Offcumden

This is used to describe someone who was not born in a place, and is  typically used in parts of Yorkshire to describe people who have moved into a village or small towns.

What we have here is an offcumden stone : Portland stone. 

The EarthCache takes you to the local war memorial to the dead of the Great War. Please be respectful, these men listed here died in the mud of Flanders, amongst the chalk of Arras and the Somme, the mountains of Italy, the sands of Mesopotamia and the rocky gullies of Gallipoli. Take a minute to think about them. 

Portland stone is a type of limestone. Now if you drive up Wharfedale, you will soon come to a landscape filled with limestone, at Grassington, Kilnsey, Kettlewell and beyond. Over in Craven, there are limestone pavements formed by Great Scar limestone.There are many different classifications of limestone:

Lithographic Limestone : this was formed in shallow pools which were stagnant, and low oxygen levels. This type of limestone, tends to be fine grained, with a grain size less than 1/250mm.

Bituminous Limestone: this is impregnanted and coloured with bitumen, which has developed from the decomposition of organic matter.

Carboniferous Limestone: this tends to be grey / off white, with a fine texture, and can be seen in great expanse further up Wharfedale and in Craven. Great Scar Limestone is a type of this limestone.

Travertine Limestone: this is deposited by hot springs, and tends to be a white or off white colour, with concentric rings.

Oolitic Limestone : this was formed on the floor of a shallow, warm, sub-tropical sea. As small sea creatures died, their shells formed calcite, this accumulated forming lime mud which covered the sea floor. Small particles such as grains of sand became coated with calcite as they were moved about. Gradually over time, layers formed, forming minute balls, less than 1/2 mm in diameter. Over time millions of these balls, which are called ooliths became partailly joined together in a process called cementation, to form oolitic limestone.Portland stone is a type of this limestone.

So why have they used an offcumden limestone?

Portland stone is used in many war memorials as it is easy to carve, the war graves in France and Flanders are made of this stone.

Portland stone at times has fossils in it:

Gastropods: these are like spiral shells.

Oysters: these are often found to form beds, which can be seen as irregular linear fossils.

Ammonites: these are tightly coiled, with linear ribs in appearance.

This being an EarthCache, in order to log it, I ask that you answer some questions. Please send them to me, and do not include them in your log. You can send them to me by using the message facility or email, both of which can be found by looking at my profile.

1.Please describe the appearance and feel of the Portland Stone.

2. Can you see any evidence of fossils, if so what types?

3. Using the above information, what classification of limestone is Portland stone?