A quiet weekend, this last one. However, on Saturday I enjoyed a walk round local woods with
The Friends of Buck Wood and in the expert company of Alison, a former geologist with Bradford Museums Service.
Buck Wood (in the bend of the River Aire, in the northern part of the map) lies on the Soft Bed Coal, Flags and associated shales, seat-earths and other rocks of the Lower Coal Measures and the Rough Rocks of the Millstone Grit Series. These were laid down in the tropical forests and river deltas of the Upper Carboniferous period about 300 million years ago.
Alison showed us, among other things, fossils. The one below is of Sigillaria, a tree-sized club-moss. The pimply holes are scars left by rootlets growing from a main root. The fossil is in a rock known as Ganister, a tough, fine-grained seat-earth (found immediately below coal seams) formed from quartz sand.