Geomorphology of Dakhla Depression
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Fig. 27 Ancient spring—Balat area
According to Adelsberger (2008) spring mounds in Dakhla Oasis are found in the
southern portion of the basin, associated with the contact between Taref Formation
sandstones and Quseir Formation shales, as well as with faults and uplifted sandstone
units associated with the Tawil Anticline.
Spring mounds are small hillocks, mostly conical in shape. They range in height
from a few to 20 cm. Each mound has a vent that is cylindrical and is surrounded
by layers of clay, ocher (especially ferric oxides), sand or carbonates (see for more
details Said 1980; Embabi 2018, p. 147).
Adelsberger (2008) concluded that spring mounds occur as erosional remnants
with variable thicknesses of Quaternary sediments; up to six meters of spring sediments may be preserved, but most mounds consist of only remnant silt overlying
an erosional “mound” of Quseir Formation bedrock shale. Identifiable spring vents
are often present, preserving iron oxide-stained silts and sands. Some preserved