The coordinates above are for the Colorado School of Mines Geology
Museum. The Museum is free, and the hours are Monday - Saturday 9am
to 4pm and Sunday 1pm to 4pm. The trail does not close and can be
accessed off hours, but since it is located on campus please use
discretion.
To receive the full enjoyment of the cache, we recommend doing
this cache during daylight hours. Stop in at the Museum first to
obtain a fascinating pamphlet to accompany this Earth-Cache
entitled "Lessons from the Mines Geology Trail." The Mines Geology
Trail continues for 3 additional stops not included in this
EarthCache, but is also very interesting. These stops are described
in the brochure "Mines Geology Trail" available at the Museum.
After touring the Museum, proceed to Stop 2 - fossil locality -
located at N 39 44.958 W105 13.569 .
The vertical rock wall to the east is a sandstone formation (the
Laramie Formation) that used to be horizontal. Extensive faulting
that occurred at the time the mountains to the West were formed
caused the layers to be tilted to almost vertical. Picture the area
you are standing on millions of years ago when it was flat. You
would be standing in mud, leaving footprint impressions just as the
dinosaurs did. There also could have been downed trees lying in the
mud around you. Later, sand was deposited on top of the tracks
left, and the logs were also buried. Millions of years later, after
being tilted to near vertical, the softer layer of earth created
from the mud has eroded away, leaving the harder sandstone layer
and preserving the tracks of the dinosaurs, seen as bumps, and the
impressions of the logs, seen as long indentations in the rock. By
looking carefully you can also see fossils of palm fronds and leaf
imprints. Use the pictures and diagrams in the brochure, and the
signs on the wall to align your location, and to locate the various
fossils and faults.
Stop 3 - Mined Clay and Environments - is located at N39 45.006
W105 13.572. By the use of the fossils and coals found here, this
stop teaches us what the earth was like when these rocks were
deposited, and is important for understanding how economic
products, like clay and coal, were formed. Beginning in the late
1800's, there were mines in the area for clay and coal, read more
from the trail pamphlets.
Proceed north to Stop 4 - End of Ridge - at N39 45.031 W105
13.633. Here you can see where a fault has occurred in the rocks to
the south. Although it is now mostly covered by the parking lot,
you can see how the resistant sandstone wall of the Laramie
Formation comes to an abrupt end. It has been faulted at this
point, so that on the far side (south side) is the sandstone rock
wall of the Laramie, and on the close side (north side) is the
softer Pierre shale that has been eroded away.
Stop 5 to the north -Rock Garden- located at N39 45.063 W105
13.667, is a chronological history, in rock, of the Colorado Front
Range, and other rocks of Colorado. Each rock type has distinctive
properties, and is named for the area where it can be found. Take
time to look in the distance at various examples of geology that
can be seen from here. Three types of rock, Metamorphic (rocks that
have been altered by heat or pressure), Igneous (rocks created by
lava flows), and Sedimentary (rocks laid down in layers of
sediment) can be seen from here. The mountains to the west are very
old, hard Metamorphic rock, the Table Mountains to east are capped
by hard igneous rocks from lava flows that occurred about 64
million years ago, and the area where you are standing is composed
of softer sedimentary rocks that have eroded over time to create
this valley. Now enjoy the various types of rocks that have been
collected and laid out here. Search out the State Rock.
To claim this cache, please e-mail to mtnbirders@yahoo.com the
name of the State Rock, and its neighbor to the west. Include in
your e-mail a description of your favorite rock. Unless you are
continuing along the rest of the Mines Geology Trail, please
retrace your route back to the Geology Museum.
I would like to give special thanks to Dr. Robert Weimer,
Professor Emeritus, for setting up this trail, and Linda G. Martin
who assisted on the computer graphics for brochure, and to Dr.
Murray Hitzman, Head of the CSM Geology Department and Paul Bartos,
Curator of the Geology Museum, for graciously allowing us to post
the Mines Geology Trail as an Earthcache on Geocaching.com. Your
efforts to teach others about the geology of this grand planet we
live on are inspiring.