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Understanding sulfate transport and retention dynamics in forest soils is a prerequisite in predicting SO4 concentration in the soil solution and in lake and stream waters. In this study forest soil samples from the Gårdsjön catchments, Sweden, were used to study SO4 transport in soil columns from the upper three soil horizons (E, Bs, and BC). The columns were leached using a sequential leaching technique. The input solutions were CaSO4 equilibrated with forest floor material. Leaching behavior of SO4 and concentration in the effluent were measured from columns from individual horizons. Sulfate was always retained in the Bs and BC horizons, while the pattern for the E horizon varied. Attempts were also made to model SO4 breakthrough results based on miscible displacement approaches and solute convection-dispersion equation (CDE) in porous media. Several retention mechanisms were incorporated into the CDE to account for possible reversible and irreversible SO4 reactions in individual soil layers. Our modeling efforts were inadequate in describing the mobility of SO4 in the top (E) horizon. Moreover, a linear equilibrium approach was generally inadequate for describing SO4 sorption during transport in the Bs and BC horizons. In contrast, we found that the model provided good descriptions of all breakthrough results when SO4 reactivity was accounted for based on nonlinear equilibrium or first-order kinetic processes. Moreover, based on model parameter estimates, the reactivity or retention of SO4 during transport is concentration dependent. We conclude that sulfate retention during transport in this forest soil is most likely controlled by kinetic reactivity of SO4 of the reversible and irreversible mechanisms.

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Channel iron deposits (CIDs) are Miocene pedogenic fluvial gravels comprised of predominately goethitic peloids and pelletoids derived from a highly ferruginous regolith. They currently supply over 40% by tonnage and over 50% by earnings of the seaborne iron ore trade out of the Hamersley Province of Western Australia. The two well documented, producing systems (Robe and Marillana palaeochannels) were both discovered during early reconnaissance mapping during the mid 1950s to early 1960s. Both crop out extensively over the majority of their length. The Solomon region was pegged by Fortescue Metals Group from late 2003 onwards on the basis that the area was dominated by the Brockman Iron Formation which hosts many Bedded iron deposits. There were also a number of previously mapped small isolated occurrences of supergene bedded and CID mineralisation within the general area. Analysis of publicly available data, and field confirmation of developing models led to the recognition of the Solomon palaeochannel system. Subsequent exploration defined a world-class resource of 2?9 Gt of iron ore mineralisation of which the great majority is buried CID. Apart from the Marillana CID system, the Solomon region is the only CID with significant tonnes of sub 2% alumina CID and with size over 500 Mt. Exploration has also outlined significant supergene bedded and detrital iron ore mineralisation.

Addressing the complex legacies of the past in architectural education and built constructions, calls for a reconsidering of the principles of architectural design and conservation. The current challenges of housing, sustainable development and heritage adaptation present huge dilemmas for architects. Yet today architects are only by exception trained to detect heritage values prior to drafting their interventions for adaptive reuse or upgrading. To this day, Western architectural thinking is influenced by the Vitruvian triad Firmitas, Utilitas and Venustas, and the truncated maxim ‘Form Follows Function’ as disseminated by the protagonists of the Modern Movement. These established a divide between the design for new-build and the care of already existing buildings. This divide is marked by the two Charters of Athens: the 1931 Carta del Restauro adopted at the First International Congress of Architects and Technicians of Historic Monuments, and La Chartre d’Athènes presented by Le Corbusier as a result of the 4th CIAM Congress on the Functional City (1933). This paper attempts to bridge the identified divide by adding the idea of ‘Dignitas’ (dignity) as an equal virtue to the Vitruvian triad. Though not new for itself, this concept may aid to raise awareness of architectural dignity in extant buildings. Keywords: architectural theory, architectural education, conservation theory, Renovation Challenge, Dignitas