Carboniferous limestone with crinoids
Collection:
Click the microscope button to view a thin section for this sample.
Microscope
Click the microscope button to view a thin section for this sample.
Microscope
Click the object button to view an object rotation for this sample.
Object

Fact sheet

Carboniferous limestone with crinoids

This Lower Carboniferous limestone contains many fragments of crinoid ossicles that were once the stems of ancient marine animals attached to the sea bed, sometimes called sea lilies. There are also many fragments of brachiopod shells. The sample comes from Bucket Rocks, Berwick upon Tweed, England, and is cemented by a carbonate rich mud.

The thin section is dominated by two species of crinoid ossicles, both in longitudinal section and cross section. One species has a circular cross section, the other has a five-sided form. The crinoids have a dusty appearance due to the microcrystalline nature. Fragments of brachiopod shells are marked out by more transparent crystalline calcite. The cement ranges from blocky carbonate grains to fine-grained calcium-rich mud.

Additional images
  • cose up of carboniferous limestone
  • cose up of carboniferous limestone
  • polished surface on hand specimen of carboniferous limestone
  • Hand specimen of carboniferous limestone
  • cose up of carboniferous limestone
Map
55.773, -1.9872
Description:
Bucket rocks, Berwick on Tweed, Berwickshire
Precision:
Good
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

Type
sedimentary
Category
limestone
Rock-forming mineral
calcite
quartz
Category guide  
Category Guide
Title
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.
Description
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.
Timescale
Selecting one or more period, for example 'Jurassic'.
Theme
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.
Category
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).
Owner
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: