Woodson County (503 Mi2) is located in southeastern Kansas
in the Osage Cuesta Physiographic Province. The bedrock is Pennsylvanian
in age and the units crop out roughly north-south and dip gently
to the west at about 30 feet/mile so that the rock units range
from the Lansing Group (oldest) through the Douglas Group to the
top of the Shawnee Group (youngest) and consist of alternating
units of bench-forming limestones and softer clastics, mostly
shale and siltstone with some sandstone. Most of the surface drainage
in the county is through the Neosho River and its tributaries,
but the Verdigris and its tributaries drain the southwestern-most
corner forming a scalloped outcrop belt. Two notable igneous intrusions
occur at Rose Dome and Silver City where basic igneous rocks were
intruded into the Pennsylvanian sediments in the late Cretaceous
and formed oval-shaped domes. Some surface faulting is associated
with the Silver City Dome. A third intrusive probably is present
near Neosho Falls, but there is no surface expression. This county
is the fourth mapped by the senior author - the others being Chautauqua,
Elk, and Greenwood (Coffey County is currently being mapped).
The surface geology is mapped in the field on 7 1/2minute quadrangles
(1:24,000), which then are digitized, coded, and overlain on topographic
and cultural bases to produce a final, full-colored map. The map,
or any portion of it, can be reproduced at any desired scale depending
on the need and use; normal scale for the final map is 1:50,000.
These county maps are just four of the 34 counties that have been
or are being mapped or remapped to produce a new geological map
of the State of Kansas.