Figure 10.27: A polished stone called a ventifact, is produced by abrasion from sand grains.
( 41 )
Figure 10.28: These petroglyphs were carved into desert varnish near Canyonlands National
Park in Utah. ( 34 )
Figure 10.27: A polished stone called a ventifact, is produced by abrasion from sand grains.
( 41 )
Figure 10.28: These petroglyphs were carved into desert varnish near Canyonlands National
Park in Utah. ( 34 )