Fig. 1a. Beach exposure of a wedge of megacrystal rock, about 60 cm wide at its widest exposure and tapering to narrow digitate projections into diorite (dark). The wedge extends 10 m and is bounded by diorite. At the digitate end (shown here), the K-feldspar megacryst crystals (2 cm long) gradationally and nearly abruptly disappear along strike (left side of photo). Black areas are puddles of water.