Here is an interesting result of beach erosion. This is a remnant tree trunk, probably a mangrove, sitting in compacted mud. It was exposed when the overlaying beach sand was removed by a storm. Because mud is an anaerobic environment it can preserve wood. This trunk could be decades old, or centuries; hard to tell without dating it.
Here's another piece of preserved wood from the same area. Here the sand itself has started cementing together. I don't no whether this rock could be classed as sandstone yet, or the wood as a true fossil.
Part of the sand overburden still remains around this remnant piece of wood. The picture also gives an indication of where the current shoreline is. Unless covered again by sand this wood will eventually weather away.
Another piece of a remnant tree, this time out in the water providing a hold for barnacles to grow.
All these pictures were taken at low tide.
