Historical:Loughridge Sandstone Member: Difference between revisions
mNo edit summary |
(No difference)
|
Latest revision as of 00:14, 21 December 2016
Lithostratigraphy: Ottawa Limestone Megagroup >>Ancell Group >>Glenwood Formation >>Loughridge Sandstone Member
Chronostratigraphy: Paleozoic Erathem >>Ordovician System >>Champlainian Series >>Blackriveran Stage
Allostratigraphy: Tippecanoe Sequence
Authors
H. B. Willman and T. C. Buschbach
Name Origin
The Loughridge Sandstone Member of the Glenwood Formation (Templeton and Willman, 1963, p. 51), the upper sandstone member, is named for Loughridge School, which is 5 miles northwest of the type section.
Type Section
The type section of the Loughridge Sandstone Member is located in a ravine 4 miles north of Grand Detour, Ogle County (N1/2 NW NE NE 25, 23N-9E), where it is 9.8 feet thick.
Extent and Thickness
The Loughridge Sandstone Member is differentiated only in the area where the Daysville Dolomite is present. The Loughridge is commonly less than 10 feet thick in the outcrop area but is 22 feet thick in a well at Dixon.
Description
The Loughridge Sandstone Member has the typical Glenwood texture. It merges westward and northward with the upper part of the Nokomis Sandstone Member and southward in subsurface with the Starved Rock Sandstone Member of the St. Peter Sandstone.
References
TEMPLETON, J. S., and H. B. WILLMAN, 1963, Champlainian Series (Middle Ordovician) in Illinois: Illinois State Geological Survey Bulletin 89, 260 p.
ISGS Codes
Stratigraphic Code | Geo Unit Designation |
---|---|