What type of rocks are in Isle Royale?

The volcanic rocks on Isle Royale are nearly all basalt, and their mineral con- stituents are plagioclase feldspar, pyroxene, and lesser amounts of olivine, magnetite, and other minerals. A few of the rocks are somewhat more silicic than basalt and would be classified as andesite.

What is the geology of Isle Royale National Park?

The current land mass of Isle Royale is the result of a geologic syncline (a fold in rock layers) that formed the Lake Superior basin. One end of the fold forms Isle Royale, while the other forms the Keweenaw Peninsula.

How was Isle Royale formed?

Isle Royale was formed by igneous rock layers that folded as a result of tectonic plate movement. The folded rock layers curve downward forming the Lake Superior basin and then curve back up again to form the Keweenaw pennisula (see the diagram below).

What landforms are in Isle Royale?

Besides these iconic big mammals, this wilderness island features landforms that speak to dramatic geological history.

Backbone Ridges.
Hiking the Backbones.
Ravines.
Old Shorelines.
Lakes and Wetlands.

What is Michigan green stone?

pumpellyite. The State Gemstone is chlorastrolite, a variety of the mineral pumpellyite. It also goes by the common name of greenstone or Isle Royal greenstone. The term greenstone can be confusing in that it is both a rock and a mineral term.

When was Isle Royale formed?

April 3, 1940
On April 3, 1940, Franklin D. Roosevelt officially established the Isle Royale National Park, which today is the least-visited National Park in the U.S. (outside of Alaska).

What type of ecosystem is Isle Royale?

The island is mostly forested in a mixture of boreal and northern hardwood ecosystems, with a selection of conifer (spruce, fir, pine) and deciduous (birch, aspen, maple, ash) trees.

How old are the Isle Royale rocks?

one billion years
The rocks of the Isle Royale archipelago exhibit more than one billion years of geologic processes, including successive volcanism, sedimentation, uplift, and erosion.

Are there mountains on Isle Royale?

Topography and climate The island is built around three primary ridges, the Minong, Greenstone, and Feldtmann (from northwest to southeast). A similar line of ridges makes up the Porcupine mountains in Michigan’s Upper Peninsula, and some other locations around Lake Superior.

What are Yooperlite rocks?

Yooperlite is a name for rocks that consist of a syenite-rich fluorescent sodalite. Sodalite is mineral that fluoresces an orange or yellow color under ultra violet light. Do these Yooperlight stones really glow in the dark? These rocks are grey in nature when you see them on the beach but glow when under a UV light.

Are there emeralds in Michigan?

There are emeralds in Michigan. Even though the colors of these emeralds are usually light they can still come in dark green to dark blue green. Theses emeralds are found in an old iron mine in Marquette County.

What is special about Isle Royale?

Isle Royale’s unique ecosystem led to it being designated an International Biosphere Reserve in 1980. These isolated islands have only 19 mammal species, compared to over 40 found on the surrounding mainland. The ecological study of wolves on Isle Royale is the longest running large mammal predator-prey study on earth.

What type of geology is Isle Royale?

Geology and Soils. The current land mass of Isle Royale is the result of a geologic syncline (a fold in rock layers) that formed the Lake Superior basin. One end of the fold forms Isle Royale, while the other forms the Keweenaw Peninsula.

How did Lake Superior affect the soil on Isle Royale?

Prior to Lake Superior were two major lake levels that influenced the soils on Isle Royale. Evidence of these different lake levels and the landforms they created is found throughout the island, but it is most obvious on the western end.

What is the relationship between Isle Royale and the Keweenaw Peninsula?

The Isle Royale and Keweenaw Peninsula relationship. The current land mass of Isle Royale is the result of a geologic syncline (a fold in rock layers) that formed the Lake Superior basin. One end of the fold forms Isle Royale, while the other forms the Keweenaw Peninsula.

What are the two major bedrock formations on the island?

There are two major bedrock formations on the island: the Portage Lake Lava series, covering about 85% of the island, and the Copper Harbor Conglomerates, covering about 15% of the island. These geologic formations were modified by four glacial periods, with the last ice-advance occurring some 12,000 years ago.