2. Franciscan blocks appear as brown areas in springtime
the majority of blocks in Franciscan bimrocks are graywacke sandstone; the matrix is sheared shale. In spring warm weather, sandy soils around near-surface buried blocks dry faster than the clay soils above matrix. Grass dries on the sandy soils above buried blocks, while grass remains green longer on matrix clayey soils; near Nicasio, California (E. Medley, 1993)
5. Patriotic block (knocker)
Blocks are often called "knockers" by earthwork contractors because their bulldozers and scrapers unexpectedly and unwelcomingly "knock" into them during excavation; Nicasio area, California
6. Franciscan melange earthflow
a large earthflow showing the "melting ice-cream topography" of unstable slopes in Franciscan bimrocks; Hwy 101, near Cloverdale, California (E. Medley, 1993)
7. block-rich toe of a landslide
The 2002 Polhemus Road landslide blocked a major rural road for several months. The slide initiated at the head; the toe, composed of block-rich melange, resisted movement; Polhemus Road, San Mateo County, California
8. buttress effect of blocks
The toe of the Polhemus Road slide was buttressed by large blocks. Some were composed of extremely strong greenstone (metamorphosed basalt) which complicated earthwork excavation and repair; Polhemus Road, San Mateo Country, California (E. Medley, 2002)
The actively eroding shoreline in Franciscan bimrock is prone to major landsliding and loss of personal property; This house has a better prospect of surviving because it is based on a large block. The road is more vulnerable; Coleman area, California (E Medley. 2021)