Kevind showed some great troughs in the blog mentioned - and he's recently posted elsewhere more photos of his many troughs- illustrating how much better a trough can look with higher, stronger landscape features using rocks.(In contrast to the flat earth versions that tend to be shown by the TV experts!)
I'll post some of Kevin's trough photos here, trying not to duplicate too many, though even then they may be photographed at a different time of year .

Killaloe Slate

Ballyhoura Mudstone, Red Sandstone conglomerate & Volcanic rock.

Ballyhoura Mudstone, Red Sandstone conglomerate & Volcanic rock.

Namurian Mudstone from Kerry.

more to follow!