Geology and regional implications of carbonatites in the Lemitar Mountains, central New Mexico

Journal Article · Sun Mar 01 04:00:00 EST 1987 · J. Geol.; (United States)

DOI:https://doi.org/10.1086/629123· OSTI ID:5599415

McLemore, V T

More than 100 carbonatite dikes and veins intrude a complex Precambrian terrain in the Lemitar Mountains, New Mexico. These Ordovician carbonatites are not associated with any alkalic rocks or kimberlites, but they exhibit textures, mineralogy, chemistry, and alteration characteristic of carbonatites. Despite variations in texture, the Leminar carbonatites can be grouped on the basis of mineralogy, chemistry, and texture as primary-magmatic and replacement silicocarbonatites and rodbergs. The Lemitar silicocarbonatites consist of more than 50% carbonate minerals and varying amounts of accessory minerals, and they are enriched in LREE. The rodberg consists of more than 50% carbonate minerals, are stained red by hematite, and exhibit flat REE patterns. Carbonate and barite-fluorite-galena veins of uncertain origin are found in the carbonatites and country rocks. Periodic episodes of alkalic magmatism occurred in New Mexico and southern Colorado during the Proterozoic, late Paleozoic, and Tertiary. The Lemitar carbonatites are part of a regional episode of alkalic and carbonatite magmatism which affected New Mexico and southern Colorado during the late Paleozoic. Continental rifting may have occurred during the Precambrian and late Paleozoic in central New Mexico, although exact geographical limits of paleorifts cannot be determined because overlapping periods of tectonism may have affected the area since Paleozoic times. 59 references.

• Research Organization: New Mexico Bureau of Mines and Mineral Resources, Socorro
• OSTI ID: 5599415
• Journal Information: J. Geol.; (United States), Journal Name: J. Geol.; (United States) Vol. 95:2; ISSN JGEOA
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580300* -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
CARBONATE MINERALS
CHEMISTRY
DIKES
ELEMENTS
FEDERAL REGION VI
GEOCHEMISTRY
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
METALS
MINERALOGY
MINERALS
MOUNTAINS
NEW MEXICO
NORTH AMERICA
ORIGIN
RARE EARTHS
TEXTURE
USA
VOLCANISM