|Title||Igneous rocks and hydrothermal alteration of Lower Carboniferous sedimentary rocks, Clarke Head, Minas Fault Zone, western Nova Scotia|
|Licence||Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences.|
|Author||Pe-Piper, G; Nagle, J; Piper, D J W|
|Source||Geological Survey of Canada, Open File 8314, 2017, 640 pages, https://doi.org/10.4095/306289 Open Access|
|Publisher||Natural Resources Canada|
|Related||This publication is related to Detailed mineralogical data
from hydrothermally altered igneous rocks at Clarke Head, Minas Fault Zone, western Nova Scotia |
|Area||Clarke Head; Parrsboro; Minas Basin|
|Lat/Long WENS|| -64.3667 -63.9667 45.5000 45.3333|
|Subjects||regional geology; economic geology; tectonics; igneous and metamorphic petrology; geochemistry; mineralogy; bedrock geology; lithology; igneous rocks; intrusive rocks; gabbros; lamprophyres; syenites;
diorites; granulites; pegmatites; mafic rocks; feldspar; analcime; scapolite; megabreccias; sedimentary rocks; limestones; sandstones; xenoliths; siltstones; gypsum; clastics; carbonates; hydroxides; oxides; structural features; faults; intrusions;
plutons; batholiths; veins; host rocks; mineral deposits; iron; ore mineral genesis; mineralization; hydrothermal alteration; paragenesis; geothermometry; chlorite; tectonic evolution; tectonic history; breccias, tectonic; scanning electron
microscope analyses; field work; textural analyses; Clarke Head Fault Zone; Minas Fault Zone; Cobequid Highlands; Cobequid Shear Zone; Cumberland Basin; Meguma Terrane; Avalone Terrane; South Mountain Batholith; Fountain Lake Group Horton Grop;
Cobequid Fault; Portapique Fault; Kirkhill Fault; Jeffers Block; Cumberland Group; Windsor Group; Horton Group; Cheverie Formation; West Bay Formation; Phanerozoic; Mesozoic; Triassic; Paleozoic; Carboniferous; Devonian|
|Illustrations||tables; geoscientific sketch maps; photographs; photomicrographs; geochemical plots; histograms; geochronological charts; digital images; graphs|
|Program||GSC Atlantic Division|
|Program||NSERC Natural Sciences and Engineering Research Council of
|Released||2017 12 14|
|Abstract||Fault zone megabreccia exposed at Clarke Head, near Parrsboro, Nova Scotia, is a splay of the mid-Carboniferous Minas Fault Zone. Lower Carboniferous sedimentary rocks and Upper Devonian-Lower
Carboniferous igneous rocks occur as megablocks within the fault zone. This study investigated: 1) the character of the igneous rocks in the Clarke Head fault zone and (2) the type of hydrothermal veins cutting sedimentary and/or igneous rocks in the
fault zone. This information is then used to make comparisons with the evolution of the igneous and hydrothermal systems in the Cobequid fault zone to the north.|
Igneous rocks comprise gabbro that was intruded by syenite and diorite that either
intruded or has xenoliths of grey silty sandstone. The syenite contains magmatic rutile and analcime; magmatic K-feldspar has been largely replaced by scapolite, which shows a temporal transition from more Cl rich to more carbonate rich varieties.
The source of the Cl was probably Windsor Group halite.
Sedimentary rocks in the fault zone include Lower Horton Group siltstones and sandstones, Windsor Group gypsum and limestones, and grey to reddish clastic rocks that might be either Cheverie
Formation or West Bay Formation. All these rocks are cut by Fe-carbonate and (hydr)oxide veins that have younger titania minerals, synchysite, barite, zircon and xenotime. These veins cross-cut older quartz-chlorite-calcite veins, which in turn only
in the Lower Horton Group cross-cut albite veins. A similar succession of vein minerals has been described in the literature from the Cobequid Fault to the north.
Taken together, the vein systems and the igneous rocks extend knowledge about the
igneous and hydrothermal systems along the mineralised Minas Fault Zone and provide opportunities for more precise dating of the complex late Paleozoic tectonic events in the region.
|Summary||(Plain Language Summary, not published)|
A new study of a major mineralized fault zone in Nova Scotia provides new evidence for its age and character.