Controlling factors on clay mineral assemblages : insights from facies analysis of Pliocene to Pleistocene coastal margin deposits, Western Portugal

The clay fractions in the Pliocene to Pleistocene coastal margin record are usually dominated by kaolinite and illite, with lesser amounts of vermiculite, 10-14 mixed layer clays and smectite. The high clay mineral crystallinity, the mineralogical relations to facies and depositional setting and some horizontal variations along coeval deposits suggest that clay assemblages are mainly detrital. Illite is more important in inner shelf deposits and particularly in alluvial deposits from eastern locations. The high illite content in eastern alluvial deposits is explained by the input from the neighbouring Iberian Variscan Massif that is rich in mica. The high kaolinite content in prograding sand and gravel coastal plain is partially explained by the availability of this mineral in the drainage areas. Given the arkosic nature of some of these deposits, post-depositional feldspars weathering would also contribute to an increase in kaolinite content. Vermiculite is particularly important close to the surface and to unconformities, in horizons influenced by pedogenetic processes that have more aluminous illite with relatively low crystallinity. In organic rich mud sediments low pH conditions favour post-depositional transformation of illite to vermiculite and mixed layer clays

Hybrid off-river augmentation system as an alternative raw water resource: the hydrogeochemistry of abandoned mining ponds

The use of water from abandoned mining ponds under a hybrid off-river augmentation system (HORAS) has been initiated as an alternative water resource for raw water. However, it raises the questions over the safety of the use of such waters. In this study, the hydrogeochemical analysis of the waters is presented to assess the degree to which the water has been contaminated. Comparisons were made between sampling sites, i.e. abandoned mining ponds, active sand mining ponds and the receiving streams within Bestari Jaya, Selangor River basin. The aqueous geochemistry analysis showed different hydrochemical signatures of major elements between sites, indicating different sources of minerals in the water. Discharges from the sand mining ponds were found to contain elevated availability of dissolved concentrations of iron, manganese, lead, copper and zinc, among others. However, the quality of the water (from the main river) that is supplied for potable water consumption is at a satisfactory level despite being partly sourced from the abandoned mining ponds. In fact, all the metal concentrations detected were well below the Malaysia Ministry of Health guideline limits for untreated raw water. In addition, the results of the geochemical index analysis (i.e. geoaccumulation index, enrichment factor and modified contamination factor) showed that the rivers and abandoned mining ponds were generally unpolluted with respect to the metals found in sediments

UA Geosciences Newsletter, Volume 3, Number 2 (Spring 1997)

Letter from the Chair / Chuck Kluth Gives Short Course / News around the Department: Spence Titley Wins Top Honors / NSF-Arizona AMS Facility / Fall 1996 Degrees Awarded / GeoDaze 25th Anniversary / Alumni News / Alumni Achievement Awards / New Faculty: Hall-Wallace and Zandt / Comparative Metallogenesis / Bill Bull Retires / The Nyanza Project / Emeritus Profile: Paul DamonThis item is part of the Geosciences Newsletters collection. It was digitized from a physical copy provided by the Department of Geosciences, University of Arizona. For more information about items in this collection, please contact the Department of Geosciences, www.geo.arizona.edu

UA Geosciences Newsletter, Volume 4, Number 1 (Fall 1998)

Colloquium Series Schedule / News Around the Department / Center for Mineral Resources / Paleoclimate, Magmas and Hydrothermal Systems / Alumni News / '98 Field Camp / Peter Coney Retires / Nyanza Project: Phase One / Climate Change in the Atacama Desert / Nuclear Explosion Epicenter / Spring '98 Degrees / Earth Week at Mineral MuseumThis item is part of the Geosciences Newsletters collection. It was digitized from a physical copy provided by the Department of Geosciences, University of Arizona. For more information about items in this collection, please contact the Department of Geosciences, www.geo.arizona.edu

UA Geosciences Newsletter, Volume 4, Number 2 (Spring 1999)

Bob Butler Receives Distinguished Teaching Award / Junior Ed Program at Tucson Gem & Mineral Show / In Memory of Peter Coney / Caledonian-Appalachian Sediment Deposition 300 MY Old / Center for Earth Surface Processes / SESS Field Trip: Sonora / Active Tectonics Field Trip / Alumni News / Alumni Achievement Award: Mark Zoback / GeoDaze '99 / List of the Lost / John Anthony Autobiography / Recent Publications & Kudos to / Fall '98 DegreesThis item is part of the Geosciences Newsletters collection. It was digitized from a physical copy provided by the Department of Geosciences, University of Arizona. For more information about items in this collection, please contact the Department of Geosciences, www.geo.arizona.edu

UA Geosciences Newsletter, Volume 3, Number 1 (Fall 1997)

Letter from the Chair / SESS Club Outreach / News Around the Department / From Zion to Bryce and Beyond / Alumni News / Viewing Live Seismic Data / R/V Gould Dedicated / Spring 1997 Degrees / A Field Trip c. 1910 / Ed McCullough and Denis Norton Retire / Faculty Awards and Honors / List of the Lost - Do You Know Where They Are? / Emeritus Profile: Joe Schreibe

UA Geosciences Newsletter, (Fall 1996)

AZPEPP Seismic Station / Advisory Board Additions / Romero Collection at UA / News around the Department / Paleomag Crew in Alaska / Alumni News / The Desert Lab / Emeritus Profile: Paul Martin / Ev Lindsay Retires / In Memory of Orlo Childs / Metal Sources in Ores / Grad Students Down Under / Field Camp '96 / New Faculty - Bob DownsThis item is part of the Geosciences Newsletters collection. It was digitized from a physical copy provided by the Department of Geosciences, University of Arizona. For more information about items in this collection, please contact the Department of Geosciences, www.geo.arizona.edu

UA Geosciences Newsletter, Volume 5, Number 2 (Spring 2000)

Farewell to Suzanne and Paul / New Faculty Profiles / Julia Cole - New Views of Recent Climate Variability / Jonathan Overpeck - A Paleoclimatic Perspective on Global Warming / Mihai Ducea - Tectonics / Jon Pelletier - Characterizing and Modeling Landforms / Alumni NewsThis item is part of the Geosciences Newsletters collection. It was digitized from a physical copy provided by the Department of Geosciences, University of Arizona. For more information about items in this collection, please contact the Department of Geosciences, www.geo.arizona.edu