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Birdseye
Marble in the Manti-La Sal National Forest, Utah County
Geologic Information:
Approximately 58 to 66 million years ago (Paleocene epoch), a large body
of water known as Lake Flagstaff covered parts of northeastern and central
Utah. This lake deposited a sequence of sediments that formed rocks known
as the Flagstaff Formation.
Although these rocks are technically a
limestone, the building stone industry has termed this deposit a
"marble." The rocks are rich in algal ball structures commonly
known as "birdseyes." These birdseye features were formed by
algae that grew around snail shells, twigs, or other debris. The algae
used these objects as a nucleus, forming into unusual, elongated,
concentric shapes.
How to get there:
From Salt Lake
City take I-15 south approximately 50 miles to Spanish Fork (exit 261).
Travel east and proceed up Spanish Fork Canyon (Rte 6) for about 13.5
miles to Hwy 89. Make a right onto Hwy 89 and go south about 5.8 miles
until you see a gravel road to your left. Make the left turn and proceed
up the road until you reach a gate. This gate marks the beginning of
Forest Service Road 126. Before you proceed up the road, remember to close
the gate after yourself. Continue up this road for about 1.5 miles until
you see a sign indicating that you have crossed into the Forest Service
lands.
Where to collect:
Specimens can be
found along the road just after crossing the Forest Service boundary. If
you feel adventurous, this road can be followed up to the abandoned
birdseye marble quarry (roughly 2.5 miles), but four wheel drive is highly
recommended.
Some of the birdseye marble contains cores
of snail fossils, which have been replaced by the mineral calcite. This
material takes a great polish and is ideal for making unusual decorative
bookends.
Useful maps:
Nephi 1:100,000-scale
topographic map; Birdseye 1:24,000-scale topographic map; Manti-La Sal
Forest Service map covering the Sanpete, Ferron, and Price ranger
districts; and a Utah highway map. Topographic and Forest Service maps can
be obtained from the Natural Resources Map & Bookstore, 1594 W. North
Temple, Salt Lake City, UT, (801) 537-3320 (or 1-800-UTAH-MAP).
Land ownership:
Manti-La Sal
National Forest.
Forest Service collecting rules:
Rock, mineral, and fossil collecting on lands managed by the U.S. Forest
Service requires a permit, which is free to the public. The permit allows
one to collect small amounts of material for personal use. This permit can
be obtained at the Manti-La Sal National Forest office, Monday through
Friday from 8:00 a.m. to 4:30 p.m. at 599 West Price River Drive, Price,
UT, (435) 637-2817 or (435) 637-3521.
Miscellaneous: Remember to bring
plenty of water and a first aid kit in case of emergencies. The usual
rockhounding tools are needed: gloves, hammer, wrapping paper, and safety
glasses. Most importantly, be patient and have fun!
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