Scremerston Fieldwork

Just a few photos from recent fieldwork at Scremerston, Northumberland, UK.

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Shaftoe Bouldering

Headed up to Shaftoe in Northumberland on Tuesday evening trying to make the most out of the decent weather and light evenings as the nights start to draw in.

Pete on Soft Centre, Shaftoe
Pete on Soft Centre
Me on Sloper masterclass, Shaftoe
Me on Sloper Masterclass

The rock at Shafoe climbs quite differently to other venues in Northumberland in that its much more rough than the sandstone found at places like Bowden Doors and Kyloe (in and out). Its still a sandstone but with a definite feel of grit about it, similar to the rock at places like The Slipstones down in Yorkshire.The rock on the problems generally has brilliant friction and is of good quality, quite different from the much finer, softer sandstone found at nearby Corby’s

The coarse fluvial Sandstone at Shaftoe
The coarse fluvial Sandstone at Shaftoe

In terms of the geology of this rougher sandstone is believed to be a fluvial deposit. This means that it is a sedimentary rock produced by a river, and is slightly younger than the Fell Sandstone which makes up Bowden and Kyloe.

Pete on Hound Dog, Shaftoe
Pete on Hound Dog
Me on Soft Centre, Shaftoe
Me on Soft Centre

Hamsterley Forest

Apologies for the lack of geology here just a few photos from a ride at Hamsterley forest at the weekend…

Also has anyone got any tips for taking photos of fast moving things like bikes? My camera (Pentax M60 compact) seems to take ages to respond then you miss the thing that you are trying to capture?

Typical North East Desolate Waseland
Typical Desolate North East Waseland scenery on Root 666
Drop off on Brain Freeze
Drop off on Brain Freeze. The Berm doesn’t seem to quite line up with the drop off…
Hamsterley Trails
Hamsterley Trails
North Shore on the Skills loop
North Shore on the Skills loop
The ground is hard...
The ground is hard…
Root 666
Root 666

All the stuff we went on can be found on either the red trail or the black trail.

Dykes on the beach

I had pretty much forgotten about this amongst everything else but I still think this is worth posting. On the way back from doing Dream of White Horses on Gogarth (2 weeks ago) we decided to have a quick stop on the beach and found some interesting geology to look at. From just a few simple observations on this beach some really key geological principles can be demonstrated.

Beach on the way back from climbing on Gogarth
Beach on the way back from climbing on Gogarth

The main rock type here is a metamorphic rock (picture below) known as a gneiss with abundant mafic intrusions cutting it perpendicular to the coastline.

Foliation in the Gneiss which the mafic dykes intrude
Foliation in the Gneiss which the mafic dykes intrude

An intrusion is when molten rock is injected into another rock and the word ‘mafic‘ refers to the composition of the intrusion. Here I am using mafic to describe an igneous rock which is dark coloured and with crystals too small to identify, but its actual definition is a silicate mineral (contains the elements silicon and oxygen) which is rich in the elements magnesium and iron. A metamorphic rock is a rock which was previously another type of rock which has been physically/chemically altered through increased pressure and temperatures in the Earth.

One of the larger intrusions observable on the beach
One of the larger intrusions observable on the beach

The patterns we can see in the gneiss (second photo down) are known as foliations. These are a planar feature caused by pressure forcing the minerals in the rock to align in a preferred plane.

Small offshoot of the dykes
Small offshoot of the dykes

This simple observation of the dykes on this beach also demonstrates a crucial geological principle, so called ‘cross-cutting relationships‘. The principle of cross-cutting relationships states that the geologic feature which cuts another geological feature is the younger of the two features. Geologists use observations like this to build up the sequence of events (relative ages as opposed to absolute ages) that led to the particular setup which we observe. From this we can reliably say (with no need for dating techniques!) that the dykes here are younger than the metamorphic rocks they intrude. This concept of relative dating was noted as early on as 1795 when James Hutton published his ‘Theory of the Earth‘, and is not just limited to intrusions, it can be applied to a whole array of geological features such as faults or erosional surfaces.

Not sure what makes this pattern in the intrusions? Maybe contraction during cooling?
This pattern was observable on some of the dykes, but I’m not sure what causes it!  Maybe contraction during cooling?

I would imagine most of the beaches this side of Anglesey have things of interest. If you find yourself passing by might be worth a quick look 😉