Spawning Lake Stock
Encyclopedia
The Spawning Lake Stock is an Archean
Archean
The Archean , also spelled Archeozoic or Archæozoic) is a geologic eon before the Paleoproterozoic Era of the Proterozoic Eon, before 2.5 Ga ago. Instead of being based on stratigraphy, this date is defined chronometrically...

 age granitoid
Granitoid
A granitoid or granitic rock is a variety of coarse grained plutonic rock similar to granite which mineralogically are composed predominately of feldspar and quartz. Examples of granitoid rocks include granite, quartz monzonite, quartz diorite, syenite, granodiorite and trondhjemite. Many are...

 stock in Northeastern Ontario
Northeastern Ontario
Northeastern Ontario is the region within the Canadian province of Ontario which lies north and east of Lakes Superior and Huron.Northeastern Ontario consists of the districts of Algoma, Sudbury, Cochrane, Timiskaming, Nipissing and Manitoulin; and the single-tier municipality of Greater...

, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, located in Briggs Township and Chambers Township of Temagami. It intrudes through the Tetapaga Syncline
Tetapaga Syncline
The Tetapaga Syncline, also known as the Lake Tetapaga Syncline, is a northeasterly trending syncline in Northeastern Ontario, Canada, located in Strathy Township of the municipality of Temagami. It represents a major structural feature in the Temagami greenstone belt, with dark green, massive and...

, a major geologic fold in the Temagami greenstone belt
Temagami greenstone belt
The Temagami greenstone belt, also known as the Temagami volcanic belt and the Temagami metavolcanic belt, is a small 2.7 billion year old greenstone belt in the Temagami region of Northeastern Ontario, Canada...

. However, it remains undeformed by strain associated with the formation of the fold. The stock is intruded by dikes
Dike (geology)
A dike or dyke in geology is a type of sheet intrusion referring to any geologic body that cuts discordantly across* planar wall rock structures, such as bedding or foliation...

 composed of biotite
Biotite
Biotite is a common phyllosilicate mineral within the mica group, with the approximate chemical formula . More generally, it refers to the dark mica series, primarily a solid-solution series between the iron-endmember annite, and the magnesium-endmember phlogopite; more aluminous endmembers...

 lamprophyre
Lamprophyre
Lamprophyres are uncommon, small volume ultrapotassic igneous rocks primarily occurring as dikes, lopoliths, laccoliths, stocks and small intrusions...

on its outer margins.
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