Geology Reference
In-Depth Information
Nonconformity:
A
nonconformity
is a break in time between a metamorphic or in-
trusive igneous rock (see Chapter 7) and layers of sedimentary rocks created
above it. A nonconformity is created when underground rocks (the metamorphic
or igneous rocks) are lifted to the surface and eroded, and then sediments are de-
posited on them (usually by water), which eventually become sedimentary rock. A
nonconformity can also be created when magma intrudes into pre-existing sedi-
mentary rock layers and forms an intrusive igneous rock.
Figure 16-1:
How
an angular uncon-
formity is created.
Figure 16-2:
How a
disconformity is
created.
