Category Archives: Geodiversity Database CD
January 2010 – Siderite
Iron carbonate (FeCO3), or siderite from the Greek sideros meaning iron, is a major source of ore for steel-making being usually low in sulphur and phosphorous, and high in manganese and/or magnesium.
This mineral is able to assume almost any colour but commonly brown, yellowish-brown, or grey specimens can be found. It occurs in Britain’s [...]
on January 6, 2010 Leave a comment
September – Whinstone
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 [...]
on September 10, 2009 Leave a comment
June – Alum Shale
Alum Shale occurs within the upper 35 metres or so of the Whitby Mudstone Formation. A suite of rocks that originated as soft sediment accumulating on the floor of an ancient sea (the Tethys) which occupied this area between c.188 million and c.182 million years ago during the late Lower Jurassic phase of Earth’s geological [...]
on June 1, 2009 Leave a comment
March – Ironstone
Iron makes up a full 35% of the whole Earth, though most is sequestered within the metallic core, with the crust containing around 6%. It is an important rock commercially, being smelted to make iron and steel. High grade deposits, often comprising more than 70% iron, were laid down in the Precambrian, around 2 billion [...]
on March 8, 2009 Leave a comment
February – Woolly Mammoth Tooth.
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 [...]
on February 3, 2009 Leave a comment
January – Flint
Flint is the dark grey to black nodular material commonly found in chalk. It is Cretaceous in age (146-65 million years old). Flint breaks with a pronounced conchoidal (curved) fracture creating sharp edges. This feature was exploited by early man to create edged tools.
It is made up of a mineral called Chalcedony, [...]
on January 7, 2009 2 Comments
December – Diamond
The name Diamond comes from the Greek word Adamas meaning indestructible. Diamonds are the hardest rock on Earth.
Diamonds form between 120 – 200km below the surface, in the Earth’s mantle, in patches amongst mantle rocks called peridotites and eclogites. Study of these rocks tell us that the material from which diamonds form is sea [...]
on December 1, 2008 Leave a comment
November – Ammonite
Ammonites are coiled relatives of the octopus (Cephalopods) and became extinct at the end of the Cretaceous Period around 65 million years ago.
Below is an image of a Harpoceras, which lived during the Jurassic Period. These fossils can be found in the Upper Liassic shale (Whitby Mudstone Formation) which crops-out widely across Cleveland and the [...]
on November 1, 2008 Leave a comment
The RIG Site Database
In 2003 Tees Valley Wildlife Trust intoroduced a Geodiversity Action Plan. Part of this involved the development of a list of all sites of geodiversity importance within the Tees Valley. This list was narrowed down and submitted to local authorities for approval. These sites are our current RIG Sites for the Tees [...]
on December 30, 2007 Leave a comment
February 2010 – Evaporites