Heavy Minerals and the Evolution of the Modern Nile

1976 ◽  
Vol 6 (3) ◽  
pp. 425-444 ◽  
Author(s):  
Fekri A. Hassan
Keyword(s):  
East Africa ◽  
Early Stage ◽  
Heavy Minerals ◽  
Middle Pleistocene ◽  
Mineral Analysis ◽  
Nile Basin ◽  
East African ◽  
System A ◽  
Ethiopian Plateau ◽  
Heavy Mineral Analysis

Heavy mineral analysis is a useful tool in tracing the changes in the hydrographic setting of the Nile through time. Analyses by the writer and others are presented to differentiate between a former Nilotic system, a Proto-Nile, and the modern Nile system, and to demonstrate the changes undergone by the modern Nile.The Proto-Nile was almost totally dependent upon discharge from equatorial and sub-equatorial tributaries in East Africa and from local Sudano-Egyptian affluents. The modern Nile system, in contrast, is dominated by contributions from the Blue Nile and the Atbara River, which drain the Ethiopian Plateau. The discharge of these rivers is governed by the monsoonal rains which are responsible for the summer floods in the Lower Nile Basin. It has been generally believed that this riverine system is very recent, perhaps not much older than 20,000 years. The evidence presented in this paper indicates that the Modern Nile system was well established by the later part of the Middle Pleistocene. In its early stage, the modern Nile was characterized by greater contributions from the non-Ethiopian East African and Sudano-Egyptian tributaries than at present.

scholarly journals Heavy-mineral analysis in Polish investigations of Quaternary deposits: a review

Geologos ◽  
2013 ◽  
Vol 19 (1-2) ◽  
pp. 5-23 ◽  
Author(s):  
Bogusław Marcinkowski ◽  
Elżbieta Mycielska-Dowgiałło
Keyword(s):  
Chemical Weathering ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Mineral Analysis ◽  
Quaternary Deposits ◽  
Mineral Research ◽  
Distinctive Features ◽  
Depositional Processes ◽  
Stratigraphic Position ◽  
Heavy Mineral Analysis

Abstract The composition of heavy-mineral assemblages is one of the main textural features of sediments because they can have significant value for the interpretation of, among others, their depositional environment, their depositional processes, and their stratigraphic position. Distinctive features of heavy minerals include their resistance to chemical weathering and mechanical abrasion, their habit, and their density. These parameters are the most widely used in the heavy-mineral research of Quaternary deposits in Poland, as well as in such research in other countries conducted by Polish scientists. Several other heavy-mineral parameters can also be used in various types of interpretation. It is discussed whether heavy-mineral analysis is decisive in the evaluation of deposits or whether it plays mainly a role that may support evidence obtained by other types of analysis. The attention is mainly devoted to transparent heavy minerals; the significance of opaque heavy minerals for interpretational purposes is only mentioned.

scholarly journals Micro-Raman—A Tool for the Heavy Mineral Analysis of Gold Placer-Type Deposits (Pianu Valley, Romania)

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 988
Author(s):  
Andreea Elena Maftei ◽  
Andrei Buzatu ◽  
Gheorghe Damian ◽  
Nicolae Buzgar ◽  
Harald G. Dill ◽  
...  
Keyword(s):  
Ionic Radius ◽  
Fine Tuning ◽  
Heavy Minerals ◽  
Solid Solution Series ◽  
Mineral Analysis ◽  
Gold Placer ◽  
Low Frequencies ◽  
Micro Raman Spectroscopy ◽  
Placer Deposits ◽  
Heavy Mineral Analysis

In the current study, different heavy minerals typical of gold placer deposits were identified by means of micro-Raman spectroscopy, and their chemical composition analyzed and discussed (garnet, kyanite, staurolite, zircon, allanite, monazite, xenotime, rutile, anatase, cassiterite, titanite, barite). Even complex solid solution series, such as those of garnets, can be deciphered with the aid of systematic trends observed in Raman line frequencies. The ν1 mode in garnets will shift from high to low frequencies as a function of the ionic radius of the X2+ cation, from Mg2+, to Fe2+ and Mn2+, while the presence of Ca2+ will make the band to be shifted strongly to even lower wavenumbers. This approach has successfully been taken to differentiate between polymorph triplets such as kyanite-sillimanite-andalusite and rutile-anatase-brookite. Minerals under consideration with high contents of REE, U and Th are affected by intensive metamictization, particularly zircon and titanite. Raman peak features, such as shape, symmetry and intensity, respond to this radiation damage of the lattice and enable fine-tuning of these heavy minerals, such as in the case of fluorite (fetid fluorite).

Heavy minerals as a guide to turbidite provenance in the Lower Palaeozoic Southern Welsh Basin: a pilot study

1992 ◽  
Vol 129 (5) ◽  
pp. 573-580 ◽  
Author(s):  
A. C. Morton ◽  
J. R. Davies ◽  
R. A. Waters
Keyword(s):  
Pilot Study ◽  
Heavy Mineral ◽  
The Other ◽  
Heavy Minerals ◽  
Mineral Analysis ◽  
Source Areas ◽  
Southern Area ◽  
Distinct Source ◽  
Lower Palaeozoic ◽  
Heavy Mineral Analysis

AbstractA pilot study has demonstrated that heavy mineral analysis is a useful guide to the provenance of Silurian turbidites in the Southern Welsh Basin. The results confirm the sedimentological evidence for two distinct source areas of coarse clastic detritus, one lying to the south and the other to the east. They also provide mineralogical criteria by which the two source areas may be distinguished. The southern area provided material with relatively low mineral diversity, and is characteristic in having low rutile/zircon ratios, whereas the eastern source provided more diverse assemblages, generally with high rutile/zircon ratios. The southern source shows variations in terms of apatite/tourmaline ratio, with the older Aberystwyth Grits Group tending to contain relatively low apatite compared with the younger Cwmystwyth Grits Group (Rhuddnant and Pysgotwr Grits formations). There is evidence for polycyclic material and volcanic detritus in both southerly and easterly derived samples; however, easterly-sourced sandstones apparently tapped a more lithologically-diverse terrain.

scholarly journals KETERKAITAN UNSUR TANAH JARANG TERHADAP MINERAL BERAT ILMENIT DAN RUTIL PERAIRAN PANTAI GUNDI, BANGKA BARAT

2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Noor C.D. Aryanto ◽  
Joni Widodo ◽  
Purnomo Raharjo
Keyword(s):  
Inductively Coupled Plasma ◽  
The Other ◽  
Source Rocks ◽  
Heavy Minerals ◽  
Mineral Analysis ◽  
Element Analysis ◽  
Rare Element ◽  
Sediment Samples ◽  
Inductively Coupled ◽  
Heavy Mineral Analysis

Berdasarkan hasil analisa unsur terhadap 7 contoh sedimen permukaan dasar laut di Perairan Pantai Gundi, Bangka Barat, yang kemudian dianalisa dengan menggunakan metode Inductively Coupled Plasma (ICP) dapat diketahui konsentrasi kandungan unsur Niobium (Nb) dan unsur Tantalum (Ta). Selain itu dilakukan pula analisa mineral berat dengan menggunakan larutan pemisah bromoform (BJ 2,83) terhadap 15 contoh. Konsentrasi kandungan unsur jarang seperti Niobium dapat mencerminkan keberadaan mineral berat ekonomis, yaitu mineral berat yang resisten terhadap pelapukan dan mengandung unsur Titanium (Ti), seperti mineral Ilmenit (FeTiO3) dan rutil (TiO2). Juga dapat dibuktikan, di daerah selidikan bahwa keberadaan unsur Niobium dan Tantalum di alam hampir dapat dipastikan selalu berasosiasi. Di daerah selidikan asosiasi ini berupa mineral columbite-tantalite (Fe,Mn)Nb2O6-(Fe,Mn)Ta2O6 dan pyrochlore (Na, Ca, Ce…)2 Nb2O6F. Selain itu masih dengan memperhatikan asosiasi kedua unsur ini dapat diketahui pula asal batuan sumber dari sedimen-sedimen dimana mineral tersebut terakumulasi, karena asosiasi antara unsur Niobium dan Tantalum merupakan penciri untuk daerah pegmatis. Based on element analysis of 7 surface sediment samples from Gundi Waters, Western Bangka by using Inductively Coupled Plasm (ICP), the content of rare element Niobium (Nb) and Tantalum (Ta) can be identified. On the other hand heavy mineral analysis with float-sink method using bromoform as separator liquid has been applied for 15 samples. Based on observations the concentration of Niobium (Nb) element reflects the present of heavy minerals consisted of Titanium (Ti) element, such as Ilmenit (FeTiO2) and Rutil (TiO2). It is can also be proved that in the investigated area Niobium (Nb) and Tantalum (Ta) elements are occure in association. In the study area, this association shows as columbite-tantalite (Fe,Mn)Nb2O6-(Fe,Mn)Ta2O6 and pyrochlore (Na, Ca, Ce…)2 Nb2O6F minerals. Moreover, based on this association, it can be recognized the source rocks of the sediment where the minerals accumulate as association of these two elements are specific for pegmatic area.

Application de la methode des mineraux lourds a quelques problemes morphologiques des Abruzzes adriatiques

1962 ◽  
Vol S7-IV (2) ◽  
pp. 264-272 ◽  
Author(s):  
Jean Demangeot ◽  
M. Ters
Keyword(s):  
Marine Sediments ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Mineral Analysis ◽  
Quaternary Deposits ◽  
Central Apennines ◽  
Heavy Mineral Analysis

Abstract Heavy mineral analysis of samples from the Adriatic side of the Abruzzi mountains gives an indication of the age of the surface of the Gran Sasso plateaus and of the Quaternary continental formations. The absence of heavy minerals characteristic of the Pontian molasse suggests the possibility that the plateaus were never completely covered by the Pontian sea. The isolated molasse deposits which have been reported from the Gran Sasso may have been deposited in small gulfs along the shore of the sea. The Quaternary marine sediments have been dated by their fossil content. The majority of the Quaternary deposits, however, are gravels, breccias and eolian loams which contain neither fossils nor pollen. Cinder showers from Quaternary eruptions on the Tyrrhenian side of Abruzzi were carried by the wind and deposited volcanic minerals which were incorporated in the Quaternary material of the central Apennines. Heavy mineral analysis of the deposits containing these minerals reveals associations which provide a basis for determining the chronology of the Quaternary strata.

scholarly journals Geothermal Energy Development in East Africa: Barriers and Strategies

2018 ◽  
pp. 1-6 ◽  
Author(s):  
Emmanuel Yeri Kombe ◽  
Joseph Muguthu
Keyword(s):  
East Africa ◽  
Geothermal Energy ◽  
Electricity Generation ◽  
Early Stage ◽  
East African ◽  
African Countries ◽  
Geothermal Resources ◽  
Resource Potential ◽  
Geothermal Potential ◽  
African Rift

The East African Rift is among the most crucial regions of the world endowed with a remarkable geothermal potential. Using current technologies, East African countries have a geothermal power potential of more than 15,000 MWe. Nevertheless, the zone is still at an early stage of geothermal development with few plants producing a few hundred MWe. Among East African countries that have carried out research on geothermal resources, Kenya is leading in utilising geothermal energy resources for electricity generation. Eritrea, Uganda, Tanzania and Djibouti are at exploration stage while Malawi and Rwanda have so far not gone past geothermal resource potential record work. This study sought to address the challenges and barriers to the adoption of geothermal energy as well as the strategies to implement geothermal energy plans in East Africa.

scholarly journals Terrestrial kaolin deposits trapped in Miocene karstic sinkholes on planation surface remnants, Transdanubian Range, Pannonian Basin (Hungary)

2020 ◽  
pp. 1-10
Author(s):  
Péter Kelemen ◽  
Gábor Csillag ◽  
István Dunkl ◽  
Andrea Mindszenty ◽  
Ivett Kovács ◽  
...  
Keyword(s):  
Pannonian Basin ◽  
Heavy Minerals ◽  
Burial History ◽  
Mineral Analysis ◽  
Planation Surface ◽  
X Ray ◽  
History Of ◽  
Transdanubian Range ◽  
Heavy Mineral Analysis ◽  
Local Block

Abstract In the Transdanubian Range, Pannonian Basin, Hungary, karstic sinkholes on a planation surface of Triassic carbonates are filled by grey clayey–silty kaolin deposits. The provenance and accumulation age of these strongly altered terrestrial karst-filling sediments are constrained by X-ray powder diffraction, heavy mineral analysis and zircon U–Pb dating. The heavy minerals of the Southern Bakony Mountains samples are dominated by the ultra-stable zircon–rutile–tourmaline association. Zircon U–Pb data indicate accumulation between 20 and 16 Ma. Furthermore, Archaean to Palaeogene grains were also determined, reflecting the principally fluvial recycling of Eocene bauxites and their cover sequences. In contrast, the sample from the Keszthely Hills consists almost exclusively of airborne material including zircons of 18–14 Ma, reflecting a dominant contribution from the Carpathian–Pannonian Neogene volcanism. The shift in the Miocene age components is inferred to have been caused by the landscape evolution and burial history of the planation surface remnants controlled by local block tectonics.

scholarly journals Semi-Automated Heavy-Mineral Analysis by Raman Spectroscopy

Minerals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 385 ◽  
Author(s):  
Lünsdorf ◽  
Kalies ◽  
Ahlers ◽  
Dunkl ◽  
von Eynatten
Keyword(s):  
Raman Spectroscopy ◽  
Lower Triassic ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Mineral Analysis ◽  
Sedimentary Provenance ◽  
Precise Tool ◽  
Mineral Data ◽  
Heavy Mineral Analysis ◽  
Spatial Referencing

A significant amount of information on sedimentary provenance is encoded in the heavy minerals of a sediment or sedimentary rock. This information is commonly assessed by optically determining the heavy-mineral assemblage, potentially followed by geochemical and/or geochronological analysis of specific heavy minerals. The proposed method of semi-automated heavy-mineral analysis by Raman spectroscopy (Raman-HMA) aims to combine the objective mineral identification capabilities of Raman spectroscopy with high-resolution geochemical techniques applied to single grains. The Raman-HMA method is an efficient and precise tool that significantly improves the comparability of heavy-mineral data with respect to both overall assemblages and individual compositions within solid solution series. Furthermore, the efficiency of subsequent analysis is increased due to identification and spatial referencing of the heavy minerals in the sample slide. The method is tested on modern sediments of the Fulda river (central Germany) draining two Miocene volcanic sources (Vogelsberg, Rhön) resting on top of Lower Triassic siliciclastic sediments. The downstream evolution of the volcanic detritus is documented and the capability to analyze silt-sized grains has revealed an additional eolian source. This capability also poses the possibility of systematically assessing the heavy-mineral assemblages of shales, which are often disregarded in sedimentary provenance studies.

scholarly journals Prospects and limitations of heavy mineral analyses to discriminate preglacial/glacial transitions in Pleistocene sedimentary successions

Geologos ◽  
2018 ◽  
Vol 24 (2) ◽  
pp. 151-162
Author(s):  
Tomasz Zieliński
Keyword(s):  
Geological Structure ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Early Pleistocene ◽  
Middle Pleistocene ◽  
Mineral Associations ◽  
Scandinavian Ice Sheet ◽  
Middle Pleistocene Transition ◽  
The Baltic ◽  
Heavy Mineral Analysis

Abstract The present study revolves around the identification of the stratigraphical boundary between Pleistocene formations that formed prior to the first advance of the Scandinavian ice sheet (Early Pleistocene, i.e., the so-called preglacial) and the overlying, glacially derived deposits (Middle Pleistocene). In particular, it focuses on variation in heavy mineral assemblages, which are an important tool for stratigraphers. The Neogene basement, described here, was most often the source of material that was redeposited by Early Pleistocene rivers. The geological structure and Early Pleistocene palaeogeographical scenarios for various Polish regions are discussed. Moreover, comparisons with other European preglacial formations are carried out. The mineral spectrum of Lower Pleistocene deposits is largely dependent of rocks of the Neogene and Mesozoic basement. If the incision of ancient catchments was into terrigenous rocks, the stratigraphical boundary between preglacial and glacial formations is easily determined with the help of a heavy mineral analysis. As a rule, this coincides with a noticeable change from resistant to non-resistant mineral associations. Such cases are noted for successions in central Poland and eastern England. On the other hand, outcrops of igneous or metamorphic rocks exist within preglacial river catchments in most parts of Europe. They were the local sources of non-resistant heavy minerals long before their glacial supply from the Baltic Shield. In these cases, mineralogical analysis fails in the search for the Early/Middle Pleistocene transition.

scholarly journals Stratigraphic discriminatory potential of heavy mineral analysis for the Neogene sediments of Belgium

2020 ◽  
Vol 23 (3-4) ◽  
Author(s):  
Jasper VERHAEGEN
Keyword(s):  
Mineral Composition ◽  
Visual Inspection ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Mineral Analysis ◽  
The West ◽  
Neogene Sediments ◽  
Heavy Mineral Analysis

The Neogene units of Belgium cannot always be easily distinguished based on visual inspection and correlation across the basin is not straightforward. To aid in the stratigraphic interpretation of units, the discriminatory potential of heavy minerals has been determined. In this study, heavy mineral composition is combined with grain size analysis, providing information on the bulk sediment. Based on heavy mineral composition important interpretations could be made, such as (1) a different provenance between the Dessel Member and the Hageland Diest sand, making it improbable that they were deposited at the same time, (2) the Kasterlee-sensu-Gulinck unit of the eastern Antwerp Campine should be redefined as a lower Mol Formation unit or as a lateral equivalent of the typical Kasterlee Formation to the west, affected strongly by southern continental sediment input, and (3) the Waubach Member in the Ruhr Valley Graben should be split into two separate units, with the upper unit correlated with the Mol Formation and the lower unit, possibly the Inden Formation, correlated with the Diest Formation and Kasterlee Formation. The ‘X’ unit of the Maaseik core is likely a local transitional unit which cannot be directly correlated with a unit in the Campine Basin.

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