The near infrared analysis (NIRA) approach was studied to examine its capability for predicting spectral feature soil properties from the reflectance curves in the near infrared (NIR) region (1-2.5 um) of arid and semiarid soils. High-resolution diffuse reflectance spectra (3113 spectral points) in the NIR region were recorded for 91 soil samples from Israel. Six soil properties (clay content, specific surface area, cation-exchange capacity, hygroscopic moisture, carbonate content, and organic matter content) were measured by routine methods employed in soil laboratories. An empirical model to predict each property from its spectral signature was developed by adapting the NIRA technique. Several data manipulations were used to obtain optimum performance. The optimum performance of all properties was found to be between 25 and 63 spectral points. Strong support for the NIRA capability was provided by its ability to examine most of the spectral assignments. A slight bias was observed for the prediction of both organic matter and hygroscopic moisture, suggesting that more attention in the prediction of these constituents is required. It was concluded that NIRA is a promising method for rapid and nonrestrictive analysis of soil materials, and further study of the synergism between NIRA and soil materials is recommended.N EAR-INFRARED ANALYSIS is a laboratory approach that analyzes the diffuse reflectance radiation with regard to a material's chemistry (Stark et al., 1986). This methodology was developed 25 yr ago for rapid analysis of moisture in grains (Ben-Gera and Norris, 1968). Today, NIRA is well accepted and widely used in many other disciplines (Davies and Grant, 1987; Norris, 1988). This method is known for its rapidity, convenience, simplicity, accuracy, and ability to analyze many constituents at the same time (Stark et al., 1986). In

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Abstract. Large portions of Mars' surface are covered with deposits of fine, homogeneous, weathered dusty-soil material. Nanophase iron oxides, silicate mineralolds, and salts prevail in the soil. The mode of formation of this somewhat peculiar type of soil is still far from being clear. One scenario suggests that weathering took place during early epochs when Mars may have been "warm and wet." The properties of the soil are not easily reconciled wi.'th this scenario. We propose another possible scenario that attributes, in part, the peculiar nature of the Martian dust and soft to a relatively "young" weathering product formed during the last few hundreds of millions of years in a process that involves acidic volatiles. We tested this hypothesis in an experimental study of the first step of acidolytic weathering of a partly palagonitized VOlcanic tephra of hawaiitic lava origin, using sulfi•c, hydrochloric and nitric acids and their mixtures. The tephra effectively "neutralize" the added acidity. The protonic acidity added to the tephra attacks the primary-minerals, releasing Fe, A1, and Mg, which control the pH, acting as Lewis-acid species of varying acid strengths. The full mount of acidity added to the tephra is stored in it, but only a very small fraction is preserved as the original protonic acidity. The majority of the added sulfate and chloride were present as salts and easily solubilized minerals. Well-crystallized sulfate salt minerals of aluminum and calcium were detected by powder X ray diffractomen, whereas secondary magnesium and iron minerals were not detected, due probably to lack of crystallinity. The presence of gyps m (CaSO4'2H20) and alunogen (A12(SO4)3'17H20) is probably responsible for the observed increased hygroscopicity of the acidified tephra and their tendency. to form hardened crusts. We suggest that if this mechanism is of importance on Mars, then the chemically weathered component of the Martian soil consists of a salt-rich mineral mixture containing the salts of the anionicligands SO4 and C1 resulting from volafiles emitted from volcanoes during more recent eruptions (up to 109 years B.P.). The lack of liquid water on Mars surface during that time slowed or halted mineralogical evolution into highly crystallized minerals having large mineral grains. The chemically weathered components are mixed wi.th _the products of physical weathering. The recently formed soil may cover and coat more evolved, hydrothermally modified, mineral deposits formed in earlier epochs Of Mars.

Heavy metals have been increasingly released into our environment. We present here, for the first time, the global industrial age production of Cd, Cu, Cr, Hg, Ni, Pb, and Zn, and their potential accumulation and environmental effects in the pedosphere. World soils have been seriously polluted by Pb and Cd and slightly by Zn. The potential industrial age anthropogenic Pb, Hg, and Cd inputs in the pedosphere are 9.6, 6.1, and 5.2 times those in the lithosphere, respectively. The potential anthropogenic heavy metal inputs in the pedosphere increased tremendously after the 1950s, especially for Cr and Ni. In 2000, the cumulative industrial age anthropogenic global production of Cd, Cr, Cu, Hg, Ni, Pb, and Zn was 1.1, 105, 451, 0.64, 36, 235, and 354 million tonnes, respectively. The global industrial age metal burdens per capita (in 2000) were 0.18, 17.3, 74.2, 0.10, 5.9, 38.6, and 58.2 kg for Cd, Cr, Cu, Hg, Ni, Pb, and Zn, respectively. Acidification may increase the bioavailability and toxicity of heavy metals in the pedosphere. The improvement of industrial processing technology reducing the metal dispersion rate, the recycling of metal-containing outdated products, by-products and wastes, and the development of new substitute materials for heavy metals are possible strategies to minimize the effects of heavy metals on our environment.

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