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National Geologic Map Database

Geologic Unit: Grondale

Usage:

Grondale Formation of Interlake Group (MT,ND)


Geologic age:

Silurian


Type section, locality, area and/or origin of name:

Type section (subsurface): depth-interval 12,840 to 12,952 ft, Kissinger 1-9 Grondale well, in sec. 9, T. 155 N., R. 94 W., Mountrail Co., ND (Megathan, 1987).


AAPG geologic province:

Williston basin


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates published by U.S. Geological Survey authors.

"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).

Slash (/) indicates name does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).