Schematic overview of a thrust system. The hanging wall block is
(when it has reasonable proportions) called a nappe. If an erosional hole is created in the nappe that is
called a window. A klippe is a solitary outcrop of the nappe in the
middle of autochthonous material.
In structural geology, an
allochthon (or allochthonous block) is a large
block of rock which has been moved from its original site of
formation, usually by low angle thrust faulting. An allochthon
which is isolated from the rock that pushed it into position is
called a klippe. If an
allochthon has a "hole" in it so that one can view the autochthon
beneath the allochthon, the hole is called a "window".
Etymology: Greek; 'allo' = other, and 'chthon' = earth.
allochthonous sources of carbon come from outside the aquatic
system (such as plant and soil material). Carbon sources from
within the system, such as algae and the microbial breakdown of
particulate organic carbon, are autochthonous. In streams and small
lakes, allochthonous sources of carbon are dominant while in large
lakes and the ocean, autochthonous sources dominate. (Eby,
Eby, G.N., 2004, Principles of Environmental Geochemistry:
Thomson Brooks/Cole, Pacific Grove, CA., 514 pp.