Clay-Mineral Assemblages from Late Quaternary Deposits on Vancouver Island, Southwestern British Columbia, Canada

1989 ◽  
Vol 31 (1) ◽  
pp. 41-56 ◽  
Author(s):  
Bertrand Blaise
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
Late Quaternary ◽  
Sedimentary Environment ◽  
Volcanic Rocks ◽  
Clay Mineralogy ◽  
Vancouver Island ◽  
Climatic Conditions ◽  
Glacial Deposits ◽  
Mineral Contents

AbstractOn Vancouver Island, the Dashwood Drift, Cowichan Head Formation, Quadra Sand, and Vashon Drift were deposited during late Pleistocene glacial and interstadial periods and show large variations in clay-mineral contents partly related to changing climatic conditions. Glacial deposits are characterized by iron-rich chlorite, illite (both well crystallized), and smectite with a morphology reflecting rapid derivation from volcanic rocks. The clay mineralogy of nonglacial deposits is more complex, and is marked by the presence of vermiculite, kaolinite, halloysite, and irregular mixed-layer minerals. Nonglacial clay minerals are poorly preserved and show a higher state of alteration due to pedogenesis. Large variations in nonglacial deposits compared to glacial deposits are also due to secondary factors such as selective sorting, soil and rock source variations, differences in sedimentary environment, and diagenesis. These secondary factors do not seem to obliterate significantly the climatic imprint on the clay minerals. These studies also permit the recognition of glacially reworked sediments, the determination of relationships between two units in the same section, and the establishment of the conditions of clay-mineral formation.

scholarly journals Geochemical Significance of Clay Minerals and Elements in Paleogene Sandstones in the Center of the Northern Margin of the Qaidam Basin, China

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 505 ◽  
Author(s):  
Guoqiang Sun ◽  
Meng Wang ◽  
Jiajia Guo ◽  
Yetong Wang ◽  
Yongheng Yang
Keyword(s):  
Clay Minerals ◽  
Chemical Weathering ◽  
Qaidam Basin ◽  
Sedimentary Environment ◽  
Climatic Conditions ◽  
Northern Margin ◽  
Magmatic Arc ◽  
Average Value ◽  
Geochemical Significance ◽  
Continental Magmatic Arc

The average thickness of Paleogene sandstones reaches about 3000–4000 m at the northern margin of the Qaidam Basin. However, the provenance and sedimentary environment of these sandstones are uncertain; thus, more comprehensive research is needed. Integrated research is conducted on the provenance and weathering process based on petrographic characteristics, clay minerals, and geochemical compositions of sandstones in the center of the northern Qaidam Basin. The results of lithofacies analysis show that the Paleogene sandstones were mainly derived from an active continental magmatic arc, subduction accretion, or a fold-thrust belt. The average illite content in the Paleogene clay minerals is more than 50%, followed by chlorite and smectite, which reflect climatic and environmental characteristics that were arid to semi-arid, whereas the characteristics of carbon–oxygen isotopes reveal a mainly freshwater sedimentary environment. The corrected chemical index of alteration (CIAcorr) is between 56.3 and 75.7, with an average value of 66.5. These results indicate that the provenance of the Paleogene sandstones in the center of the northern Qaidam Basin mainly formed under cold and dry climatic conditions and experienced limited chemical weathering with a small amount that underwent intermediate chemical weathering under warm and humid conditions.

Clay mineralogy in southern Africa river muds

Clay Minerals ◽  
2014 ◽  
Vol 49 (5) ◽  
pp. 717-733 ◽  
Author(s):  
M. Setti ◽  
A. Lόpez-Galindo ◽  
M. Padoan ◽  
E. Garzanti
Keyword(s):  
Chemical Composition ◽  
Southern Africa ◽  
Chemical Weathering ◽  
Volcanic Rocks ◽  
Clay Mineralogy ◽  
Climatic Conditions ◽  
Continental Scale ◽  
Transmission Electron ◽  
Mineral Associations ◽  
Physical And Chemical

AbstractThe composition, morphology and crystal order of clay minerals in silt-sized sediments carried in suspensions from 25 major rivers across tropical southern Africa have been studied by X-ray diffractometry and scanning and transmission electron microscopy. Our goal was to determine the spatial variability of clay-mineral associations in diverse geological settings, and in climatic conditions ranging from humid Angola and Zambia to hyperarid Namibia and the Kalahari. Specific attention was paid to the micromorphology and chemical composition of smectite particles. The relative abundance of smectites, illite/mica, kaolinite and chlorite enabled identification of regions characterized by different physical and chemical processes: (1) negligible chemical weathering is documented in Namibia, where river muds mostly contain illite/mica or smectite derived from Damara metasedimentary or Etendeka volcanic rocks; (2) kaolinite documenting intense weathering, reaches a maximum in the Okavango, Kwando and Upper Zambezi, sourced in subequatorial Angola and Zambia; (3) suspended-load muds in the Limpopo and middle Zambezi catchments display intermediate features, with varied assemblages and smectite compositions reflecting diverse parent lithologies. Clay mineralogy and chemical composition are confirmed as a most effective tool to unravel present and past climatic conditions on a continental scale.

scholarly journals A importância da acção do frio do Quaternário final em Portugal e suas implicações nas morfodinâmicas de vertente.

2012 ◽  
Vol 5 (2) ◽  
pp. 421
Author(s):  
António Sousa Pedrosa
Keyword(s):  
Little Ice Age ◽  
Late Quaternary ◽  
Climatic Conditions ◽  
Ice Age ◽  
Glacial Deposits ◽  
Central Portugal

Resumo   De entre os  factores que tiveram maior influência na evolução do relevo de Portugal no decurso final do Quaternário é incontestável que o frio e os processos que lhe estão associados tiveram um papel muito importante na modelação das formas de relevo. Neste trabalho procuraremos fazer uma síntese dos principais aspectos da evolução das vertentes relacionados com os frio, inferir através dos vestígios que chegaram até ao nossos dias quais as condições morfo-climáticas em que ocorreram e quais os processos que lhes estavam encontravam associados. Realçamos assim o papel da acção dos glaciares nas áreas onde ocorreram assim como a importância dos processos periglaciares na evolução das vertentes. O período tardiglaciar também se mostrou marcante na dinâmica de vertentes tendo mobilizado e remobilizado muito material nas vertentes através de solifluxões generalizadas levando muitas delas à sua regularização. O período conhecido como a pequena idade do gelo também deixou as suas marcas na dinâmica das vertentes às quais se associam as escombreiras de gravidade. Por fim enfatizamos um pouco o papel do frio na actual morfodinâmica de vertentes no Norte de Centro de Portugal.   Palavras-chave: Norte de Portugal; Montanhas, depósitos glaciares, depósitos periglaciares, dinâmica de vertentes Summary   Among the factors that most influenced the evolution of the relief of Portugal during the late Quaternary is incontestable that the cold and the processes associated with it had a very important role in modeling the forms of relief. In this paper, we will try to summarize the importance that the cold had on the evolution of slopes, inferred through the vestiges that have come down to our day, which morpho-climatic conditions in which they occur, and also what processes if they were associated with. Thus enhancing the role of action in areas where glaciers have occurred and the importance of periglacial processes in the evolution of the slopes. In tardiglaciar the dynamics of slopes was very active and mobilized a lot of material through the process of solifluction regularized many of them. The period known as the Little Ice Age has also left its mark on the dynamic slopes which relate to tailings heaps of gravity. Finally we emphasize the role of cold in the current slopes of morphodynamics in north and central Portugal.   Keywords: North of Portugal; mountains, glacial deposits, periglacial deposits, morphodynamics of slopes 

Clay minerals in onshore and offshore strata of the British Isles: origins and clay mineral stratigraphy

Clay Minerals ◽  
2006 ◽  
Vol 41 (1) ◽  
pp. 1-3 ◽  
Author(s):  
C. V. Jeans ◽  
R. J. Merriman
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
Clay Mineralogy ◽  
Petroleum Exploration ◽  
British Isles ◽  
Mineral Research ◽  
Mineral Data ◽  
The Cost ◽  
First Time ◽  
Source Of Information

AbstractThe publication of The Clay Mineralogy of British Sediments by Perrin in 1971 collated several decades of clay mineral research in the British Isles and for the first time presented all the data in a stratigraphical framework. While it quickly became a useful source of information for geologists, engineers and soil scientists, it also revealed many gaps in clay mineral data through the geological succession, stimulating further research. Within ten years of publication, a successor to Perrin's book was under discussion by the Clay Minerals Group. Inevitably, the enthusiasm for the concept of the project gave way to the patience of a long gestation. A successor to Perrin (1971) became a standing item on the agenda of Clay Minerals Group Committee meetings, and the bane of many a Chairman's three years in office. By the mid-1990s the project began to show real progress, gathering momentum from the success of an international series of 'Cambridge clay mineral diagenesis conferences' (1981, 1984, 1986, 1989, 1993, 1998) that were supported by the oil industry. A timely injection of financial support from the Joint Association for Petroleum Exploration Courses (JAPEC) ensured a successful conclusion for the project.The cost of publication has been borne by three sponsors: the Clay Minerals Group, JAPEC (UK: training), and the Mineralogical Society. Consequently, the financing of this Special Volume of Clay Minerals is entirely independent of the usual costs of publishing the journal. We owe our particular thanks to Kevin Murphy, Editorial Manager, for his care and humour in guiding Clay minerals in onshore and offshore strata of the British Isles through publication.

Land erosion and associated evolution of clay minerals assemblages from soils to artificial lakes in two distinct climate regimes in Portugal and Brazil

Clay Minerals ◽  
2007 ◽  
Vol 42 (2) ◽  
pp. 161-179 ◽  
Author(s):  
R. Fonseca ◽  
F. J. A. S. Barriga ◽  
K. Tazaki
Keyword(s):  
Comparative Study ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Mixed Layer ◽  
Climatic Conditions ◽  
Soil Productivity ◽  
Reservoir Sediments ◽  
Complex Transformation ◽  
Parent Rocks ◽  
Transformation Mechanisms

AbstractGiven that reservoirs contain most of the leached materials from soils, we have studied the sediments accumulated in the bottom of two groups of reservoirs developed under different climatic conditions and thus with contrasting rates of weathering/erosion regimes. Through detailed comparative study of clay minerals of the parent rocks and soils with the clay fractions of the dam sediments, we have concluded that, during cycles of erosion-transport-deposition, the leached materials have complex transformation mechanisms, making them much more active in the environment. All clay-mineral groups are well represented in the reservoir sediments, including abundant mixed-layer and partly disordered minerals. Moreover, the sediments are nutrient-rich and potentially useful as agricultural fertilizers and hence in reversing the declining soil productivity in some regions.

Pre-Illinoian Glacial Stratigraphy in North-Central Missouri

1996 ◽  
Vol 45 (1) ◽  
pp. 17-29 ◽  
Author(s):  
Charles W. Rovey ◽  
William F. Kean
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
Clay Content ◽  
Magnetic Polarity ◽  
Laurentide Ice Sheet ◽  
Similar Sequence ◽  
Flow Lines ◽  
Mineral Contents ◽  
North Central ◽  
Reversed Polarity

AbstractFive pre-Illinoian tills are recognized and named informally in northern Missouri, near the southernmost margin of the pre-Illinoian Laurentide ice sheet. The three youngest tills (McCredie formation) have high (50–60%) expandable clay mineral contents and normal remanent magnetic polarity. The next oldest till (Moberly formation) has low (30–40%) expandable clay content and reversed polarity. The oldest till (Atlanta formation) has very low or no expandable clay minerals. Its remanent magnetic polarity is unknown.The sequence of four pre-Illinoian tills above the Atlanta formation probably correlates with the similar sequence of four pre-Illinoian “A type” tills in western Iowa and eastern Nebraska. The upper four tills in Missouri are also correlated, in order of increasing age, with the three members of the Wolf Creek Formation and the older Alburnett Formation in eastern Iowa. The oldest till in Missouri possibly correlates with the “C type” till in western Iowa.Pre-Illinoian Laurentide ice reached the same approximate southern margin at least five times. Those advances deposited tills which maintain characteristic compositions over distances of at least 350 km along flow lines.

Clay minerals in response to the Pleistocene climate change on the Yermak Plateau, Arctic Ocean (ODP, Site 911)

Polar Record ◽  
2002 ◽  
Vol 38 (206) ◽  
pp. 241-248 ◽  
Author(s):  
Mattiina Ruikka ◽  
Kari Strand
Keyword(s):  
Clay Minerals ◽  
Ocean Circulation ◽  
Clay Mineralogy ◽  
Source Area ◽  
Climatic Conditions ◽  
The Arctic ◽  
Ocean Drilling Program ◽  
Climate Conditions ◽  
Pleistocene Climate ◽  
Cyclic Changes

AbstractThe Arctic plays an important role in controlling the Earth's climate and ocean circulation. Studies of past climate conditions in high latitudes are important to understand this role more precisely. Clay mineralogy of sediments was detected to be comparative with cyclic changes in climatic conditions during the past 0.8 Ma in the northernmost Atlantic-Arctic gateway (Ocean Drilling Program, Site 911). Clay minerals are transported by sea ice, icebergs, glaciofluvially, or by ocean currents. Smectite is assumed to be transported predominantly during interglacial periods. Its content decreases from about 0.4 Ma to the present, which may indicate lesser eroded smectite in the provenance area, assumed to be mostly in the Laptev Sea. Illite is due to erosion from Svalbard during glacial periods, and shows a negative correlation with smectite. Chlorite is not a good climate indicator because of its high frequency in the northern regions. Zemlya Frantsa-Iosifa (Franz Josef Land) is the most likely source area of kaolinite and the output seems to have slightly increased from 0.5 to 0.4 Ma. The correlation of kaolinite and chlorite means coincidental sedimentation. Kaolinite and chlorite are negatively correlated with illite, which indicates transportation during the more open ocean conditions that prevailed between repeated Pleistocene glaciations.

scholarly journals Soil Chemistry and Clay Mineralogy of an Alluvial Chronosequence from the North Carolina Sandhills of the Upper Coastal Plain, USA

Soil Systems ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Bradley E. Suther ◽  
David S. Leigh ◽  
Larry T. West
Keyword(s):  
North Carolina ◽  
Clay Mineral ◽  
Coastal Plain ◽  
Chemical Properties ◽  
Clay Mineralogy ◽  
Mineral Contents ◽  
Fluvial Terraces ◽  
The North ◽  
Translocation Mechanism ◽  
Appalachian Piedmont

Temporal changes in soil development were assessed on fluvial terraces of the Little River in the upper Coastal Plain of North Carolina. We examined five profiles from each of six surfaces spanning about 100,000 years. Soil-age relationships were evaluated with inter-surface clay mineral comparisons and regression of chemical properties versus previously reported optically-stimulated luminescence ages using the most developed subsoil horizon per profile. Bases to alumina (Bases/Al2O3) ratios have negative correlations with age, whereas dithionite-Fe (FeD) concentrations are positively correlated with time and differentiate floodplain (<200 yr BP) from terrace (≥10 ± 2 ka) soils and T4 pedons (75 ± 10 ka) from younger (T1-T3b, 10 ± 2–55 ± 15 ka) and older (T5b, 94 ± 16 ka) profiles. Entisols develop into Ultisols with exponentially decreasing Bases/Al2O3 ratios, reflecting rapid weatherable mineral depletion and alumina enrichment during argillic horizon development in the first 13–21 kyr of pedogenesis. Increasing FeD represents transformation and illuviation of free Fe inherited from parent sediments. Within ~80–110 kyr, a mixed clay mineral assemblage becomes dominated by kaolinite and gibbsite. Argillic horizons form by illuviation, secondary mineral transformations, and potentially, a bioturbation-translocation mechanism, in which clays distributed within generally sandy deposits are transported to surface horizons by ants and termites and later illuviated to subsoils. T5b profiles have FeD concentrations similar to, and gibbsite abundances greater than, those of pedons on 0.6–1.6 Ma terraces along Coastal Plain rivers that also drain the Appalachian Piedmont. This is likely because the greater permeability and lower weatherable mineral contents of sandy, Coastal Plain-sourced Little River alluvium favor more rapid weathering, gibbsite formation, and Fe translocation than the finer-grained, mineralogically mixed sediments of Piedmont-draining rivers. Therefore, recognizing provenance-related textural and mineralogical distinctions is crucial for evaluating regional chronosequences.

scholarly journals A distal 145 ka sediment record of Nile discharge and East African monsoon variability

2015 ◽  
Vol 11 (5) ◽  
pp. 4273-4308 ◽  
Author(s):  
W. Ehrmann ◽  
G. Schmiedl ◽  
M. Seidel ◽  
S. Krüger ◽  
H. Schulz
Keyword(s):  
Mediterranean Sea ◽  
Clay Mineral ◽  
Late Quaternary ◽  
Eastern Mediterranean ◽  
Volcanic Rocks ◽  
Minor Importance ◽  
Sediment Discharge ◽  
Climate Regime ◽  
African Monsoon

Abstract. Clay mineral assemblages in a sediment core from the distal Nile discharge plume off Israel have been used to reconstruct the late Quaternary Nile sediment discharge into the Eastern Mediterranean Sea (EMS). The record spans the last ca. 145 ka. Smectite abundances indicate the influence of the Blue Nile and Atbara that have their headwaters in the volcanic rocks of the Ethiopian highlands. Kaolinite abundances indicate the influence of wadis, which contribute periodically to the suspension load of the Nile. Due to the geographical position, the climate and the sedimentary framework of the EMS is controlled by two climate systems. The long-term climate regime was governed by the African monsoon that caused major humid periods with enhanced sediment discharge at 132 to < 122 ka (AHP 5), 113 to 104 ka (AHP 4), and 86 to 74 ka (AHP 3). They lasted much longer than the formation of the related sapropel layers S5, S4 and S3. During the last glacial period (MIS 4–2) the long-term changes of the monsoonal system were superimposed by millennial-scale changes of an intensified mid-latitude glacial system. This climate regime caused short but pronounced drought periods in the Nile catchment, which are linked to Heinrich Events and alternate with more humid interstadials. The clay mineral record further implies that feedback mechanisms between vegetation cover and sediment discharge of the Nile are detectable but of minor importance for the sedimentary record in the southeastern Mediterranean Sea during the investigated African Humid Periods.

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