Everything about Cornbrash totally explained
In
geology,
Cornbrash was the name applied to the uppermost member of the
Bathonian stage of the
Jurassic formation in
England. It is an old English agricultural name applied in
Wiltshire to a variety of loose rubble or brash which, in that part of the country, forms a good soil for growing corn. The name was adopted by
William Smith for a thin band of shelly
limestone which, in the south of England, breaks up in the manner indicated. Although only a thin group of rocks (1025 feet c. 300 m), it's remarkably persistent; it may be traced from
Weymouth to the
Yorkshire coast, but in
north Lincolnshire it's very thin, and probably dies out in the neighborhood of the
Humber. It appears again, however, as a thin bed in
Gristhorpe Bay,
Cayton Bay,
Wheatcroft,
Newton Dale and
Langdale. In the inland exposures in Yorkshire it's difficult to follow on account of its thinness, and the fact that it passes up into dark
shales in many places the so-called clays of the Cornbrash, with
Avicula echinata.==Fossils==
The Cornbrash is a very
fossiliferous formation; the fauna indicates a transition from the Lower to the Middle
Oolites, though it's probably more nearly related to that of the beds above than to those below. Good localities for fossils are
Radipole near
Weymouth,
Closworth,
Wincanton,
Trowbridge,
Cirencester,
Witney,
Peterborough and
Sudbrook Park near
Lincoln. A few of the important fossils are:
Waldheimia lagenalis,
Pecten levis,
Avicula echinata,
Ostrea fiabelloides,
Mycicites decurtatus,
Echinobrissus clunicularis.
Macrocephalites macrocephalus is abundant in the midland counties but rarer in the south;
belemnites are not known. The remains of
saurians (
Steneosaurus) are occasionally found. The Cornbrash is of little value for building or road-making, although it's used locally; in the south of England it isn't oolitic, but in Yorkshire it's a rubbly, marly, frequently ironshot oolitic limestone. In
Bedfordshire it has been termed the
Bedford limestone.
Further Information
Get more info on 'Cornbrash'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://cornbrash.totallyexplained.com">Cornbrash Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |
