The Mountain Geologist

• Year: 2004
• Title: The Mountain Geologist
• Author: Rocky Mountain Association of Geologists
• Description: October 2004, Volume 41, Number 4
• Publications - Doc Type: Other

AQUIFERS of THE DENVER BASIN, COLORADO
0 SCALE 1;750,000 80 Miles
The Arapahoe aquifer is underlain by up to 400 ft of
shale with minor beds of coal, sandstone, and siltstone
known as the Laramie Formation. In places, the basal por-
tion of this formation contains relatively thick fluvial sand-
stone units. In conjunction with the near -shore to beach
facies Fox Hills sandstone, these sandstones comprise what
is known as the Laramie -Fox Hills aquifer. This aquifer
underlies the entire 6700 -mi2 area of the Basin and marks
the areal extent of the commercially economic groundwater
Figure 1. Location of the
Denver Basin (groundwater
administration boundary)
development for the Denver Basin. The aquifer is up to
350 ft thick with 40 to 60% being fine- to medium - grained
sandstones. The total thickness of water yielding materials
rarely exceeds 200 ft (Fig. 3)•
WATER LEVELS AND WATER STORAGE
In their respective outcrop areas, the Denver Basin
aquifers are under water -table (unconfined) conditions. In
147 The Rocky Mountain Association of Geologists
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0 SCALE 1;750,000 80 Miles
The Arapahoe aquifer is underlain by up to 400 ft of
shale with minor beds of coal, sandstone, and siltstone
known as the Laramie Formation. In places, the basal por-
tion of this formation contains relatively thick fluvial sand-
stone units. In conjunction with the near -shore to beach
facies Fox Hills sandstone, these sandstones comprise what
is known as the Laramie -Fox Hills aquifer. This aquifer
underlies the entire 6700 -mi2 area of the Basin and marks
the areal extent of the commercially economic groundwater
Figure 1. Location of the
Denver Basin (groundwater
administration boundary)
development for the Denver Basin. The aquifer is up to
350 ft thick with 40 to 60% being fine- to medium - grained
sandstones. The total thickness of water yielding materials
rarely exceeds 200 ft (Fig. 3)•
WATER LEVELS AND WATER STORAGE
In their respective outcrop areas, the Denver Basin
aquifers are under water -table (unconfined) conditions. In
147 The Rocky Mountain Association of Geologists