tvrigs.org.uk » Quaternary

Glossary (L – S)

cliff.rigg — Sun, 06 Feb 2011 10:39:58 +0000

This page provides a glossary of geological terms to be found on the TVRIGS website and elsewhere. It is an evolving document and will grow as the site expands.

L

Liquor Channel (or Conduit)

Wood or stone-lined channel along which alum liquor was transferred between the quarry and the alum-house.

M

Malm

(Obsolete) Chalky-clayey soil or rock, in part equivalent to marl and other impure calcareous rocks. It is also an old name for the Upper Jurassic.

Mineral

Naturally occurring solid element or compound, exclusive of biologically formed carbon components. Has definite composition or range of composition and orderly internal atomic arrangement (crystalline structure), which gives unique physical and chemical properties, including tendency to assume certain geometrical forms known as crystals.

[Source: Leet, L. Don. 1982. Physical Geology, 6th Edition. Englewood Cliffs, NJ: Prentice-Hall]

Mothers

Concentrated liquid residue recovered from casks after roaching alum.

Mudstone

Fine-grained, argillaceous rock generally (though not exclusively) formed in deep quiet water. Mudstone differs from shale in having little or no bedding planes and a ‘blocky’ fracture.

P

Particle Size

When dealing with sediments and sedimetary rocks precise dimensions are applied to the terms clay, sand, silt, etc. The most widely-accepted, and used as an international standard, is the Wentworth-Udden Scale shown below. The list shows particle size limits which, in some instances, may be further subdivided into fine, medium and coarse grades.

**Particle Size Table**
Size Range	Particle
> 256mm	Boulder
64-256mm	Cobble
4-64mm	Pebble
2-4mm	Gravel
1/16-2mm	Sand
1/256-1/16mm	Silt
< 1/256mm	Clay

Permian

Named (by Murchison, 1841) after the Perm region of Russia where these beds are well-exposed. The Permian covers an episode in Earth’s history between c.299 million and 251 million years before present. The Permian is further subdivided into Lower, Middle and Upper episodes. Locally, these rocks comprise dolomitic limestones and chemical sedimentary rocks (evaporites), which include halite, sylvinite and anhydrite,deposited during shrinkage of the ancient Zechstein Sea .

Q

Quaternary

Named (by Arduino, 1759) this is the most recent episode in Earth’s history which commenced c.2.5 million years ago and continues into the present day. The Quaternary is characterised by the advance and retreat of continental ice-sheets from high latitudes.
It is divided into the Pliestocene and Holocene epochs. The Pliestocene covers numerous advances and retreats of ice-sheets up to the last retreat (c.20,000 years before present locally), the Holocene covers the time since the last retreat of ice-sheets to high latitudes.

R

Rudaceous Rocks

The coarsest group of detrital sedimentary rocks composed of clasts greater than 2mm across, including pebbles, cobbles and boulders. Rudaceous rocks, from the Latin Rudus meaning ‘rubble’, may form through the lithifaction of talus, fault breccia, alluvial deposits and relict boulder clays known as tillites. When interbedded with marine deposits such beds may be indicative of an unconformity or episode of no-deposition. Another name for water-lain deposits of this grade is conglomerate.

S

Sabkha

The Arabic term sabkha normally refers to broad coastal flats in arid regions known as salt flats, the ‘type area’ is on the Trucial Coast in Abu Dhabi. These environments can be broadly divided into two types;

Coastal Sabkha: Comprising a mixture of offshore and wind-borne land-sourced material.
Continental Sabkha: Comprising dune-bedded sands and wind-borne carbonate dust from the coast.

Sabkhas are only occasionally flooded and hence evaporation of the flood water leaves behind evaporite deposits (gypsum, anhydrite, halite, etc.)

Shale

Clay-based, argillaceous, sedimentary rock the definition of which varies. Shale tends to be a very fine-grained, laminated and fissile rock. For example the Jet Rock member of the Whitby Mudstone Formation. Rocks having a similar grain-size, but little or no bedding and a blocky fracture, may be referred to as mudstone.
Within the Cleveland ore-field, miners would refer to the argillaceous beds between ironstone seams as shale regardless of grain-size, up to fine sand.

Steeping

The soaking of calcined alum shale in water-filled pits. A process which dissolves the salts released during calcination to produce alum liquor. This stage in processing occurred within the quarry.

«Glossary(F-K) Glossary(T-Z)»

PLEASE NOTE: TVRIGS Group cannot be held responsible for the content of external sites.

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.

A Geological Timescale

cliff.rigg — Wed, 02 Jan 2008 14:11:31 +0000

GEOLOGICAL TIMESCALE

Shown below is a representation of the rocks underlying the Tees Valley and Darlington districts in Northeast England. The diagram depicts the relative thickness of the different systems. Absolute ages are given alongside. Click on the different areas to view more details about a particular time period.

Geological column showing the relative thickness and absolute ages of rocks underlying the Tees Valley and Darlington.

Home page

cliff.rigg — Wed, 02 Jan 2008 13:50:03 +0000

Welcome to the Tees Valley RIGS Group Website.

The place for you to find out more about the geology and industrial heritage of Redcar & Cleveland, Middlesbrough,
Stockton, Hartlepool and Darlington.

Alum, Alchemy and Ammonites Page

Future Events Page

Past Events Page

Why not check out our new site description pages and geo-trails

Boulby – Cowbar Hummersea
Loftus Quarries Boulby Quarry

Latest News

RIGS News

Tuesday 8th November 2011: November’s Rock of the Month offering can now be viewed by clicking here…

Thursday 13th October 2011: The RIGS Group’s recently published Geodiversity Action Plan has been recognised and used as a case study by Geoconservation UK. More details can be seen here and by clicking on the navigation bar at the top of this page.

Wednesday 12th October 2011: Why not view Tees Valley Wildlife Trust’s Alum, Alchemy & Ammonites pages.

Wednesday 1st June 2011: Our latest Rock of the Month article is now online. We would like to thank RIGS Group member Scott Bradley for providing the article.

The group’s expansion into the Darlington district is approaching the end of its first phase. A number of sites have been identified and five summarily surveyed.

Announcements

For details concerning the next RIGS meeting please contact the RIGS Group by e-mail.

Ramblers walking with the RIGS Group descend Boulby Bank after visiting cliff-side alum quarries near Staithes.

TVRIGS are always keen to recruit new members. So if you have an interest in the region’s geology, would like to find out more about the Tees Valley’s industrial heritage, or simply wonder what all of the fuss is about, then why not join us, it’s free – and we have only the very best biscuits at our meetings…

Quaternary

cliff.rigg — Thu, 22 Nov 2007 12:17:59 +0000

Contents

Introduction
Devensian
Holocene

Introduction

Sub-divisions in the Quaternary of the British Isles.

The Quaternary Period is the shortest division of time in the geological column covering only the last 2.6 million years or so of Earth’s history. The period is characterised by extraordinary changes in global climate producing several major phases of ice-sheet advance, (glacial), and retreat (interglacial) across lower latitudes than permanent ice cover is restricted to today. Many minor cycles of advance and retreat are superimposed upon each major phase making deposits of this age difficult to interpret and correlate between different areas.

Furthermore, each re-advance more-or-less erases the evidence of any preceding glacial activity exacerbating the problems facing Quaternary geologists. Because of this analysis of pollen grains (palynology) and oxygen isotopes provide some of the best clues to the different environments under which deposits of this age accumulated.

The Quaternary can be sub-divided into two series, the Pleistocene – which covers all deposits between 2.6 million years and around 20,000 years ago (locally), and the Holocene – encompassing deposits from around 20,000 years ago to the present day.

Solid rocks of the Tees Valley district below c.300m are covered by till, sand and gravel laid down by wastage of the local ice-sheet at the close of the most recent glacial episode. The youngest deposits in the district are the Flandrian sand dunes and estuarine silts, sands and clays currently being deposited around the the mouth of the River Tees.

Devensian

The most recent ice-sheet to occupy the Tees Valley did so during the Devensian Stage of the Pleistocene, between around 120,000 and 20,000 years before present, when ice advanced on the area from seats in the Lake District to the west, and Scotland to the north. Pressure, applied by Scandinavian ice from the North Sea Basin, affected the advance locally by forcing the Scottish ice stream inland at suitable low points in the landscape.

View of Freeborough Hill looking south east from Stanghow Ridge.

Some landforms, such as Freeborough Hill, were sculpted as the ice-sheet carved up the original landscape during advance. Others, such as Cat Nab at Saltburn, resulted as the ice melted and the material which had been acquired en-route was unceremoniously dumped. Immense amounts of melt water, unable to escape in any other direction, flowed along the ice margins forming temporary lakes where conditions allowed. Longer-lived water bodies tended to fill until they eventually overflowed, the escaping streams often cut distinctive channels which were abandoned as flow rates diminished. Water also travelled through, beneath and upon the ice-sheet where conditions allowed.

The most extensive evidence of former occupation by ice-sheets is a thick deposit of boulder clay (or till) which cloaks the landscape, softening its contours to heights of between 250 and 300 metres above sea level. This material has also in-filled some of the pre-Devensian features producing buried valleys, most notably at Upgang and Saltwick Bay, near Whitby.

Boulder clay is a mixture of clay-, silt- and sand-sized particles (dubbed rock flour) within which grit, pebbles and boulders are embedded. It forms as an ice-sheet advances and tears up the bedrock over which it passes. Large boulders enhance ice’s abrasive ability and are gradually pulverised by movement of the ice to form rock flour. When ice-sheets eventually melt the boulder clay left behind contains fragments of rock acquired en-route which are non-native to the district in which the clay ends up being deposited. These erratics provide important clues to the source and route taken by the originating ice.

Holocene

Since the retreat of the Devensian ice-sheets, around 20,000 years ago in the Tees Valley and Cleveland, many changes have occurred to the landscape. On both sides of the River Tees, at Seaton Carew and Redcar, are ancient peat deposits buried beneath the sands on the beaches. These date from around 8,000 years ago.

As water becomes locked up in the form of ice, so sea levels fall. Even though ice had left the area by 8,000 years ago, sea levels were still much lower than they are today. Up to 150m lower. Forest extended far seaward from Teesside at this time, it was later occupied by early human resettlers. Finds at Seaton Carew include signs of flint-working, a skull, wattle-work and much more, and the Peat & Forest Beds have been designated a SSSI. No such work has been undertaken at Redcar despite the ongoing sea-defence work and these valuable deposits are likely to be lost.

Tree-trunk in the Redcar Peat & Forest Beds.

Eventually, c.6,000 years ago, sea levels rose to (roughly) their present levels and the former forest was overwhelmed. The only clues to its former existence these two patches of peat on either side of the River Tees estuary. As these deposits contain evidence of past sea-level change, they are a valuable resource for the study of future sea-level rise.

« Tertiary

Geological periods

admin — Tue, 20 Nov 2007 11:21:23 +0000

The word Geology comes from the ancient Greek, Ge (γη) meaning Earth (not to be confused with Gaia (Γαια) the Greek Earth goddess) and Logos (λογος) meaning word or study of, amongst other things. So Geology literally means Study of the Earth.

The the addition of the letter ‘o’ to spell geo was simply to make the word sound better: “gelogy” would sound awful!

It is the rocks of the Tees Valley that have brought industry and money into the area. Some of the rocks to be found here are more important than others. But all of them have in some way played a part in building the Tees Valley.

To find out more about any of the rocks in the Tees Valley select a geological period from the list below. The geological periods are given in chronological order (order of time) with the oldest period at the bottom of the list.

Click here for a detailed geological timescale for rocks in the Tees Valley.

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