225 MYA - 1800 CE
This movement helped to push the vein of Onondaga limestone into its current position |
As the sediments in both the Onondaga Limestone and Bedford Indiana Limestone were busy cementing, the face of our planet was changing drastically, or should I say Jurassic-ally? The Landmass known as Pangea (of which Euramerica was a part) was slowly breaking up to form the continents we know today. During this time, the continental plate on which present day New York resides switched from traveling southward to traveling northward.
The Atlantic plate continued to expand, causing a continual subversion of it under the Acadian plate. This movement helped to push the vein of Onondaga limestone into its current position.1 Evidence of the effects of the Acadian orogeny on the position of Onondaga limestone lies in the abundance of non-parallel strata (layers of rock), the presence of intrusion of igneous rock in Devonian formations, regional metamorphism of some devonian era rocks, and deformation of Devonian era rocks. Subsequent movement from the Taconic orogeny to the east of the Hudson River Valley also helped to move some of the Onondaga limestone into its current position. 2 Meanwhile, the Salem limestone in Indiana was also being pushed north with the reversal of the direction of the euramerican plate. The formation of two basins, or depressions in the bedrock, allowed for the sediment eroded from small hills and mountains built from tectonic movement and from the calcium rich microfossil sediment to settle in thick layers. Today, these basins are located to the Northeast and Southwest of Indiana in Illinois and Michigan. However, the presence of these basins provides for the existence of Salem limestone in Indiana. 3 |
Image from: https://igs.indiana.edu/images/bedrock/about1.jpg
Proceed to tag #5
Sources:
1 Rogers, W. B., Isachsen, Y. W., Mock, T. D., & Nyanay, R. E. (1990). New York
state geological highway map [Map]. The University of the State of New York.
2 United States Geological Survey (Ed.). (2015). Valley and ridge province.
Retrieved May 17, 2016, from United States Geological Survey website:
http://3dparks.wr.usgs.gov/nyc/valleyandridge/valleyandridge.htm
3 Powell, W. G. (2004). Indiana limestone. Retrieved May 16, 2016, from
http://academic.brooklyn.cuny.edu/geology/powell/613webpage/NYCbuilding/
IndianaLimestone/IndianaLimestone.htm
1 Rogers, W. B., Isachsen, Y. W., Mock, T. D., & Nyanay, R. E. (1990). New York
state geological highway map [Map]. The University of the State of New York.
2 United States Geological Survey (Ed.). (2015). Valley and ridge province.
Retrieved May 17, 2016, from United States Geological Survey website:
http://3dparks.wr.usgs.gov/nyc/valleyandridge/valleyandridge.htm
3 Powell, W. G. (2004). Indiana limestone. Retrieved May 16, 2016, from
http://academic.brooklyn.cuny.edu/geology/powell/613webpage/NYCbuilding/
IndianaLimestone/IndianaLimestone.htm