U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database

Geologic Unit: Amalia

Usage:

Amalia Tuff (NM*)
Amalia Formation (CO?,NM)


Geologic age:

Tertiary*
Oligocene*


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

Named from Amalia [New Mexico] Post Office which lies on west side of Costilla Valley, 5 mi southeast of town of Costilla, Taos Co., northern NM. Unit is best exposed east of the Rio Costilla [now Costilla Creek], 4 or 5 mi south of Costilla [approx. Lat. 36 deg. 56 min. 45 sec. N., Long. 105 deg. 27 min. 45 sec. W., Amalia 7.5-min quadrangle], and on north side of canyon formed by Rito de los Cedros [now Cedro Canyon; approx. Lat. 36 deg. 55 min. 45 sec. N., Long. 105 deg. 31 min. 20 sec. W., Costilla 7.5-min quadrangle], Sangre de Cristo Mountains, Taos Co., northern NM (McKinlay, 1956).
Principal reference section: along State Highway 196, 0.5 km west of Amalia (Lipman, 1983).
Reference section designated south of pass between upper Costilla Valley and Underwood Lakes (Lipman, 1983).


AAPG geologic province:

San Luis 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 conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).