The Homestake gold mine, an early Proterozoic iron-formation-hosted gold deposit, Lawrence County, South Dakota

1991 ◽  
Keyword(s):  
South Dakota ◽  
Gold Deposit ◽  
Iron Formation ◽  
Gold Mine ◽  
Early Proterozoic ◽  
Lawrence County

scholarly journals Presence of glucose, xylose, and glycerol fermenting bacteria in the deep biosphere of the former Homestake gold mine, South Dakota

2013 ◽  
Vol 4 ◽  
Author(s):  
Gurdeep Rastogi ◽  
Raghu N. Gurram ◽  
Aditya Bhalla ◽  
Ramon Gonzalez ◽  
Kenneth M. Bischoff ◽  
...  
Keyword(s):  
South Dakota ◽  
Gold Mine ◽  
Deep Biosphere ◽  
Fermenting Bacteria

scholarly journals Topographic Map Analysis of High Elevation Black Hills Through Valleys Linking Spearfish and Rapid Creek Headwaters Valleys, Lawrence County, South Dakota, USA

2017 ◽  
Vol 10 (1) ◽  
pp. 8
Author(s):  
Eric Clausen
Keyword(s):  
South Dakota ◽  
Drainage Basin ◽  
Water Source ◽  
High Elevation ◽  
Black Hills ◽  
Topographic Map ◽  
Drainage Basins ◽  
Converging Channel ◽  
Lawrence County ◽  
Map Analysis

The Spearfish-Rapid Creek drainage extends from elevations greater than 7130 feet (2173 meters) roughly in a north direction across the northern Black Hills upland to where it becomes the Spearfish-Whitewood Creek drainage divide at an elevation of approximately 6440 feet (1963 meters) and separates north-oriented Spearfish Creek headwaters from southeast- and east-oriented Rapid Creek headwaters. This study used detailed topographic maps to investigate through valleys (and wind gaps) now crossing the Spearfish-Rapid Creek drainage divide, which is one of the Black Hills’ highest drainage divides. Through valley (or wind gap) floor elevations were determined and ranged from approximately 6150 feet (1875 meters) to approximately 7050 feet (2149 meters) and through valley (and wind gap) depths were also calculated and ranged from approximately 30 feet (9 meters) to about 290 feet (88 meters). Map evidence suggesting these through valleys (and wind gaps) originated as components of diverging and converging complexes of bedrock-walled channels is described and suggests large and prolonged southeast-oriented floods once flowed from or across the Spearfish Creek drainage basin to the Rapid Creek drainage basin. Based on today’s topography there is no upland Black Hills region capable of generating the large and prolonged floods required to erode the observed through valleys (and wind gaps) and their associated diverging and converging channel complexes so the erosion is interpreted to have taken place while the Black Hills were just beginning to emerge as the topographic high they are today. A water source could not be determined from map evidence, but large and prolonged southeast-oriented floods across the region are consistent with a recently proposed hypothesis that massive southeast-oriented (continental ice sheet) ice-marginal melt water floods eroded what are today western South Dakota and North Dakota river drainage basins. 

Occurrence and genetic implications of hyalophane in manganese-rich iron-formation, Cuyuna Iron Range, Minnesota, USA

1994 ◽  
Vol 58 (392) ◽  
pp. 387-399 ◽  
Author(s):  
Peter L. McSwiggen ◽  
G. B. Morey ◽  
Jane M. Cleland
Keyword(s):  
Depositional Environment ◽  
Iron Formation ◽  
East Central ◽  
Early Proterozoic ◽  
Iron Range ◽  
The North ◽  
History Of ◽  
Ferromanganese Deposits ◽  
Iron Formations ◽  
Chemical Sediments

AbstractThe recent discovery of hyalophane [(K,Ba)Al1−2Si3−2O8] on the North range segment of the Early Proterozoic Cuyuna Iron Range of east-central Minnesota has shed new light on the depositional environment of these rocks. This Ba-feldspar occurs in a 10 m thick interval within the main iron-formation and typically contains between 8 and 26 mol.% celsian (BaAl2Si2O8). Its occurrence in several textural settings suggests that barium was being deposited at various stages in the paragenetic history of the iron-formation. Some of the hyalophane grains occur as the cores of micronodules, which are structurally similar to oolites or oncolites, but mineralogically are very complex. The hyalophane also occurs as rims on core grains of diverse mineral composition and as discrete phases in late crosscutting veins.Hyalophane, like other Ba-silicates, has a very restricted paragenesis. They are associated typically either with sedimentary manganese and ferromanganese deposits, or with Cu-Pb-Zn-Ba deposits. The presence of hyalophane in the Early Proterozoic manganiferous iron ores of east-central Minnesota casts doubt on the historic interpretation of these deposits as typical Superior-type sedimentary iron-formations and instead supports the view that these deposits, at least in part, consist of chemical sediments from a hydrothermal fumarolic system. The suggested involvement of a hydrothermal system is also supported by the occurrence of aegirine within the hyalophane-rich layer, and the occurrence of tourmalinites and Sr-rich baryte veins elsewhere in the Cuyuna North range.

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