Quarries

Jacobsville Building Stone

The Jacobsville Sandstone was quarried extensively in the Keweenaw, and the red stone was used all over the midwest and eastern US as a building material. The beds of sandstone had very thick homogeneous layers which facilitated quarrying of very large blocks. Other buildings feature the varigated coloration of the more irregular layers. The rock is cemented sand grains and the variable types of cement, including water soluble calcium carbonate (calcite) cement, means that the Jacobsville blocks can weaken if they are subject to moisture over long time periods. In our local buildings we see the effects of dissolution of this calcite cement.

Decorative Jacobsville blocks are used in many buildings such as the Powerhouse near the Portage Lake Lift Bridge in Houghton. The color variation is typical of many layers in the Jacobsville.

On the eaves and along the ground level, calcite cement dissolves and the rock weakens. The microscopic view below shows the quartz grains and the calcite cement around them. This is what dissolves and causes the rock to crumble.

Michigan Tech Archives

Copper Country Explorer: (an inspiration to all of us!)

Jacobsville Quarries p. 1 Images

Jacobsville Quarries p. 2

Jacobsville Quarries p. 3

Main Quarries of Jacobsville Sandstone:

1.Wolf & Jacobs Quarry (Portage Entry Quarry), north of the lighthouse, began in 1883 and continued to 1898, producing more than 2.5 million cubic feet of top grade and variegated stone.
2.Hebard Quarry (Traverse Bay Redstone), located 22 miles N or Jacobsville, near Mohawk. 1894-6.
3.Kerber-Jacobs Quarry (Stone Quarry Lake), 1892-96, located 2 miles NNW of Jacobsville, near the old town of Red Rock (now abandoned).