Benalmadena, Costa del Sol, Spain, some 20 miles West of Malaga, and perhaps readers can enlighten me about what I’m seeing:

Rocks within rocks within rocks; red sandstone matrix (no stratification or bedding apparent), containing fragments of varied origin and degree of processing; some examples include fragments of chert-veined basalt. Note at far left, and also beneath scaling coin, pebbles of chert-containing cnglomerate.

How did any of this happen and in what kind of environment? The diversity of the pebbles in composition and processing suggests rapid river transport, but what process would leave so much sand between them? I haven’t seen an outcrop of this kind of rock, but there are chunks of it all along the coastline, and some examples (e.g. those to left and right in this picture) are far poorer in pebbles.

Rocks within rocks: chert vein within a very strange looking rock indeed; dark, micaceous, bands…