Posted by john palmes on May 26, 1999 at 15:23:07:
I was drawn to this website by the glossary of glacial landforms.
I have found landform and drainage symmetries involving two and four drainages that are symmetrical on either side of a divide. that is these drainages are right and left handed versions of each other.
A twin drainage pattern of about 1200 square miles from Norway is an almost exact copy of a simiar pair of twin bays near Sitka Alaska.
These twin drainages are sometimes almost exactly equal in area, as well as in the way they branch, and these patterns stack up to form a series of basins.
The underlying bedrock seems to have nothing to do with the twin drainage patterns, which are best formed facing souhwest...into the prevailing weather.
The only explanation for these twin drainages seems to be that something organized them into left and right handed versions of each other.
I suggest that glaciers are the organizer of the terrain and that twin valleys are formed by drainage on either side of a glacial front. Yakataga glacier is the best model i have, but in this neck of the woods, glaciers are drainaed mostly by two or four streams, and cirques also show drainage symmetry.
However, if glaciation is the cause of the symmetry, then there were no pre-glacial V shaped valleys that later became U shaped..
Are you familiar with this symmetry ? Have you ever heard and explanation? who would like to read my paper on the subject and give me some feedback?
Trying to explain this symmetry has kept me awake for many nights. I hope its exciting stuff to somebody else.
john palmes, box 20454 juneau, alaska 99802-0454
(907)586 2252