Geologic Map of the Maysville Quadrangle, Chaffee County, Colorado

sediment supply is abundant. Frontal slope is at the angle of repose. Boulders on top,
sides, and front are lichen free, so deposits are inferred to have moved recently. Probably
contain ice cores. Maximum thickness about 33 ft.
Qrgo Rock glacier deposits, older (early to middle Holocene) – Poorly sorted angular
to sub-angular boulders, cobbles, gravel, and sandy silt in a matrix of firn or glacier ice.
Mapped only at the head of Como Creek. The outer part of the rock glacier is typically
clast supported, matrix free, and composed of angular to subangular, predominantly
boulder-sized rock fragments. Downslope movement is the result of internal deformation
of the firn or ice core. Rock glaciers commonly have a lobate or tongue-like morphology
and form in cirque basins where sediment supply is abundant. Frontal slope is below the
angle of repose. Boulders on top, sides, and front are covered with lichen and/or trees, so
deposits are inferred to be stationary. Probably does not contain an ice core. May be
covered with younger talus and colluvium on edges. Maximum thickness about 33 ft.
Qt Talus deposits, undivided (Holocene) – Angular, cobbly and bouldery rubble as
much as 6 ft in diameter. Mapped at the base of oversteepened glacial valley sidewalls in
the cirques of both branches of Squaw Creek. Deposits are derived from bedrock that was
transported downslope by gravity principally as rockfalls, rock avalanches, rock topples,
and rockslides. Downslope movement may have been locally aided by water and freezethaw
action. Unit typically lacks matrix material near the surface, but dissected talus
reveal significant matrix at depth. Surface is partly vegetated, indicating that most of the
surface is no longer receiving active deposition. Thickness is probably less than 15 feet.
Talus areas are subject to rockfall, rock-topple, and rockslide hazards.
Qta Talus deposits, active (late Holocene to Historic) – Angular, cobbly and
bouldery rubble as much as 6 ft in diameter. Mapped at the base of oversteepened glacial
valley sidewalls in the cirques of both branches of Squaw Creek and in the North Fork.
Also found on open slopes above timberline west of the summit of Mount Shavano and in
three long gullies that descend south from the Shavano massif to the North Fork.
Deposits are derived from bedrock that was transported downslope by gravity principally
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