Point of Rocks


Thanks to Peter G.Seroka for the information.


Point of Rocks is a Mesa 15km E of Springer on I-25 in NE New Mexico. It is a phonolite sill, consisting of alkali feldspar, zeolites and nepheline, which caps a mesa of olivine basalts and certaceous sedimentary rocks.


Mineral list: (probably incomplete):
Aegirine
Albite
Analcime
Aragonite
Barite
Calcite
Cancrinite
Carbonate-Fluorapatite
Cryolite
Eudialyte
Fluorite
Galena
Hematite
Kenyaite
Kupletskite
Lorenzenite
Lovdarite
Manganneptunite
Natrolite
Nepheline
Neptunite
Opale
Pectolite
Polylithionite
Pyrrhotite
Rasvumite
R

hodochrosite
Searlesite
Serandite
Sphalerite
Tetranatrolite
Thorbastnaesite
Titanite
Villiaumite


Wind Mountain


Thanks to László Horváth and Peter G.Seroka for providing me with the literature, to Chris Grohusko for the Wind Mt.foto, and especially to Prof.Dr.Wolfgang Stoll for information and the fantastic micro fotos !

There is a second alkaline locality in New Mexico, which is much lesser known and more difficult to access:
Wind Mountain is one of several (about 20) intrusive bodies of syenite, nepheline syenite, phonolite and trachyte, hornfels, too, in the Cornudas Mts. in southern Otero County in New Mexico close to the NM/Texas border, part of the Cornubas Mts./Diablo Plateau complex. They were emplaced in the Eocene as sheets, sills and laccolites in sediments. Namely W.M. is a nepheline syenite with miarolitic cavities.
Obviously there are just blocks on the mountain slope from which to collect, and it shall be difficult to find unweathered blocks with vugs.

Fotos of the mountains courtesy of Chris Grohusko left Wind Mt., reight Cornubas Mts.

Mineral Fotos courtesy of Prof.Dr.Wolfgang Stoll, Hanau, Germany

Mineral list for Wind Mt. (bold=type locality, italics=variety):
Aegirine
Aenigmatite
Analcime
Barite
Catapleiite
Chabazite
Chlorite-group
Eudialyte
Fluorapatite
Fluorite
Gaydonnaite
Georgechaoite
Hematite
Kentbrooksite
Lemoynite
Lovozerite
Microcline
Miserite
Monazite-(Ce?)
Mosandrite
Narsarsukite
Natrolite
Nepheline
Petarasite
Reedmergnerite
Sphalerite
Tetranatrolite
Thomsonite
Xenotime

Mineral list for Cornubas Mts./Diablo Plateau:
Aenigmatite
Analcime
Anorthoclase
Arfvedsonite
Augite
Bastnaesite
Biotite

Catapleiite
„Clinopyroxene“
Eudialyte
Fayalite
Hornblende
Kaersutite
Nepheline
Olivine
Riebeckite
Sodalite


 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


 &Suggested reading:
Boggs,R.C., S.Ghose: Georgechaoite, a new mineral species from Wind Mountain, New Mexico, Can.Mineralogist 23(1985), pp.1-4
Woolley, A.R.: Alkaline Rocks and Carbonatites of the World. Part 1: North and South America. British Museum (Natural History), London, 1987

 

 

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