Late Cretaceous volcanism in south-central New Mexico: Conglomerates of the McRae and Love Ranch Formations

Conference · Thu Apr 01 00:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5291158

Chapman-Fahey, J L; McMillan, N J; Mack, G H; Seager, W R ^[1]

---

1. New Mexico State Univ., Las Cruces, NM (United States). Dept. of Geological Sciences

Evidence to support Late Cretaceous volcanism in south central New Mexico is restricted to a small area of 75-Ma-old andesitic rocks at Copper Flats near Hillsboro, and volcanic clasts in the McRae (Late Cretaceous/Paleocene ) and Love Ranch (Paleocene/Eocene). Formations located in the Jornada del Muerto basin east and northeast of the Caballo Mountains. Major and trace element data and petrographic analysis of 5 samples from Copper Flats lavas and 40 samples of volcanic clasts from the McRae and Love Ranch conglomerates will be used to reconstruct the Cretaceous volcanic field. The McRae Formation consists of two members: the lower Jose Creek and the upper Hall Lake. The lowermost Love Ranch Formation is unconformable in all places on the Hall Lake Member. Stratigraphic variations in clast composition from volcanic rocks in the lower Love Ranch Formation to Paleozoic and Precambrian clasts in the upper Love Ranch Formation reflect the progressive unroofing of the Laramide Rio Grande Uplift. Volcanic clasts in the McRae and Love Ranch Formations were derived from the west and south of the depositional basin, but the source area for McRae clasts is less well constrained. Stratigraphic, chemical, and petrographic data will be used to reconstruct the volcanic complex and more clearly define magma genesis and metasomatism associated with Laramide deformation.

• OSTI ID: 5291158
• Report Number(s): CONF-9305259-; CODEN: GAAPBC
• Journal Information: Geological Society of America, Abstracts with Programs; (United States), Vol. 25:5; Conference: 89. annual meeting of the Cordilleran Section and the 46th annual meeting of the Rocky Mountain Section of the Geological Society of America (GSA), Reno, NV (United States), 19-21 May 1993; ISSN 0016-7592
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
CONGLOMERATES
GEOCHEMISTRY
PETROGRAPHY
STRATIGRAPHY
GEOLOGIC FORMATIONS
NEW MEXICO
ANDESITES
CHEMICAL COMPOSITION
CRETACEOUS PERIOD
GEOLOGIC HISTORY
VOLCANISM
CHEMISTRY
DEVELOPED COUNTRIES
GEOLOGIC AGES
GEOLOGY
IGNEOUS ROCKS
MESOZOIC ERA
NORTH AMERICA
ROCKS
SEDIMENTARY ROCKS
USA
VOLCANIC ROCKS
580000* - Geosciences