Np. Chizhikova et al., MINERALOGY OF DESERT SOILS IN THE HADRAMAWT VALLEY (YEMEN) AND CHANGES FOLLOWING IRRIGATION, Eurasian soil science, 27(3), 1995, pp. 91-109
The mineralogy of calcareous salinized Desert soils in the Wadi Hadram
awt valley (Yemen) was studied. The soils were located in different pa
rts of the valley (adjacent to the channel, at intermediate sites, and
on a piedmont terrace), differed in their degree of salinity, and had
been under irrigation for different lengths of time. The finely dispe
rsed separates of the Desert soils and sediments consisted mainly of p
alygorskite, which accounted for more than 50 percent of the total con
stituents of this fraction, and much smaller amounts of hydromica of t
he sericite-muscovite type (15-24 percent), magnesium-iron chlorites (
4-9 percent), kaolinite (6-9 percent), sepiolite, mixed-layer formatio
ns of two types (totaling no more than 2 percent), and finely disperse
d quartz. During pedogenesis, the structure of all components of the c
lay fraction was degraded and sericites were transformed into rectorit
e. Human intervention led to changes in the behavior of minerals of th
e carbonate group, layered silicates, and most of all, the mixed-layer
formations.