Proterozoic , an uplifted Mesoproterozoic batholith The crust underlying the state formed between 1.7 and 1.8 billion years ago as
island arcs. This is recorded in the rocks of the
Moppin Complex, the Gold Hill complex, and the Pecos
greenstone belt in northern New Mexico. These are described as juvenile crust, because their
Nd model ages are close to the crystallization ages determined from
U-Pb dating. This indicates that the material making up the island arcs was extracted from the
Earth's mantle only shortly before the island arcs formed. These rocks are mostly
amphibolites thought to be formed by
metamorphism of
tholeiitic basalt. The island arcs were carried into a
subduction zone along the margin of
Laurentia, the ancient core of North America, around 1700 million years ago, an event called the
Yavapai orogeny. The arcs
accreted to the continental margin, forming a band of new continental crust stretching from Arizona to Newfoundland and from the Wyoming-Colorado border to central New Mexico. These events are recorded in the rocks of the
Vadito Group and
Hondo Group. A second set of slightly younger island arcs accreted to the continented shortly after, around 1650 to 1600 Mya, during the Mazatzal orogeny.
Precambrian rocks crop out across approximately five percent of New Mexico and underlie the entire state. The rocks now exposed at the surface were uplifted during the
Paleozoic, the early
Cenozoic Laramide orogeny as well as block faulting and tilting in the more recent geologic past. For the most part, these rocks are exposed along the Rio Grande rift in the center of New Mexico, except in the
Zuni Mountains and
Big Burro Mountains. The total relief of Precambrian rocks is 11 kilometers. The rocks are 70 percent
plutons and 30 percent supracrustal formed between 1.765 and 1.4 billion years ago in the
Proterozoic, based on
uranium-lead dating. All of the rocks more than 1.65 billion years old show evidence of metamorphism ranging between
greenschist and
amphibolite grade on the sequence of
metamorphic facies. An area in the
Cimarron Range in the vicinity of Taos reached
granulite facies. Geologists debate the extent of different terranes—sections of continental crust—that joined. Metavolcanic rocks in the
Tusas Mountains may be among the oldest, which are intruded by 1.65 billion year old
trondhjemite, but display more than one metamorphic fabric.
Metasomatic 1.68 billion year old stratabound tourmalinites in the Tusas Mountains suggest a localized crustal boron sequestration event occurred during the Yavapai Orogeny. Precambrian rocks formed
volcanogenic polymetallic sulfides, rich in gold, silver and tungsten,
kyanite, copper veins and
pegmatite with
beryllium, lithium,
niobium,
tantalum and
mica. The region was tectonically quiescent until around 1400 Mya, when the poorly understood
Picuris orogeny deformed and metamorphosed much of the crust of New Mexico. This event is recorded in the rock of the
Trampas Group and in extensive
batholiths intruded into the crust throughout the western United States, such as the
Sandia Crest batholith. Following the Picuris orogeny, northern New Mexico was again tectonically quiet, while southern New Mexico experience some deformation associated with the
Grenville orogeny. This is recorded in the
Allamoore and
Tumbledown Formations (about 1250 Mya) and the
De Baca Group and
Los Animas Formation (about 1200 Mya). Thereafter the region experienced steady erosion, which in some cases brought rock near the surface that had been buried as deep as . This beveled much of New Mexico almost completely flat, forming a
peneplain.
Paleozoic (541-251 million years ago) in the
Sangre de Cristo Mountains New Mexico at the start of the Paleozoic was dominated by the
Transcontinental Arch, an elevated region from
Minnesota to northern New Mexico. Small quantities of
alkaline magma were intruded in the early Cambrian along north–south faults, which may indicate incipient rifting of the
New Mexico aulacogen. Later in the Cambrian, the sea began to advance northeast across New Mexico, beginning in the boot heel of the state (
Sauk sequence) and sedimentary beds were deposited during the
Cambrian through
Devonian, beginning with the Cambrian
Bliss Formation. The sea did not submerge the Transcontinental Arch until
Mississippian time. By the late Paleozoic, in the Pennsylvanian and
Permian, the rise of the
Ancestral Rocky Mountains broke the ancient peneplain into basins separated by uplifts. Fossiliferous marine
limestone such as the
Madera Group was deposited in the basin shelves, while areas receiving debris eroded off the highlands formed clastic sedimentary formations such as
Flechado Formation or
Sangre de Cristo Formation. Towards the end of the Pennsylvanian, fluctuations in sea level caused by global
glaciation produced cyclic formations like the
Bursum Formation, marking the transition from marine to continental sedimentation. The latter is recorded by
red bed formations such as the
Abo Formation or the
Cutler Group. The Cutler Group contain important fossil quarries that shed light on the early evolution of
tetrapods. Continental sedimentation began in the north and
prograded to the south. At the same time, a deep basin, the
Delaware Basin, formed in southeastern New Mexico and Texas, surrounded by the massive
Capitan barrier reef. A brief rise in sea level deposited the limestone of the
San Andres Formation across much of New Mexico, making this the most extensive Paleozoic formation exposed in the state. The subsequent retreat of the sea resulted in deposition of large deposits of
gypsum,
potash and salt of the
Castile and
Salado Formations in the Delaware Basin. The
Sevier and
Nevadan orogenies pushed up mountains to the west of New Mexico that produced a
rain shadow, giving New Mexico an exquisitely hot and dry climate through much of the early Mesozoic. The
lower Triassic is recorded nowhere in the rock beds of New Mexico, but the
middle Triassic is recorded in beds of the
Moenkopi and
Anton Chico Formations. The Moenkopi represents deposition in a coastal plain by rivers running to the west. This pattern continued into the
late Triassic, when the climate become somewhat cooler and wetter, and a substantial river system developed through New Mexico that deposited the
Chinle Group. The
Rock Point Formation of the Chinle Group preserved large numbers of fossils of
Coelophysis, one of the earliest known
genera of
dinosaurs. The
Jurassic was again a time of arid climate. A great dune sea, or
erg, spread across northern New Mexico and deposited the sandstone of the
Entrada Formation. This was followed by flooding of northern New Mexico by an arm of the
Sundance Sea, leading to deposition of the limestone and
gypsum beds of the
Todilto Formation. The Jurassic ended with the deposition of the
Summerville and
Morrison Formations, the latter deposited in a vast
foreland basin east of the coastal mountains thrown up by the Sevier orogeny. The increasing weight of the Sonoma mountains to the west drove subsidence of its foreland basin, which included most of New Mexico. During the
Cretaceous, the region was submerged by the
Western Interior Seaway, which deposited shore formations such as the
Dakota Formation and marine formations such as the
Mancos Formation. Advances and retreats of the coastline are recorded in formations such as the
Mesaverde Group. Towards the end of the Cretaceous, shallow subduction of the
Farallon plate drove the
Laramide orogeny, which uplifted the Rocky Mountains and lasted into the
Cenozoic.
Cenozoic (66 million years ago-present) The Laramide Orogeny changed the topography of New Mexico into one of high uplifts and deep basins. The basins began to fill with sediments during the
Eocene, recorded in formations such as the
San Jose Formation, the
Galisteo Formation, and the
Baca Formation. As the Farallon plate disintegrated and sank into the mantle, hot
asthenosphere rock rose to take its place. This helped trigger the
Mid-Tertiary ignimbrite flare-up, which deposited significant ash falls across much of New Mexico. The vast
Mogollon-Datil volcanic field was active during this time, as were the smaller
Latir volcanic field and the
Ortiz porphyry belt beginning about 30 Mya, and the development of Basin and Range geology across the southern part of the state. The development of the Rio Grande rift is recorded in the rocks of the
Santa Fe Group. The
Jemez volcanic field began to develop around 15 Mya, and volcanic activity subsequently spread southwest and northeast along the
Jemez Lineament. The
Valles Caldera (or Jemez Caldera) formed in the Jemez Mountains 1.25 Mya ago in the
Pleistocene, exploding and then collapsing into its magma chamber and emplacing the
Bandelier Tuff. Small mountain glaciers formed in the Brazos and Sangre de Cristo Mountains. ==Natural resource geology==