Tertiary mafic intrusive rocks

Includes many long basaltic andesite dikes of Oligocene age near Pie Town, Acoma, Riley, Chupadera, Truth or Consequences, Roswell, Raton, and Dulce; and several elongate or shoestring-like sills of basalt or basaltic andesite. Also includes basaltic necks of Pliocene age that dot the landscape northeast of Mount Taylor. Where dikes extend into Quaternary alluvium the contact is an unconformity.
State New Mexico
Name Tertiary mafic intrusive rocks
Geologic age Pliocene to upper Eocene
Lithologic constituents
Major
Igneous > Hypabyssal > Mafic-hypabyssal > Hypabyssal-basaltic-andesite (Dike or sill)
Igneous > Hypabyssal > Mafic-hypabyssal > Hypabyssal-basalt (Dike or sill)
References

New Mexico Bureau of Geology and Mineral Resources, 2003, Geologic Map of New Mexico, scale 1:500,000 (includes some new polygons, faults, and attributes not in NM001 - heads up digitizing by JHorton).

NGMDB product
Counties Catron - Cibola - Colfax - McKinley - Otero - Rio Arriba - Sandoval - San Juan - Sierra - Socorro - Taos - Torrance - Valencia