maharlu saline lake is located in the sw of iran. to assess the environmental pollution of thelake, the total concentrations of as, cr, co, cu, cd, pb, zn, ni, fe, and mn were determined in the surfacesediments and water of the lake. as and cr were not detected in the water samples, however, the meanconcentrations of other dissolved metals in maharlu lake water were 0.28 mg/l for cu, 0.28 μg/l ...

The development of conceptual geochemical models is enhanced by saturation index calculations that can identify the equilibrium state of minerals. Speciation modeling provides saturation indices that indicate reactions thermodynamically possible, minerals dissolving and precipitating in an aquifer system. In the present study, aqueous speciation modeling is carried out for the high fluoride gro...

A chemical kinetics algorithm is presented for geochemical applications. The algorithm is capable of handling both equilibriumand kinetically-controlled reactions in multiphase systems. The ordinary differential equations (ODEs) are solved using an implicit multistep backward differentiation formula (BDF) algorithm to ensure efficiency and stability when integrating stiff ODEs. An adaptive cont...

Dynamic models are presented to investigate the consequences of melting and melt transport for stable trace element geochemistry in open systems. These models show that including explicit melt transport in 2-D adds non-trivial behaviour because melts and residues can travel and mix along very diierent tra-jectories. Calculations are presented for both equilibrium and disequilibrium transport an...

Uranium and thorium within the Earth produce a major portion of terrestrial heat along with a measurable flux of electron antineutrinos. These elements are key components in geophysical and geochemical models. Their quantity and distribution drive the dynamics, define the thermal history, and are a consequence of the differentiation of the Earth. Knowledge of uranium and thorium concentrations ...

The geochemical model PHREEQC is capable of simulating a wide range of equilibrium reactions between water and minerals, ion exchangers, surface complexes, solid solutions, and gases. It also has a general kinetic formulation that allows modeling of nonequilibrium mineral dissolution and precipitation, microbial reactions, decomposition of organic compounds, and other kinetic reactions. To faci...

The ability of the EQ3 and EQ6 geochemical modeling codes and the GEMBOCHS thermodynamic data bases (Wolery, 1992; Wolery and Daveler, 1992) to simulate geochemical changes in the post-emplacement environment at the potential Yucca Mountain, Nevada repository is being tested using observed mineral-fluid relations in the Taupo Volcanic Zone of New Zealand. In this report, comparisons between obs...

kajal kaolin deposit is located ~20 km northwest of hashtjin, ardebil province. field evidence and laboratory investigations show that the deposit is an alteration product of ignimbrites, tuffs, and trachy-andesites of eocene age. according to mineralogical data, the major rock-forming minerals include kaolinite, montmorillonite, polygorskite, orthoclase, zeolite (stilbite), quartz, and chalced...