scholarly journals Stream sediment sampling in the Atâ area, central West Greenland

1988 ◽  
Vol 140 ◽  
pp. 24-26
Author(s):  
P.W.U Appel ◽  
C Knudsen
Keyword(s):  
Close Correlation ◽  
Stream Sediments ◽  
Stream Sediment ◽  
Amphibolite Facies ◽  
Gold Content ◽  
Sediment Samples ◽  
Sediment Sampling ◽  
Gneiss Granite ◽  
Field Season ◽  
Granite Complex

In 1982 scheelite was identified in stream sediments in the: Nuuk/Godthåb area, about 600 km south of Atâ. Subsequentlya regional stream-sediment programme was carried out in the Nuuk area from 1982 to 1987 as a result of which scheelite was found to be quite abundant in the 3800 m.y. old Isukasia supracrustalrocks as well as in the 3300 to 3000 m.y. old Malene supracrustal sequence (Appel, 1988). It was also recognised that there is a close correlation between the number of scheelite grains and the gold content of the heavy mineral concentrates in the Nuuk area (Appel, 1988). In the Ata area (fig. 1) extensive outcrops of supracrustal rocks are found. In these supracrustals, which have been metamorphosed to greenschist and amphibolite facies, abundant sulphide-rich horizons are found, as well as sulphide-bearing breccia zones with appreciable gold contents (Knudsen et al., 1988). During the 1987 field season geological reconnaissance mapping was carried out in two of the supracrustal areas and the gneiss-granite complex enclosing the supracrustal rocks ·was investigated (Knudsen et al., 1988). A limited programme of stream-sediment sampling was carried out in the Atâ area, where stream sediment samples were collected in all the main streams draining the supracrustal rocks.

scholarly journals Granulometry, heavy mineral and geochemical studies of stream sediments around Bula, Dass District, Northeast Nigeria

2020 ◽  
Vol 18 ◽  
pp. 63-73
Author(s):  
C. I. Adamu ◽  
E.E. Okon ◽  
D.O. Inyang
Keyword(s):  
Trace Elements ◽  
Stream Sediments ◽  
Stream Sediment ◽  
Heavy Mineral ◽  
Geochemical Data ◽  
Provenance Analysis ◽  
Sediment Samples ◽  
Granulometric Analysis ◽  
Elemental Analyses ◽  
Geochemical Studies

Active stream sediments generally consist of broken-down fragments of pre-existing rocks by the action of river (stream) flow. This makes them target materials for routine geochemical surveys and provenance analysis. Fifteen (15) stream sediment samples were collected in some parts of Bula and its environs, northeastern Nigeria, in order to determine their textural characteristics, heavy mineral and elemental composition. The sediments were subjected to granulometric, heavy mineral and elemental analyses. The result of granulometric analysis show that the streamsediments are poorly to moderately well sorted, very platykurtic to leptokurtic, fine to medium grained and positively skewed. Zircon, rutile and tourmaline are the dominant heavy mineral species occurring in the sediments. The computed Zircon-Tourmaline-Rutile (ZTR) index values for the samples range from 59.18 - 83.53, indicating mineralogical maturity. The geochemical data of the stream sediment samples show that the mean contents of the trace elements [Ti (0.73 ± 0.74%), Fe (0.39±0.19%), Cr (816±639ppm), Ni (258±108ppm), Pb (48±12.37ppm) and Zn (502±126ppm)] were higher than their respective average crustal values except for Fe. Computed threshold values indicate possible mineralization containing Fe and Ti. The elements have variable spatial distribution. The study shows that the trace elements composition of the stream sediments is majorly lithogenic. Because mineralization in rocks and sediments are often characterized by considerable variation in their trace elements contents, the metal concentrations in these sediments are large enough for Ilmenite and Rutile mineralization to be suspected within the study area.

scholarly journals Stratabound scheelite and stratiform tourmalinites in the Archaean Malene supracrustal rocks, southern West Greenland

1987 ◽  
Vol 156 ◽  
pp. 1-26
Author(s):  
P.W.U Appel ◽  
A.A Garde
Keyword(s):  
West Coast ◽  
Stream Sediment ◽  
Amphibolite Facies ◽  
The West ◽  
Late Archaean ◽  
Sea Floor ◽  
West Greenland ◽  
Sediment Sampling ◽  
Geological Map ◽  
Boron Complexes

The Malene supracrustal rocks form large enclaves in the late Archaean Nûk gneisses within an area of at least 36 000 km2 on the west coast of Greenland and have been repeatedly deformed and metamorphosed under amphibolite facies conditions. Stream sediment sampling has shown that scheelite occurs in the supracrustal enclaves throughout the area. It occurs stratabound in amphibolites, micaceous quartzites, siliceous cordierite-bearing metasediments and tourmalinites. A detailed geological map has been made of the central part of Store Malene mountain close to Nuuk. Banded metavolcanic Malene amphibolites and siliceous cordierite-bearing metasediments contain stratiform tourmalinites, often with appreciable scheelite, in addition to common accessory tourmaline. The tourmaiinites predate the earliest recognisable phase of deformation as well as prominent simple pegmatites. The tourmaline probably originated as primary sea floor precipitates, and the primary or diagenetic tourmaline crystals were later overgrown with tourmaline during metamorphism. The scheelite and tourmaline are probably syngenetic and of submarine exhalative origin, and boron complexes may have played a role in transporting tungsten in hot brines.

scholarly journals Scheelite in Malene supracrustals of the Ivisârtoq area, southern West Greenland

1988 ◽  
Vol 140 ◽  
pp. 57-58
Author(s):  
P.W.U Appel
Keyword(s):  
Ultra Violet ◽  
Field Work ◽  
Stream Sediments ◽  
Stream Sediment ◽  
Ultra Violet Light ◽  
Violet Light ◽  
Field Season ◽  
Sampling Programme ◽  
Snow Precipitation

In 1982 the first traces of scheelite were found in the Godthåbsfjord area in heavy mineral concentrates from stream sediments. The same year the first in situ scheelite occurrences were found. In the folIowing year a stream-sediment sampling programme was carried out in the area and in the area to the south. This programme demonstrated that scheelite is a frequent constituent of the 3800 m.y. old Isua supracrustal rocks and in the 3300 to 3000 m.y. old Malene supracrustals, whereas the gneisses in the Nuuk/Godthåb area are barren. The Malene supracrustal rocks, which form extensive outcrops, are the larger of the two supracrustal belts, and outcrops are found scattered over an area of at least 35000 km2. During the field season of 1986 stream sediment samples were collected in the Ivisârtoq area of the inner Godthåbsfjord region, and they proved to contain high amounts of scheelite. It was thus decided to carry out field work with ultra-violet light, but early snow precipitation prevented any field work. During the field season the folIowing year, another attempt was made to carry out field work with ultra-violet light in the lvisârtoq area.

scholarly journals Bjørnesund Project, West Greenland

1992 ◽  
Vol 155 ◽  
pp. 24-27
Author(s):  
P.W.U Appel
Keyword(s):  
Hydrothermal Alteration ◽  
Late Stage ◽  
Mineral Resources ◽  
Stream Sediments ◽  
Stream Sediment ◽  
Heavy Mineral ◽  
Mineral Deposits ◽  
Mineral Potential ◽  
Sediment Sampling ◽  
Sampling Programme

The Bjørnesund Project is aimed at an evaluation of the mineral potential of the southernmost part of the municipality of Nuuk, between Bjørnesund and the large glacier Frederikshåb Isblink. One of the reasons that economic mineral deposits were expected to occur in the Bjørnesund area, was the presence of gold anomalies in heavy mineral concentrates from stream sediments (Appel, 1989). Another reason was the presence of anthophyllite-rich zones, presumed to have formed by hydrothermal alteration. At a fairly late stage in the planning of the field programme, the project was enlarged to include a regional geochemical stream sediment sampling programme in the area between 64°N and Bjørnesund. This latter part of the project was financed by a separate contribution from the Mineral Resources Administration, Ministry of Energy.

scholarly journals Chemical and Statistical Studies on Water and Stream Sediments Around the Coal Mine Area in Dazhu, China

2021 ◽  
Author(s):  
Dongping Deng ◽  
Yong Wu ◽  
Bangzheng Ren ◽  
Heng Yin
Keyword(s):  
Coal Mine ◽  
Mine Drainage ◽  
Principal Component ◽  
Stream Sediments ◽  
Stream Sediment ◽  
World Health ◽  
Mine Area ◽  
Sediment Samples ◽  
Study Results ◽  
Mine Pollution

Abstract Coal mine pollution has become one of the most serious environmental problems in China and elsewhere. Water, in the form of groundwater and streams, as well as stream sediment samples, were collected from the coal mine area in Dazhu, Southwestern China. Different analyses, including the hydro-geochemical, multivariate analyses and X-ray analyses, were conducted to examine the coal mine pollution effect. The study results show that the groundwater and stream samples are slightly acidic to alkaline with pH values of 6.36 to 7.17 and 6.51 to 7.39, respectively. With the dissolution of carbonate and sulfate, a large amount of Ca2+, Mg2+, and SO42- is found in the groundwater and stream samples, which is higher than the environmental background value. Typically, the water samples are dominated by Ca2++Mg2+-HCO3- and Ca2++Mg2+-Cl-. According to Chinese standard and the World Health Organization’s guidelines, the water in the coal mine area is of good quality in terms of its physical and chemical properties, except for the concentrations of Fe and Mn (1925.14 and 12872.882 μg/L, respectively). Principal component analysis reveal two groups that explained the variance in the data consisting of SO42−, Ca2+, Mg2+, and low pH as well as HCO3−, Na+, and Cl−, which can reflect the acid mine drainage effects as well as different human activities or the evaporation found in low mountains and hills, respectively. Hence, the concentrations of metals and metalloids in the stream sediments are affected by the coal mine drainage, which are generally enriched in Cr, Mn, Zn, Sr, Co, Ni, Cu, Al, Ca, Fe, and Mg. Mn and Fe average concentrations are higher in the downstream Kongjiagou drain stream sediment samples were 2035.03 ppm and 6%, respectively, relative to the Mn and Fe average concentrations in Xiaojiagou of 453.04 ppm and 2.96%, respectively. Both Mn and Fe concentrations are higher than the background values. Ultimately, mine closures can help with the process of ecological and environmental recovery.

scholarly journals Multielement study in the drainage sediments of a part of Lesser Himalaya, central Nepal

1981 ◽  
Vol 1 (2) ◽  
pp. 1-9
Author(s):  
B. M Jnawali
Keyword(s):  
Regression Analysis ◽  
Close Association ◽  
Stream Sediments ◽  
Stream Sediment ◽  
Lesser Himalaya ◽  
Sediment Samples ◽  
Positive Correlation ◽  
Significant Variance ◽  
Central Nepal ◽  
Variance Explained

Distribution of different elements from 183 regional stream sediment samples representing 600 Km2 of Chitwan-Dhading Districts (Toposheet 72A/14) has been described. The study of inter-element relationships demonstrated positive correlation among Cu, Pb & Zn. Arsenic Sb & Bi correlations are found to be positive except that Bi & Sb exhibit antipathetic relation, the former showing affinity towards granite in contrast to the latter, which was virtually absent in anomalous amount over granites. A close association of As with Cu, Pb & Zn anomalies suggest that As could be used as a pathfinder for basemetal mineralization. Regression analysis was used to study the effect of secondary hydroxides of Fe, Mn & Ni on Cu & Zn dispersion, and that of K on Sn & Pb dispersion. The only significant variance explained was Fe on regression of Cu, which was attributed to primary coherence of Cu with Fe probably in chalcopyrite or mafic minerals. The geochemical associations found in stream sediments reflect primary environment and secondary processes in surficial condition modify these very little.

scholarly journals Geochemical exploration in central and western North Greenland

1987 ◽  
Vol 133 ◽  
pp. 113-121
Author(s):  
U.H Jakobsen ◽  
H Stendal
Keyword(s):  
Stream Sediment ◽  
Geochemical Exploration ◽  
Sediment Samples ◽  
Lithostratigraphic Units ◽  
Field Season ◽  
Good For ◽  
North Greenland

The 1985 geochemical exploration programme in central and western North Greenland completed the present geochemical exploration programme. A total of 424 stream sediment samples were collected during the 1985 field season. The reproducibility of drainage sampling is reasonably good for the elements Ba and Zn. Follow-up of anomalous Ba and Zn values from drainage samples collected in 1984 has not revealed any new mineralised localities. The high contents of Ba and Zn are interpreted as associated with: (1) pyrite-bearing strata, and/or (2) carbonate conglomerate, and/or (3) a higher general content of these elements in some lithostratigraphic units. A known zinc mineralisation in Navarana Fjord, eastern Freuchen Land, contains baryte in addition to sphalerite.

scholarly journals Occurrence of scheelite in the early Archaean Isua supracrustal belt, West Greenland

1985 ◽  
Vol 125 ◽  
pp. 45-47
Author(s):  
P.W.U Appel
Keyword(s):  
Stream Sediment ◽  
Laboratory Work ◽  
Field Observations ◽  
Sediment Samples ◽  
X Ray ◽  
Rock Samples ◽  
Sediment Sampling ◽  
Supracrustal Belt ◽  
Sampling Programme

As part of the regional stream sediment sampling programme in the Godthåb area (Appel, 1983, 1984),22 stream sediment samples were collected in the Isukasia area in 1983, of which 21 appeared to contain scheelite. In 1984 a one-week field programme was carried out towards the end of August in order to find in situ scheelite within the Isua supracrustal rocks. The folIowing brief report is based on field observations only; laboratory work has been confined to X-ray identification of scheelite in three stream sediment samples and in three rock samples.

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