Temat: placer - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Placer scheelite and gold from alluvial sediments as indicators of the primary mineralization – examples from SW Poland
Autorzy:: Mikulski, S.Z.
Wierchowiec, J.
Powiązania:: https://bibliotekanauki.pl/articles/2060602.pdf
Data publikacji:: 2013
Wydawca:: Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:: gold
scheelite
placer
prospecting
Lower Silesia
Sudetes
Opis:: Detailed morphologic studies of detrital scheelite and gold grains from clastic Cenozoic sediments (alluvial and eluvial-colluvial) in two selected areas of the Lower Silesia region allowed to describe their specific features (size, roundness, lustre, and lack or remnants of primary intergrowths with other minerals). It allows estimating length of hydrodynamic transport and distance from the source area. Such features are also an important tool in determining the source of ore mineralization and to establish the parent area for detrital accumulations. Moreover, electron microprobe (EMPA) investigation of detrital gold allowed to recognized internal structure and chemical composition of placer gold grains. The grains commonly revealed zonal structures due to chemical supergene gold mobility recognized nearly in all studied pan-concentrate samples.
Źródło:: Geological Quarterly; 2013, 57, 3; 503--514
1641-7291
Pojawia się w:: Geological Quarterly
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 2.

Tytuł:: Origin of placer gold and other heavy minerals from fluvial Cenozoic sediments in close proximity to Rote Fäule-related Au mineralisation in the North Sudetic Trough, SW Poland
Autorzy:: Wierchowiec, J.
Zieliński, K.
Powiązania:: https://bibliotekanauki.pl/articles/2060333.pdf
Data publikacji:: 2017
Wydawca:: Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:: gold
Au-Ag-Pd-Hg alloys
placer minerals
Rote Fäule
North Sudetic Trough
Sudetes
Opis:: Detailed morphological and geochemical studies of placer gold grains and other heavy minerals from Cenozoic fluvial clastic sediments in the area of the Zimnik Creek drainage basin (North Sudetic Trough, Lower Silesia) allowed the description of their specific features: shape and morphology, flatness index, internal textural features and chemical composition of the gold grains. It enables an estimation of the distance from the source area and determination of the source of the ore mineralisation, along with establishing the feeder areas for placer mineralisation including Rote Fäule-related gold hosted by Rotliegend-Zechstein transitional sediments. The comparison of the heavy mineral contents of placer grains from the Zimnik Creek drainage basin makes it possible to identify the area of origin for the gold particles. The crystalline Au-Ag-Pd-Hg (polymetallic) alloy grains of fluvial gold are assumed to come from the transitional sediments between the Rotliegend and the Zechstein in the North Sudetic Basin. The morphological and geochemical features of the polymetallic grains strongly suggest that the grains from the upper course of the Zimnik Creek valley sediments represent what has eroded from the local gold mineralisation and this mineralisation is probably in the vicinity of the upstream sampling site. The bimodal chemical composition of the Au-Ag-Pd-Hg alloy grains with electrum and medium-Ag grains (<15 wt.% Ag) found in the study area is typical of the Rote Fäule and Kupferschiefer-related gold mineralisation on the southern side of the North Sudetic Trough and the Sieroszowice-Polkowice copper mining district of the Fore-Sudetic Monocline. The study of the Ag contents of placer grains from the Zimnik Creek drainage basin highlights the contrast between the placer gold grains derived from Paleozoic orogenic gold mineralisation in the Sudetes (typically simple Au-Ag alloys containing between 5 and 20 wt.% of Ag) and the one formed by the oxidizing chloride hydrothermal systems. The grains identified in this manner as originating from the oxidizing hydrothermal system of the transitional zone can be distinguished from the placer gold derived from other styles of mineralisation, which are not Rote Fäule-related. It is particularly important considering the ongoing reconnaissance exploration in the North Sudetic Trough (SW Poland), which employs gold grain analyses as a prospecting tool for the detection of potentially economic primary gold mineralisation.
Źródło:: Geological Quarterly; 2017, 61, 1; 60--78
1641-7291
Pojawia się w:: Geological Quarterly
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Informacja

Wyszukujesz frazę "placer" wg kryterium: Temat

Źródło danych

Dostawca treści

Kolekcja

Rok wydania

Wydawca

Temat

Autor

Typ dokumentu

Język