Kiruna porphyry ( Swedish: Kirunaporfyr) is a group of igneous rocks found near Kiruna in northernmost Sweden. [1] The Kiruna Porphyry formed 1,880 to 1,900 million years ago [1] [2] during the Paleoproterozoic Era in connection to the Svecofennian orogeny. [2]
The iron- apatite ore mined in Kiruna, Malmberget and Svappavaara are all hosted in Kiruna porphyry. [2] While generally well-preserved for its age at some locations such as Malmberget the Kiruna porphyry is more metamorphosed. [1]
In detail, various rock types are distinguished in the Kiruna porphyry such as trachyandesite lava and quartz-bearing porphyry of rhyolitic composition. [1] These two rocks are traditionally known as " syenite porphyry" and "quartz porphyry" respectively ( Swedish: syenitporfyr , kvartsporfyr). [2] [1] The former is found on the foot wall of the Kiruna iron ore body, while the latter is found in the hanging wall. [1] Part of the quartz-bearing porphyry is thought to be ignimbrite. [1] The Haparanda Series of rocks found to east near the Sweden-Finland border are thought to have the same origin as the Kiruna porphyry. [3]
Kiruna porphyry ( Swedish: Kirunaporfyr) is a group of igneous rocks found near Kiruna in northernmost Sweden. [1] The Kiruna Porphyry formed 1,880 to 1,900 million years ago [1] [2] during the Paleoproterozoic Era in connection to the Svecofennian orogeny. [2]
The iron- apatite ore mined in Kiruna, Malmberget and Svappavaara are all hosted in Kiruna porphyry. [2] While generally well-preserved for its age at some locations such as Malmberget the Kiruna porphyry is more metamorphosed. [1]
In detail, various rock types are distinguished in the Kiruna porphyry such as trachyandesite lava and quartz-bearing porphyry of rhyolitic composition. [1] These two rocks are traditionally known as " syenite porphyry" and "quartz porphyry" respectively ( Swedish: syenitporfyr , kvartsporfyr). [2] [1] The former is found on the foot wall of the Kiruna iron ore body, while the latter is found in the hanging wall. [1] Part of the quartz-bearing porphyry is thought to be ignimbrite. [1] The Haparanda Series of rocks found to east near the Sweden-Finland border are thought to have the same origin as the Kiruna porphyry. [3]