Hatchet Mountains Research Articles

In search of bachelorettes: Observations of male Leptonycteris yerbabuenae with dorsal patches across its range

The lesser long-nosed bat (Leptonycteris yerbabuenae) is a partially migratory, nectarivorous species that exhibits reproductive asynchrony across its range. Both migratory and resident populations of sexually active males of L. yerbabuenae may form an odoriferous dorsal patch during their mating season. This is created by smearing saliva, urogenital fluids, and anal secretions over the interscapular dorsal region with their feet. Dorsal patches are believed to influence female mate choice. We synthesized the sightings of male dorsal patches across the species’ range, including gathering new observations of male L. yerbabuenae with dorsal patches captured at the northern extent of their range and citing previously unreported observations that we obtained by contacting other researchers. We also conducted a literature review to include all previously documented records of male L. yerbabuenae presenting dorsal patches. We document the first observations of male L. yerbabuenae with dorsal patches in the southwestern United States. In the Big Hatchet Mountains in New Mexico, we captured 1 male with a developed dorsal patch (i. e., bare dorsal skin with sticky fur) on 25 July 2019 and two others on the night of 13 August 2019. New observations of males with developed dorsal patches were obtained from Hilltop Mine in Arizona (June 2006 or 2007) and at a hummingbird feeder at a residence near the Hilltop Mine (July 2013). A male with a recovering dorsal patch (i. e., bare dorsal skin with regenerating fur) was also captured in a roost near Patagonia, Arizona, in late August 2008 and at a hummingbird feeder at a residence near Silver City, New Mexico (September 2021). All previously published records of males with dorsal patches occurred in roosts in Mexico during known mating seasons. These new observations suggest that L. yerbabuenae may breed in New Mexico and Arizona between June and August, but follow-up studies are needed to confirm this behavior. Much of the reproductive biology of this important pollinator remains unknown. Therefore, identifying regions where males present dorsal patches may not only assist in locating and protecting mating roosts, but would also further our understanding of the population ecology of this migratory species.

Mesozoic–Paleogene structural evolution of the southern U.S. Cordillera as revealed in the Little and Big Hatchet Mountains, southwest New Mexico, USA

Mesozoic–Paleogene structural evolution of the southern U.S. Cordillera as revealed in the Little and Big Hatchet Mountains, southwest New Mexico, USA

Lithostratigraphy and microfossil biostratigraphy of the Pennsylvanian-lower Permian Horquilla Formation at New Well Peak, Big Hatchet Mountains, New Mexico, USA

Lithostratigraphy and microfossil biostratigraphy of the Pennsylvanian-lower Permian Horquilla Formation at New Well Peak, Big Hatchet Mountains, New Mexico, USA

Onset of the Laramide orogeny and associated magmatism in southern New Mexico based on U-Pb geochronology

The Laramide orogeny is a classic yet controversial mountain-building event that resulted, in the southwest United States, in uplifts, sedimentation, and magmatism that can be used to constrain the onset of this event in the region and expand our knowledge of Late Cretaceous to Paleogene tectonism. The McRae Formation marks the onset of deposition in the Laramide Love Ranch Basin, which was located to the northeast of the west-northwest-trending coeval Rio Grande uplift in south-central New Mexico, but its age is not well constrained. A previously published late Maastrichtian age for the McRae Formation was based on the presence of dinosaur bones in the upper of two members of the formation. We obtained new U-Pb dates from one dacite clast and three ash-fall tuffs from the lower Jose Creek Member and from one ash-fall tuff from the lower part of the overlying Hall Lake Member of the McRae Formation. The clast yielded a date of 75.0 ± 1.1 Ma, whereas the ages of the tuffs, in ascending stratigraphic order, are 74.9 ± 0.7 Ma, 74.7 ± 0.6 Ma, 75.2 ± 1.3 Ma, and 73.2 ± 0.7 Ma. These dates indicate that the onset of Laramide deposition in the Love Ranch Basin must have occurred earlier, in late Campanian time, similar to deposition in the Laramide Ringbone Basin in southwestern New Mexico. In addition, U-Pb zircon dates of 75.7 ± 1.3 Ma and 75.0 ± 2.8 Ma were obtained on the Twin Peaks stock and on a dacite sill, respectively, in the Burro Mountains of southwestern New Mexico. These dates are similar to those of other Laramide arc magmatic centers in southern New Mexico, which have a limited range of ages from 75 to 70 Ma, including the Hidalgo Formation in the Little Hatchet Mountains, the Silver City-Pinos Altos region, and the Copper Flat porphyry system. These new and previously published dates indicate that during the onset of Laramide deformation in southwestern and south-central New Mexico, the angle of subduction of the Farallon plate may have been steep enough to allow partial melting of an asthenospheric wedge, resulting in arc magmatism far inboard of the trench.

Timing of Late Cretaceous shortening and basin development, Little Hatchet Mountains, southwestern New Mexico, USA – implications for regional Laramide tectonics

AbstractLaser ablation‐multi collector‐inductively coupled mass spectrometry U‐Pb geochronology, detailed field mapping and stratigraphic data offer improved insights into the timing and style of Laramide deformation and basin development in the Little Hatchet Mountains, southwestern New Mexico, USA, a key locality in the ‘southern Laramide province.’ The Laramide synorogenic section in the northern Little Hatchet Mountains comprises upper Campanian to Maastrichtian strata consisting of the Ringbone and Skunk Ranch formations, with a preserved maximum thickness of >2400 m, and the correlative Hidalgo Formation with a total thickness >1700 m. The Ringbone Formation and superjacent Skunk Ranch Formation are each generally composed of (1) a basal conglomerate member; (2) a middle member consisting of lacustrine shale, limestone, sandstone, and interbedded ash‐fall tuffs; and (3) an upper sandstone and conglomerate member. Basaltic andesite flows are intercalated with the upper member of the Ringbone Formation and the middle member of the Skunk Ranch Formation. The Hidalgo Formation, which crops out in the northern part of the range, is dominantly composed of basaltic andesite breccias and flows equivalent to those of the Ringbone and Skunk Ranch formations. The Laramide section was deposited in an intermontane basin partitioned across intrabasinal thrust structures, which controlled growth‐stratal development. U‐Pb zircon ages from five tuffs indicate that the age range of the Laramide sedimentary succession is ca. 75–70 Ma. U‐Pb detrital‐zircon age data (n = 356 analyses) from the Ringbone Formation and a Lower Cretaceous unit indicate sediment contribution from uplifted Lower and Upper Cretaceous rocks adjacent to the basin and the contemporary Tarahumara magmatic arc in nearby northern Sonora, Mexico. The new ages, combined with published data, indicate that uplift, basin development, and magmatism in the region proceeded diachronously northeastwards as the subducting Farallon slab flattened under northern Mexico and southern New Mexico from Campanian to Palaeogene time.

Amphibians and Reptiles of the Madrean Archipelago of Arizona and New Mexico

The Madrean Archipelago in southern Arizona and southwestern New Mexico consists of 22 mountain ranges south of the Mogollon Rim. Herpetofaunal lists for these ranges and a segment of the rim were constructed based on museum specimens from Madrean evergreen woodland, petran montane conifer forest, and interior chaparral. Few or no species have been recorded from these communities in the Sierrita, Little Dragoon, and Big Hatchet mountains, emphasizing the need for additional sampling in the archipelago. A total of 83 species are found in the remaining 20 ranges, with lizards (28) and snakes (35) predominating. No two mountain ranges had the same herpetofauna. Species richness varies from 15 to 44 (mean 28.1). Phenetic analyses of herpetofaunal similarity among the ranges identify three groups: a northern group with eight ranges from the Rincon Mountains to the Pinaleño Mountains to the Sierra Ancha; a southwestern group consisting of the Baboquivari, Santa Rita, Pajarito, and Patagonia mountains; and a southeastern group with seven ranges from the Huachuca and Whetstone mountains to the Animas Mountains; the Mogollon Rim segment is placed as the first “branch” of the phenogram. The analyses place the Patagonia Mountains in the SW group and the Huachuca Mountains in the SE group, although the two are connected by woodland. The Madrean line separating the northern group from the two southern groups approximates the southern limit of interior chaparral. The ranges of the southwestern group are in contact with semitropical Sonoran desert scrub at low elevations, whereas Chihuahuan desert scrub and semidesert grassland surround the southeastern ranges. With few exceptions, published studies of phylogeography within species suggest that divergence among montane populations in the archipelago does not predate the Pleistocene. Phylogeographic analyses using nuclear and mitochondrial gene sequences and including all ranges of the Madrean Archipelago inhabited by a species are needed to determine the extent to which shared historic biogeographic events may underlie the groups of mountain ranges identified on the basis of herpetofaunal similarities in this study.

Late Cretaceous U–Pb tuff ages from the Skunk Ranch Formation and their implications for age of Laramide deformation, Little Hatchet Mountains, southwestern New Mexico, U.S.A.

LA-ICPMS U–Pb ages of individual zircon crystals from reworked ash-fall tuff beds in lacustrine strata of the Skunk Ranch Formation, a synorogenic unit deposited in a Laramide intermontane basin in the Little Hatchet Mountains, southwestern New Mexico, indicate an early Maastrichtian depositional age of 71–70 Ma. The dated beds are equivalent to nearby growth strata that are partially cut by, and folded over, a Laramide reverse fault. The strata thus record final displacement on the reverse fault and indicate an early Maastrichtian age for fault offset. The Skunk Ranch Formation was previously interpreted as Eocene in age and inferred to record the second event in a two-stage Laramide deformational history in the mountain range. In addition to significantly condensing the age range of the Laramide section and clarifying stratigraphic correlation in the Little Hatchet Mountains, the new ages of the formation also indicate that Laramide deformation in the range was likely restricted to a single Late Cretaceous episode.

Detrital zircon geochronology from the Cambrian-Ordovician Bliss Sandstone, New Mexico: Evidence for contrasting Grenville-age and Cambrian sources on opposite sides of the Transcontinental Arch

Cambrian sandstones of the western United States and northern Mexico record deposition above a major unconformity on the rift margin of Laurentia. Detrital zircon ages from the Cambrian-Ordovician Bliss Sandstone in southern New Mexico are used to test models for the influence and significance of the Transcontinental Arch during the early Paleozoic. We obtained U-Pb zircon ages of basement rocks to test potential local source rocks in New Mexico. An orthogneiss in the Florida Mountains has an age of 1627 ± 18 Ma (all errors 2σ). The San Diego Mountain granite underlying the Bliss Sandstone is ∼1400 Ma. A rapakivi granite in the Little Hatchet Mountains has a U-Pb Concordia age of 1077 ± 4 Ma, coeval with the Pikes Peak granite and several granites in Sonora, Mexico. Three samples of the Florida Mountains granite underlying the Bliss Sandstone yield an average age of 510 ± 5 Ma; this is a rare and distinctive age of magmatism in western Laurentia. Zircons with these ages can be used as tracers for understanding transportation paths of sediment. The Bliss Sandstone was studied from eight localities in southern New Mexico; one overlies the Cambrian Florida Mountains granite, and three lie to the west. The sandstones are quartzarenite, subarkose, and arkose. The most abundant detrital zircon population included Grenville ages with a main peak at 1250 Ma. Other significant peaks are at 1465 Ma, 1625 Ma, 1710 Ma, and 1850 Ma, and these populations generally decrease in abundance with increasing age. Only five Archean zircons (out of 845) were discovered. Cambrian detrital zircons are present in the Florida Mountains Bliss Sandstone locality, directly overlying the Cambrian granite. They are also present in two localities 60–80 km southwest and northwest of the Florida Mountains. Maximum depositional ages from sandstones with Cambrian zircons range from 509 ± 7 Ma to 504 ± 12 Ma, overlapping with the age of the Florida Mountains granite. The four localities east of the Florida Mountains did not have any Cambrian detrital zircons. We interpret these data as indicating that the Cambrian intrusions of the Oklahoma-Colorado rift were not a source for the Cambrian zircons in the Bliss Sandstone. The Tapeats Sandstone in the Grand Canyon does not have Cambrian zircons and has a minor Grenville peak at 1070 Ma (Gehrels et al., 2011), significantly younger than the 1250 Ma Grenville peak in the Bliss Sandstone. We interpret these differences as being related to different source areas on opposite sides of the Transcontinental Arch. The differences in the specific ages of Cambrian plutons between the Oklahoma rift and the Florida Mountains granite can be used to test depositional models for other Cambrian sandstones of the southwest U.S. and in Mexico, where the presence of Cambrian zircons in the Caborca Block has implications for the Mojave-Sonora megashear hypothesis.

Upper Cretaceous marine strata in the Little Hatchet Mountains, southwestern New Mexico

Upper Cretaceous marine strata in the Little Hatchet Mountains, southwestern New Mexico

Late Jurassic invertebrate fossils from the Little Hatchet Mountains, southwestern New Mexico

Late Jurassic invertebrate fossils from the Little Hatchet Mountains, southwestern New Mexico

Abstract: Structural controls on shelf margin evolution and reservoir distribution in Pennsylvanian Icehouse conditions: South Dagger Draw Field, New Mexico and Big Hatchet Mountains, New Mexico

Abstract: Structural controls on shelf margin evolution and reservoir distribution in Pennsylvanian Icehouse conditions: South Dagger Draw Field, New Mexico and Big Hatchet Mountains, New Mexico

Broken Jug Formation--Redefinition of lower part of Bisbee Group, Little Hatchet Mountains, Hidalgo County, New Mexico

Broken Jug Formation--Redefinition of lower part of Bisbee Group, Little Hatchet Mountains, Hidalgo County, New Mexico

Newly Discovered Pennsylvanian Channel, Big Hatchet Mountains, Southwestern New Mexico: ABSTRACT

Newly Discovered Pennsylvanian Channel, Big Hatchet Mountains, Southwestern New Mexico: ABSTRACT

Relationship of Laramide and Basin and Range Structures in the Pedregosa Basin, Southwestern New Mexico: ABSTRACT

The Pedregosa basin of southwestern New Mexico has long been recognized as a frontier hydrocarbon exploration target. The Paleozoic sedimentary rocks contain petroleum source and reservoir units that correlate with important producing zones in the Permian basin of west Texas and southeastern New Mexico. Factors that are commonly considered to limit the petroleum potential of the region include multiple episodes of deformation, heating due to local igneous intrusion and volcanism, and fresh-water flushing. Laramide (late Cretaceous-early Tertiary) fold-and-thrust traps are structural targets. Subsequent fracturing by Basin and Range (late Tertiary) normal faulting may have partially destroyed the Laramide traps. Seismic reflection and gravity data from the Playas and Hatchita valleys in southwestern New Mexico constrain the structural styles of Laramide shortening and later Basin and Range extensional deformation. These data show that Precambrian basement was involved in Laramide thrusting. This observation refutes the interpretation of some previous workers who interpreted the Precambrian basement surface as a regional decollement for Laramide thrusting. An east-west seismic profile that crosses the southeast end of the Little Hatchet Mountains images a range-bounding listric normal fault and associated antithetic faults beneath the Hatchita Valley fill. Near the range, [open quotes]antithetic[close quotes] faults show a normalmore » sense of motion, but farther east, faults are reverse. The latter may be high-angle Laramide structures or unusual features of Basin and Range deformation. The major range-bounding fault is steeply dipping Near the surface, but becomes a low-angle listric fault at a depth of about 10 km.« less

Laramide stratigraphy of the Little Hatchet Mountains, southwestern New Mexico

Laramide stratigraphy of the Little Hatchet Mountains, southwestern New Mexico

Late cretaceous dinosaurs from the ringbone formation, southwestern New Mexico, U.S.A.

Fossils of theropod dinosaurs (cf. Albertosaurus ) indicate that the Ringbone Formation in the northern Little Hatchet Mountains of southwestern New Mexico is of Late Cretaceous (late Campanian-Maastrichtian) age. The broad distribution of the Ringbone and probable correlatives suggests the presence of one or more Laramide basins of lacustrine and fluvial deposition across southwestern New Mexico, southeastern Arizona and northern Mexico during the latest Cretaceous. This confirms previous paleogeographies that posit nonmarine conditions in this area by Coniacian time and thus does not support a recent suggestion of a latest Cretaceous-Eocene seaway in northern Mexico and southern New Mexico.

Mineral Lick Use and Movement in a Remnant Desert Bighorn Sheep Population

Following a precipitous decline from approximately 150 animals in the 1950's, bighorn sheep (Ovis canadensis mexicana) in the Big Hatchet Mountains of southwestern New Mexico had failed to increase beyond 20-25 sheep. Monitoring of this herd from June 1976 to May 1978 revealed an unusual trans-desert movement pattern which resulted in the disappearance of young lambs (Lenarz 1979). Sheep apparently left the mountain range to use sodium-rich mineral licks (Watts 1979). Our paper examines the relationships between this movement pattern, possible recurring sodium deficiencies in the sheep, and associated lamb mortalities.

Aptian-Albian ammonoids of the Oyster Limestone Member of the U-Bar Formation, Big Hatchet Mountains, southwestern New Mexico

Aptian-Albian ammonoids of the Oyster Limestone Member of the U-Bar Formation, Big Hatchet Mountains, southwestern New Mexico

Devonian and Mississippian Stratigraphy and Depositional Environments in Big Hatchet Mountains of Southwestern New Mexico: ABSTRACT

In the Big Hatchet Mountains the Upper Devonian Percha Shale rests unconformably on the Upper Ordovician Montoya Formation and is overlain by strata referred to the upper part of Sabin's Portal Formation. To date, this is the farthest east the Portal has been observed. Devonian rocks record a shallowing-up sequence from the lower Percha (Ready Pay-Box Members) deposited in quiet water to the Portal grainstone deposited at or above wave base. The Portal contains Upper Devonian (Famennian) conodonts indicative of Sandberg's shallow-water polygnathid-icriodid biofacies. Mississippian strata, represented by the Escabrosa Group, contain Early Mississippian (Osagean) conodonts at the base. Lower Mississippian strata record 2 Osagean cycles of submergence and emergence. Encroachment began in the early Osagean (isosticha-upper crenulata Zone) when the basal oolitic grainstones of the Bugle member of the Keating Formation were deposited. A shallowing-up sequence followed, culminating in the deposition of high-energy grainstones of the upper Bugle. The end of Bugle deposition is marked by a second submergence (lower typicus-Anchoralis latus Zone) when argillaceous wackestones were deposited. This deepening continued during deposition of the basal Witch member. Regression began during deposition of the Witch, as suggested by the vertical sequence from fine-g ained mudstones to high-energy grainstones. This shallowing sequence continues into the lower Hatchita Formation. End_of_Article - Last_Page 509------------

Tertiary Volcanic Centers as Constraints on Oil and Gas Potential of Basin and Range Province: New Mexico Segment of Pedregosa Basin: ABSTRACT

Stratigraphic similarities with the Permian basin and structural similarities with the Overthrust belt make the New Mexico segment of the Pedregosa basin an attractive target for petroleum exploration. Middle Tertiary volcanic cover and postvolcanic faults introduce constraints, as elsewhere in the Basin and Range province. Geologic mapping in southwesternmost New Mexico (Hidalgo County) has traced Oligocene ash-flow tuff sheets to at least nine major cauldrons, including Valles-type resurgent cauldrons 10 to 40 km wide (Apache Hills: Apache cauldron; southern Pyramid Mountains: Muir cauldron; southern Animas Mountains: Tullous, Juniper, Animas Peak, Cowboy Rim, San Luis cauldrons; southern Peloncillo Mountains: Rodeo and Geronimo Trail cauldrons). Faulted-off cauldron segments continue beneath the Playas, Animas-San Luis, and San Simon-San Bernadino Valleys. Composite batholiths probably underlie cauldron clusters, as in the San Juan and Mogollon-Datil volcanic fields. Exposed monzonitic plutons (Apache Hills, Pyramid Mountains, Animas Mountains) are apophyses, emplaced during resurgence. Other plutons, apparently unrelated to cauldrons, are present in the northern Pyramid and Little Hatchet Mountains. Distribution of cauldrons and plutons suggests that much of the Pyramid, Peloncillo, Little Hatchet, and Animas Mountains, Apache Hills, and adjacent valleys are unfavorable for petroleum accumulations. However, destructive thermal effects may be confined to aureoles extending only about 1,000 m from intrusive contacts, as in the KCM 1 Forest Federal wildcat. Cauldrons and thermal effects deleterious to petroleum potential are unknown in so theastern Hidalgo County (Dog, Alamo Hueco, Big Hatchet Mountains, southern Sierra Rica). End_of_Article - Last_Page 759------------