Heavy mineral response to the progradation of an alluvial fan: implications concerning unroofing of source area, chemical weathering and palaeo-relief (Upper Cretaceous Parkstein fan complex, SE Germany)

1995 ◽  
Vol 95 (1-2) ◽  
pp. 39-56 ◽  
Author(s):  
Harald G. Dill
Keyword(s):  
Chemical Weathering ◽  
Upper Cretaceous ◽  
Source Area ◽  
Alluvial Fan ◽  
Heavy Mineral

scholarly journals Provenance and weathering index of the Upper Cretaceous São Carlos Formation and its tectonic significance in the eastern Bauru Basin, SE Brazil

2019 ◽  
Vol 19 (3) ◽  
pp. 77-94
Author(s):  
Lara Ferreira Neves ◽  
Alessandro Batezelli
Keyword(s):  
Trace Elements ◽  
Chemical Weathering ◽  
Upper Cretaceous ◽  
Source Area ◽  
Sedimentary Basins ◽  
Major And Trace Elements ◽  
Published Data ◽  
Weathering Index ◽  
Se Brazil ◽  
Eastern Border

Geochemistry of major and trace elements has been used as an important tool for the study of provenance and tectonic and climatic evolution of sedimentary basins. The São Carlos Formation is an Upper Cretaceous unit that lies on the eastern border of the Bauru Basin. Despite the paleontological and paleodepositional studies performed in this unit in the last years, little is known about the correspondence between tectonic and climatic conditions acting during the first stages of sedimentation. The hypothesis of this paper is to evaluate São Carlos and Araçatuba formations and understand the evolution of the eastern border of the basin. Thus, were conducted geochemical studies using X-ray fluorescence on sandstones, siltstones, and shales from the São Carlos Formation. According to the chemical weathering index, which presented values ranging from 57.12 to 71.58%, the oxides of major elements indicate that moderate weathering processes affected the source area, possibly associated with the arid-semiarid climate. Alkaline rocks, granites, gneisses, and metasediments were the main lithotypes of the source area. Ternary diagrams show that the tectonic environment was equivalent to the passive continental margin, coinciding with the Serra do Mar and, secondarily, Alto Paranaíba Uplift regions. Based on major and trace elements, their ratios, and published data on the basin, was elaborated a paleogeographic model of the eastern border of the Bauru Basin, concluding that the source area of the sediments was constituted by intermediate and felsic rocks, sometimes recycled by sedimentary processes.

Mineralogy and origin of the upper Eastend and Whitemud Formations of south-central and southwestern Saskatchewan and southeastern Alberta

1969 ◽  
Vol 6 (2) ◽  
pp. 317-334 ◽  
Author(s):  
P. N. Byers
Keyword(s):  
Chemical Weathering ◽  
Upper Cretaceous ◽  
Volcanic Rocks ◽  
Source Area ◽  
Heavy Minerals ◽  
Major Constituent ◽  
Abrupt Decrease ◽  
South Central ◽  
Mechanical Weathering ◽  
Kaolinitic Clay

The Upper Cretaceous non-marine Whitemud Formation of south-central and southwestern Saskatchewan and southeastern Alberta consists of kaolinitic, metamorphic lithic sands and silts, and kaolinitic clays. The sands and silts are not highly feldspathic as was originally thought. The major constituent is metamorphic lithic grains with minor kaolinitic clay and vermicular kaolin, clear angular quartz, chert, muscovite, and minor volcanic lithic grains and feldspar. The upper part of the Upper Cretaceous Eastend Formation, which conformably underlies the Whitemud Formation, consists of non-marine sands, silts, and clays. Kaolin is very rare. The bulk of the sands are composed of volcanic lithic grains with minor metamorphic lithic grains, clear angular quartz, chert, feldspar, muscovite, and biotite.The contact is characterized by the following changes from the Eastend Formation upward into the Whitemud Formation: an abrupt decrease in volcanic lithic grains and increase in metamorphic lithic grains; the appearance of kaolin and the disappearance of biotite and apatite; a slight increase in clear angular quartz and muscovite and a decrease in feldspar; a general increase in metamorphic heavy minerals; and an increase in the percentage of ilmenite (both as solitary grains and intergrown with magnetite), which is altered to leucoxene.On the basis of mineralogy, the Whitemud Formation is definitely a correlative of the Colgate Member of the Fox Hills Formation in Montana and North Dakota.The upper Eastend and Whitemud Formations were derived from Upper Cretaceous volcanic rocks, Precambrian and Paleozoic metamorphic rocks, and Paleozoic carbonates all situated in Montana. Upper Eastend sediments represent fast mechanical weathering of mountains of freshly extruded volcanic rocks, whereas the Whitemud sediments represent slow chemical weathering and leaching, which predominated once the mountainous volcanic rocks were worn down. This deep chemical weathering altered the volcanic tuffs and flows into kaolinitic clay at the source area; the kaolin of the Whitemud Formation is not derived from the weathering of feldspars at the site of deposition.It is suggested that the Frenchman and Ravenscrag Formations were also derived from Upper Cretaceous and Lower Tertiary volcanic rocks in Montana.

scholarly journals Heavy-mineral provenance signatures during the infill and uplift of a foreland basin: An example from the Jaca basin (southern Pyrenees, Spain)

2020 ◽  
Vol 90 (12) ◽  
pp. 1747-1769
Author(s):  
Xavier Coll ◽  
David Gómez-Gras ◽  
Marta Roigé ◽  
Antonio Teixell ◽  
Salva Boya ◽  
...  
Keyword(s):  
Foreland Basin ◽  
Source Area ◽  
Late Eocene ◽  
Alluvial Fan ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Source Areas ◽  
The North ◽  
Sediment Routing ◽  
Central Pyrenees

ABSTRACT In the Jaca foreland basin (southern Pyrenees), two main sediment routing systems merge from the late Eocene to the early Miocene, providing an excellent example of interaction of different source areas with distinct petrographic signatures. An axially drained fluvial system, with its source area located in the eastern Central Pyrenees, is progressively replaced by a transverse-drained system that leads to the recycling of the older turbiditic foredeep. Aiming to provide new insights into the source-area evolution of the Jaca foreland basin, we provide new data on heavy-mineral suites, from the turbiditic underfilled stage to the youngest alluvial-fan systems of the Jaca basin, and integrate the heavy-mineral signatures with available sandstone petrography. Our results show a dominance of the ultrastable Ap-Zrn-Tur-Rt assemblage through the entire basin evolution. However, a late alluvial sedimentation stage brings an increase in other more unstable heavy minerals, pointing to specific source areas belonging to the Axial and the North Pyrenean Zone and providing new insights into the response of the heavy-mineral suites to sediment recycling. Furthermore, we assess the degree of diagenetic overprint vs. provenance signals and infer that the loss of unstable heavy minerals due intrastratal dissolution is negligible at least in the Peña Oroel and San Juan de la Peña sections. Finally, we provide new evidence to the idea that during the late Eocene the water divide of the transverse drainage system was located in the North Pyrenean Zone, and areas constituted by the Paleozoic basement were exposed in the west-Central Pyrenees at that time. Our findings provide new insights into the heavy-mineral response in recycled foreland basins adjacent to fold-and-thrust belts.

Provenance of lower Cambrian quartz arenite on southwestern Baltica: Weathering versus recycling

2020 ◽  
Vol 90 (5) ◽  
pp. 493-512
Author(s):  
Sanne Lorentzen ◽  
Tonje Braut ◽  
Carita Augustsson ◽  
Johan P. Nystuen ◽  
Jens Jahren ◽  
...  
Keyword(s):  
Lower Cambrian ◽  
Mineral Assemblage ◽  
Chemical Weathering ◽  
Source Area ◽  
Heavy Mineral ◽  
Provenance Analysis ◽  
Source To Sink ◽  
Quartz Arenite ◽  
Chemical Index Of Alteration ◽  
Southern Norway

ABSTRACT Lower Cambrian quartz arenite deposits have a world-wide occurrence and are also present on Baltica. However, the processes influencing the deposits from source to sink have not been accordingly investigated. The provenance of these deposits is crucial for the understanding of the extent of chemical weathering in the cratonic drainage area and reworking at the broad shallow shelves of Baltica during early Cambrian time. Provenance analysis and study of weathering effects was done for lower Cambrian sandstone from southern Scandinavia, including southern Norway, southern Sweden, and Bornholm (Denmark). For the quartz-arenite sandstone of the Ringsaker Member and the Hardeberga Formation, predominantly moderately weathered felsic–intermediate plutonic and meta-igneous source terranes are suggested from negative Eu anomalies, high LaN/YbN, and low to moderate Ti/Nb ratios, as well as trace amounts of plutonic lithoclasts. Similarly, a felsic–intermediate igneous and metamorphic signature is indicated in the heavy-mineral assemblage and a dominance of dark cathodoluminescence of quartz in a special study of samples from Bornholm, thus suggesting a mixed provenance of local granitoid–orthogneissic Mesoproterozoic basement and distant sources from the Transscandinavian Igneous Belt for the Hardeberga Formation on Bornholm. High percentages of mostly rounded ultra-stable heavy-mineral grains, quartz, and extremely high SiO2/Al2O3 ratios indicate a compositionally and texturally mature sand that was subjected to extensive to moderate weathering following removal of detritus from the source area. The main controls on the alteration of framework composition and the heavy-mineral assemblage are interpreted as surface weathering, based on moderate Chemical Index of Alteration values and meteoric flushing, and reworking by waves, based on an estimated low amount of feldspar before burial. Thus, the maturation of lower Cambrian quartz arenite on southwestern Baltica can be ascribed to a combination of processes including weathering in the source-rock area, extensive reworking, and early diagenesis. This study also highlights the importance of understanding alteration processes affecting the deposits from source to sink, and to be careful to describe quartz-rich rocks as simply recycled deposits.

scholarly journals Provenance analysis of the Permo-Carboniferous fluvial sandstones of the southern part of the Boskovice Basin and the Zöbing Area (Czech Republic, Austria): implications for paleogeographical reconstructions of the post-Variscan collapse basins

2012 ◽  
Vol 63 (5) ◽  
pp. 365-382 ◽  
Author(s):  
Slavomír Nehyba ◽  
Reinhard Roetzel ◽  
Lubomír Maštera
Keyword(s):  
Chemical Weathering ◽  
Wide Spectrum ◽  
Source Area ◽  
Heavy Mineral ◽  
Minor Role ◽  
Provenance Analysis ◽  
Volcanic Material ◽  
Physical Weathering ◽  
Source Areas ◽  
Metamorphic Complexes

Abstract The provenance analyses of Permo-Carboniferous fluvial sandstones of the southern part of the Boskovice Basin and the Zöbing area are based on a wide spectrum of analytical techniques (petrography, heavy mineral assemblages, chemistry of garnet, rutile and spinel, zircon study, major and trace elements). The studied sandstones are poorly sorted and reveal a relatively immature composition implying short distance transport, rapid deposition, a high-relief source area, mainly physical weathering and the minor role of chemical weathering. Different source areas for the Boskovice Basin and the Zöbing area were proved. The Zöbing material was predominantly derived from crystalline units, mainly formed by metamorphic complexes, although the portions of magmatic and volcanic material were significant. The source area is supposed to be located in the Moldanubian Unit. The Boskovice Basin deposits, on the other hand, seem to be mainly derived from metamorphic complexes, corresponding especially to the Moravian Unit, with a relatively wider spectrum of metamorphites, together with the derivation of the detritus from pre-existing sedimentary rocks (especially from Moravo- Silesian Paleozoic deposits/Drahany Culm unit). The transport direction in the basin was more complex, both from the west and east. These results did not confirm the possibility of communication between the Boskovice Basin and the Zöbing area during the Late Paleozoic. The existence of “colinear” marginally offset half grabens with predominant transversal sources is here hypothesized. The general heavy mineral evolution in time does not indicate the successive exhumation of a simple structured orogen but may be interpreted as differences in the extent of the source areas.

Detrital zircon geochronology and heavy mineral analysis as complementary provenance tools in the presence of extensive weathering, reworking and recycling: the Neogene of the southern North Sea Basin

2021 ◽  
pp. 1-13
Author(s):  
Jasper Verhaegen ◽  
Hilmar von Eynatten ◽  
István Dunkl ◽  
Gert Jan Weltje
Keyword(s):  
North Sea ◽  
Chemical Weathering ◽  
Heavy Mineral ◽  
Mineral Analysis ◽  
Provenance Analysis ◽  
Detrital Zircon Geochronology ◽  
Southern North Sea ◽  
Variable Heavy ◽  
Mineral Data ◽  
Heavy Mineral Analysis

Abstract Heavy mineral analysis is a long-standing and valuable tool for sedimentary provenance analysis. Many studies have indicated that heavy mineral data can also be significantly affected by hydraulic sorting, weathering and reworking or recycling, leading to incomplete or erroneous provenance interpretations if they are used in isolation. By combining zircon U–Pb geochronology with heavy mineral data for the southern North Sea Basin, this study shows that the classic model of sediment mixing between a northern and a southern source throughout the Neogene is more complex. In contrast to the strongly variable heavy mineral composition, the zircon U–Pb age spectra are mostly constant for the studied samples. This provides a strong indication that most zircons had an initial similar northern source, yet the sediment has undergone intense chemical weathering on top of the Brabant Massif and Ardennes in the south. This weathered sediment was later recycled into the southern North Sea Basin through local rivers and the Meuse, leading to a weathered southern heavy mineral signature and a fresh northern heavy mineral signature, yet exhibiting a constant zircon U–Pb age signature. Thus, this study highlights the necessity of combining multiple provenance proxies to correctly account for weathering, reworking and recycling.

The ratio of mechanical to chemical denudation in alluvial systems, derived from geochemical mass balance

1993 ◽  
Vol 84 (1) ◽  
pp. 73-78 ◽  
Author(s):  
A. D. Stewart
Keyword(s):  
Mass Balance ◽  
Chemical Weathering ◽  
Amazon Basin ◽  
Source Area ◽  
Large River ◽  
Suspended Load ◽  
Bed Load ◽  
Load Transport ◽  
Bed Load Transport ◽  
Dissolved Load

ABSTRACTMass balance equations are derived which link the ratios Ts/ (suspended load/dissolved load from chemical weathering) and Tb/Ts (bed load/suspended load), with any two geochemical components present in the source rock and the alluvial system. If the dissolved load is unknown the ratios can be estimated from the relatively insoluble silica and alumina. The ratio Ts/, which for large river basins depends on climate and relief, can thus potentially be determined from ancient alluvial sequences.The equations help define the source composition of a group of 13 modern rivers for which Ts, and alluvial geochemistry are known. These rivers together drain 27% of the continental surface. For a source area with the average continental sandstone to shale ratio of 0·6 the observed average value of Ts/ is obtained when limestone, sandstone and shale are present in the proportions 6·7:21·6:35·7. The figure of 64% sediment in the source area is very similar to the 66% determined by Blatt and Jones (1975) from geological maps of the continents. The equations also show that average bed load transport rate into these 13 basins is about 27% of total transport, and into the Amazon basin about 37%. Bed load transport rates out of the basins, into the sea, are relatively very small.

scholarly journals Clay mineral genesis and chemical evolution in the Miocene sediments of Somosaguas, Madrid Basin, Spain

Clay Minerals ◽  
2007 ◽  
Vol 42 (2) ◽  
pp. 187-201 ◽  
Author(s):  
O. Fesharaki ◽  
E. García-Romero ◽  
J. Cuevas-González ◽  
N. López-Martínez
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clay Minerals ◽  
Analytical Electron Microscopy ◽  
Source Area ◽  
Alluvial Fan ◽  
Granitic Rocks ◽  
Central System ◽  
Transmission Electron ◽  
Spanish Central System

AbstractA mineralogical and microtextural study of Somosaguas Miocene deposits, located in the Madrid Basin (western Madrid, Spain), was carried out using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and optical microscopy, whereas crystal chemistry data were obtained by analytical electron microscopy-transmission electron microscopy and electron icroprobe analysis. Four stratigraphic sections were studied, compising detrital rocks representing intermediate and distal facies from alluvial fan deposits. The predominant source area of these sediments was the granitic rocks of the Spanish Central System with a lesser contribution of metamorphic rocks. Clayey arkoses are the most abundant rocks of these sections, typical of granite alteration under warm, semi-arid climates. The mineralogy is characterized by phyllosilicates, followed by feldspars and quartz. The data obtained reveal mineral mixtures of detrital (quartz, feldspars, kaolinite, micas and chlorite), transformed (illite and beidellite) and neoformed (montmorillonite) origin. Clay minerals resulted from interactions between detrital minerals and meteoric waters. Two trends of degradation of micas are detected. The first shows a transition from muscovites and dioctahedral illites, to beidellites. The other trend is defined by the biotite degradation to beidellites with different layer charge and octahedral Fe content. Montmorillonites were neoformed from the hydrolysis and weathering of primary minerals (feldspars and muscovite). Magnesian clay minerals such as sepiolite, palygorskite and trioctahedral smectites, extremely abundant in the centre of the basin, were not detected in Somosaguas sediments.

Alluvial fan depositional records from north and south-facing catchments in semi-arid montane terrain

2017 ◽  
Vol 89 (1) ◽  
pp. 237-253 ◽  
Author(s):  
Michael J. Poulos ◽  
Jennifer L. Pierce
Keyword(s):  
Late Holocene ◽  
Source Area ◽  
Alluvial Fan ◽  
Potential Bias ◽  
Landform Evolution ◽  
Sediment Yields ◽  
Erosion Rates ◽  
South Central ◽  
Valley Incision ◽  
North And South

AbstractValley asymmetry reflects differences in landform evolution with aspect; however, few studies assess rates and timing of asymmetric erosion. In south-central Idaho, we combine alluvial fan volume reconstructions with radiocarbon deposit dating to compare the source-catchment normalized fan deposition rates of catchments incised into north (n=5) and south-facing (n=3) valleys, which differ during the late Holocene from 7.7 to 10.1 mm/ka, respectively, but are not significantly different. South-facing catchments produced 1.3× more fan sediment per unit source-area during the late Holocene, whereas over the last 10 Ma they have evolved to be 2.1× larger with 2.8× greater eroded volumes and 7.6° gentler slopes (24.5° versus 32.1°, average). Late Holocene differences in sediment yields with aspect cannot fully explain differences in landforms. Potential bias in sediment deposition and/or remobilization cannot fully explain the similarity of erosion rates during the late Holocene. Valley asymmetry appears to have developed primarily during different conditions. While valley asymmetry development may be quicker during glacial climates, development is likely accelerated early in a valley’s history, such as during initial valley incision, because asymmetric degradation serves as a negative feedback that reduces aspect-related differences in erosion and drives valleys towards steady state.

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