Characterizing some major Archean faults at depth in the Superior craton, North America
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F25%3A00638963" target="_blank" >RIV/67985530:_____/25:00638963 - isvavai.cz</a>
Result on the web
<a href="https://se.copernicus.org/articles/16/785/2025/" target="_blank" >https://se.copernicus.org/articles/16/785/2025/</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.5194/se-16-785-2025" target="_blank" >10.5194/se-16-785-2025</a>
Alternative languages
Result language
angličtina
Original language name
Characterizing some major Archean faults at depth in the Superior craton, North America
Original language description
The geometry of ancient (2.75-2.65 Ga) faults at depth can only be mapped in detail by high-resolution geophysical surveys such as seismic reflection profiling. Recent deep (35-48 km) reflection profiles acquired throughout the Archean southern Superior craton of North America provided such data with which to map some major shear zones in 3D, many of which are associated with significant orogenic gold or volcanogenic massive sulfide (VMS) deposits. Most faults are (re-)interpreted as low-angle (<35 degrees) thrusts, a few appear as sub-vertically (>75 degrees) aligned truncations of prominent reflectors. Asymmetry of reflectors suggests that the sub-vertical faults may have originated as 2.75-2.70 Ga syn-volcanic leaky transform faults. We relate thrust structures primarily to the dominant phase of folding and horizontal shortening strain that occurred at 2.72-2.66 Ga during regional crustal deformation, mineralization, and peak metamorphism, associated with terrane accretion. Palinspastic restoration near Timmins, Ontario, indicates 40 km of horizontal shortening. Previous mapping indicates that deformation after this orogenic shortening event resulted in modest lateral movement. Coincident magnetotelluric (MT) surveys indicate that pervasive conductive minerals, such as graphite/carbon and sulfide, exist within the mid-crust and in near-vertical channels within the more brittle and resistive upper crust. Many such channels, but not all, coincide with fault zones and mineral deposits. Palinspastic and paleomagnetic-based reconstructions suggest many faults had multiple periods of activity with evolving vertical to horizontal offsets. Some prominent faults appear paired, partitioning normal and oblique strains on vertical shear zones and dipping thrust zones, respectively.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10505 - Geology
Result continuities
Project
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Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2025
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Solid Earth
ISSN
1869-9510
e-ISSN
1869-9529
Volume of the periodical
16
Issue of the periodical within the volume
9
Country of publishing house
DE - GERMANY
Number of pages
22
Pages from-to
785-806
UT code for WoS article
001566050200001
EID of the result in the Scopus database
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