Tectonic history of the Chihuahua trough, Mexico and adjacent USA, Part I: the pre-Mesozoic setting

Abstract

Elements of a broad zone of northwesterly-trending lineaments, along the southwest margin of the North American craton, have been recurrently active since Middle Proterozoic time. Stratigraphic and structural data indicate the influence of this zone on Paleozoic, Mesozoic, Tertiary and Recent geology of northeastern Chihuahua. The Carrizo Mountain Group (estimated age 1,400-1,300 Ma) must have been deposited in a basin (northwesttrending graben?). Sparse examples of "older" granitic rocks (ca. 1,350-1,270 Ma) suggest widespread magmatism over a large area of Chihuahua, that is in part coeval with emplacement of granitic rocks to the north. The Carrizo Mountain Group depositional basin (graben?) may be the earliest manifestation of the dominant northwesterly-trending structural grain of the region; timing is consistent with oldest known strike-slip movement along the Texas Lineament zone (Stockton Pass, Arizona ca. 1,370±70 Ma). Following deposition of the Carrizo Mountain Group, inferred 1,260-1,160 Ma De Baca rifting affected areas to the north and northwest of the present Carrizo Mountain Group outcrop and subcrop. The rift probably extended into northern Chihuahua and metasedimentary rocks record a marine incursion; presumably from an ocean to the south. It is postulated that the De Baca/Swisher metasedimentary and basaltic rocks represent an intracontinental rift and that there is a genetic relationship between them and the Midcontinent rift. At about the same time as rifting, rocks of the Carrizo Mountain Group underwent their first metamorphism. At around 1,100 Ma, the region was subjected to "Grenville" diastrophism that includes extensive batholith emplacement, thrust faulting, retrograde metamorphism and synorogenic deposition of the Hazel Formation. Pre-Mississippian Paleozoic rocks of the region are the consequence of widespread cratonic shelf deposition along a relatively passive margin of the North American craton. Cambrian and Ordovician rocks include basal transgressive sandstones that reflect a general northeastern advance of seas onto North America. The major event during the early Paleozoic was a change in the boundary of the North American craton during Ordovician time. At about 450 Ma, the Cuyania terrane was separated from the craton and eventually was attached to South America. Local Ordovician, Silurian and Devonian faulting in Texas and New Mexico and disconformities on the Diablo Platform and in central New Mexico indicate periods of shelf exposure. These features may reflect tectonism over large areas, including northern Chihuahua, but their origin and significance is not clear. Four late Paleozoic tectonic pulses, affecting the Ouachita-Marathon system, are recognized in northeastern Chihuahua and adjacent parts of the United States: 1) Mississippian-Pennsylvanian deformation in Ouachita hinterland; 2) Pennsylvanian orogeny; 3) Pennsylvanian-Permian folding and thrusting; 4) Permian erosion/truncation and subsequent tilting

Tectonic history of the Chihuahua trough, Mexico and adjacent USA, Part II: Mesozoic and Cenozoic

“…Near Minas Plomosas an atypical basal conglomerate, derived from underlying Paleozoic rocks, ranges from 2 to 150 m thick and rests on rocks as old as Pennsylvanian. In Part I of this paper (Haenggi, 2001) a small Jurassic island is postulated over a late Paleozoic fold in this area; Araujo-Mendieta and Casar-González (1987) also proposed a Jurassic island (Isla de Guadalupe) here during Kimmeridgian time. Kimmeridgian ammonites are found near the base of the La Casita and Tithonian forms are common near the top of the formation.…”

“…Figure 3A shows a pre-Jurassic regional structural fabric consisting of the broad zone of northwesterlytrending lineaments and intersecting north-trending zones of crustal weakness. Elements of the northwesttrending zone, along the southwest margin of the North American craton, have been recurrently active since middle Proterozoic time (Haenggi, 2001). Intermittent activity of faults of the northerly-trending zones has probably occurred over a similar time span.…”

“…Part I describes pre-Mesozoic events that culminated in development of the late Paleozoic Pedregosa basin, in effect, the proto-Chihuahua trough (see Haenggi, 2001). Part II is an effort to tell the rest of the story.…”

Geologic structure of the northern margin of the Chihuahua trough: Evidence for controlled deformation during Laramide Orogeny

“…This debate has centered on whether the main style of deformation is the thin-or thick -skinned model. Only a few descriptive models (Haenggi, 2001) have been presented to explain the tectonic evolution of the trough. In order to investigate the basin, we reconstructed the tectonic history by means of dynamic, kinematic and geometric analysis.…”

“…In its present confi guration, the Chihuahua trough is a NW -SE elongated elliptical basin bounded by the Aldama Platform to the southwest and by the Diablo Platform to the northeast. The late Paleozoic Pedregosa basin is, in effect, the proto -Chihuahua trough (Haenggi, 2001 …”