No abstract

The sabkha of Abu Dhabi was formed during the past 7,000 years by wind erosion of pre-existing dunes and progradation of subaqueous, intertidal, and supratidal carbonate sediments. Marine transgression began in this area about 7,000 years ago and reached an apparent high about 1 m above its present level somewhat prior to 4,000 years B.P. Since then progradation of intertidal and supratidal sediments has taken place; this began 3,750 years ago. Arid conditions over the sabkha have produced large amounts of gypsum and anhq'drite and lesser amounts of dolomite, magnesite, celestite and halite. G . EVANS ET AL. Fig.2. The sabkha. related to topography and groundwater levels, the error in vertical closure in the survey was limited to a maximum of 5 cm. At strategically located stations, pits were dug, piston barrel cores obtained, and samples recovered from cased holes by means of a wire line bailer (Fig.3). Sedimentology, 12 (1969) 145-159Sedimentology, 12 (1969) 145-159

No abstract

Quantitative density measurements from electron scattering show that shear bands in deformed Al 88 Y 7 Fe 5 metallic glass exhibit alternating high and low density regions, ranging from -9 % to +6 % relative to the un-deformed matrix. Small deflections of the shear band from the main propagation direction coincide with switches in density from higher to lower than the matrix and vice versa, indicating that faster and slower motion (stick-slip) occurs during the propagation. Nano-beam di↵raction analyses provides clear evidence that the density changes are accompanied by structural changes suggesting that shear alters the packing of tightly-bound short-or mediumrange atomic clusters. This bears a striking resemblance to the packing behavior in granular shear bands formed upon deformation of granular media.

No abstract