Sacramento Mountains Research Articles

Mechanical Stratigraphy and Deformation of the Gobbler Anticline, Sacramento Mountains, New Mexico, USA

Mechanical Stratigraphy and Deformation of the Gobbler Anticline, Sacramento Mountains, New Mexico, USA

Carbonate submarine fan deposits of the Mississippian Lake Valley Formation, Sacramento Mountains, New Mexico

AbstractDeep‐water carbonate deposition is relatively poorly understood but an area of vigorous research in academia and industry, where these deposits are a significant component of many unconventional petroleum reservoirs. Recent studies of modern deep‐water carbonates have highlighted the wide variety of depositional processes, sediment types and resultant geomorphology; however, well‐documented outcrops of ancient systems, their rock types and architecture are relatively sparse. The Mississippian Lake Valley Formation provides world‐class exposures of slope‐basinal carbonate deposits. The Tierra Blanca and Doña Ana members comprise submarine fans that are >14 to 20 km in length, >5 km wide, and exposed in strike and dip view, affording a unique opportunity to constrain the architecture, rock types and sedimentary processes. Tierra Blanca and Doña Ana sedimentation was dominated by crinoids shed from an up‐dip platform and supplemented by sediments sourced locally from Waulsortian mounds. Depositional processes include turbidity flows, debris flows and hybrid sediment‐gravity flows. The Tierra Blanca submarine fan thins towards its lateral flanks and distal fringe, where deposits become more mud‐dominated, gravelly grain‐supported flows are less common, and fewer beds have scoured bases. In proximal settings, bed tracing complemented by measured sections allow mapping of stratal surfaces and identification of stories, elements and complexes. The Tierra Blanca evolved from more unconfined to confined deposition. Point‐sourced deposition of the Tierra Blanca fan required a funnelling mechanism, probably due to bathymetry created by Waulsortian mounds or possibly a platform margin re‐entrant. Outcrop exposures illustrate that younger Doña Ana submarine fan deposits onlap onto, and compensationally stack with, the thickest portions of the antecedent Tierra Blanca fan. These outcrops illustrate both similarities and differences between carbonate and siliciclastic gravity flow deposits. Similarities include comparable deposit types, depositional processes and architecture; differences relate to hydrodynamics of carbonate grains, funnelling mechanisms for point‐sourced deposits and sequence stratigraphic forcing.

To model or not to model: false positive detection error in camera surveys

AbstractOccupancy models are commonly used with motion‐sensitive camera data to estimate patterns of species occurrence while accounting for false negative detection error (i.e., the species is present but not detected). False positive detection error (i.e., the species is not present but is detected) is present in camera data sets, especially when morphologically similar species co‐occur. Researchers use different approaches to address this problem: ignore the potential for false positive detections, remove all ambiguous detections and treat them as non‐detections, or model false positive detection error by dividing detections into ambiguous detections (could be true or false positives) and unambiguous detections (true positives). We performed a simulation study to compare these 3 strategies. To implement these modeling strategies, detections must be classified as ambiguous or unambiguous, or all ambiguous detections must be re‐classified as non‐detections. We also performed a simulation study to assess the impact of researcher confidence in the designation of ambiguous and unambiguous detections. Ignoring false positive detection error resulted in biased parameter estimates, whereas removing ambiguous detections and modeling false positive detections resulted in similar estimates of occupancy probability (ψ) in most situations. Researcher over‐confidence (i.e., the tendency for observers to overestimate their own ability) positively biased estimates of ψ. Moderate under‐confidence did not increase bias or decrease precision in estimates of ψ. Consistent with the patterns observed in simulations, analysis of example data from a chipmunk (Neotamias minimus atristriatus) population in the Sacramento Mountains of south‐central New Mexico during 2019 indicated that removing ambiguous detections and modeling false positives resulted in similar estimates of ψ and that over‐confidence biased estimates of ψ. Our results expand on previous literature, suggesting that removing ambiguous detections provides similar estimates of occupancy compared to modeling false positives in many scenarios, and emphasizing the importance of the designation of ambiguous and unambiguous detections. We provide guidance on simple methods to define ambiguous and unambiguous detections, thus mitigating the chances for erroneous inferences.

Middle Pennsylvanian (Desmoinesian) Fusulinids of the Bug Scuffle Limestone Member of the Gobbler Formation, Sacramento Mountains, South-Central New Mexico

Analysis of fusulinids from the Bug Scuffle Limestone Member of the Gobbler Formation along the western escarpment of the Sacramento Mountains in south-central New Mexico demonstrates that all four Desmoinesian regional fusulinid zones documented in Midcontinent and Southwest North America are present in the stratigraphic unit. Earliest Desmoinesian (Df1 Zone) fusulinids from the basal Bug Scuffle limestone beds suggest that the carbonate unit transgressed northward on the Sacramento Shelf, with Beedeina insolita in basal beds of the southernmost canyon exposures, and the slightly more advanced B. hayensis and B. curta in basal limestone beds of more northern outcrops. Late early Desmoinesian (Df2 Zone) fusulinids are common and widespread throughout the escarpment outcrop belt indicating that it was the time period with the most widespread normal marine shelf paleoenvironmental conditions. The diverse assemblage of the Df2 Zone is characterized by Beedeina novamexicana, B. euryteines, B. leei, B. socorroensis, B. joyitaensis, Wedekindellina euthysepta, and W. excentrica. The microprobematical branching fossil Komia is also common in this zone. Wedekindellina and Komia do not range above the mid-Desmoinesian CSB1 composite sequence boundary. Above that sequence boundary, the early late Desmoinesian Df3 Zone is characterized by sparse Beedeina haworthi, and the closely related B. illinoisensis and B. tumida. The late late Desmoinesian Df4 Zone is represented by a diverse assemblage of fusulinids in the uppermost part of the Bug Scuffle Limestone Member in the southern canyon exposures, including Beedeina acme, B. megista, B. mysticensis, B. lonsdalenesis, B. bellatula, B. gordonensis, and B. vintonensis. No Beedeina identifiable to species were found in upper part of the Bug Scuffle Limestone Member in the northernmost canyon exposures, demonstrating that late Desmoinesian paleoenvironments became more restricted marine northward along the Sacramento Shelf. Above the CSB2 composite sequence boundary in the uppermost Bug Scuffle Limestone Member, the lower part of the uppermost depositional sequence continues to contain latest Desmoinesian Df4 Zone fusulinids in the southern canyon sections. Early Missourian conodonts have been reported in a limestone unit near the top of the Gobbler clastic detrital member in the north-central part of the outcrop belt(Wahlman and Barrick 2018; Lucas et al. 2021), but no early Missourian conodonts or fusulinids have been reported yet from the uppermost Bug Scuffle Limestone Member in the southern canyons.

Comprehensive analysis of superconducting gravimeter data, GPS, and hydrology modelling in support of lunar laser ranging at Apache Point Observatory, New Mexico

SUMMARYThe Apache Point Observatory Lunar Laser-ranging Operation (APOLLO) project began in 2006 using a 3.5 m telescope on a high peak in the Sacramento Mountains of New Mexico. It has been one of the best performing (in terms of returned photons per viewing period and range uncertainty) of a handful of similar sites worldwide. The purpose of installing a superconducting gravimeter (SG) in 2009 was to improve the determination of local deformation, directly affecting the telescope motions, as part of an effort to reduce the error in lunar distance to the mm level. We have now accumulated 10 yr of gravity measurements, together with data from a nearby permanent GPS Plate Boundary Observatory (P027) site. This paper describes the traditional analysis of SG data to produce a local tidal model and to determine a number of necessary dynamic corrections that are specific to the site, of which local atmospheric and hydrology attraction and loading are the most important. Loading corrections are available through the Ecole et Observatoire des Sciences de la Terre (EOST) website as part of the International Earth Rotation Service, and we consider 12 different EOST loading series for global atmosphere and hydrology loading and attraction. Nonetheless, local hydrology can only be addressed at the required level of detail using local models determined directly from the gravity data. We devote a major portion of the paper to the development of several water storage and conceptual tank models that succeed in reducing the large seasonal variance of the SG residuals by more than 90 per cent. Yet there remain episodes in the corrected residuals that depart by up to 4 $\mu {\rm{Gal}}\,$ from the hydrological models, and the mean error of our fit remains between 1.5–2.0 $\mu {\rm{Gal}}\,$ for our two data sets, 2009–2012 and 2013–2018 respectively. Unfortunately the vertical GPS data relies on the UNAVCO processing, and has typically poor vertical accuracy. We find the correlation between the GPS and gravity residuals to be correspondingly weak, and then discuss briefly the incorporation of the displacement and gravity data into the Planetary Ephemeris Program for solving for the lunar distance.

Trends of forest and ecosystem services changes in the Mescalero Apache Tribal Lands

Forests are critically important for the provision of ecosystem services. The Sacramento Mountains of New Mexico, USA, are a hotspot for conservation management and the Mescalero Apache Tribe's homeland. The multiple ecosystem services and functions and its high vulnerability to changes in climate conditions make their forests of ecological, cultural, and social importance. We used data from the Mescalero Apache Tribal Lands (MATL) Continuous Forest Inventory over 30 yr to analyze changes in the structure and composition of ecosystems as well as trends in ecosystem services. Many provisioning, regulating, cultural, and supporting services were shared among the MATL ecosystems and were tied to foundational species dominance, which could serve as a reliable indicator of ecosystem functioning. Our analysis indicates that the MATL are in an ongoing transition from conifer forests to woodlands with declines in two foundation species, quaking aspen and ponderosa pine, linked to past forest management and changing climate. In addition, we detected a decrease in species richness and tree size variability, amplifying the risk of forest loss in a rapid climatic change. Continuous permanent plots located on a dense grid (1 × 1 km) such as the ones monitored by the Bureau of Indian Affairs are the most detailed data available to estimate forests multiresource transitions over time. Native lands across the USA could serve as the leading edge of detecting decadal-scale forest changes and tracking climate impacts.

The Pennsylvanian System in the Sacramento Mountains, New Mexico, USA

Pennsylvanian sedimentary rocks in the Sacramento Mountains, New Mexico, comprise an ~1 km thick stratigraphic section. The Morrowan-Desmoinesian Gobbler Formation was deposited by shallow marine processes in and near the Alamo clastic trough. In this trough, the Desmoinesian-Missourian Gray Mesa Formation (Bug Scuffle Member, Gobbler Formation) is a relatively thin unit (Space History Member) representing the glacioeustatic Amado event. The Missourian-Virgilian Beeman Formation includes the lower, siliciclastic Indian Wells Canyon Member and overlying, carbonate-rich Horse Ridge Member. The Virgilian Holder Formation consists of algal bioherms (Little Dry Canyon Member) overlain by the mixed carbonate-siliciclastic Mill Ridge Member. The Virgilian-Wolfcampian Bursum Formation is mixed siliciclastic-carbonate strata that represent shallow marine and nonmarine paleoenvironments. Animal and plant remains occur throughout the section. Unit age determinations are primarily based on conodont faunas recovered from the Gobbler, Gray Mesa, and Beeman Formations. Many conodont faunas correlate with Midcontinent cyclothems. Extensive algal and foraminiferal fossils also were identified in limestones from the section and contributed to age determinations. The Beeman Formation in particular contains an extensive Missourian macroflora. The macroflora is of “mixed” composition, containing typical wetland elements intimately intermixed with taxa indicative of seasonally dry habitats. A seasonally wet-dry background climate is indicated. It is unlikely that droughttolerant plants were transported exclusively from “uplands.” Some plant remains have arthropod-feeding evidence. Previous analyses identified late Paleozoic ice-age glacioeustasy as the primary depositional driver of Pennsylvanian sedimentation in the Sacramento Mountains. We question this because of problems with those analyses and because of ample evidence of local tectonics and microclimate changes as important drivers of sedimentation in this area. Three Pennsylvanian Ancestral Rocky Mountain orogeny tectonic pulses can be identified in the Sacramento Mountains: Morrowan-Atokan, Missourian, and late Virgilian-Wolfcampian.

Host recognition by Rhinocyllus conicus of floral scents from invasive and threatened thistles

One of the main obstacles of classical biological control is that biological control organisms cannot be recalled once they are released in nature. It is particularly true for the flowerhead weevil, Rhinocyllus conicus Frolich, which was released as a biological control organism for the invasive musk thistle, Carduus nutans L. (MT). While weevils successfully suppressed introduced populations of musk thistles and other invasive thistle species, non-target attacks have been reported on multiple native thistles including federally listed threatened and endangered (T&E) thistle species. To investigate the foraging behavior of female weevils on invasive and native thistles, we examined volatile organic compounds (VOCs) emitted from MT and a T&E plant species, Sacramento Mountains thistle, Cirsium vinaceum Wooton & Standley (SMT) in the Lincoln National Forest, New Mexico. We used a dynamic headspace volatile collection system and gas chromatography-mass spectrometry to compare volatile profiles between MT and SMT. Female weevils reacted to 7 electrophysiologically active chemical compounds in the blends based on gas chromatography-electroantennography. The behavioral response of female weevils was indifferent when VOCs from both thistles were offered in y-tube olfactometry experiments. Yet, they preferred VOCs collected from MT to purified air. The searching time of female weevils was longer to VOCs collected from SMT over controls. Investigating signals during the initial host recognition of released biological control organisms may open new opportunities to reduce non-target attacks on T&E plant species.

Annual climate in Mexican Spotted Owl habitat in the Sacramento Mountains, New Mexico: implications for responding to climate change

Annual climate in Mexican Spotted Owl habitat in the Sacramento Mountains, New Mexico: implications for responding to climate change

Threats to aquatic taxa in an arid landscape: Knowledge gaps and areas of understanding for amphibians of the American Southwest

AbstractThe American Southwest is a dryland region with variable, seasonal precipitation, and a wide range of freshwater habitats. Amphibians are among the diverse freshwater taxa that rely on aquatic habitats of the southwest, yet the state‐of‐the‐science regarding vulnerability of the region’s amphibians to threats recognized globally is unclear. To address this knowledge gap, we reviewed 81 publications and 341 species:threat relationships to assess coverage in the peer‐reviewed literature of potential threats to 35 amphibians native to the region. We classified threats into three major categories: climate change, biological, and land use. Using a new trait database for anurans (frogs and toads) of the United States, we evaluated these threats in the context of life history diversity of the region's anurans. We found high coverage for hydrological alteration and introduced species as well as changes to community dynamics, land use, and precipitation. Other potential threats—particularly those linked to climate change such as changes in seasonality and fire—had comparatively low coverage. Coverage varied widely among species, with the number of reported species:threat relationships ranging from 37 (the lowland leopard frog, Lithobates yavapaiensis) to no coverage for some species—including some of conservation concern (e.g., Sacramento Mountains salamander, Aneides hardii). Our findings support leveraging available information to test hypothesized linkages between amphibian life histories and risk and response to threats; using high coverage species and threats to inform simulations and experiments exploring species:threat relationships and efficacy of management strategies; and addressing knowledge gaps for species and threats with no proxies through on‐the‐ground natural history efforts.This article is categorized under: Water and Life > Stresses and Pressures on Ecosystems > Conservation, Management, and Awareness Science of Water > Water and Environmental Change

Tracing gypsiferous White Sands aerosols in the shallow critical zone in the northern Sacramento Mountains, New Mexico using Sr/Ca and 87Sr/86Sr ratios

White Sands (New Mexico, USA) emits gypsum dust with a unique chemical and mineralogical signature, providing an opportunity to investigate its loading and regional movement. This study tracked White Sands dust input to montane soils downwind in the northern Sacramento Mountains, and provided better understanding of the effects of gypsum dust on sources of bioavailable plant nutrients in an active critical zone. Four soil profiles were collected over bedrocks of different weatherabilities, from the most reactive limestone, mixed limestone, diorite, to the least reactive sandstone, as well as different atmospheric end-members (rain, regional dust, and White Sands gypsum). Annual dry deposition rate observed at the Sacramento Mountains was approximately at 11 g m−2 yr−1, up to an order of magnitude lower than those at the Chihuahuan Desert basins upwind and closer to dust sources at lower elevations. Elemental chemistry, Ca/Sr and 87Sr/86Sr of bulk soils were mostly controlled by those of bedrocks and modified by chemical weathering over carbonate substrates, whereas the atmospheric input was only detectable in shallow soils over the least reactive sandstone through addition profiles of Ca, Sr and Na. Although only making up a small portion of a bulk soil in mass, White Sands dust, along with wet deposition, dominantly controlled the Ca/Sr and 87Sr/86Sr ratios of plants and the water leachable fraction of the soils. Particles from White Sands, predominantly gypsum, were very soluble, and dissolved quickly in soils of the Sacramento Mountains but re-precipitated at the impermeable bedrock-soil interface. Although absolute concentrations of Ca and Sr in plants differed widely among four sites and among different local plant types, Sr/Ca ratios were largely controlled by plant type, and thus the rooting depth. This study highlighted the importance of regional dust and rainfall in loading nutrients even in a semi-humid environment.

Isolation by elevation: mitochondrial divergence among sky island populations of Sacramento Mountain salamander (Aneides hardii)

The Sacramento Mountain salamander (Aneides hardii) is a fully terrestrial plethodontid endemic to mountains in south-central New Mexico. This species is of conservation concern but there is scant knowledge regarding the degree of genetic divergence among populations. This information is vital for developing an appropriate species management strategy. To address this issue, we generated sequence data from the mitochondrial cytochrome b gene and four nuclear loci to explore population demographic history. Cytochrome b data revealed three deeply divergent (2.3–2.8%) mitochondrial lineages corresponding to distinct mountains (Capitan, White, and Sacramento). Divergence dates suggest separation since the early Pleistocene, and signatures of population expansion in the mid to late Pleistocene. Of 25 haplotypes identified, none were shared among mountains, but genetic diversity differed among mitochondrial lineages and suggested different demographic histories within lineages. A single microsatellite locus identified private alleles in each of the three lineages. Other nuclear loci screened were invariant within and among populations, which corresponds to a lower mutation rate compared with mtDNA. Together these results indicate that each mountain population of A. hardii represents a demographically and genetically distinct management unit.

Spatiotemporal variability of fire regimes in adjacent Native American and public forests, New Mexico, USA

AbstractStatistical descriptions of reconstructed fire regimes are often extrapolated from a composite of small forest stands to represent extensive geographical areas. However, statistical properties of fire regimes are scale‐dependent, thus causing some extrapolations from fine scale to coarse scale and comparisons between fire‐scar‐based reconstructions to be inappropriate. We assessed landscape fire regimes of the Sacramento Mountains, in southern New Mexico, using dendrochronological methods and a variety of fire statistics and analysis filters. We reconstructed historical and recent fire regimes for the Mescalero Apache Tribal Lands (MATL) at tree and site scale (25 ha). We then estimated the Sacramento Mountains historical and recent fire regimes by combining paleo fire data from this study with published data from the adjacent Lincoln National Forest (LNF). We applied filters to provide fire statistics that are relatively unbiased to the different spatial measurement extent of the studies. This is the first study to assess fire regime in the MATL over multiple spatial and temporal scales. The results show that frequent surface fires occurred at all scales in the Sacramento Mountains until fire was excluded from the landscape in the early 1900s. Historical fires were found to be synchronous with drought years, typically La Niña events, and often preceded by wet years. We did not find evidence supporting differences in fire regimes between the MATL and the LNF, suggesting that fire cessation following intensive Euro‐American settlement was widespread. The interruption of frequent surface fires, together with other changes in forest structure and climate, pose a significant threat to sustainability of forest ecosystems on Native American tribal lands.

Density of American black bears in New Mexico

ABSTRACTConsidering advances in noninvasive genetic sampling and spatially explicit capture–recapture (SECR) models, the New Mexico Department of Game and Fish sought to update their density estimates for American black bear (Ursus americanus) populations in New Mexico, USA, to aide in setting sustainable harvest limits. We estimated black bear density in the Sangre de Cristo, Sandia, and Sacramento Mountains, New Mexico, 2012–2014. We collected hair samples from black bears using hair traps and bear rubs and used a sex marker and a suite of microsatellite loci to individually genotype hair samples. We then estimated density in a SECR framework using sex, elevation, land cover type, and time to model heterogeneity in detection probability and the spatial scale over which detection probability declines. We sampled the populations using 554 hair traps and 117 bear rubs and collected 4,083 hair samples. We identified 725 (367 male, 358 female) individuals. Our density estimates varied from 16.5 bears/100 km2 (95% CI = 11.6–23.5) in the southern Sacramento Mountains to 25.7 bears/100 km2 (95% CI = 13.2–50.1) in the Sandia Mountains. Overall, detection probability at the activity center (g0) was low across all study areas and ranged from 0.00001 to 0.02. The low values of g0 were primarily a result of half of all hair samples for which genotypes were attempted failing to produce a complete genotype. We speculate that the low success we had genotyping hair samples was due to exceedingly high levels of ultraviolet (UV) radiation that degraded the DNA in the hair. Despite sampling difficulties, we were able to produce density estimates with levels of precision comparable to those estimated for black bears elsewhere in the United States. © 2018 The Wildlife Society.

Using MODIS NDVI phenoclasses and phenoclusters to characterize wildlife habitat: Mexican spotted owl as a case study

Abstract Most uses of remotely sensed satellite data to characterize wildlife habitat have used metrics such as mean NDVI (Normalized Difference Vegetation Index) in a year or season. These simple metrics do not take advantage of the temporal patterns in NDVI within and across years and the spatial arrangement of cells with various temporal NDVI signatures. Here we use 13 years of data from MODIS (Moderate Resolution Imaging Spectroradiometer) to bin individual MODIS pixels (5.3 ha) into phenoclasses, where each phenoclass consists of pixels with a particular temporal profile of NDVI, regardless of spatial location. We present novel procedures that assign sites to phenoclusters, defined as particular composition of phenoclasses within a 1 km radius. We apply these procedures to Mexican spotted owl (Strix occidentalis lucida) nesting locations in the Sacramento Mountain range in south-central New Mexico. Phenoclasses at owl nest sites and phenoclusters around owl nest sites differed from those at and around points randomly placed in forest types that are known to support nesting owls. Stand exam data showed that the phenoclasses associated with owl nest sites are dominated by Douglas-fir (Pseudotsuga menziesii) and white fir (Abies concolor). The availability of phenoclusters and phenoclasses on Mescalero Apache tribal lands differed from those on adjacent National Forest lands within the Sacramento Mountain, consistent with different elevations and forest management practices. Nonetheless owls predominately used the same phenoclasses and phenoclusters in both land ownerships. MODIS phenoclasses and phenoclusters offer a useful means of remotely identifying forest conditions suitable for wildlife. Because the remote sensing data are freely available and regularly updated, they can be part of a cost effective approach to monitor and assess forested wildlife habitat over large temporal and spatial scales.

Meta-replication reveals nonstationarity in multi-scale habitat selection of Mexican Spotted Owl

ABSTRACT Anthropogenic environmental changes are leading to habitat loss and degradation, driving many species to extinction. In this context, habitat models become increasingly important for effective species management and conservation. However, most habitat studies lack replicated study areas and do not properly address the role of nonstationarity and spatial scales in determining factors that limit species occurrence under different environmental settings. Here we provide an optimized multi-scale framework for analyzing habitat selection of the threatened Mexican Spotted Owl (Strix occidentalis lucida) between 2 meta-replicated study areas: the Sacramento Mountains, New Mexico, and the Mogollon Plateau, Arizona. The optimized scales of habitat variables strongly differed between the 2 study areas. Percent cover of mixed-conifer was more strongly associated with the relative likelihood of Mexican Spotted Owl occurrence in the Sacramento Mountains than in the Mogollon Plateau. Topographic covariates str...

Detrital zircon geochronology of quartzite clasts in the Permian Abo Formation, Sacramento Mountains, New Mexico, USA

More than 2500 m of Paleozoic strata, ranging in age from Cambrian to Permian occur in the Sacramento Mountains of New Mexico, making these rocks the largest and most complete exposures of Paleozoic strata in North America. The core of the Sacramento Mountains reveals compressional structures associated with the Pennsylvanian-Permian Ancestral Rocky Mountain orogeny. The Permian Abo Formation is 120–450 m in thickness, and consists of interbedded sandstone, conglomerate, limestone and shale and rests above the Ancestral Rocky Mountain unconformity. U-Pb analysis of detrital zircons extracted from quartzite clasts in basal conglomerates reveal a maximum depositional age of their protolith to be 1110 ± 15 Ma. Most (∼40%) of the detrital zircon age spectrum is Grenville (1000–1300 Ma) in age, with a peak age of 1209 Ma. Midcontinent Granite-Rhyolite (1300–1500 Ma) ages comprise about 33% of the data, and have a peak age of 1431 Ma. Smaller age populations of Yavapai-Mazatzal (1600–1800 Ma; age peak =1676 Ma), Trans-Hudson (1800–2000 Ma; peak age = 1820 Ma), and Archean (>2.5 Ga, age peak = 2819 Ma) also are present. U-Pb detrital zircon ages from these quartzite clasts indicate that they were likely derived from the Proterozoic Lanoria Formation, which is exposed now in the Franklin Mountains >150 km to the south. The Lanoria is identical to the Abo clasts in terms of maximum depositional age and detrital zircon age peaks. The protolith sandstone of these quartzite clasts and quartzites of the Lanoria were derived from the Grenville high-lands of the Llano region of central Texas, and then transported west to the Rodinian continental margin at ∼1110 Ma, where they were eventually buried and metamorphosed to quartzite. These quartzites were subsequently uplifted and eroded during the Ancestral Rocky Mountain orogeny and transported north and west along the Pedernal Uplift to the adjacent Orogrande Basin during the early Permian.

Landscape Scale and Microhabitat of the Endangered New Mexico Meadow Jumping Mouse in the White Mountains, Arizona

Abstract The New Mexico meadow jumping mouse Zapus hudsonius luteus was listed as endangered under the U.S. Endangered Species Act in 2014, with critical habitat designated in 2016. Despite these recent conservation actions, there is a paucity of published information regarding its habitat associations. The taxon is a riparian obligate that occurs along both low-elevation rivers and high-elevation headwater streams in several disjunct areas of the American Southwest. Habitat information from one region might not apply to others. The distribution and habitat preferences of the New Mexico meadow jumping mouse in the White Mountains in eastern Arizona are poorly known. Objectives of this study were to 1) identify and resurvey historical locations in the White Mountains, 2) survey for new populations in areas with potentially suitable habitat in the White Mountains, and 3) use quantitative data to evaluate habitat associations at the landscape and microhabitat scales and to compare habitat at sites where I captured or did not capture the New Mexico meadow jumping mouse. I found 123 historical records of the New Mexico meadow jumping mouse from 21 locations in the White Mountains, indicating a formerly broad distribution. I conducted field surveys and collected habitat data at 35 sites (14 historical, 21 new) and caught 37 (39 total captures) New Mexico meadow jumping mice at 12 sites, including 6 of 12 historical locations surveyed. The overall capture rate was 0.36%, with an average capture rate at sites where it was present of 1.28% (range = 0.25–2.5%). All historical sites where I caught the New Mexico meadow jumping mouse were in the drainage of the Black River. The six new sites included the first records for Nutrioso Creek and Corduroy Creek and confirmed persistence of the taxon in the East Fork Little Colorado River, San Francisco River, and Blue River watersheds. Habitat used by the New Mexico meadow jumping mouse in the White Mountains was similar to that reported for other montane populations, characterized by tall, dense herbaceous vegetation composed primarily of forbs and sedges on saturated soil in close proximity to flowing water. However, there was significantly more cover provided by alders Alnus spp. at capture sites at both the stream reach and microhabitat scales. All sites where I captured the New Mexico meadow jumping mouse had no authorized livestock grazing, and the taxon was more likely to occur at sites where there were no signs of unauthorized livestock grazing. Further, there was a significant positive relationship between alder cover and time since an area was excluded from livestock grazing. The widespread exclusion of livestock from riparian areas in the White Mountains may have contributed to the higher rate of population persistence of the New Mexico meadow jumping mice in the White Mountains compared with the Jemez and Sacramento mountains, New Mexico. Although the overall persistence rate in the White Mountains (47%) was higher than other populations, the population is at risk of further losses due to small, isolated occupied areas and ongoing threats.

Fluxo das águas subterrâneas em um aquífero carbonático ‘subajustado’ em clima semiárido: aplicação de traçadores ambientais para a Bacia Salt, Novo México (EUA)

The Salt Basin is a semiarid hydrologically closed drainage basin in southern New Mexico, USA. The aquifers in the basin consist largely of Permian limestone and dolomite. Groundwater flows from the high elevations (∼2,500 m) of the Sacramento Mountains south into the Salt Lakes, which are saline playas. The aquifer is ‘underfit’ in the sense that depths to groundwater are great (∼300 m), implying that the aquifer could transmit much more water than it does. In this study, it is speculated that this characteristic is a result of a geologically recent reduction in recharge due to warming and drying at the end of the last glacial period. Water use is currently limited, but the basin has been proposed for large-scale groundwater extraction and export projects. Wells in the basin are of limited utility for hydraulic testing; therefore, the study focused on environmental tracers (major-ion geochemistry, stable isotopes of O, H, and C, and 14C dating) for basin analysis. The groundwater evolves from a Ca–HCO3 type water into a Ca–Mg (Na) – HCO3–Mg (Cl) water as it flows toward the center of the basin due to dedolomitization driven by gypsum dissolution. Carbon-14 ages corrected for dedolomitization ranged from less than 1,000 years in the recharge area to 19,000 years near the basin center. Stable isotopes are consistent with the presence of glacial-period recharge that is much less evaporated than modern. This supports the hypothesis that the underfit nature of the aquifer is a result of a geologically recent reduction in recharge.

(美国)新墨西哥州中南部沙加缅度山脉地下水补给的量和位置

The Sacramento Mountains and the adjacent Roswell Artesian Basin, in south-central New Mexico (USA), comprise a regional hydrologic system, wherein recharge in the mountains ultimately supplies water to the confined basin aquifer. Geologic, hydrologic, geochemical, and climatologic data were used to delineate the area of recharge in the southern Sacramento Mountains. The water-table fluctuation and chloride mass-balance methods were used to quantify recharge over a range of spatial and temporal scales. Extrapolation of the quantitative recharge estimates to the entire Sacramento Mountains region allowed comparison with previous recharge estimates for the northern Sacramento Mountains and the Roswell Artesian Basin. Recharge in the Sacramento Mountains is estimated to range from 159.86 × 106 to 209.42 × 106 m3/year. Both the location of recharge and range in estimates is consistent with previous work that suggests that ~75 % of the recharge to the confined aquifer in the Roswell Artesian Basin has moved downgradient through the Yeso Formation from distal recharge areas in the Sacramento Mountains. A smaller recharge component is derived from infiltration of streamflow beneath the major drainages that cross the Pecos Slope, but in the southern Sacramento Mountains much of this water is ultimately derived from spring discharge. Direct recharge across the Pecos Slope between the mountains and the confined basin aquifer is much smaller than either of the other two components.