The pattern description (page 32) reads:

This Aran afghan is as unique as the textured clam shells that wash up on the beach! Rows of stitch combinations resembling seashells are flanked by cables formed using post stitches. The result is a cozy blanket that you’ll love to wrap around yourself.

Gauge: One repeat in pattern = 6 1/2 inches; 6 rows = 3 inches

The blanket is very textured.

Stitch Guide: Back Post Double Crochet (BPdc), Front Post Double Crochet (FPdc), Front Post Treble Crochet (FPtr), 3-DC Popcorn, 4-DC Popcorn