Mud volcanoes are typically viewed as positive landforms. At Hite,
Utah shallow-sourced mud volcanoes are developing on the modern
delta plain formed as the Colorado River enters Lake Powell. These
features display a complex evolution that has not been documented
from either modern or ancient mud volcanoes. Hence this work adds to
the understanding of the geomorphic variability of short-lived mud
volcanoes from initial activity to dormancy unrecognized in modern
and ancient settings.
The mud volcanoes reflect two distribution patterns across the delta
plain: linear, along slump failure planes and random, elsewhere. Mud
volcanoes, developing nearest to the Colorado River, display a
linear trend with caldera elongation parallel to the river. The
river incision related to falling lake levels causes slope failure
and creates a planar conduit for sediment and gas expulsion at
vents. Farther from the river, larger mud volcano fields develop
randomly with greater vent density.
These mud volcanoes display various stages of landform evolution,
beginning as positive features then collapse to caldera-like forms.
The initial form is a blistering phase, breaching the surface and
leading to typical mud volcano landforms. The positive form actively
erupts mud and gas from single or multiple clustered vents. After a
period of eruption, the landform undergoes collapse and the positive
inverts to a negative, caldera-like form that can then be either
active or dormant. Active, collapsed forms can expel gas, up to 95%
methane or potentially resurge to create another mud volcano in the
confines of the caldera. As these conduits fill with sediment or gas
pressure drops, the mud volcano becomes dormant.
These documented modern geomorphic changes in mud volcanoes
illustrate the growth history of shallow-sourced, fluid escape
features, from initial landform through dormancy that can
potentially be recognized in the rock record.
The geomorphic evolution of
shallow-sourced methane produced mud volcanoes Lake Powell, Hite
Utah