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 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.

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 lower Proterozoic Fern Creek Formation, northern Michigan: mineral and bulk geochemical evidence for its glaciogenic origin

2002 ◽  
Vol 39 (4) ◽  
pp. 481-492 ◽  
Author(s):  
Anne Argast
Keyword(s):  
Rare Earth ◽  
Chemical Weathering ◽  
Chemical Index ◽  
Quartz Arenite ◽  
Bulk Chemical ◽  
Chemical Index Of Alteration ◽  
Rare Earth Mineral ◽  
Chemical Trends ◽  
Northern Michigan ◽  
Bulk Chemistry

Bulk chemical data indicate the Fern Creek Formation (Early Proterozoic, Marquette Range Supergroup, Lower Chocolay Group) originated as a glacial till, resolving an old argument about the correct interpretation for diamictite-containing units within the formation. There are poor correlations among SiO2, Al2O3, and K2O, and the chemical index of alteration averages 55. These are qualities characteristic of tills and other sediments accumulated in the absence of chemical weathering and transport-induced sorting and inconsistent with an origin as a fluvial deposit (the principal alternate hypothesis). The Archean Carney Lake Gneiss might be the source for at least the lower portions of the Fern Creek Formation. Compositions are similar, and rare earth element trends in the Fern Creek Formation are consistent with derivation from an Archean high-grade terrane. Pegmatites in the gneiss could be the source for monazite, huttonite, and an unnamed fluor-hydroxy-rare earth mineral that occurs in the midsection of the Fern Creek Formation. In addition, mineral and bulk chemical trends are consistent with models involving deep erosion of a complex Archean source, similar to models previously developed for Gowganda tills in the Huronian Supergroup. Samples of the Sturgeon River Quartzite occurring above the Fern Creek Formation were also analyzed. The bulk chemistry is consistent with a well-sorted, supermature quartz arenite.

Sourceland controls and dispersal pathways of Holocene muds from boreholes of the Ionian Basin, Calabria, southern Italy

2015 ◽  
Vol 152 (6) ◽  
pp. 957-972 ◽  
Author(s):  
FRANCESCO PERRI ◽  
SALVATORE CRITELLI ◽  
ROCCO DOMINICI ◽  
FRANCESCO MUTO ◽  
MAURIZIO PONTE
Keyword(s):  
Chemical Weathering ◽  
Drainage Basin ◽  
Source Area ◽  
Drainage Area ◽  
Moderate Intensity ◽  
Minor Role ◽  
Marine Deposits ◽  
Tectonically Active ◽  
Chemical Index Of Alteration ◽  
A Minor

AbstractDeep-marine muds were collected from two boreholes (Crati II and Neto VI) along the Ionian Calabrian Basin. The samples from the Crati II and the Neto VI boreholes show a similar mineralogical distribution; the marine muds contain mostly phyllosilicates, quartz, calcite, feldspars and dolomite. Traces of gypsum are present in a few samples. The Neto muds show higher concentrations of carbonates than the Crati muds; these contents are mainly related to recycling of the Neogene–Quaternary carbonate-rich marine deposits of the Crotone Basin, which mostly influences the composition of the Neto muds. The geochemical signatures of the muds mainly reflect a provenance characterized by felsic rocks with a minor, but not negligible, mafic supply. In particular, the hinterland composition of the Crati drainage area is on average more mafic in composition than the Neto drainage area. The higher mafic concentration of the Crati sample muds is probably related to the ophiolitiferous units that are exposed in the Crati drainage basin. The degree of source area weathering was most probably of low–moderate intensity because the Chemical Index of Alteration values for the studied muds range from 67 to 69. Furthermore, the low and constant Al/K and Rb/K ratios suggest low–moderate weathering without important fluctuations in weathering intensity. The Al2O3–TiO2–Zr ternary diagram and the values of the Index of Compositional Variability indicate that both the Neto and Crati muds are first-cycle, compositionally immature sediments, related to a tectonically active (collision) setting such as the Calabria–Peloritani Arc, where chemical weathering plays a minor role.

A combined petrographical—geochemical provenance study of the Newland Formation, Mid-Proterozoic of Montana

1992 ◽  
Vol 129 (2) ◽  
pp. 223-237 ◽  
Author(s):  
Jürgen Schieber
Keyword(s):  
Chemical Weathering ◽  
Source Area ◽  
Source Rocks ◽  
Arid Climate ◽  
Provenance Study ◽  
Rock Fragments ◽  
Crystalline Dolomite ◽  
Chemical Index Of Alteration ◽  
Granitoid Gneisses ◽  
Semi Arid

AbstractA provenance study was conducted on the Mid-Proterozoic Newland Formation, in which petrographical features of sandstones and geochemical characteristics of shales were integrated to arrive at an internally consistent interpretation.Sandstones of the Newland Formation are typically arkosic sands and arkoses with very-well-rounded quartz and feldspar grains and only minor amounts of extrabasinal rock fragments. The predominant feldspar types are K-spar and microcline, feldspar grains are smaller than quartz grains, and feldspars show little alteration due to weathering. Detrital modes of Newland sandstones (QFL diagrams) indicate that they were derived from a stable cratonic source. These petrographical features imply a source area dominated by granites and granitoid gneisses, semi-arid to arid climate, tectonic quiescence, and overall peneplain conditions.Shales of the Newland Formation are dominated by illite, quartz silt, and fine crystalline dolomite. They have small La/Th rations, relatively large Hf contents, and small contents of Cr, Co, and Ni, all indicative of derivation from crust of granitic composition. Small Tio2/Al2O3ratios also suggest source rocks of granitic composition. The average chemical index of alteration (CIA) for Newland shales is 71.8, which in light of the probable granitoid source indicates modest amounts of chemical weathering. Relatively large SiO2contents and large K2O/Na2O ratios reflect derivation from stable cratonic areas and tectonic quiescence.Thus, in general, the petrography of sandstones and geochemistry of shales provides the same provenance clues for the Newland Formation. One notable discrepancy between the two approaches is that the sandstones indicate an arid to semi-arid climate with very minor chemical weathering, whereas the CIA of the shales indicates at least modest amounts of chemical weathering. This indicates on one hand the need to better calibrate the CIA with a large variety of muds from modern climatic settings, and on the other hand the possibility that this discrepancy is due to transport segregation.

scholarly journals Paleoclimatologia dos Depósitos Continentais Cenozóicos da Bacia de Resende

1977 ◽  
Vol 1 ◽  
pp. 135-156
Author(s):  
Elmo Da Silva Amador
Keyword(s):  
Coastal Plain ◽  
Mineral Assemblage ◽  
Chemical Weathering ◽  
Ice Sheets ◽  
Source Area ◽  
Climatic Changes ◽  
Climatic Conditions ◽  
Dry Period ◽  
Controversial Subject ◽  
Structural Aspects

An examination of mineralogical data together with textural and structural aspects, from Cenozoic con tinental sediments of the Resende Basin, middle Paraiba river Valley (Rio de Janeiro, Brazil) provide some considerations about paleoclimatology in relation to deposition and source area. Based on predominance of the montmorillonite clay mineral group, unstable heavy mineral assemblage and fresh roudness feldspar contents in the deposits, the lower unit, Resende Formation, Miocene to Pliocene in age, is interpreted as deposited in semiarid climatic conditions. It is suggested that there has been a predominance of mechanical morphogenetic processes and a poor chemical weathering in the source area. The dry period recorded in the Resende Formation is related to the begginning of a extensive glaciation that covered the Antartic Continent with massive ice Sheets according to Jacobs (1974) and others and initiated prior to the late Miocene. On the other hand, the base of similar correlated formations in the brasilian coastal plain are presently found at 80 m. to 100 m. below sea level (Alexandra and Graxaim Formations). In Pliocene/Pleistocene boundary time the climate changed to a humidic type. The Fleistocene period shows great climatic instability and its interpretation is still a mather of dispute. According to Bigarella et al (1965 b) the pleistocenic sedimentary formations indicate an alternating climatic cycle caused mainly by periods of extreme climatic changes from humid to semiarid and from warm to cold. Other authors have considered such brazilian cenozoic sedimentations as related to humid climates (Almeida, 1965 and Wernick, 1966). It is not the purpose of this paper to settle all arguments on this controversial subject. Moreover, the present results of mineralogical data suggest that the Upper Formation (Floriano Fm) exhibited climatic conditions that probably changed between humid to semi-humid.

scholarly journals Provenance of sediments from Barra del Tordo and Tesoro beaches, Tamaulipas State, northwestern Gulf of Mexico

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Mayla A. Ramos-Vázquez ◽  
John S. Armstrong-Altrin
Keyword(s):  
Gulf Of Mexico ◽  
Age Groups ◽  
Source Area ◽  
Detrital Zircons ◽  
Sediment Provenance ◽  
Geochemical Composition ◽  
Chemical Index ◽  
Beach Sediments ◽  
Chemical Index Of Alteration ◽  
Ree Patterns

AbstractThe mineralogy, bulk sediment geochemical composition, and U–Pb ages of detrital zircons retrieved from the Barra del Tordo (Tordo) and Tesoro beach sediments in the northwestern Gulf of Mexico were analyzed to determine their provenance. The beach sediments are mainly composed of quartz, ilmenite, magnetite, titanite, zircon, and anorthite. The weathering proxies such as the Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), and Plagioclase Index of Alteration (PIA), reveal a moderate-to-high intensity of weathering in the source area. The chondrite-normalized rare earth element (REE) patterns are similar to felsic igneous rocks, with large negative europium anomaly (Eu/Eu* = ~ 0.47–0.80 and ~ 0.57–0.67 in the Tordo and Tesoro beach sediments, respectively).Three major zircon U–Pb age groups are identified in the Tordo and Tesoro beach sediments, i.e., Proterozoic (~ 2039–595 Ma), Mesozoic (~ 244–70.3 Ma), and Cenozoic (~ 65.9–1.2 Ma). The differences of the zircon age spectrum between the Tordo and Tesoro beach sediments are not significant. The comparison of zircon U–Pb ages in this study with ages of potential source terranes suggests that the Mesozoic and Cenozoic zircons of the studied Tordo and Tesoro beach sediments were derived from the Eastern Alkaline Province (EAP) and Mesa Central Province (MCP). Similarly, the likely sources for the Proterozoic zircons were the Sierra Madre Oriental (SMOr) and Oaxaquia in the northwestern Gulf of Mexico. The results of this study further indicate that the sediments delivered to the beaches by rivers and redistributed by longshore currents were crucial in determining the sediment provenance.

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