scholarly journals Airborne geophysical survey of the Tulks Volcanic Belt, Red Indian Lake area, Newfoundland, 1991

1991 ◽  
Author(s):  
K L Ford ◽  
P B Holman
Keyword(s):  
Volcanic Belt ◽  
Geophysical Survey ◽  
Lake Area

U–Pb zircon ages from the eastern Savant Lake – Crow Lake metavolcanic–metasedimentary belt, northwest Ontario

1982 ◽  
Vol 19 (4) ◽  
pp. 868-877 ◽  
Author(s):  
D. W. Davis ◽  
N. F. Trowell
Keyword(s):  
Volcanic Belt ◽  
Time Span ◽  
Lake Area ◽  
The South ◽  
Air Abrasion ◽  
Angular Unconformity ◽  
Volcanic Sequence ◽  
Northwest Ontario ◽  
Lake Sample ◽  
Volcanic Cycles

Five rocks from three areas in the eastern part of the Savant Lake – Crow Lake metavolcanic–metasedimentary belt have been dated by U–Pb analysis of zircons.The Sioux Lookout area is composed of a sequence of generally fault-bounded metavolcanic and metasedimentary belts. The age of a felsic tuff in the Central volcanic belt is [Formula: see text]. This is possibly the youngest sequence in the area.The Savant Lake volcanic belt comprises the Jutten volcanic unit at its base separated by an angular unconformity from the Handy Lake volcanic sequence. The age of a dacitic tuff near the base of the Handy Lake volcanic sequence is [Formula: see text].The South Sturgeon Lake volcanic belt is composed of four volcanic cycles. The age of a felsic tuff from the top of the uppermost cycle is [Formula: see text]. The felsic Beidelman Bay pluton and the mafic Pike Lake pluton, which both intruded the lower part of the sequence, give ages of [Formula: see text] and [Formula: see text], respectively. This establishes a minimum time span of [Formula: see text] for deposition of the sequence. This interval, along with the 27 Ma span between the ages of the Handy Lake sample and the volcanic sample from the South Sturgeon Lake area, suggests that the sequences were laid down by a series of discrete volcanic episodes.For samples subjected to multistage lead loss, the reliability of ages has been greatly enhanced by air abrasion of zircons. Several cases of suspected biasing of analyses by the air abrasion process have been encountered. It appears that this biasing problem can be overcome by selection and abrasion of low uranium grains that are free of imperfections.

scholarly journals Detailed mapping and lithogeochemistry of Neoarchean volcanic rocks: Beaulieu volcanic belt, Slave Craton, NWT

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Shelby Brandon Austin-Fafard ◽  
Michelle DeWolfe ◽  
Camille Partin ◽  
Bernadette Knox
Keyword(s):  
Volcanic Rocks ◽  
Volcanic Belt ◽  
Massive Sulfide ◽  
Lake Area ◽  
Density Currents ◽  
Volcanogenic Massive Sulfide ◽  
The South ◽  
Slave Craton ◽  
Volcaniclastic Rocks ◽  
Tuff Breccia

Neoarchean volcanic rocks of the Beaulieu River volcanic belt structurally overlie basement rocks of the Sleepy Dragon Complex (ca. 2.85 Ga), approximately 100 km east northeast of Yellowknife. The volcanic belt is comprised of complex lithofacies, including basalt, andesite, rhyolite, and associated volcaniclastic rocks, and hosts the Sunrise volcanogenic massive sulfide deposit. The absolute age of the volcanic strata is not known, nor is the stratigraphy well-defined; therefore, the Beaulieu River volcanic belt cannot be easily correlated to other greenstone belts within the Slave craton. The main objective of this study is to document the litho- and chemo-stratigraphy of the volcanic rocks, and particularly the rhyolite dome, located at the south end  of Sunset Lake to reconstruct their volcanic and petrogenetic evolution, and determine their relationship to the volcanic strata that hosts the Sunrise VMS deposit, located ~6km to the north of the study area. Detailed mapping (1:2000) was completed over two field seasons (2018 and 2019) and shows that the volcanic rocks in the south Sunset Lake area comprise a complex stratigraphy consisting of basaltic, andesitic and rhyolitic lithofacies. This includes massive to pillow basalt and andesite, with lesser amounts of massive to in-situ brecciated, weakly quartz-plagioclase porphyritic rhyolite, heterolithic tuff to lapilli- tuff and felsic tuff to tuff breccia. The felsic clasts within the felsic volcaniclastic rocks are similar in composition to the coherent rhyolite. Units have a trace element geochemical signatures that vary from tholeiitic to calc-alkaline, arc-like rocks. Volumetrically, the volcanic strata in the south Sunset Lake area has a significant amount of volcaniclastic rocks, ranging from tuff to tuff breccia units. The volcaniclastic rocks are interpreted to have been deposited by a series of debris flows and eruption-fed density currents. The stratigraphy of the volcanic rocks in south Sunset Lake is very similar to that of the stratigraphy that hosts the Sunrise VMS deposit. Evidence of a vent proximal environment (e.g. rhyolite dome, peperite, syn-volcanic intrusions) and porous, volcanic debris accumulating on the seafloor highlight conditions favourable for volcanogenic massive sulfide-type mineralization in the south Sunset Lake area.

U–Pb geochronology of late Neoarchean tonalites in the Flin Flon Belt, Trans-Hudson Orogen: surprise at surface

1994 ◽  
Vol 31 (12) ◽  
pp. 1785-1790 ◽  
Author(s):  
J. David ◽  
E. C. Syme
Keyword(s):  
Shear Zone ◽  
Tectonic Evolution ◽  
Volcanic Belt ◽  
Lake Area ◽  
Magmatic Rocks ◽  
Flin Flon ◽  
First Time

The Flin Flon volcanic belt of the Trans-Hudson Orogen in northern Manitoba comprises magmatic rocks (1.88 – 1.90 Ga) generated in an intra-oceanic arc and identified as one of the best examples of juvenile Paleoproterozoic crust. In the Flin Flon – Athapapuskow Lake area, the belt consists of a series of fault-bounded blocks, each having distinct stratigraphic and magmatic affinities, juxtaposed to form an accretionary collage. Two tonalitic bodies within the Northeast Arm shear zone, a major deformation corridor separating two of the most important blocks in the area, have been dated by the U–Pb zircon method at [Formula: see text] and [Formula: see text]. These results indicate the presence of fragments of late Neoarchean crust within the Flin Flon belt, possibly related to ca. 2.5 Ga granitic bodies found in terranes beyond the western limit of the belt. The presence of ca. 2.5 Ga tonalites within the Flin Flon Belt, herein reported for the first time, has major implications for basement involvement in the early tectonic evolution of the Flin Flon Belt.

scholarly journals Airborne geophysical survey, Flin Flon-Hanson Lake area, Saskatchewan

1996 ◽  
Author(s):  
R B K Shives ◽  
R J Hetu ◽  
P B Holman
Keyword(s):  
Geophysical Survey ◽  
Lake Area ◽  
Flin Flon

Isotopic studies of ore-leads of the circum-Kisseynew volcanic belt of Manitoba and Saskatchewan

1978 ◽  
Vol 15 (7) ◽  
pp. 1112-1121 ◽  
Author(s):  
D. F. Sangster
Keyword(s):  
Volcanic Rocks ◽  
Volcanic Belt ◽  
Massive Sulfide ◽  
Good Evidence ◽  
Lake Area ◽  
Sulfide Deposits ◽  
North West ◽  
The North ◽  
Isotopic Abundances ◽  
Host Rocks

Volcanic rocks, distributed to the north, west, and south of the Kisseynew gneissic belt in Manitoba and Saskatchewan, define a crescent-shaped belt herein informally referred to as the 'circum-Kisseynew volcanic belt'. Field relationships lead to the conclusion that the flanking volcanics are correlative with, and grade basinward to, greywackes and shales.Nearly 30 volcanogenic massive sulfide deposits, interpreted as coeval with their host rocks, are distributed throughout the circum-Kisseynew volcanic belt. Lead isotopic abundances in a representative number of these deposits are, apart from 204-error, relatively homogeneous in composition and model lead ages determined from these isotopic ratios fall, for the most part, between 1700 and 1900 Ma. This is regarded as good evidence that the circum-Kisseynew volcanic belt, as well as its greywacke equivalent, is largely Aphebian in age.Model lead ages for sulfide deposits from the entire circum-Kisseynew volcanic belt, with one exception, agree well with recent Rb–Sr and U–Pb age determinations from the southern portion of the belt. Reasons for the exception, in the Hanson Lake area, are discussed in some detail.

The Makrakomi Archaeological Landscapes Project. A preliminary report on investigations carried out in 2010–2012

2013 ◽  
Vol 6 ◽  
pp. 211-260 ◽  
Author(s):  
Maria-Foteini Papakonstantinou ◽  
Arto Penttinen ◽  
Gregory N. Tsokas ◽  
Panagiotis I. Tsourlos ◽  
Alexandros Stampolidis ◽  
...  
Keyword(s):  
Preliminary Report ◽  
Geophysical Survey ◽  
Small Scale ◽  
Hellenistic Period ◽  
Surface Survey ◽  
Multiple Structures ◽  
Recorded Data ◽  
Architectural Survey ◽  
The Hill ◽  
The Town

In this article we provide a preliminary report of the work carried out between 2010 and 2012 as part of the Makrakomi Archaeological Landscapes Project (MALP). The programme of research is carried out in co-operation between the Swedish Institute at Athens and the 14th Ephorate of Prehistoric and Classical Antiquities at Lamia. The interdisciplinary project started in the summer of 2010, when a pilot survey was conducted in and around the hill of Profitis Elias, in the modern municipality of Makrakomi, where extensive traces of ancient fortifications are still visible. Systematic investigations have been conducted since 2011 as part of a five-year plan of research involving surface survey, geophysical survey and small-scale archaeological excavation as well as geomorphological investigation. The primary aim of MALP is to examine the archaeology and geomorphology of the western Spercheios Valley, within the modern municipality of Makrakomi in order to achieve a better understanding of antiquity in the region, which has previously received scant scholarly attention. Through the archaeological surface survey and architectural survey in 2011 and 2012 we have been able to record traces of what can be termed as a nucleated and structured settlement in an area known locally as Asteria, which is formed by the projecting ridges to the east of Profitis Elias. The surface scatters recorded in this area suggest that the town was primarily occupied from the late 4th century BC and throughout the Hellenistic period. The geophysical survey conducted between 2011 and 2012 similarly recorded data which point to the presence of multiple structures according to a regular grid system. The excavation carried out in the central part of Asteria also uncovered remains of a single domestic structure (Building A) which seems to have been in use during the Late Classical and Hellenistic periods. The combined data acquired through the programme of research is thus highly encouraging, and has effectively demonstrated the importance of systematic archaeological research in this understudied area of Central Greece.

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