Erosion: History

2020 ◽  
pp. 131-135
Author(s):  
Andrew S. Goudie
Keyword(s):  
Erosion History

scholarly journals Detrital zircon provenance of north Gondwana Palaeozoic sandstones from Saudi Arabia

2020 ◽  
pp. 1-17
Author(s):  
Guido Meinhold ◽  
Alexander Bassis ◽  
Matthias Hinderer ◽  
Anna Lewin ◽  
Jasper Berndt
Keyword(s):  
Saudi Arabia ◽  
Detrital Zircon ◽  
Detrital Zircons ◽  
Igneous Rocks ◽  
East African ◽  
Terrigenous Sediment ◽  
Erosion History ◽  
East African Orogen ◽  
North Gondwana ◽  
Ne Africa

Abstract We present the first comprehensive detrital zircon U–Pb age dataset from Palaeozoic sandstones of Saudi Arabia, which provides new insights into the erosion history of the East African Orogen and sediment recycling in northern Gondwana. Five main age populations are present in varying amounts in the zircon age spectra, with age peaks at ~625 Ma, ~775 Ma, ~980 Ma, ~1840 Ma and ~2480 Ma. Mainly igneous rocks of the Arabian–Nubian Shield are suggested to be the most prominent sources for the Ediacaran to middle Tonian zircon grains. Palaeoproterozoic and Archaean grains may be xenocrystic zircons or they have been recycled from older terrigenous sediment. A primary derivation from Palaeoproterozoic and Archaean basement is also possible, as rocks of such age occur in the vicinity. Approximately 4 % of the detrital zircons show Palaeozoic (340–541 Ma) ages. These grains are likely derived from Palaeozoic post-orogenic and anorogenic igneous rocks of NE Africa and Arabia. A few single grains gave up to Eoarchaean (3.6–4.0 Ga) ages, which are the oldest zircons yet described from Arabia and its vicinity. Their origin, however, is yet unknown. Detrital zircons with U–Pb ages of ~1.0 Ga are present in varying amounts in all of the samples and are a feature of terrigenous sediment belonging to the Gondwana super-fan system with an East African – Arabian zircon province.

scholarly journals Human impact and population dynamics in the Neolithic and Bronze Age: Multi-proxy evidence from north-western Central Europe

The Holocene ◽  
2019 ◽  
Vol 29 (10) ◽  
pp. 1596-1606 ◽  
Author(s):  
Ingo Feeser ◽  
Walter Dörfler ◽  
Jutta Kneisel ◽  
Martin Hinz ◽  
Stefan Dreibrodt
Keyword(s):  
Population Dynamics ◽  
Population Density ◽  
Bronze Age ◽  
Human Impact ◽  
Central Europe ◽  
Human Activity ◽  
Temporal Distribution ◽  
Relative Population ◽  
Erosion History ◽  
North Western

This paper aims at reconstructing the population dynamics during the Neolithic and Bronze Age, c. 4500–500 cal. BC, in north-western Central Europe. The approach is based on the assumption that increased population density is positively linked with human activity and human impact on the environment, respectively. Therefore, we use archaeological 14C dates and palaeoenvironmental data from northern Germany and south-western Denmark to construct and compare independent proxies of human activity. The latter involves relative quantification of human impact based on pollen analysis and soil erosion history inferred from summarizing of dated colluvial layers. Concurring patterns of changes in human activity are frequently recorded on a multi-centennial scale. Whereas such multi-proxy patterns are interpreted to indicate relative population changes, divergent patterns are discussed in the context of proxy-related uncertainties and potential biases. Patterns of temporal distribution of increasing and decreasing human activity are understood as ‘boom and bust’ phases in population density/size. Based on the comparison of the three proxies, we identify five phases of growing (boom) and four phases of decreasing (bust) population. The boom phases date to ca. 4000–3500, 3000–2900, 2200–2100, 1450–1300 and 1000–750 cal. BC. The bust phases to ca. 3200–3000, 2400–2300, 1650–1500 and 1200–1100 cal. BC.

scholarly journals Using topographic map interpretation methods to determine Tookany (Tacony) Creek erosion history upstream from Philadelphia, Pennsylvania, USA

2016 ◽  
Vol 8 (4) ◽  
pp. 30
Author(s):  
Eric Clausen
Keyword(s):  
Drainage Basin ◽  
Walking Distance ◽  
Deep South ◽  
Topographic Map ◽  
Map Interpretation ◽  
Narrow Valley ◽  
Erosion History ◽  
Schuylkill River ◽  
Relationship Of ◽  
Flood Flow

Topographic map interpretation methods are used to determine erosional landform origins in and adjacent to the Tookany (Tacony) Creek drainage basin, located upstream from and adjacent to Philadelphia, PA. Five wind gaps notched into the Tookany-Wissahickon Creek drainage divide (which is also the Delaware-Schuylkill River drainage divide), a deep through valley crossing the Tookany-Pennypack Creek drainage divide, a Tookany Creek elbow of capture, orientations of Tookany Creek tributary valleys, a narrow valley carved in erosion resistant metamorphic bedrock, and the relationship of a major Tookany Creek direction change with a Pennypack Creek elbow of capture and a Pennypack Creek barbed tributary are used along with other evidence to reconstruct how a deep south oriented Tookany Creek valley eroded headward across massive southwest oriented flood flow. The flood flow origin cannot be determined from Tookany Creek drainage basin evidence, but may have been derived from a melting continental ice sheet, and originally flowed across the Tookany Creek drainage basin region on a low gradient topographic surface equivalent in elevation to or higher than the highest present day Tookany Creek drainage divide elevations with the water flowing in a complex of shallow diverging and converging channels that had formed by scouring of less resistant bedrock units and zones. William Morris Davis, sometimes referred to as the father of North American geomorphology, spent much of his boyhood and several years as a young man living in the Tookany Creek drainage basin and all landforms discussed here were within walking distance of his home and can be identified on a topographic map published while he was developing and promoting his erosion cycle ideas. Davis never published about Tookany Creek drainage basin erosion history, but he developed and promoted uniformitarian and erosion cycle models that failed to recognize the significance of Tookany Creek drainage basin erosional landform features providing evidence of the immense floods that once crossed present day drainage divides and eroded the Tookany Creek drainage basin.

scholarly journals Cenozoic lateritic weathering and erosion history of Peninsular India from 40Ar/39Ar dating of supergene K–Mn oxides

2016 ◽  
Vol 446 ◽  
pp. 33-53 ◽  
Author(s):  
Nicolas J. Bonnet ◽  
Anicet Beauvais ◽  
Nicolas Arnaud ◽  
Dominique Chardon ◽  
Mudlappa Jayananda
Keyword(s):  
Peninsular India ◽  
Erosion History ◽  
History Of ◽  
Mn Oxides

Discussing the dating of ferruginous duricrusts: promises from mineralogy of supergene minerals with non-destructive microsampling

2020 ◽  
Author(s):  
Karina Marques ◽  
Thierry Allard ◽  
Guillaume Morin ◽  
Benoît Baptiste ◽  
Cécile Gautheron ◽  
...  
Keyword(s):  
Mineralogical Composition ◽  
Alluvial Fan ◽  
Secondary Minerals ◽  
Origin And Evolution ◽  
Late Neogene ◽  
Erosion History ◽  
Powder Samples ◽  
History Of ◽  
Different Populations ◽  
Fine Resolution

<p>Ferruginous duricrusts record a part of the Earth’s geodynamical and climatic history in tropical area, because they can be formed over a wide geologic period. However, the events and processes related to their formation, transformation and distribution are still obscure. This is mainly due to the complexity arising from their finely divided and polycrystalline nature together with the coexistence of various generations of supergene minerals, such as iron and aluminum oxides, oxyhydroxides or hydroxides (e.g. goethite, hematite and gibbsite) and kaolinite, even at microscopic scale. Classical mineralogical investigations are often realized using powders samples, which hinders subsequent analyses on the same sample, such as SEM or (U-Th)/He dating. Thus, the aim of this study was to propose a new way to investigate the mineralogy of supergene ferruginous samples on micrometric grains that will be analyzed by (U-Th)/He dating method. Prior to this analysis, we first compare the X-ray diffraction data of grains and small amounts of powders looking to reveal the mineralogical composition of populations of secondary minerals of a ferruginous duricrust by taking into account the heterogeneity of the material. Samples were collected from a ferruginous duricrust with pisolitic structure developed over epiclastic conglomerates and sandstones deposited by alluvial fan and fluvial streams from the Upper Cretaceous at the western Minas Gerais state (Brazil). The geomorphology of the study area is delineated by remnants of paleosurface (up to 1,000 m a.s.l.), which comprises an important record of long-term Brazilian continental history.Macroscopic facies recognized on duricrusts sections were described, which allowed the identification of various populations of secondary minerals. After this detailed description, grains (size < 0.5 mm) were collected and powder samples of each population were prepared by crushing. Overall, the results point out that the grain and powder samples could be used to identify mineralogical composition at fine resolution of secondary minerals from ferruginous duricrusts. In addition, XRD results are similar for both types of sample preparation, however the < 0.5 mm grain samples are more advantageous because they are not destructive and thus allow to get a finer description of the mineralogy of different populations and can subsequently be used for e.g. (U-Th)/He dating, providing critical information for interpreting and discussing the ages of iron oxides.</p><p><strong>Grant:</strong> 19/10708-7; 17/22292-4; 17/20788-2, São Paulo Research Foundation (FAPESP)</p><p><strong>References</strong></p><p>Allard, T., Gautheron, C., Riffel, S.B., Balan, E., Soares, B.F., Pinna-Jamme, R., Derycke, A., Morin G., Bueno, G.T., Nascimento, N., 2018. Combined dating of goethites and kaolinites from ferruginous duricrusts. Deciphering the Late Neogene erosion history of Central Amazonia. Chemical Geology 479, 136-150.</p><p>Monteiro, H.S., Vasconcelos, P.M.P., Farley, K.A., Spier, C.A., Mello, C.L., 2014. (U-Th)/He geochronology of goethite and the origin and evolution of cangas. Geochim. Cosmochim. Acta  131, 267–289.</p><p>Vasconcelos, P.M., Heim, J.A., Farley, K.A., Monteiro, H.S., Waltenberg, K., 2013. <sup>40</sup>Ar/<sup>39</sup>Ar and (U–Th)/He - <sup>4</sup>He/<sup>3</sup>He geochronology of landscape evolution and channel irondeposit genesis at LynnPeak, Western, Australia. Geochim. Cosmochim. Acta 117, 283-312.</p>

The erosion history of the Central Alps: evidence from zircon fission track data of the foreland basin sediments

Terra Nova ◽  
2000 ◽  
Vol 12 (4) ◽  
pp. 163-170 ◽  
Author(s):  
C. Spiegel ◽  
J. Kuhlemann ◽  
I. Dunkl ◽  
W. Frisch ◽  
H. von Eynatten ◽  
...  
Keyword(s):  
Fission Track ◽  
Foreland Basin ◽  
Central Alps ◽  
Zircon Fission Track ◽  
Erosion History ◽  
History Of

The Nomenclature of Lower Carboniferous “Reef” Limestones in the North of England

1950 ◽  
Vol 87 (4) ◽  
pp. 267-278 ◽  
Author(s):  
Geoffrey Bond
Keyword(s):  
Lower Carboniferous ◽  
The North ◽  
Erosion History

AbstractVarious ways in which Lower Carboniferous reef limestones have accumulated are described, and terms defining them are introduced. Regional sedimentation, lithology, structure, fauna, and erosion history are kept separate in the discussion. The reef limestones of Northern England are briefly reviewed in the light of this classification.

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