Mount Elden is one of five large peripheral
silicic volcanic features within the greater
San Francisco Peaks volcanic system (part of the
San Francisco volcanic field) which include the nearby
Dry Lake Hills, the
Hochderffer and White Horse Hills to the northwest, and
O'Leary Peak to the northeast. Because these features developed within close proximity of the San Francisco Mountain
strato-volcano there is a strong likelihood that each is a geologic subsidiary of the larger mountain. Geologically, Mount Elden is a
lava dome composed almost entirely of
dacitic lava flows which emerged from several vents. These features emerged as
intrusive emplacements within sedimentary blocks or as
viscous extrusive flows in which the younger flows partially covered the older, lower flows. Geologic evidence suggests that the eruption of the mountain, which occurred at
linear vents along regional
faults, was a non-explosive event that took place during several
flow sequences. Likewise, because of the high viscosity of the dacite, it is likely that the mountain formed in the short period of a few months' time. The mountain's overlapping flows commonly take lobe-like shapes which display a variety of flow characteristics and features including concentric
benches,
spires, ramping shear
fractures, longitudinal tension fractures, and conjugate shear fractures. Positioned within the central part of Mount Elden, on the mountain's eastern and northwestern flanks, are two
sedimentary blocks. Both of these blocks display characteristics of
uplift that most likely occurred as dacitic
magma intruded into the sedimentary
strata at a shallow depth and uplifted the layers, causing them to
dip away from the mountain. These blocks of sedimentary material are unique to the mountain, which otherwise is uniformly composed of silicic dacite. == Contemporary history ==