The Mesoproterozoic Eon [1,600-1,000 million years ago (Ma)] is emerging as a key interval in Earth history, with a unique geochemical history that might have influenced the course of biological evolution on Earth. Indeed, although this time interval is rather poorly understood, recent chromium isotope results suggest that atmospheric oxygen levels were <0.1% of present levels, sufficiently low...

The geochemical history of an upper deltaic plain pending tidal wetland restoration was reconstructed to assess remobilization of redox-sensitive constituents in sediment, identify depositional processes promoting geochemical retention, and determine the extent of contamination with Hg, As, Pb, Cu, and Zn. Three 12-14-m sediment cores were analyzed for bulk sediment geochemistry using ICP-AES. ...

The geochemical analysis was carried out in the center-south portion of state Bahia, semi-arid region where outcrop Paramirim Complex, Boquira Unit, Granite, Veredinha Serra do Espinhaço, detritus coverings and alluvial deposits. Unit is known for lead-zinc mineralization. In this unit operated mine, considered largest lead zinc mine Brazil, until it suddenly abandoned, leaving significant envi...

In the Mănăila alpine area, soil layer developed in situ on top of sericite-schists, which belong to Tulghes 3 metamorphic unit. The aim present work was determine degree formation using both mineralogical and geochemical exploration methods. XRD, FTIR SEM-EDS results showed that constituents were dioctahedral 2:1 minerals, quartz, chlorite, Na-feldspar, rutire ilmenite. Mainly illite secondari...

This report presents some strategies to predict metal mobility at mining sites. These strategies are based on chemical, physical, and geochemical information about metals and their interactions with the environment. An overview of conceptual models, metal sources, and relative mobility of metals under different geochemical conditions is presented, followed by a discussion of some important phys...

Introduction: The Iberian Pyritic Belt (IPB) consists of a 250-km long geological unit included into the South-Portuguese geotectonical zone of the Iberian Peninsula. It is comprised by an acid volcanosedimentary complex ranging in age from upper Devonian to Carboniferous where different metallic ores were formed in response to hydrotermalism and tectonic related to the Variscan Orogeny [1, 2]....

Strontiu• isotope data from three larg e plutons interpreted as derived from dynamic mag• chambers (Hill, this issue; Hill et al., this issue) show the existence of pronounced isotopic heteroEeneity within each unit. Ranges of calculated initial 8?St/BeSt are unit I, 0.70600.7076; unit II, 0.7060-0.7074; unit III, 0.70580.7073. A limited sample of mafic inclusions and dyke rocks, interpreted as...

Editorial Geochemical Transactions, the first online-only journal in geochemistry and environmental chemistry, is now the first major open access journal in this subject area. All issues of Geochemical Transactions, including the back content, will be fully and permanently available online to all, without a subscription charge. Copyright of all future articles will be retained by the authors. G...

Lithium isotopes have many advantageous characteristics as geochemical tracers for a wide range of geological processes, covering fluid/melt-mineral interactions from the Earth’s surface to the mantle. The latest developments in Li isotope geochemistry, in terms of measuring techniques, major geochemical reservoirs, the contrasting behaviors during near-surface weathering, and crust/ mantle cyc...