scholarly journals Climatic signals in lacustrine deposits of the Upper Yacoraite Formation, Western Argentina: Evidence from clay minerals, analcime, dolomite and fibrous calcite

Sedimentology ◽  
2020 ◽  
Vol 67 (5) ◽  
pp. 2282-2309
Author(s):  
João Paulo B. Gomes ◽  
Rodrigo B. Bunevich ◽  
Sandra N. Tonietto ◽  
Daisy B. Alves ◽  
Julice F. Santos ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Lacustrine Deposits ◽  
Climatic Signals

Wisconsinan stratigraphy of the Cuyahoga Valley in the Erie Basin, northeastern Ohio

1987 ◽  
Vol 24 (2) ◽  
pp. 279-290 ◽  
Author(s):  
John P. Szabo
Keyword(s):  
Clay Minerals ◽  
Carbonate Content ◽  
Glacial Erosion ◽  
Radiocarbon Dates ◽  
The Core ◽  
Lacustrine Deposits ◽  
Organic Debris ◽  
Il Y A ◽  
Proglacial Lake ◽  
Minéraux Argileux

During the Wisconsinan Stage, ice of the Cuyahoga Lobe flowed southward from the Erie Basin through a lowland created by an ancestral Cuyahoga River. The paleovalley of the Cuyahoga River is filled with the pre-Woodfordian tills and lacustrine deposits. The oldest till, the Mogadore Till, overlies proglacial lacustrine deposits. After retreat of Mogadore ice into the Erie Basin, ice readvanced to deposit a previously unnamed till, Northampton Till, over deltaic and lacustrine deposits of Lake Cuyahoga. Northampton ice melted back into the Erie Basin after depositing the core of the Summit County morainic complex. Northampton ice then readvanced over deposits of proglacial Lake Independence and formed the Defiance Moraine. Aside from minor leaching of carbonates and weathering of clay minerals, little evidence of the Farmdalian Substage exists. Woodfordian, Kent, Lavery, and Hiram tills were deposited over pre-Woodfordian deposits.The multiple nature of the pre-Woodfordian tills in the Cuyahoga Lobe is similar to that of the Titusville Till in Pennsylvania and northeastern Ohio. Northampton Till is distinctive in having a significantly different matrix texture and carbonate content from either the Mogadore or the Kent Till. Organic debris suitable for dating from pre-Woodfordian deposits is rare because of glacial erosion and drainage changes. Lack of radiocarbon dates continues to complicate the interpretation of the Pre-Woodfordian stratigraphy.Durant l'épisode wisconsinien, la glace du lobe de Cuyahoga s'écoulait vers le sud à partir du bassin Érié en traversant une plaine créée par l'ancien lit de la rivière Cuyahoga. La paléovallée de la rivière Cuyahoga est comblée de tills et de dépôts lacustres. Le till le plus ancien, Mogadore, recouvre les dépôts lacustres proglaciaires. La régression du glacier de Mogadore fut suivie d'une progression qui édifia un till, jadis sans nom, mais ultérieurement appelé le till Northampton, lequel recouvre les dépôts deltaïques et lacustres du lac Cuyahoga. Le front du glacier de Northampton recula dans le bassin Érié après y avoir déposé la partie centrale du complexe morainique de Summit County. Ensuite, le glacier de Northampton réavança et recouvrit les dépôts du lac proglaciaire Independence et y déposa la moraine Defiance. À part un lessivage mineur des carbonates et une légère altération des minéraux argileux, il y a peu d'indice de l'exitence du sous-épisode farmdalien. Les tills du Woodfordien, Kent, Lavery et Hiram furent ont été mis en place par-dessus les dépôts pré-woodfordiens.

Mineralogy and geochemistry of Miocene deposits at Alcubierre Sierra, central sector of the Ebro Basin, Spain

Clay Minerals ◽  
1994 ◽  
Vol 29 (3) ◽  
pp. 391-400 ◽  
Author(s):  
B. Bauluz Lazaro ◽  
C. Arenas Abad ◽  
C. Fernandez-Nieto ◽  
J. M. Gonzalez Lopez
Keyword(s):  
Clay Minerals ◽  
Source Area ◽  
Pore Waters ◽  
Ebro Basin ◽  
Authigenic Carbonates ◽  
Lacustrine Deposits ◽  
Diagenetic Processes ◽  
Activity Ratios ◽  
Ree Patterns ◽  
Significant Chemical

AbstractTwo profiles in Miocene fluvio-lacustrine deposits consist of sandy, marly, lutitic and carbonatic levels constituted by variable percentages of quartz, calcite and clay minerals as major components, and feldspars, dolomite and occasionally gypsum and anhydrite as minor ones. The clay minerals are inherited and consist mostly of micas, with minor quantities of chlorites, pyrophyllites and kaolinites. The crystallochemical parameters of the micas indicate muscovitic compositions and their uniformity through both the different rocks and their silt and clay fractions suggest the same provenance source area, possibly located northward.Clay minerals concentrate preferentially Li, Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Cs, Ba, Zr, Hf, Th, U and REE whereas the authigenic carbonates concentrate Mn and Sr. The Sc, Cr, Th, Y, Zr and REE values in clay minerals indicate that the provenance source area of these deposits was similar in composition to the average continental upper crust, probably as a result of sedimentary recycling processes.Zeolitic levels constituted by different proportions of analcime and smectite as major components outcrop at the top of the profiles. The analcimes show anhedral to euhedral morphologies, with grain-size ranging between 1 and 20 μm, and Si/Al ratios ranging from 2.2 to 2.5. The smectites are dioctahedral and beidellitic in composition. The zeolitic levels present significant chemical differences relative to the other ones, such as higher overall REE contents, more pronounced negative Eu anomalies and higher (La/Yb)n, Th/Sc and La/Sc ratios, suggesting a different provenance source area. Their chondrite-normalized REE patterns reflect the possibility that the starting materials were pyroclastic eruptive rocks originating from intracrustal partial melting. The variable analcime and smectite percentages are attributed to variations in H+/(Na+ + K+) and K+/(Na + Ca2+ + Mg2+) activity ratios and silica and water activities in the pore-waters during diagenetic processes.

Hydrated form of some clay minerals observed using a film sealed environmental cell

1978 ◽  
Vol 36 (1) ◽  
pp. 72-73
Author(s):  
N. Kohyama ◽  
K. Fukushima ◽  
A. Fukami
Keyword(s):  
Clay Minerals ◽  
Morphological Changes ◽  
Carbon Film ◽  
Electron Microscopic Observation ◽  
Adsorbed Water ◽  
Electron Microscopic ◽  
Hydrated Form ◽  
Thin Carbon ◽  
Environmental Cell ◽  
Thin Carbon Film

Since the interlayer or adsorbed water of some clay minerals are quite easily dehydrated in dried air, in vacuum, or at moderate temperatures even in the atmosphere, the hydrated forms have not been observed by a conventional electron microscope(TEM). Recently, specific specimen chambers, “environmental cells(E.C.),” have been developed and confirmed to be effective for electron microscopic observation of wet specimen without dehydration. we observed hydrated forms of some clay minerals and their morphological changes by dehydration using a TEM equipped with an E.C..The E.C., equipped with a single hole copper-microgrid sealed by thin carbon-film, attaches to a TEM(JEM 7A) with an accelerating voltage 100KV and both gas pressure (from 760 Torr to vacuum) and relative humidity can be controlled. The samples collected from various localities in Japan were; tubular halloysite (l0Å) from Gumma Prefecture, sperical halloysite (l0Å) from Tochigi Pref., and intermediate halloysite containing both tubular and spherical types from Fukushima Pref..

Colloidal systems in soils

1994 ◽  
Vol 52 ◽  
pp. 64-65
Author(s):  
J. Thieme ◽  
J. Niemeyer ◽  
P. Guttman
Keyword(s):  
Clay Minerals ◽  
Polymeric Materials ◽  
Spatial Arrangement ◽  
High Specific Surface Area ◽  
Turnover Rates ◽  
Colloidal Systems ◽  
Chemical Conditions ◽  
Aggregation Phenomena ◽  
Iron And Manganese ◽  
Soil Colloids

In soil science the fraction of colloids in soils is understood as particles with diameters smaller than 2μm. Clay minerals, aquoxides of iron and manganese, humic substances, and other polymeric materials are found in this fraction. The spatial arrangement (microstructure) is controlled by the substantial structure of the colloids, by the chemical composition of the soil solution, and by thesoil biota. This microstructure determines among other things the diffusive mass flow within the soils and as a result the availability of substances for chemical and microbiological reactions. The turnover of nutrients, the adsorption of toxicants and the weathering of soil clay minerals are examples of these surface mediated reactions. Due to their high specific surface area, the soil colloids are the most reactive species in this respect. Under the chemical conditions in soils, these minerals are associated in larger aggregates. The accessibility of reactive sites for these reactions on the surface of the colloids is reduced by this aggregation. To determine the turnover rates of chemicals within these aggregates it is highly desirable to visualize directly these aggregation phenomena.

Mineral nitrogen isotope signature in clay minerals formed under high ammonium environment conditions in sediment associated with ammonium-rich sediment-hosted hydrothermal system

2018 ◽  
Vol 52 (4) ◽  
pp. 317-333 ◽  
Author(s):  
Jaeguk Jo ◽  
Toshiro Yamanaka ◽  
Tomoki Kashimura ◽  
Yusuke Okunishi ◽  
Yoshihiro Kuwahara ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Hydrothermal System ◽  
Nitrogen Isotope ◽  
Mineral Nitrogen ◽  
Isotope Signature

Stratigraphy, sedimentology, paleontology, and paleomagnetism of Pliocene-early Pleistocene lacustrine deposits in two cores from western Utah

1995 ◽  
Author(s):  
R.S. Thompson ◽  
Charles G. Oviatt ◽  
A.P. Roberts ◽  
J. Buchner ◽  
R. Kelsey ◽  
...  
Keyword(s):  
Early Pleistocene ◽  
Lacustrine Deposits

DISTRIBUTION OF THE CLAY MINERALS IN SURFACE SEDIMENTS OF THE SOUTH CHINA SEA AND THEIR PROVENANCE

2010 ◽  
Vol 30 (4) ◽  
pp. 57-66 ◽  
Author(s):  
Qian GE ◽  
Fengyou CHU ◽  
Jingpu LIU ◽  
Yuansheng DU ◽  
Zuo XUE ◽  
...  
Keyword(s):  
South China Sea ◽  
Clay Minerals ◽  
South China ◽  
Surface Sediments ◽  
The South China Sea ◽  
The South ◽  
China Sea
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