Clay mineral assemblages as palaeoclimatic indicators in a shallowing carbonate lacustrine system: Oligocene- Miocene, central Ebro Basin (NE Spain)

Clay Minerals ◽  
2011 ◽  
Vol 46 (3) ◽  
pp. 355-370
Author(s):  
M. J. Mayayo ◽  
A. Yuste ◽  
A. Luzόn ◽  
B. Bauluz
Keyword(s):  
Clay Mineral ◽  
Association Analysis ◽  
Chemical Weathering ◽  
Clay Mineralogy ◽  
Source Area ◽  
Ebro Basin ◽  
Humid Climate ◽  
Sem And Tem ◽  
Mineral Assemblages ◽  
Ne Spain

AbstractThis paper focuses on the clay mineralogy (using XRD, SEM and TEM methods) of the lacustrine “Calizas de Torrente de Cinca” unit that represents the Oligocene-Miocene transition in the central part of the Ebro Basin (NE Spain). Phyllosilicates are mainly detrital although Mgsmectites could have been generated in the lake.Although a temperate, relatively humid climate dominated the source area during the Oligocene-Miocene transition (Chattian-Aquitanian), as deduced by detrital phyllosilicates assemblage, mineralogical vertical trends along with sedimentological studies indicate some changes.Relatively warmer and more humid conditions during the late Chattian, that favoured increasing chemical weathering, were replaced during the early Aquitanian by drier conditions coinciding with the Mi-1 glaciation effects; this change is coeval with a transition from deeper to shallower lacustrine facies.Phyllosilicate association analysis has also permitted an improvement in the palaeogeographical sketch and infers that the Pyrenees are the main source area for the lacustrine system.

Clay mineral variations in Holocene terrestrial sediments from the Indus Basin

2012 ◽  
Vol 77 (3) ◽  
pp. 368-381 ◽  
Author(s):  
Anwar Alizai ◽  
Stephen Hillier ◽  
Peter D. Clift ◽  
Liviu Giosan ◽  
Andrew Hurst ◽  
...  
Keyword(s):  
Clay Mineral ◽  
Chemical Weathering ◽  
Clay Mineralogy ◽  
Flood Plain ◽  
Indus Basin ◽  
Sediment Reworking ◽  
Flood Plains ◽  
Mineral Assemblages ◽  
Terrestrial Sediments ◽  
Show Evidence

We employed X-ray diffraction methods to quantify clay mineral assemblages in the Indus Delta and flood plains since ~ 14 ka, spanning a period of strong climatic change. Assemblages are dominated by smectite and illite, with minor chlorite and kaolinite. Delta sediments integrate clays from across the basin and show increasing smectite input between 13 and 7.5 ka, indicating stronger chemical weathering as the summer monsoon intensified. Changes in clay mineralogy postdate changes in climate by 5–3 ka, reflecting the time needed for new clay minerals to form and be transported to the delta. Samples from the flood plains in Punjab show evidence for increased chemical weathering towards the top of the sections (6–≪ 4 ka), counter to the trend in the delta, at a time of monsoon weakening. Clay mineral assemblages within sandy flood-plain sediment have higher smectite/(illite + chlorite) values than interbedded mudstones, suggestive of either stronger weathering or more sediment reworking since the Mid Holocene. We show that marine records are not always good proxies for weathering across the entire flood plain. Nonetheless, the delta record likely represents the most reliable record of basin-wide weathering response to climate change.

Late Cretaceous—Palaeocene mid-latitude climates: inferences from clay mineralogy of continental-coastal sequences (Tremp-Graus area, southern Pyrenees, N Spain)

Clay Minerals ◽  
2011 ◽  
Vol 46 (1) ◽  
pp. 105-126 ◽  
Author(s):  
J. Arostegi ◽  
J. I. Baceta ◽  
V. Pujalte ◽  
M. Carracedo
Keyword(s):  
Clay Mineral ◽  
Chemical Weathering ◽  
Clay Mineralogy ◽  
Source Area ◽  
Climatic Conditions ◽  
Sem Images ◽  
Climatic Trend ◽  
Mineral Associations ◽  
Continental Basin ◽  
Mixed Layers

AbstractThe origin and distribution of late Maastrichtian–early Palaeocene clay mineral associations were investigated in the Tremp-Graus basin (South Pyrenees, Spain) to assess palaeoclimate changes during that period. The studied succession is made up of expanded continental and transitional terrigeneous and carbonate deposits accumulated in a coastal plain setting. X-ray diffraction, SEM-EDX and TEM-AEM analysis reveal that the main clay components are illite and smectite, but kaolinite, chlorite and illite-smectite mixed layers are present, although irregularly distributed, all of them showing a platy morphology typical of a detrital origin. Persistence of the chemical features of the Al-dioctahedral smectites throughout the whole succession demonstrates the persistence of the same source area during the interval studied. Palygorskite occurs in the late Danian and Selandian, within carbonate tidal flats as sabkha-like facies. In SEM images, the palygorskite displays straight fibre morphologies, both coating and branched curling out, a clear proof of authigenic origin.Physical or chemical weathering (PhW/ChW) determined as illite + chlorite/smectite + kaolinite ratio, smectite/kaolinite ratio and palygorskite distribution have been used as clay proxies for palaeoclimate reconstructions. Such data suggest a shift from temperate subhumid (perennial) conditions in late Maastrichtian times to a warm seasonal climate during early Palaeocene times. This trend, however, was dramatically altered during the late Danian–Selandian interval, when prevailing warm and semi-arid to arid climatic conditions caused intense evaporation and the development of an alkaline environment in which the palygorskite authigenesis took place.The proposed climatic trend partly concurs with that established for earliest Danian time by Domingoet al.(2007), also in the Tremp-Graus basin, from isotopic and geochemical proxies, as well as with the reconstruction of Cojan & Moreau (2006), in which a semiarid Danian phase for the near continental basin of Aix-en-Provence is postulated. However, it is at odds with the notion of a humid Danian state in the Pyrenees, as inferred by Gawendaet al.(1999) from clay mineral proxies of deep marine successions.

Chemical and mineralogical characteristics of Pleistocene caliche deposits from the Central Ebro Basin, NE Spain

Clay Minerals ◽  
1992 ◽  
Vol 27 (3) ◽  
pp. 293-308 ◽  
Author(s):  
C. Sancho ◽  
A. Melendez ◽  
M. Signes ◽  
J. Bastida
Keyword(s):  
Relative Concentration ◽  
Source Area ◽  
Arid Environment ◽  
Host Material ◽  
Ebro Basin ◽  
East Central ◽  
Mineralogical Characteristics ◽  
Mineral Assemblages ◽  
Form Part ◽  
Mixed Layers

AbstractChemical and mineralogical analyses of fossil caliche profiles developed on top of Lower Pleistocene alluvial formations in the East-central sector of the Ebro basin indicate that they have high content of carbonate (average 84%) and high Ca/Mg ratios (average 136). The clay mineral assemblages vary slightly depending on the host material, and, therefore, on the alluvial formation in the source area. Inherited detrital minerals (illite, kaolinite and chlorite), transformed components (from chlorite to mixed-layers of chlorite-vermiculite, and from smectite to palygorskite) and a neoformed phase (palygorskite) have been observed. The contents of carbonate and magnesian clay minerals (smectite and palygorskite) increase from the bottom to the top of the profiles, in relation to hardpan laminated caliche facies. The amount of palygorskite is controlled by the concentration of Mg2+ which in turn depends on the absolute content of Mg2+ in the host material and on its relative concentration by processes of evaporation linked to decreasing permeability in the profile during the biogenic-pedogenetic carbonate accumulation stages. These processes form part of the development of caliche profiles in a semi-arid environment.

scholarly journals Clay minerals as provenance indicators in continental lacustrine sequences: the Leza Formation, early Cretaceous, Cameros Basin, northern Spain

Clay Minerals ◽  
2005 ◽  
Vol 40 (1) ◽  
pp. 79-92 ◽  
Author(s):  
J. Alonso-Azcárate ◽  
M. Rodas ◽  
J. F. Barrenechea ◽  
J. R. Mas
Keyword(s):  
Clay Mineral ◽  
Source Area ◽  
Local Source ◽  
Northern Spain ◽  
Source Areas ◽  
Kübler Index ◽  
Facies Associations ◽  
Mineral Assemblages ◽  
Cameros Basin

AbstractVariations in clay mineral assemblages, changes in Kübler index (KI), and the chemical composition of chlorites are used to identify source areas in the lacustrine materials in the Lower Cretaceous Leza Limestone Formation of the Cameros Basin, northern Spain. This formation has fairly homogeneous lithological characteristics and facies associations which do not allow for identification and characterization of local source areas. The Arnedillo lithosome of the Leza Limestone Formation contains a clay mineral association (Mg-chlorite, illite and smectite) indicative of its provenance. Chlorite composition and illite KI values indicate that these minerals were formed at temperatures higher than those reached by the Leza Formation which indicates its detrital origin. The similarity in the Mg-chlorite composition between the Arnedillo lithosome and the Keuper sediments of the area indicates that these materials acted as a local source area. This implies that Triassic sediments were exposed, at least locally, at the time of deposition of the Leza Formation. The presence of smectite in the Leza Formation is related to a retrograde diagenesis event that altered the Mg-chlorites in some samples.

scholarly journals Geochemistry and mineralogy of the Truc Thon Clay, Hai Duong Province, North Vietnam: implication for paleoclimatic and provenance analysis

2021 ◽  
Author(s):  
Tha Hoang Van ◽  
Shahid Iqbal ◽  
Urszula Czarniecka ◽  
Anna Wysocka ◽  
Pha Phan Dong ◽  
...  
Keyword(s):  
Chemical Weathering ◽  
Clay Mineralogy ◽  
Source Area ◽  
Mineralogical Composition ◽  
Provenance Analysis ◽  
Geological Investigation ◽  
Basement Rocks ◽  
Chemical Index Of Alteration ◽  
Geochemical Analyses ◽  
North Vietnam

During the Miocene-Pleistocene, generally sub-tropical to tropical warm and humid paleoclimate prevailed in Southeast Asia with a gradual cooling trend. The Truc Thon clay (TTC) mine presents interesting outcrops for sedimentological and provenance analysis. The present study uses results of geological investigation in 16 outcrops and wells at the clay mine Truc Thon. The TTC has lens-shaped geometry, filled with two clay bodies, including grey-white clay and multicolor clay. Bulk mineralogy indicates the predominance of quartz and a relatively high amount of pyrophyllite. Clay mineralogy shows the presence of main kaolinite, followed by illite and mixed-layer illite-smectite. These may interpret a warm, humid paleoclimatic condition in the source areas. Illite may be inherited from basement rocks. The bulk rock geochemistry supports intense chemical weathering with the Chemical Index of Alteration (CIA) in the TTC ranged ca. 80.6-98 (average = 90.4). In combination with the geochemical proxies and the mineralogical composition of the TTC, the chemical weathering intensity indicated warm/hot, semi-humid/humid tropical paleoclimate in the source area. A combination of mineralogical and geochemical analyses with regional geological features show that the Hon Gai Triassic rocks are the main source for the TTC. Source materials are originally related to silicic rocks of granitic-granodioritic composition. Paleoclimatic conditions favored intense chemical weathering of the Hon Gai Triassic rocks and surrounding rocks, creating a ceramic mine of great industrial value.

Mineralogy and geochemistry of the Ossa lake Complex sediments, Southern Cameroon: implications for paleoweathering and provenance

2021 ◽  
Vol 14 (4) ◽  
Author(s):  
Armel Zacharie Ekoa Bessa ◽  
Paul-Désiré Ndjigui ◽  
Gentry Calistus Fuh ◽  
John S. Armstrong-Altrin ◽  
Thierry Bineli Betsi
Keyword(s):  
Lake Sediments ◽  
Chemical Weathering ◽  
Source Area ◽  
Compositional Variation ◽  
Climatic Index ◽  
Humid Climate ◽  
Elemental Ratios ◽  
Margin Setting ◽  
Chemical Index ◽  
High Maturity

AbstractThis study investigates the provenance, paleoweathering, and paleoclimate of the Ossa lake sediments, based on the mineralogy and geochemistry data. Ossa lake sediments are characterized by silt and clay with high content of total organic carbon (TOC). Clay minerals are identified as kaolinite and illite types. Other dominant minerals identified are quartz, zircon, rutile, goethite, gibbsite, feldspar, and accessory vivianite. The major, trace, and rare earth element concentrations indicate that the sediments were derived from felsic rocks, such as gneisses and granitoids. The tectonic discrimination diagrams revealed an active margin setting. Weathering indices such as the chemical index of alteration (CIA), the plagioclase index of alteration (PIA), and chemical index of weathering (CIW) suggest intense chemical weathering in the source area. K2O/Na2O ratio and index of compositional variation (ICV) are consistent with high maturity of the sediments. The mineral assemblages and trace elemental ratios and climatic index “C” of the Ossa Lake sediments suggest a warm to semi-humid climate and deposition in an oxic shallow environment.

Clay mineralogy of the Permo-Triassic strata of the British Isles: onshore and offshore

Clay Minerals ◽  
2006 ◽  
Vol 41 (1) ◽  
pp. 309-354 ◽  
Author(s):  
C. V. Jeans
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
North Sea ◽  
Mixed Layer ◽  
Early Stage ◽  
Regional Distribution ◽  
Clay Mineralogy ◽  
British Isles ◽  
Mineral Assemblages ◽  
Red Bed

AbstractThe regional distribution, mineralogy, petrology and chemistry of the detrital and authigenic clay minerals associated with the Permo-Triassic strata (excluding the Rotliegend: see Ziegler, 2006; this volume), of the onshore and offshore regions of the British Isles are reviewed within their stratigraphical framework. The origin of these clay minerals is discussed in relation to current hypotheses on the developments of the Mg-rich clay mineral assemblages associated with the evaporitic red-bed Germanic facies of Europe and North Africa.Composite clay mineral successions are described for seven regions of the British Isles — the Western Approaches Trough; SW England; South Midlands; Central Midlands; the Cheshire Basin; NE Yorkshire; and the Central North Sea. The detrital clay mineral assemblages of the Early Permian strata are variable, consisting of mica, smectite, smectite-mica, kaolin and chlorite, whereas those of the Late Permian and the Trias are dominated by mica, usually in association with minor Fe-rich chlorite. The detrital mica consists of a mixture of penecontemporaneous ferric mica, probably of pedogenic origin, and recycled Pre-Permian mica. In the youngest Triassic strata (Rhaetian), the detrital clay assemblages may contain appreciable amounts of poorly defined collapsible minerals (irregular mixed-layer smectite-mica-vermiculite) and kaolin, giving them a Jurassic aspect. There are two types of authigenic clay mineral assemblages. Kaolin may occur as a late-stage diagenetic mineral where the original Permo-Triassic porewaters of the sediment have been replaced by meteoritic waters. A suite of early-stage diagenetic clay minerals, many of them Mg-rich, are linked to the evaporitic red-bed facies — these include sepiolite, palygorskite, smectite, irregular mixed- layer smectite-mica and smectite-chlorite, corrensite, chlorite and glauconite (sensu lato). The sandstones and mudstones of the onshore regions of the British Isles display little or no difference in their detrital and authigenic clay mineral assemblages. In contrast, the sandstones of the offshore regions (North Sea) show major differences with the presence of extensive chloritic cements containing Mg-rich and Al-rich chlorite, irregular mixed-layer serpentine-chlorite, and mica.

Clay mineral assemblages in flysch from the Campo de Gibraltar area (Spain)

Clay Minerals ◽  
1999 ◽  
Vol 34 (2) ◽  
pp. 345-364 ◽  
Author(s):  
M. D. Ruiz Cruz
Keyword(s):  
Clay Mineral ◽  
Clay Mineralogy ◽  
Transport Processes ◽  
Source Rocks ◽  
Coarse Grained ◽  
Tectonic Activity ◽  
X Ray Diffraction ◽  
Fine Grained ◽  
Mineral Assemblages ◽  
Climatic Cooling

AbstractIn order to determine the relative influence of palaeoenvironmental and diagenetic processes in clay assemblages, as well as their significance, both fine- and coarse-grained sediments from the Campo de Gibraltar flysch have been studied by means of X-ray diffraction, optical and electron microscopy, and chemical analysis. Diagenetic modifications appear to be lithologically controlled and mainly affect coarse-grained sediments, where Fe-chlorites, illite and kaolinite are the more characteristic authigenic clay minerals. The evolution of detrital assemblages, determined in fine-grained beds, indicates that, from Cretaceous to Eocene times, clay mineralogy, characterized by the opposite kaolinite+smectite and illite + I-S mixed-layer assemblages, was mainly controlled by sources, climate and transport processes. On the other hand, from the Oligocene, clay mineral assemblages, characterized either by the abundance of kaolinite, or by the illite+chlorite association, mainly reflect the petrology of source rocks, as a consequence of climatic cooling and the increasing tectonic activity, which impede the development of soils.

scholarly journals Continental weathering using combined Hf-Nd isotope system and clay mineralogy: new insights for the Late Cretaceous climate

2021 ◽  
Author(s):  
Pauline Corentin ◽  
Emmanuelle Puceat ◽  
Pierre Pellenard ◽  
Nicolas Freslon ◽  
Michel Guiraud ◽  
...  
Keyword(s):  
Clay Mineral ◽  
Late Cretaceous ◽  
Chemical Weathering ◽  
Clay Mineralogy ◽  
Global Scale ◽  
Climatic Conditions ◽  
Silicate Weathering ◽  
Nd Isotope ◽  
Continental Weathering ◽  
The Impact

<p>The Late Cretaceous period records a pronounced decrease in marine temperatures at a global scale initiating the last greenhouse-icehouse transition, whose origin still remains enigmatic. Continental weathering represents a major sink of atmospheric CO<sub>2</sub> through silicate weathering reactions yet the importance of this process in the Late Cretaceous cooling has only been scarcely explored.</p><p>In this study we explore the impact of the eastern South American margin uplift, concomitant to the long-term Late Cretaceous cooling, on the evolution of chemical weathering of the Brazilian margin, using a new proxy of silicate weathering based on the coupled Lu-Hf and Sm-Nd isotope systems in clays. This proxy, expressed as Δε<sub>Hf</sub>, has been recently calibrated in modern environments (Bayon et al., 2016) but has only been scarcely applied to deep-time environments. This proxy, applied on sediments from DSDP site 356 on the São Paulo Plateau, highlights a marked increase in silicate chemical weathering of the southeastern Brazilian margin from the Santonian to the Maastrichtian, also supported by the evolution of the chemical index of alteration (CIA) and clay mineralogy.</p><p>This increase follows an episode of enhanced mechanical erosion of the margin revealed in the Turonian to Santonian by an increase of primary clay mineral (illite, chlorite) and Ti/Al ratio, linked to the tectonic uplift of the margin. Clay mineral assemblages additionally point to an evolution of local climatic conditions from arid to a more hydrolysing climate following this episode, that we link to a “rain shadow effect” affecting the eastern side of the newly formed relief that would have enhanced chemical weathering of the margin.</p><p>Importantly the temporal coincidence of the increase in chemical weathering depicted here with the marked acceleration of the global cooling recorded worldwide during the Campanian points to a potentially important role of this process on the overall climate decline initiating the descent into our icehouse climate mode. Although records from additional sites are needed to establish the spatial extent of the margin affected by this process, our new dataset brings new insights about the impact of tectonic forcing on climate.</p><p>Bayon et al. (2016) EPSL 438, p. 25-36.</p>

Clay mineralogy of the Jurassic strata of the British Isles

Clay Minerals ◽  
2006 ◽  
Vol 41 (1) ◽  
pp. 187-307 ◽  
Author(s):  
C. V. Jeans
Keyword(s):  
Clay Mineral ◽  
North Sea ◽  
Mixed Layer ◽  
Clay Mineralogy ◽  
List Type ◽  
British Isles ◽  
Southern England ◽  
The North ◽  
Wide Range ◽  
Mineral Assemblages

AbstractThe nature and origin of the clay mineralogy of the Jurassic strata of the British Isles are described and discussed within their lithological and biostratigraphical framework using published and unpublished sources as well as 1800 new clay mineral analyses. Regional clay mineral variation is described systematically for the following formations or groups:England and Wales(i)Hettangian-Toarcian strata (Lias Group): Redcar Mudstone Fm.; Staithes Sandstone Fm.; Cleveland Ironstone Fm.; Whitby Mudstone Fm.; Scunthorpe Mudstone Fm.; Blue Lias Fm.; Charmouth Mudstone Fm.; Marlstone Rock Fm.; Dyrham Fm.; Beacon Limestone Fm.; Bridport Sand Fm.(ii)Aalenian-Bajocian (Inferior Oolite Group): Dogger Fm.; Saltwick Fm.; Eller Beck Fm.; Cloughton Fm.; Scarborough Fm.; Scalby Fm. (in part); Northampton Sand Fm.; Grantham Fm.; Lincolnshire Limestone Fm.; Rutland Fm. (in part); Inferior Oolite of southern England.(iii)Bathonian (Great Oolite Group): Scalby Fm. (in part); Rutland Fm. (in part); Blisworth Limestone Fm.; Great Oolite Group of southern England; Forest Marble Fm.; Cornbrash Fm. (in part).(iv)Callovian-Oxfordian: Cornbrash Fm. (in part); Kellaways Fm.; Oxford Clay Fm.; Corallian Beds and West Walton Beds; Ampthill Clay Fm.(v)Kimmeridgian-Tithonian: Kimmeridge Clay Fm.; Portland Sandstone Fm.; Portland Limestone Fm.; Lulworth Fm.; Spilsby Sandstone Fm. (in part). Scotland(vi)Hettangian-Toarcian: Broadfoot Beds, Dunrobin Bay Fm. Aalenian-Portlandian: Great Estuarine Group (Dunkulm, Kilmaluag and Studiburgh Fm.s); Staffin Shale Fm.; Brora Coal Fm.; Brora Argillaceous Fm.; Balintore Fm.; Helmsdale Boulder Beds (Kimmeridge Clay Fm.).Dominating the Jurassic successions are the great marine mudstone formations — the Lias Group, Oxford Clay, Ampthill Clay and Kimmeridge Clay. These are typically characterized by a detrital clay mineral assemblage of mica, kaolin and poorly defined mixed-layer smectite-mica-vermiculite minerals with traces of chlorite. Detailed evidence suggests that this assemblage is derived ultimately from weathered Palaeozoic sediments and metasediments either directly or by being recycled from earlier Mesozoic sediments. A potassium-bearing clay is a persistent component and formed at approximately the same time as the deposition of the host sediment, either in coeval soils or during very early diagenesis.At three periods during the deposition of the Jurassic (Bajocian-Bathonian, Oxfordian and late Kimmeridgian-Tithonian), the detrital clay assemblage was completely or partially replaced by authigenic clay mineral assemblages rich in kaolin, berthierine, glauconite or smectite minerals. Associated with these changes are major changes in the lithofacies, with the incoming of non-marine and proximal marine strata. The authigenic clay assemblages rich in kaolin and berthierine are generally restricted to the non-marine and very proximal marine beds, those rich in glauconite or smectite are typical of the marine lithofacies. Clay mineral assemblages containing vermiculite and mixed-layer vermiculite-chlorite sometimes occur in the non-marine and proximal marine facies. The causes of these major changes in lithofacies and clay mineralogy are discussed, and present evidence favours an important volcanogenic influence and not climatic control. It is suggested that the Bajocian-Bathonian, Oxfordian and Late Kimmeridgian-Tithonian were periods of enhanced volcanic activity, with centres probably located in the North Sea and linked to regional tectonic changes which caused major modifications of the palaeogeography of the British Isles. The most important of these changes was the development of the central North Sea Rift Dome during the Bajocian and Bathonian. Volcanic ash was widespread in both the non-marine and marine environments and its argillization under different conditions provided the wide range of authigenic clay mineral assemblages.Metre-scale clay mineral cyclicity is widespread in most of the Jurassic mudstone formations that have been examined in sufficient detail. The cyclicity is defined by systematic variations in the mica/ collapsible minerals (mixed-layer smectite-mica-vermiculite) ratio. This variation is unrelated to changes in lithology and its possible origins are discussed in detail using data from the Kimmeridge Clay provided by Reading University's contribution to the Rapid Global Geological Events (RGGE) Project.

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