The Karelides is an ancient mountain

Mountain

Image:Himalaya_annotated.jpg|thumb|right|The Himalayan mountain range with Mount Everestrect 58 14 160 49 Chomo Lonzorect 200 28 335 52 Makalurect 378 24 566 45 Mount Everestrect 188 581 920 656 Tibetan Plateaurect 250 406 340 427 Rong River...

 chain located between Eastern Finland

Eastern Finland

Eastern Finland was a province of Finland from 1997 to 2010. It bordered the provinces of Oulu, Western Finland and Southern Finland. It also bordered Russia.- History :...

 and Lapland. It forms the current hill zone of Eastern Finland and Lapland's arctic hills, splitting central Finland. The Karelides formed about 2000 million years ago, when thick sandstone

Sandstone

Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

 sediments rocked and then folded when continental plates smashed. This made a ridge of quartzite

Quartzite

Quartzite is a hard metamorphic rock which was originally sandstone. Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts. Pure quartzite is usually white to gray, though quartzites often occur in various shades of pink...

, which has stood there for millions of years. The mountains in the north-west corner of Finnish Lapland belong to the newer Scandinavian Mountains

Scandinavian Mountains

The Scandinavian Mountains or the Scandes, in Swedish Skanderna, Fjällen or Kölen , in Finnish Köli and in Norwegian Kjølen, with the three latter meaning The Keel, are a mountain range that runs through the Scandinavian Peninsula...

; because they are newer, they are higher than other Finnish mountains. The third mountain group is Svecofennides, which runs from Southern Finland

Southern Finland

Southern Finland was a province of Finland from 1997 to 2010. It bordered the provinces of Western Finland and Eastern Finland. It also bordered the Gulf of Finland and Russia.- History :...

 to Sweden

Sweden

Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

.