Location 3.

St. Thibéry

This outcrop is at the back of the basketball court in the town.

Outcrop 3.

This outcrop comprises a conglomerate which lies under the basaltic unit.

Picture 3:

This picture shows outcrop 3.

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This is a sketch of the outcrop:

Sketch 1:

This is a sketch section showing the basaltic agglomerate (c) lying on top of the conglomerate (a)

Click on the image to enlarge

Conglomerate:

The conglomerate is made up of small to very large well rounded clasts of mainly quartz along with chert and low grade metamorphic rocks. The conglomerate appears to be grain supported in some areas and matrix supported in others. The matrix is very fine grained. Within the conglomerate there is an ash band (b) which is divided into two different lithologies:

Dark band:

The dark bands contain dark, grey and white crystals. They seem to be matrix supported. There is also a presence of some orange grains within this band.

Light bands:

This band contains fine grained sandstone/mudstone. This appears to be the the material which makes up the matrix of the dark bands.

The conglomerate is the oldest unit in this outcrop. It contains sedimentary structures such as bedding and imbrication. It is not very easy to establish a flow direction using this imbrication, however it was suggested that there was a North - South flow direction.

Basaltic unit:

This deposit is very rubbly and there appears to be evidence of ductile deformation.

Upon closer inspection it was evident that this is an agglomerate, as it consists mostly of bombs. It probably represents the distal edge of a spatter cone.