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.

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.

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.

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.

Tracking Late Quaternary ice sheet dynamics by multi-proxy detrital mineral U-Pb analysis: A case study from the Odyssea contourite, Ross Sea, Antarctica

2020 ◽  
Author(s):  
Roland Neofitu ◽  
Chris Mark ◽  
Michele Rebesco ◽  
Renata Giulia Lucchi ◽  
Nessim Douss ◽  
...  
Keyword(s):  
Ross Sea ◽  
Late Quaternary ◽  
Ice Sheet ◽  
Source Area ◽  
Coarse Sand ◽  
Turbidity Currents ◽  
Provenance Analysis ◽  
Geophysical Research ◽  
Antarctic Ice Sheet ◽  
Volcanic Material

<p>Late Quaternary Antarctic ice-sheet instability is recorded by ice-rafted debris (IRD) in mid- to high-latitude marine sediment, especially during marine isotope stages (MIS) 2-3, but drivers of this instability remain enigmatic (Labeyrie et al., 1986). A key step in resolving this puzzle is to determine the location of iceberg calving sites, thus highlighting ice sheet sectors exhibiting repeated instability. Single-grain U-Pb provenance analysis applied to clastic IRD provides a suitable high-resolution tool for this task, and also permits discrimination of continental IRD from volcanic material. The application of multiple proxies (apatite, rutile, and zircon) is critical in order to reduce source area fertility biases: for example, the near exclusive occurrence of zircon in felsic-intermediate igneous rocks (e.g., Hietpas et al., 2010).</p><p>Here, we present detrital apatite, zircon, and rutile U-Pb data from samples taken from a gravity core from the Odyssea contourite drift system, located on the margin of the Ross Sea (Rebesco et al., 2018) and deposited during MIS2-3. Contourites are marine clastic sediment deposits forming by along-slope, bottom currents reworking of fine-grained (clay-silt) sediments delivered by down-slope sedimentary processes (e.g. meltwaters, turbidity currents, debris flows). Crucially, contourite targetting eliminates the challenge of distinguishing IRD from coarse (sand-gravel) turbidite material in basin deposits, as ice-sheet instability is also associated with turbidite production at glaciated shelf margins (e.g., Bart et al., 1999).</p><p>We couple our analysis with the multi-proxy sediment analyses previously performed by Lucchi et al. (2019). We consider the implications of our data for the advance and retreat of the Antarctic Ice Sheet during MIS 2-3, and discuss the further applicability of our multi-proxy approach around Antarctica.</p><p>Bart, P.J, et al., 1999, Journal of Sedimentary Research, v. 69, p. 1276–1289, doi:10.2110/jsr.69.1276.</p><p>Hietpas, J, et al., 2010, Geology, v. 38, p. 167–170, doi:10.1130/G30265.1.</p><p>Lucchi, R.G, et al., 2019. EGU General Assembly 2019, Vienna April 7<sup>th</sup>–12<sup>th</sup>, Geophysical Research Abstracts Vol. 21, EGU2019-10409-1</p><p>Rebesco, M, et al., 2018, preliminary results, in POLAR 2018 SCAR/IASC Open Science Conference, v. GG2 Arctic, p. 14133.</p><p>Labeyrie, L, et al., 1986, Nature, v. 322, p. 701–706.</p>

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.

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.

scholarly journals Provenance Analysis and Structural Study of the Cycladic Blueschist Unit Rocks from Iraklia Island: From the Paleozoic Basement Unroofing to the Cenozoic Exhumation

2021 ◽  
Author(s):  
Sofia Laskari ◽  
Konstantinos Soukis ◽  
Stylianos Lozios ◽  
Daniel F. Stockli ◽  
Eirini M. Poulaki ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Detrital Zircon ◽  
Field Data ◽  
Late Triassic ◽  
Rift Basin ◽  
Provenance Analysis ◽  
Volcanic Material ◽  
Source Areas ◽  
High Pressure Metamorphism ◽  
Orogenic Events

Detailed mapping and structural observations on the Cycladic Blueschist Unit (CBU) of Iraklia island integrated by detrital zircon (DZ) U-Pb ages elucidate the Mesozoic pre-subduction evolution and the Cenozoic orogenic events. Field data reveal that the Iraklia tectonostratigraphy includes a heterogeneous Lower Schist Unit juxtaposed against a Variegated Marble Unit and an overlying Upper Schist Unit. The contact is an extensional ductile-to-brittle-ductile, top-to-N shear zone, associated with the Oligo-Miocene exhumation. The DZ spectrum of the Lower Schist Unit characterized by Gondwanan/peri-Gondwanan provenance signatures points to Late Triassic maximum depositional ages (MDAs). A quartz-rich schist layer yielded Precambrian DZ ages exclusively, considered part of the pre-Variscan metasedimentary Cycladic Basement, equivalent to those observed on Ios island. A significant change occurred during the deposition of the Upper Schist Unit, revealing Late Cretaceous MDAs and a high amount of Late Paleozoic DZ ages, attesting to more internal Pelagonian source areas. The imprint of Paleotethyan vs. Neotethyan geodynamic events is revealed in the DZ U-Pb ages record. The Triassic DZ input demonstrates eroded volcanic material related to the final Paleotethys closure and the Pindos/CBU rift basin opening. Late Cretaceous metamorphic/magmatic zircons and ~48-56 Ma zircon rims constrain the onset of subduction and high-pressure metamorphism.

scholarly journals An efficient semi-distributed hillslope erosion model for the subhumid Ethiopian Highlands

2013 ◽  
Vol 17 (3) ◽  
pp. 1051-1063 ◽  
Author(s):  
S. A. Tilahun ◽  
C. D. Guzman ◽  
A. D. Zegeye ◽  
T. A. Engda ◽  
A. S. Collick ◽  
...  
Keyword(s):  
Surface Runoff ◽  
Source Area ◽  
Sediment Concentration ◽  
Erosion Model ◽  
Ethiopian Highlands ◽  
Source Areas ◽  
Blue Nile Basin ◽  
Field Evidence ◽  
Sediment Loss ◽  
Main Variable

Abstract. Erosion modeling has been generally scaling up from plot scale but not based on landscape topographic position, which is a main variable in saturation excess runoff. In addition, predicting sediment loss in Africa has been hampered by using models developed in western countries and do not perform as well in the monsoon climate prevailing in most of the continent. The objective of this paper is to develop a simple erosion model that can be used in the Ethiopian Highlands in Africa. We base our sediment prediction on a simple distributed saturated excess hydrology model that predicts surface runoff from severely degraded lands and from bottom lands that become saturated during the rainy season and estimates interflow and baseflow from the remaining portions of the landscape. By developing an equation that relates surface runoff to sediment concentration generated from runoff source areas, assuming that baseflow and interflow are sediment-free, we were able to predict daily sediment concentrations from the Anjeni watershed with a Nash–Sutcliffe efficiency ranging from 0.64 to 0.78 using only two calibrated sediment parameters. Anjeni is a 113 ha watershed in the 17.4 million ha Blue Nile Basin in the Ethiopian Highlands. The discharge of the two watersheds was predicted with Nash–Sutcliffe efficiency values ranging from 0.80 to 0.93. The calibrated values in Anjeni for degraded (14%) and saturated (2%) runoff source area were in agreement with field evidence. The analysis suggests that identifying the runoff source areas and predicting the surface runoff correctly is an important step in predicting the sediment concentration.

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