Geology and mineral resources of the Mifflintown quadrangle, Pennsylvania

Use this link to zoom in and pan around the map: https://ngmdb.usgs.gov/ngm-bin/pdp/zui_viewer.pl?id=46722

Use this link to zoom in and pan around the cross-sections: https://ngmdb.usgs.gov/ngm-bin/pdp/zui_viewer.pl?id=46723

The link to the page for this map is: https://ngmdb.usgs.gov/Prodesc/proddesc_32840.htm

Questions

13. Rock unit Sr (the Rose Hill Formation) in the center of structure A is _______ unit Sb (the Bloomsburg Formation) in the outside of Structure A.

• younger than
• the same age as
• older than

14. Examine the strike and dip symbols around Structure A, especially near the center of the map. The rock beds dip towards the ________ of Structure A.

• center
• outside

15. Structure A is:
(Hint: look at the cross-sections and review structures at Folds and Plunging Folds)

• an anticline
• a plunging anticline
• a syncline
• a plunging syncline

16. Structure B is:
(Hint: look at the cross-sections and review structures at Folds and Plunging Folds)

• an anticline
• a plunging anticline
• a syncline
• a plunging syncline

Curious as to which (compressional) plate tectonic event caused this geologic mess?  Read about it here: http://faculty.kutztown.edu/friehauf/Pennsylvania_history/0275_Pennsylvania_tectonic_history.html

You can also check out this event on the plate tectonic animation through time- look around 300 million years ago. Plate Motion Through Geologic Time