scholarly journals Borehole logging techniques applied to base metal ore deposits

1979 ◽  
Author(s):  
W E Glenn ◽  
P H Nelson
Keyword(s):  
Base Metal ◽  
Ore Deposits ◽  
Borehole Logging

K–Ar ages of clay concentrates from Irish orebodies and their bearing on the timing of mineralisation

1983 ◽  
Vol 74 (1) ◽  
pp. 1-14 ◽  
Author(s):  
A. N. Halliday ◽  
J. G. Mitchell
Keyword(s):  
Base Metal ◽  
Early Carboniferous ◽  
Hydrothermal Activity ◽  
Ore Deposits ◽  
Mineral Deposits ◽  
Powerful Method ◽  
Lower Carboniferous ◽  
Hercynian Orogeny ◽  
Vein Deposits

ABSTRACTThe K–Ar ages of 117 clay concentrates from samples associated with mineral deposits in Ireland indicate that most, if not all of the major ore deposits were formed during Carboniferous times or earlier. The Avoca orebodies are pre-400 Ma in age. Many of the vein deposits traversing Palaeozoic rocks were either formed or rejuvenated during the Hercynian orogeny c. 300 Ma ago. The SW Ireland Cu–Ba ores are 290 Ma old, and the major, frequently stratiform, base metal deposits stratabound in the Lower Carboniferous were, at least largely, formed during the Carboniferous period. In the case of the Navan orebody, an early Carboniferous age is indicated. Previous models invoking major mineralisations during Mesozoic or Tertiary times are rendered invalid. However, in some areas there appears to have been hydrothermal activity during the Triassic and possibly the Permian. The Triassic event is thought to be genetically related to coeval hydrothermal avtivity found throughout the N Atlantic regions. The data suggest that probably <10 km of cover has been removed from the majority of Ireland since Lower Carboniferous times. K–Ar dating of clays is shown to be a powerful method for constraining the ages of oredeposits.

An occurrence of todorokite in the deuteric stage of a basalt

1968 ◽  
Vol 36 (282) ◽  
pp. 757-760 ◽  
Author(s):  
L. J. Lawrence ◽  
P. Bayliss ◽  
Paul Tonkin
Keyword(s):  
Base Metal ◽  
New South ◽  
New South Wales ◽  
Ore Deposits ◽  
South Wales ◽  
Tertiary Basalt

SummaryAn occurrence of todorokite having a formula is recorded from Ardglen, 150 miles N.N.W. of Sydney, New South Wales. The composition of Ardglen todorokite is somewhat simpler than previously recorded occurrences, most of which were in manganese and manganese—base-metal ore deposits. The simpler composition is explained in terms of its occurrence as a late deuteric mineral associated with manganocalcite and zeolites in an altered Tertiary basalt. The manganese is believed to have been derived from the deuteric alteration of the augite of the basalt.

The Paleoproterozoic Kristineberg mining area, northern Sweden: Results from integrated 3D geophysical and geologic modeling, and implications for targeting ore deposits

Geophysics ◽  
2009 ◽  
Vol 74 (1) ◽  
pp. B9-B22 ◽  
Author(s):  
Alireza Malehmir ◽  
Hans Thunehed ◽  
Ari Tryggvason
Keyword(s):  
Base Metal ◽  
Volcanic Rocks ◽  
Mining Area ◽  
Gold Deposits ◽  
Ore Deposits ◽  
Granitic Rocks ◽  
Gravity Modeling ◽  
Northern Sweden ◽  
Seismic Profiles ◽  
Geologic Model

The Kristineberg mining area in the western part of the Paleoproterozoic Skellefte Ore District, northern Sweden, is well known for its base-metal and recent gold discoveries. A pilot 3D geologic model has been constructed on a crustal scale, covering an area of [Formula: see text] to depths of [Formula: see text]. Constrained 3D inverse and forward gravity modeling have been performed to confirm and refine previous modeling along seismic profiles using mainly 2.5D techniques. The 3D inverse gravity modeling was geared to generating isodensity surfaces that enclose regions within the model of anomalous density contrast. The 3D forward gravity modeling was conducted to include faulting and folding systems that are difficult to include in the inversion. The 3D geologic model supports many previous interpretations but also reveals new features of the regional geology that are important for future targeting of base-metal and gold deposits. The margins of a thick granite in the south dip steeply inward, suggesting the possibility of room to accommodate another large base-metal deposit if the granitic rocks are juxtaposed with volcanic rocks at depth. Gravity modeling also suggests the observed Bouguer gravity high within the western metasediments can be explained by a large mafic intrusion that has dioritic to tonalitic composition and no significant magnetic signature. Because mafic-ultramafic intrusions within metasediments can indicate gold, this interpretation suggests the western metasediments have a high gold potential.

Environment of generation of some base metal ore deposits

1968 ◽  
Vol 63 (7) ◽  
pp. 846-847
Author(s):  
Ira B. Joralemon
Keyword(s):  
Base Metal ◽  
Ore Deposits

Enhancing base-metal exploration with seismic imagingThis article is one of a series of papers published in this Special Issue on the theme Lithoprobe — parameters, processes, and the evolution of a continent.

2010 ◽  
Vol 47 (5) ◽  
pp. 741-760 ◽  
Author(s):  
David W. Eaton ◽  
Erick Adam ◽  
Bernd Milkereit ◽  
Matthew Salisbury ◽  
Brian Roberts ◽  
...  
Keyword(s):  
Base Metal ◽  
Direct Detection ◽  
Mineral Exploration ◽  
Geophysical Methods ◽  
Shear Zones ◽  
Ore Deposits ◽  
Mining District ◽  
Borehole Data ◽  
Minimum Thickness ◽  
Metal Mining

Commencing in 1988 and continuing for 5 years, Lithoprobe acquired a series of high-resolution seismic experiments within and near base-metal mining camps in Canada, including the Abitibi subprovince of Quebec and Ontario, the world-class Sudbury Ni–Cu mining district, the Buchans mine in Newfoundland, and the Thompson Ni belt in Manitoba. This work, undertaken in close cooperation with the Geological Survey of Canada and major Canadian mining companies, stimulated an intensive and broadened series of followup studies with the common objective of assessing potential applications of multichannel seismic (MCS) imaging for deep mineral exploration and mine development. This research was motivated by a widely recognized disparity between the depths from which ores can be profitably mined (up to 2 km or more) and the resolving depths (typically <500 m) of commonly used geophysical methods for mineral exploration. Initial rock-property studies established that the expected contrast in acoustic impedance between ores and host rocks should be sufficient to generate observable reflections and (or) scattered waves. For an ore deposit to be directly detectable with MCS, however, it is also necessary for it to meet geometrical criteria including a minimum thickness of 1/8 wavelenth (typically ∼5 m) and a lateral extent similar to the Fresnel radius (typically ∼100 m). Both Lithoprobe and followup seismic studies, calibrated with borehole data, reveal that lithologic contacts that are characterized by large impedance contrast and significant lateral continuity, such as igneous intrusive contacts between mafic and felsic rocks, are the most likely features to be imaged with the MCS techniques. In some camps such as Buchans, however, faults and shear zones are better imaged than lithologic contacts. In either case, these studies show that well-designed and carefully processed seismic profiles can provide a valuable geophysical tool for interpreting the stratigraphic and structural framework of mineral systems and, more rarely, direct-detection capabilities for deep ore deposits.

Workshop on Base Metal Ore Deposits of Brazil, Salvador, Brazil

1999 ◽  
Vol 2 (2) ◽  
pp. 320-322
Author(s):  
Sundaram S. Iyer ◽  
Aroldo Misi ◽  
Maria da Gloria de Silva
Keyword(s):  
Base Metal ◽  
Ore Deposits

scholarly journals Contrasting styles of lead-zinc-barium mineralization in the Lower Benue Trough, Southeastern Nigeria

2017 ◽  
Vol 21 (1) ◽  
pp. 7 ◽  
Author(s):  
Ifeanyi Andrew Oha ◽  
Kalu Mosto Onuoha ◽  
Silas Sunday Dada
Keyword(s):  
Base Metal ◽  
Field Studies ◽  
Ore Deposits ◽  
Southeastern Nigeria ◽  
Benue Trough ◽  
Remarkable Increase ◽  
Metal Type ◽  
Lower Benue Trough ◽  
Lead Zinc ◽  
Vein Deposits

In the Lower Benue Trough of Southeastern Nigeria, lead-zinc-barium mineralization occurs as widely distributed epigenetic fracture-controlled vein deposits which are restricted to Albian – Turonian sediments. Detailed field studies carried out in Ishiagu, Enyigba-Ameki-Ameri, Wanikande-Wanakom, and Gabu-Oshina which together constitute the four main areas of mineralization in the Lower Benue Trough, show that mineralization appears restricted to NW-SE and N-S fractures while the more common NE-SW fractures are barren. Apart from the Enyigba area, igneous bodies are found in the vicinity of the ore deposits while in the Wanikande area, barite veins and veinlets were observed to be closely interwoven with intrusive bodies. The host lithologies are highly varied, ranging from shales to siltstones, sandstones and occasionally igneous bodies. The ore assemblage also varies remarkably, with lead:zinc:barium ratios ranging from approximately 3:1:0 at Ishiagu, to 2:1:0 at Enyigba, 1:0:2 at Wanikande and nearly 100% barite at Gabu-Oshina. Thus, there is a remarkable increase in barite content from the southwest (Ishiagu) to the northeast (Gabu). The characteristics of the ore deposits roughly fit the base metal type mineralization known as clastic dominated lead-zinc-barium deposits. This study forms part of a mineral potential database which is invaluable for any detailed exploration venture in the area. Contraste de estilos de mineralización de plomo-zinc-bario en la parte baja de la Formación Benue Trough, en el sudeste de NigeriaResumenEn la parte baja de la Formación Benue Trough, en el sudeste de Nigeria, la mineralización de plomo-zinc-bario ocurre en depósitos epigenéticos de fractura controlada ampliamente distribuidos pero que se restringen a sedimentos Albian-Turonian. Estudios de campo detallados realizados en Ishiagu, Enyigba-Ameki-Ameri, Wanikande-Wanakom y Gabu-Oshina (que conforman las cuatro áreas principales de mineralización en la parte baja de Benue Trough) muestran que la mineralización aparece restringida a fracturas NW-SE y N-S, mientras que las fracturas NE-SW, que son más comunes, aparecen estériles. Aparte del área Enyigba, los cuerpos ígneos se encontraron junto a los depósitos de minerales, mientras en el área Wanikande se observaron vetas y vetillas de baritina que están prácticamente entretejidas con cuerpos intrusivos. Las litologías sede son ampliamente variadas, y van desde esquistos a limolitas, areniscas y ocasionalmente cuerpos ígneos. El ensamble de la mena también varía con proporciones de plomo:zinc:bario que van aproximadamente desde 3:1:0 en Ishiagu, 2:1:0 en Enyigba, 1:0:2 en Wanikande y cerca del 100 % de baritina en Gabu-Oshina. Por ende, hay un incremento importante en el contenido de baritina desde el suroeste (Ishiagu) hacia el noroeste (Gabu). Las características de los depósitos minerales se enmarcan aproximadamente en el tipo de mineralización de base metálica, conocido como depósitos plomo-zinc-bario de dominación clástica. Este estudio hace parte de una base de datos de minerales potenciales que es invaluable para una exploración detallada en el área.

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