Igneous Rocks:
* Intrusive Igneous:
* Granite: Found in the Harding Icefield, forming the bedrock beneath the glaciers. It's a coarse-grained rock, rich in quartz, feldspar, and mica.
* Diorite: Less common than granite, but still present in the area. It's a darker, more mafic rock with less quartz and more plagioclase feldspar.
* Extrusive Igneous:
* Basalt: Found as lava flows and volcanic ash deposits. It's a dark, fine-grained rock rich in iron and magnesium.
* Rhyolite: Less common, but found in the form of volcanic domes and ash layers. It's a light-colored, fine-grained rock with high silica content.
Sedimentary Rocks:
* Sandstone: Formed from eroded and deposited sand grains, often found along the coast and in valleys.
* Conglomerate: Composed of rounded pebbles and larger rock fragments cemented together.
* Shale: A fine-grained sedimentary rock formed from clay and silt.
Metamorphic Rocks:
* Schist: Formed from the transformation of sedimentary or igneous rocks under high pressure and heat. It has a foliated texture, meaning it has layers.
* Gneiss: A metamorphic rock with a distinct banded appearance, often formed from granite.
Other Notable Features:
* Glacial Deposits: The park showcases various glacial deposits, including moraines (piles of rock and debris left behind by retreating glaciers), outwash plains (flat areas formed by meltwater deposits), and till (unsorted glacial debris).
* Fjords: These dramatic, U-shaped valleys were carved by glaciers and now fill with seawater.
The rock formations in Kenai Fjords National Park are a testament to the powerful geological forces that have shaped this region over millions of years. They offer a fascinating insight into the earth's history and the impact of glaciers and volcanic activity on the landscape.
