Ancient lahar in Ireland

Lahar is a mudflow on the flanks of a volcano. It consists of mud and fragments of volcanic rocks plus any other available material. It is loose sediment and most examples photographed are recent. I want to demonstrate you a lahar that is hundreds of millions of years old (probably from the Carboniferous). It is a hard greenish rock resembling moderately altered basalt or andesite but it contains lots of clasts which are mostly volcanic but there is fair amount of limestone fragments as well.

http://picasaweb.google.com/107509377372007544953/Ireland#5759869328170930178
Muddy matrix with volcanic clasts.
http://picasaweb.google.com/107509377372007544953/Ireland#5759869689480296242
This lahar is exposed at the coast.
http://picasaweb.google.com/107509377372007544953/Ireland#5759869647421940770
There are lots of clam shells.
http://picasaweb.google.com/107509377372007544953/Ireland#5759869875097211074
http://picasaweb.google.com/107509377372007544953/Ireland#5759869247067310386
http://picasaweb.google.com/107509377372007544953/Ireland#5759869591583801874
Conglomerate boulder on top of lahar.
http://picasaweb.google.com/107509377372007544953/Ireland#5759869897150058354
http://picasaweb.google.com/107509377372007544953/Ireland#5759870083300858514
Pink clasts are limestone fragments.
http://picasaweb.google.com/107509377372007544953/Ireland#5759870150028765010
http://picasaweb.google.com/107509377372007544953/Ireland#5759870135525906834

Want to visit the place? Here are some guidelines. Go to Portraine (north of Dublin) and park by the sea in a parking lot with the following coordinates: 53° 29′ 22″ N 6° 05′ 56″ W. Go few hundred meters to the north/northwest.

This is my 200th post on Sandatlas.