framboid

[′fram‚bȯid]

(geology)

A microscopic aggregate of pyrite grains, often occurring in spheroidal clusters.

References in periodicals archive ?

3A) as scattered euhedral cubic-octahedral crystallites, framboid aggregates or bundles (concretions) of framboidal aggregates.

Magnetic susceptibility of Middle Ordovician sedimentary rocks, Pakri Peninsula, NW Estonia/Pakri poolsaare Kesk-Ordoviitsiumi labiloike magnetiline vastuvotlikkus

Dean, "History of watercolumn anoxia in the Black Sea indicated by pyrite framboid size distributions," Earth and Planetary Science Letters, vol.

Multiscale erosion surfaces of the organic-rich Barnett Shale, Fort Worth Basin, USA

In modern euxenic environments the mean framboid diameters are generally smaller (below 10 [micro]m) and have a narrower size range than for oxic and dysoxic environments (Wilkin et al.

Micromorphological evidence for mineral weathering pathways in a coastal acid sulfate soil sequence with Mediterranean-type climate, South Australia

The composition of a typical electron opaque coating was determined by elemental analysis on a transect across the framboids' outer coating, fractured whilst mounting the framboid on the SEM stub (Fig.

Pyrite micromorphology in three Australian Holocene sediments

It occurred as isolated framboids, as elongated clusters of framboids disseminated in the clay matrix (Figure 4(e)), as replacement/infillings of bioclasts (Figure 4(b)), and as rare pyrite nodules.

A Deep Alteration and Oxidation Profile in a Shallow Clay Aquitard: Example of the Tegulines Clay, East Paris Basin, France

Pyrite and other sulfide minerals are often found in shales and carbonate bedrock as small (2-20 pm) framboids (Schieber, 2011; Smedley & Kinniburgh, 2002, 2005).

Elevated arsenic in private wells of Cerro Gordo County, Iowa: causes and policy changes

Pyrite is common as crystals or small nodules, framboids or replacement of macrofauna (mainly ammonites).

The hydrocarbon source rocks of the Pliensbachian (early Jurassic) in the Asturian Basin (northern Spain): their relationship with the palaeoclimatic oscillations and gamma-ray response

The mineral matrix pores are mainly developed between and within calcite crystals, quartz grains, clay minerals and pyrite framboids. The organic matter usually contains pores of several shapes and sizes (micro-meter to nanometer scale), which are sometimes connected by narrow throats.

Caracterizacion microestructural de tipos de poros en reservorios no convencionales de gas utilizando MEBFEC: Un ejemplo del Miembro Galembo de la Formacion La Luna del Cretaceo, Cuenca del Valle Medio del Magdalena (Colombia)

The presence of what appear to be degraded pyrite framboids in the deeper horizons of both apicum soils (Fig.

Soil genesis on hypersaline tidal flats (apicum ecosystem) in a tropical semi-arid estuary (Ceara, Brazil)

A lump of biological indicators as algae, framboids, disseminated pyrites, rhizolithes, rhizocretions, calcimicrobes, and filamentous bodies argue for deposition in reducing environment and extensive anoxia lead to biodegradation of organic matter.

Fossilized microbial and algal textures in post eocene lacustrine zeolite tuff sequence, G. Abu Treifiya, Cairo-Suez road, Egypt

During the late stationary growth phase or death phase, the gold NPs which were initially precipitated inside the cells were released into the bulk solution and formed suboctahedral to octahedral, subspherical to spherical aggregates resembling framboids, and ultimately millimeter-thick gold foil at longer experimental duration [148,149].

Bacteria in nanoparticle synthesis: current status and future prospects

The SEM observation and microanalysis results indicated the presence of calcite, organic matter, and pyrite in the bulk lignite samples as framboids and as isolated euhedral forms (Figure 4).

Arsenic, chromium, and other potentially toxic elements in the rocks and sediments of Oropos-Kalamos basin, Attica, Greece

Full browser ?

CITE

Site: Follow: Share:

Open / Close