ANOMALOUS IRON DISTRIBUTION IN SHALES AS A MANIFESTATION OF NON-CLASTIC IRON SUPPLY TO SEDIMENTARY BASINS - RELEVANCE FOR PYRITIC SHALES, BASE-METAL MINERALIZATION, AND OOLITIC IRONSTONE DEPOSITS

被引：8

作者：

SCHIEBER, J

机构：

[1] Department of Geology, The University of Texas at Arlington, Arlington, 76019-0049, Texas

来源：

MINERALIUM DEPOSITA | 1995年 / 30卷 / 3-4期

关键词：

D O I：

10.1007/BF00196365

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

In previous investigations, nearshore pyritic shale horizons in the Mid-Proterozoic Newland Formation were interpreted to be due to ''non-clastic'' colloidal iron supply by streams. New data on the chemical composition of shales in the Newland Formation support this interpretation. In these shales, Fe and Al show a positively correlated trend that intercepts the Fe axis above the origin. These relationships suggest control of Fe by clays (via iron oxide coatings on clay minerals), and the presence of an additional, ''non-clastic iron'' component. Shales from stratigraphic intervals during which pyritic shale horizons weredeposited plot above the Fe/Al trend typical for the remainder of the Newland Formation. Pyritic shale horizons in sediments are favourable hosts for base-metal deposits of the pyrite-replacement type. Fe/Al relationships as found in the Newland Formation may help to identify stratigraphic horizons in other sedimentary basins that contain pyritic shale horizons and potentially base-metal mineralization.

引用

页码：294 / 302

页数：9

共 44 条

[31]

Schieber J., The possible role of benthic microbial mats during the formation of carbonaceous shales in shallow Proterozoic basins, Sedimentology, 33, pp. 521-536, (1986)

[32]

Schieber J., Small scale sedimentary iron deposits in a Mid-Proterozoic basin: viability of iron supply by rivers, Precambrian iron-formations, pp. 267-295, (1987)

[33]

Schieber J., Redistribution of rare earth elements during diagenesis of carbonate rocks from the Mid-Proterozoic Newland Formation, Montana, U.S.A., Chem. Geol., 69, pp. 111-126, (1988)

[34]

Schieber J., Pyrite mineralization in microbial mats from the Mid-Proterozoic Newland Formation, Belt Supergroup, Montana, U.S.A., Sed. Geol., 64, pp. 79-90, (1989)

[35]

Schieber J., Facies and origin of shales from the Mid-Proterozoic newland Formation, Belt basin, Montana, U.S.A., Sedimentology, 36, pp. 203-219, (1989)

[36]

Schieber J., Pyritic shales and microbial mats: significant factors in the genesis of stratiform Pb-Zn deposits of the Proterozoic?, Mineral. Deposita, 25, pp. 7-14, (1990)

[37]

Schieber J., The origin and economic potential of disseminated Pb-Zn mineralization in pyritic shale horizons of the Mid-Proterozoic Newland Formation, Montana, U.S.A., Mineral. Deposita, 26, pp. 290-297, (1991)

[38]

Schieber J., Facies and deposition of a mixed terrigenouscarbonate suite in a Mid-Proterozoic epicratonic sea: the Newland Formation, Belt Supergroup, Montana, U.S.A., N. Jb. Geol. Pal. Abh., 184, pp. 155-180, (1992)

[39]

Schieber J., A combined petrographical-geochemical provenance study of the Newland Formation, Mid-Proterozoic of Montana, Geol. Mag., 129, pp. 223-237, (1992)

[40]

Sears J.W., Price R.A., The Siberian connection: a case for precambrian separation of the North American and Siberian cratons, Geology, 6, pp. 267-270, (1978)

← 1 2 3 4 5 →