Crinoidal limestone - Derbyshire
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Fact sheet

Crinoidal limestone - Derbyshire

Crinoidal limestone deposits found in Derbyshire, England were laid down during the Lower Carboniferous times prior to progradation of large deltas from the north, which formed the later Millstone Grits. At that time, the part of the UK that would become the English Peak District was the bed of a sub-tropical shallow continental shelf sea with a variety of life some of which has been preserved in this rock. The location of this sample was far from shore although the sea remained shallow and the water was rich in nutrients, producing the perfect conditions for the buildup of platforms of carbonate-rich rock. Crinoids were common in this shallow shelf environment during the Carboniferous and have been referred to as ‘Derbyshire Screws’ because of their abundance in the Peak District limestone. The thin section illustrates the coarse-grained, poorly sorted, well-cemented nature of this limestone rock. It contains bivalves, brachiopods, corals and crinoids in a fragmental matrix cemented by crystalline calcite (known as sparite). 

Additional images
  • crinoidal limestone - width 4 cm
  • crinoidal limestone - width 3 cm
  • crinoidal limestone - width 2.3 cm
53.208837, -1.766385
Once a Week quarry, Monyash, near Buxton, Derbyshire
About this collection

The United Kingdom Virtual Microscope (UKVM) collection consists of igneous, sedimentary and metamorphic rocks from around the UK.

It is intended as a teaching resource, helping to tell the story of the common rock types and how they form, and reflecting the history of the UK at the margins of the continent of Europe. The collection is a series of teaching sets, for example igneous rocks from the North Atlantic Igneous Province and SW England; high-temperature metamorphic rocks from Scotland and low-temperature metamorphic rocks from Wales; and sedimentary rocks, including English limestones and sandstones.

Sample details

Rock-forming mineral
Category guide  
Category Guide
Refers to any word or phrase that appears in the individual rock names. Names are generally descriptive; they allow users to search for broad terms like ‘granite’ as well as more specific names such as ‘breccia’. However, the adjacent descriptions of the specimens captures a wider range of general words and phrases and is a more powerful search tool.
Refers to any word or phrase that appears anywhere in the descriptions of the specimens
Accessory minerals
Minerals that occur in very low abundance in a rock. They are usually not visible with the naked eye and contribute perhapssver, they often dominate the rare elements such as platinum group metals.
Rock-forming minerals
Minerals that make up the bulk of all rock samples and are also the ones used in rock classi?cation.
Selecting one or more period, for example 'Jurassic'.
A term used to group together related samples that are not already gathered into a single Collection. For instance, there is a ‘SW England granites’ theme that includes such rock types as granite, hydrothermal breccia, skarn and vein samples.
A general term used to label a rock sample. It is a useful way of grouping similar samples throughout a collection. Category names are often, but not exclusively, common rock names (e.g. granite, basalt, dolerite, gabbro, greisen, skarn, gneiss, amphibolite, limestone, sandstone).
The owner of the sample that appears in the collection. For example, NASA owns all the samples that appear in the Moon Rocks collection
We would like to thank the following for the use of this sample: