Steep rock

Preliminary investigation into tailings-ground water interactions at the former Steep Rock iron mines, Ontario, Canada... 

Fig. 1. Map showing location of the study sites relative to Hogarth and Caland pit lakes. Black outline represents original lake level (prior to draining for mining). Inset shows location of the Steep Rock iron deposit within Ontario.

Figure 4 shows the variation in carbon and sulfur isotopes for Steep Rock ground water and surface water. S34S ratios for... 

Cockerton, S. 2008a. Experimental constraints for the source of sulfate toxicity and predictive water quality for the Hogarth and Caland pit lakes, Steep Rock Iron Mine, Northwestern Ontario, Canada. Mine Water and the Environment Proceedings, 10, 551-554. 

Goold, A.R. 2008. Water quality and toxicity investigations of two pit lakes at the former Steep Rock iron mines, near Atikokan, Ontario. MSc. thesis, Lakehead University, Thunder Bay, Ontario. 

Steep Rock Lumby Lake Belts Superior Province 3.0-2.9 Tomlinson et al (1999)... 

Tomlinson K. Y., Hughes D. 1., Thurston P. C., and Hall R. P. (1999) Plume magmatism and crustal growth at 2.9 to 3.0 Ga in the Steep Rock and Lumby Lake area. Western Superior Province. Lithos 46, 103-136. 

Steep Rock, Ontario, and Pongola, South Africa... 

Figure 3 (a) The surface of the 3 Ga Earth, Steep Rock, NW Ontario, Canada. The hill-face is very close to a 3 Ga unconformity surface, and the rocks (granitoids and mafic dikes) exposed on the hill-face are immediately helow the unconformity. Above them are assorted sediments, including thick stromatolitic limestones, (b) Stromatolitic limestone, Steep Rock, Ontario, Canada (ca. 3 Ga old). The palaeohorizontal surface dips 70°. Stromatolitic domes are up to 4-5 m long and 2 m high. 

WiUcs M. E. and Nisbet E. G. (1985) Archean stromatohtes from the Steep Rock group NW Ontario. Can. J. Earth Sci. 22, 792-799. 

Kusky, T. M. Hudleston, P. J. 1999. Growth and demise of an Archean carbonate platform. Steep Rock Lake, Ontario, Canada. Canadian Journal of Earth Sciences, 36, 565-584. 

Wilks, M. E. Nisbet, E. G. 1988. Stratigraphy of the Steep Rock Group, northwest Ontario a major Archaean unconformity and Archaean stromatolites. Canadian Journal of Earth Sciences, 25, 370-391. 

The carbonate horizons of the Cheshire and Manjeri Formations contain extensive well-preserved stromatolites. These were formed in shallow or intertidal waters, as demonstrated by interbedded ripple-marked and mud-cracked silts. Texturally, the limestones show many indications of organic activity and gas release structures (Martin et al. 1980). The simplest uni-formitarian explanation is that the structures were built by cyanobacteria. Isotopically, carbon from kerogen in the stromatolites typically has 6 C = -25 to -30%o. This implies but does not prove fractionation by rubisco of carbon captured from the atmosphere-ocean system. Carbonate in Cheshire limestones is typically close to 0%o, suggesting that carbon in the atmosphere-ocean system was modulated by rubisco and dominated by oxygenic photosynthesis on a planetary scale (Fig. 1) at least by this date. It should be noted that the c. 3 Ga Steep Rock stromatolites are similar (work by Abell, Grassineau and Nisbet). 

Late Archaean stromatolites Younger stromatolites have been described from 3.0 Ga rocks at Steep Rock in Canada (Wilks St Nisbet, 1985), from the 2.7 Ga Cheshire formation of the Belingwe Greenstone belt (Martin et al., 1980) and from 2.52 Ga shelf carbonate sediments in the Campbellrand subgroup, South Africa. In this latter locality there are also well-documented calcified microfossils of cyanobacteria (Kazmierczak St Altermann, 2002). It is also possible that at this locality the mineralization of the dead bacteria was the result of the action of het-erotrophic bacteria. 

Wilks, M.E. and Nisbet, E.G., 1985. Archaean stromatolites from the Steep Rock Group, northwestern Ontario, Canada. Can. f. Earth Sci., 22, 792-9. 

Wu Haibin. 2002. Stabilization Technology on the High-Steep Rock Slope in the Three Gorges Project Shiplock. Chinese J. of Rock Mechanics and Engineering, 2002, 21(2) 261-267. 

Sites of former mineral workings 0 - steep rock facet or infill of varied properties... 

Wu Faquan, Deformation and stability of high-steep rock slope, Beijing Science Press, 2008 (In Chinese). 

Steep rock walls are unsuitable for planting with vegetation, except where sinks (dolines) filled with loamy material already exist. A certain amount of plant life will, however, gain a foothold in loam-filled crevices and at the junctions between strata and will in course of time spread to give a natural covering of greenery to parts of the rock. In any case the walls should be stable and properly trimmed. It has been found that the stability can be considerably improved by leaving a relatively thin layer of the workable deposit in situ. 

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