime. (Much like modern day elephants). They moved forward from the back of the jaw and replaced older worn out teeth as they fell out. This means that there are lots of teeth that can be preserved. Thin enamel plates cemented together. This makes a tall strong, wear resistant tooth.

They are often dredged up from the North Sea. Here they are from a land bridge between England and the Netherlands, which was cut off as sea levels rose 6 – 8,000 years ago. The teeth have then been reworked by the sea bringing them to the surface to be collected by trawlers.

The remains of a species of Dwarf Woolly Mammoths have been found on an island between Russia and North America. These have been dated back to 7,000 – 3,500 at the same time that the pyramids and Stonehenge were being built.

Langbaurgh Ridge

admin — Sat, 16 Aug 2003 15:44:49 +0000

Contents

Site Description
Site Map
Site Assessment
Surveyors

Grid Reference NZ 564 120
BGS Sheet 34
OS Sheet 93
Forwarded as RIGS 30/09/2003

Site Description

Site Status
Description of Geodiversity Intruded igneous ridge forming exposed igneous faces and a relic quarried trench
Literature References

Site Map

Site Assessment

Access and Safety	Comments	Rating
Safety of access	Access along footpath from Quarry House	10
Safety of exposure	Flat viewing platform	10
Restricting conditions	Permission from landowner
Multiple exposure	Along length of ridge	5
Note	It is strongly suggested that on-site safety be the responsibility of the party leader(s), as the safety information above is given only as a guide.

Education and Science	Comments	Rating
Surface processes	Biological weathering	5
Geomorphology	Igneous ridge	8
Sedimentary rock	None
Igneous rock	Cleveland Dyke	10
Metamorphic rock	None
Fossils	None
Minerals	None specific	2
Structural features	Contact faulting due to cooling	5
Stratigraphy	None

Geodiversity Value	Comments	Rating
Education	Limited educational value	2
Scientific	Study by Earth scientists	8
Historical	Disused quarry	5
Aesthetic	Part of Cleveland Dyke feature	10

Surveyors

Andrew Carter

Gravel Hole Quarry

admin — Mon, 19 May 2003 14:57:35 +0000

Contents

Site Description
Site Map
Site Assessment
Surveyors

Grid Reference NZ 445 231
BGS Sheet 33
OS Sheet 93
Forwarded as RIGS 30/09/2003

Site Description

Site Status SNCI
Description of Geodiversity Disused and landscaped sand and gravel quarry
Literature References

Site Map

Site Assessment

Access and Safety	Comments	Rating
Safety of access	Along footpath over railway line	8
Safety of exposure	Shallow quarry environment	10
Restricting conditions	None
Multiple exposure	None
Note	It is strongly suggested that on-site safety be the responsibility of the party leader(s), as the safety information above is given only as a guide.

Education and Science	Comments	Rating
Surface processes	Pluvial and aeolian processes	10
Geomorphology	None
Sedimentary rock	Various erratics in outwash	2
Igneous rock	Various erratics in outwash	2
Metamorphic rock	Various erratics in outwash	2
Fossils	None
Minerals	None specific	2
Structural features	None
Stratigraphy	Current bedding laminations	10

Geodiversity Value	Comments	Rating
Education	Limited educational value	2
Scientific	Glacial deposits	10
Historical	Disused quarry	2
Aesthetic	Close to Nature Reserve	5

Surveyors

Andrew Carter, John Waring

Dalton Piercey

admin — Tue, 06 May 2003 14:08:11 +0000

Contents

Site Description
Site Map
Site Assessment
Surveyors

Grid Reference NZ 469 307
BGS Sheet 27
OS Sheet 93
Forwarded as RIGS 30/09/2003

Site Description

Site Status SNCI
Description of Geodiversity Natural river-cliff exposure of fluvio-glacial deposits. The cliff reveals an exposure of middle sand, gravels and clays.
Literature References The Geology of the Country Between Durham and West Hartlepool – Dennis Smith 1967

Site Map

Site Assessment

Access and Safety	Comments	Rating
Safety of access	Along footpath to exposure	10
Safety of exposure	Level viewing platform on river bank	10
Restricting conditions	Possible high flow episodes	9
Multiple exposure	Other smaller cliffs downstream	8
Note	It is strongly suggested that on-site safety be the responsibility of the party leader(s), as the safety information above is given only as a guide.

Education and Science	Comments	Rating
Surface processes	Various fluvial and glacial processes	10
Geomorphology	River cliff feature	8
Sedimentary rock	Examples in outwash stratigraphy	2
Igneous rock	Examples in outwash stratigraphy	2
Metamorphic rock	Examples in outwash stratigraphy	2
Fossils	None
Minerals	None specific	2
Structural features	None specific	2
Stratigraphy	Excellent stratigraphical examples	10

Geodiversity Value	Comments	Rating
Education	Fluvial processes and glacial deposit example	10
Scientific	Glacial deposit for Earth scientists	10
Historical	No historical value
Aesthetic	River corridor environment	10

Surveyors

Andrew Carter, John Waring

Barwick Dyke Quarry

admin — Tue, 22 Apr 2003 15:10:57 +0000

Contents

Site Description
Site Map
Site Assessment
Surveyors

Grid Reference NZ 431 152
BGS Sheet 33
OS Sheet 93
Forwarded as RIGS 30/09/2003

Site Description

Site Status SNCI
Description of Geodiversity Disused flooded quarry revealing an exposure of the Cleveland Dyke. The site also reveals a unique exposure of the contact between the Dyke and Sherwood sandstone country rock.
Literature References

Site Map

Site Assessment

Access and Safety	Comments	Rating
Safety of access	Along footpath to quarry	10
Safety of exposure	Deep water danger in flooded quarry	5
Restricting conditions	None
Multiple exposure	None
Note	It is strongly suggested that on-site safety be the responsibility of the party leader(s), as the safety information above is given only as a guide.

Education and Science	Comments	Rating
Surface processes	Weathering and leaching of dyke faces	2
Geomorphology	Underlying dyke ridge	5
Sedimentary rock	Contact with Sherwood sandstone	10
Igneous rock	Cleveland Dyke	10
Metamorphic rock	Limited metamorpism of Sherwood sandstone at contact
Fossils	None
Minerals	None specific	2
Structural features	Unique contact point	10
Stratigraphy	None specific	2

Geodiversity Value	Comments	Rating
Education	Limited educational value	2
Scientific	Excellent contact point	10
Historical	Disused Cleveland Dyke quarry	5
Aesthetic	Disused quarry close to the River Tees	8

Surveyors

Andrew Carter, John Waring

Stainsby Beck Dyke

admin — Thu, 10 Apr 2003 15:35:29 +0000

Contents

Site Description
Site Map
Site Assessment
Surveyors

Grid Reference NZ 465 146
BGS Sheet 33
OS Sheet 93
Forwarded as RIGS 30/09/2003

Site Description

Site Status SNCI
Description of Geodiversity Stream bed exposure of the Cleveland Dyke
Literature References

Site Map

Site Assessment

Access and Safety	Comments	Rating
Safety of access	On footpath from industrial estate	10
Safety of exposure	On opposite riverbank footpath	10
Restricting conditions	High flow episodes obscure exposure	6
Multiple exposure	Mercia mudstone exposure downstream	7
Note	It is strongly suggested that on-site safety be the responsibility of the party leader(s), as the safety information above is given only as a guide.

Education and Science	Comments	Rating
Surface processes	Various fluvial processes	10
Geomorphology	Various fluvial features	10
Sedimentary rock	None
Igneous rock	Dyke intrusion	10
Metamorphic rock	None apparent
Fossils	None
Minerals	None specific
Structural features	Apparent dip of 2° & NNW orientation	7
Stratigraphy	Tertiary igneous intrusion	5

Geodiversity Value	Comments	Rating
Education	Various fluvial processes	10
Scientific	Small Cleveland Dyke exposure	5
Historical	None
Aesthetic	River corridor environment	10

Surveyors

Andrew Carter, John Waring