Carlsbad Caverns National Park Research Articles

Summertime Ozone Production at Carlsbad Caverns National Park, New Mexico: Influence of Oil and Natural Gas Development

AbstractSoutheastern New Mexico's Carlsbad Caverns National Park (CAVE) has increasingly experienced summertime ozone (O3) exceeding an 8‐hr average of 70 parts per billion by volume (ppbv). The park is located in the western part of the Permian oil and natural gas (O&G) basin, where production rates have increased fivefold in the last decade. We investigate O3–precursor relationships by constraining the F0AM box model to observations of nitrogen oxides (NOx = NO + NO2) and a suite of volatile organic compounds (VOCs) collected at CAVE during summer 2019. O&G‐related VOCs dominated the calculated VOC reactivity with hydroxyl radicals (OH) on days when O3 concentrations were primarily controlled by local photochemistry. Radical budget analysis showed that NOx levels were high enough to impose VOC sensitivity on O3 production in the morning hours, while subsequent NOx loss through photochemical consumption led to NOx‐sensitive conditions in the afternoon. Maximum daily O3 was responsive to both NOx and O&G‐related VOC reductions, with NOx reductions proving most effective. The model underestimated observed O3 during a 5‐day high O3 episode that was influenced by photochemically aged O&G emissions, as indicated by back‐trajectory analysis, low i‐/n‐pentane ratios, enhanced secondary VOCs, and low ratios of NOx to total reactive oxidized nitrogen (NOy). Model‐observation agreement was improved by constraining model NOx with observed NOy, which approximates NOx at the time of emission, indicating that a large fraction of O3 during this episode was formed nonlocally.

Source characterization of volatile organic compounds at Carlsbad Caverns National Park

ABSTRACT Carlsbad Caverns National Park (CAVE), located in southeastern New Mexico, experiences elevated ground-level ozone (O3) exceeding the National Ambient Air Quality Standard (NAAQS) of 70 ppbv. It is situated adjacent to the Permian Basin, one of the largest oil and gas (O&G) producing regions in the US. In 2019, the Carlsbad Caverns Air Quality Study (CarCavAQS) was conducted to examine impacts of different sources on ozone precursors, including nitrogen oxides (NOx) and volatile organic compounds (VOCs). Here, we use positive matrix factorization (PMF) analysis of speciated VOCs to characterize VOC sources at CAVE during the study. Seven factors were identified. Three factors composed largely of alkanes and aromatics with different lifetimes were attributed to O&G development and production activities. VOCs in these factors were typical of those emitted by O&G operations. Associated residence time analyses (RTA) indicated their contributions increased in the park during periods of transport from the Permian Basin. These O&G factors were the largest contributor to VOC reactivity with hydroxyl radicals (62%). Two PMF factors were rich in photochemically generated secondary VOCs; one factor contained species with shorter atmospheric lifetimes and one with species with longer lifetimes. RTA of the secondary factors suggested impacts of O&G emissions from regions farther upwind, such as Eagle Ford Shale and Barnett Shale formations. The last two factors were attributed to alkenes likely emitted from vehicles or other combustion sources in the Permian Basin and regional background VOCs, respectively. Implications: Carlsbad Caverns National Park experiences ground-level ozone exceeding the National Ambient Air Quality Standard. Volatile organic compounds are critical precursors to ozone formation. Measurements in the Park identify oil and gas production and development activities as the major contributors to volatile organic compounds. Emissions from the adjacent Permian Basin contributed to increases in primary species that enhanced local ozone formation. Observations of photochemically generated compounds indicate that ozone was also transported from shale formations and basins farther upwind. Therefore, emission reductions of volatile organic compounds from oil and gas activities are important for mitigating elevated O3 in the region.

Observations of ozone, acyl peroxy nitrates, and their precursors during summer 2019 at Carlsbad Caverns National Park, New Mexico

ABSTRACT Carlsbad Caverns National Park (CAVE) is located in southeastern New Mexico and is adjacent to the Permian Basin, one of the most productive oil and natural gas (O&G) production regions in the United States. Since 2018, ozone (O3) at CAVE has frequently exceeded the 70 ppbv 8-hour National Ambient Air Quality Standard. We examine the influence of regional emissions on O3 formation using observations of O3, nitrogen oxides (NOx = NO + NO2), a suite of volatile organic compounds (VOCs), peroxyacetyl nitrate (PAN), and peroxypropionyl nitrate (PPN). Elevated O3 and its precursors are observed when the wind is from the southeast, the direction of the Permian Basin. We identify 13 days during the July 25 to September 5, 2019 study period when the maximum daily 8-hour average (MDA8) O3 exceeded 65 ppbv; MDA8 O3 exceeded 70 ppbv on 5 of these days. The results of a positive matrix factorization (PMF) analysis are used to identify and attribute source contributions of VOCs and NOx. On days when the winds are from the southeast, there are larger contributions from factors associated with primary O&G emissions; and, on high O3 days, there is more contribution from factors associated with secondary photochemical processing of O&G emissions. The observed ratio of VOCs to NOx is consistently high throughout the study period, consistent with NOx-limited O3 production. Finally, all high O3 days coincide with elevated acyl peroxy nitrate abundances with PPN to PAN ratios > 0.15 ppbv ppbv−1 indicating that anthropogenic VOC precursors, and often alkanes specifically, dominate the photochemistry. Implications: The results above strongly indicate NOx-sensitive photochemistry at Carlsbad Caverns National Park indicating that reductions in NOx emissions should drive reductions in O3. However, the NOx-sensitivity is largely driven by emissions of NOx into a VOC-rich environment, and a high PPN:PAN ratio and its relationship to O3 indicate substantial influence from alkanes in the regional photochemistry. Thus, simultaneous reductions in emissions of NOx and non-methane VOCs from the oil and gas sector should be considered for reducing O3 at Carlsbad Caverns National Park. Reductions in non-methane VOCs will have the added benefit of reducing formation of other secondary pollutants and air toxics.

PM2.5 in Carlsbad Caverns National Park: Composition, sources, and visibility impacts

ABSTRACT Carlsbad Caverns National Park in southeastern New Mexico is adjacent to the Permian Basin, one of the most productive oil and gas regions in the country. The 2019 Carlsbad Caverns Air Quality Study (CarCavAQS) was designed to examine the influence of regional sources, including urban emissions, oil and gas development, wildfires, and soil dust on air quality in the park. Field measurements of aerosols, trace gases, and deposition were conducted from 25 July through 5 September 2019. Here, we focus on observations of fine particles and key trace gas precursors to understand the important contributing species and their sources and associated impacts on haze. Key gases measured included aerosol precursors, nitric acid and ammonia, and oil and gas tracer, methane. High-time resolution (6-min) PM2.5 mass ranged up to 31.8 µg m−3, with an average of 7.67 µg m−3. The main inorganic ion contributors were sulfate (avg 1.3 µg m−3), ammonium (0.30 µg m−3), calcium (Ca2+) (0.22 µg m−3), nitrate (0.16 µg m−3), and sodium (0.057 µg m−3). The WSOC concentration averaged 1.2 µg C m−3. Sharp spikes were observed in Ca2+, consistent with local dust generation and transport. Ion balance analysis and abundant nitric acid suggest PM2.5 nitrate often reflected reaction between nitric acid and sea salt, forming sodium nitrate, and between nitric acid and soil dust containing calcium carbonate, forming calcium nitrate. Sulfate and soil dust are the major contributors to modeled light extinction in the 24-hr average daily IMPROVE observations. Higher time resolution data revealed a maximum 1-hr extinction value of 90 Mm−1 (excluding coarse aerosol) and included periods of significant light extinction from BC as well as sulfate and soil dust. Residence time analysis indicated enrichment of sulfate, BC, and methane during periods of transport from the southeast, the direction of greatest abundance of oil and gas development. Implications: Rapid development of U.S. oil and gas resources raises concerns about potential impacts on air quality in National Parks. Measurements in Carlsbad Caverns National Park provide new insight into impacts of unconventional oil and gas development and other sources on visual air quality in the park. Major contributors to visibility impairment include sulfate, soil dust (often reacted with nitric acid), and black carbon. The worst periods of visibility and highest concentrations of many aerosol components were observed during transport from the southeast, a region of dense Permian Basin oil and gas development.

Tritium, Chlorine-36, and water isotopologue profiles from Lechuguilla Cave and Carlsbad Cavern, New Mexico, USA

Carlsbad Cavern and Lechuguilla Cave are large limestone caves located within Carlsbad Caverns National Park, southeastern New Mexico, USA. Both caves feature numerous pools that enable sampling of locally perched water bodies at different depths within the thick vadose zone. Isotopic analysis of multiple water samples from both caves revealed clear evidence of bomb-pulse tritium (up to 6.1% bomb-pulse maximum, BPM) and 36Cl (up to 5.2% BPM) in many pools. In all cases, isotope concentrations were well below peak bomb-pulse levels, indicating complex mixing processes between the ground surface and the cave pools. The deepest bomb-pulse detections in the caves indicate vertical transport velocities of up to 6–9 m/yr for the fastest flowpaths. Peak tritium levels in Lechuguilla are lower than those in Carlsbad, potentially due to mixing and dilution via vapor-phase exchange through the high relative humidity cave atmosphere, processes that may be less effective in Carlsbad's drier atmosphere. Peak 36Cl/Cl ratios in Carlsbad are lower than those in Lechuguilla, possibly due to dilution by introduced stable Cl− associated with tourist developments in the cave. Stable isotope results demonstrate the different evaporative regimes of the two caves, caused by Carlsbad Cavern's large natural entrance, in contrast to Lechuguilla's complete lack of a present-day natural entrance. Our results bolster the use of speleothem records for paleoclimate reconstruction, demonstrating the effective transmission of the bomb-pulse signal to depths of hundreds of meters within a few decades. At the same time, the pronounced and variable impact of evaporation on some samples shows the potential importance of local conditions on specific sample results.

DIVERSITY OF SIDEROPHORE-PRODUCING BACTERIAL CULTURES FROM CARLSBAD CAVERNS NATIONAL PARK (CCNP) CAVES, CARLSBAD, NEW MEXICO.

Siderophores are microbially-produced ferric iron chelators. They are essential for microbial survival, but their presence and function for cave microorganisms have not been extensively studied. Cave environments are nutrient-limited and previous evidence suggests siderophore usage in carbonate caves. We hypothesize that siderophores are likely used as a mechanism in caves to obtain critical nutrients such as iron. Cave bacteria were collected from Long-term parent cultures (LT PC) or Short-term parent cultures (ST PC) inoculated with ferromanganese deposits (FMD) and carbonate secondary minerals from Lechuguilla and Spider caves in Carlsbad Caverns National Park (CCNP), NM. LT PC were incubated for 10-11 years to identify potential chemolithoheterotrophic cultures able to survive in nutrient-limited conditions. ST PC were incubated for 1-3 days to identify a broader diversity of cave isolates. A total of 170 LT and ST cultures,18 pure and 152 mixed, were collected and used to classify siderophore production and type and to identify siderophore producers. Siderophore production was slow to develop (>10 days) in LT cultures with a greater number of weak siderophore producers in comparison to the ST cultures that produced siderophores in <10 days, with a majority of strong siderophore producers. Overall, 64% of the total cultures were siderophore producers, which the majority preferred hydroxamate siderophores. Siderophore producers were classified into Proteobacteria (Alpha-, Beta-, or Gamma-), Actinobacteria, Bacteroidetes, and Firmicutes phyla using 16S rRNA gene sequencing. Our study supports our hypothesis that cave bacteria have the capability to produce siderophores in the subsurface to obtain critical ferric iron.

Cave and karst management at Carlsbad Caverns National Park

Cave and karst management at Carlsbad Caverns National Park

The Coryphantha sneedii Complex is Indeed Complex and Continuously Intergrades with Coryphantha vivipara

The Coryphantha sneedii complex is a confusing assemblage of the following intergrading or ill-defined varieties: orcuttii, organensis, sandbergii, villardii, albicolumnaria, leei, guadalupensis, sneedii, and possibly other undescribed taxa. These varieties comprise a continuum of morphological forms, many with overlapping or proximate distributions, and with some morphological variability possibly arising from phenotypic plasticity to the point that the various variety names are not warranted. There is also debate about geographic range of varieties, e.g. is the type variety actually found in Carlsbad Caverns National Park, Big Bend National Park, and Bishop's Cap. Not only is it impossible to consistently distinguish individual plants of the different varieties of Coryphantha sneedii (Britton & Rose) A. Berger, but it is also sometimes impossible to distinguish them from the sympatric Coryphantha vivipara (Nuttall) Britton & Rose, especially from C. vivipara var. neomexicana (Engelmann) Backeberg. Coryphantha vivipara and C. sneedii are distinguishable from all other species of Coryphantha by their 0.5–1.0 mm diameter lenticular druses and usually (but not always) having green fruits/pericarpels, but these two species with overlapping distributions are not always clearly distinguishable from one another. I therefore propose subsuming the entire Coryphantha sneedii complex as a single variety of C. vivipara.

A Bryophyte Inventory of Carlsbad Caverns National Park

The bryophytes of Carlsbad Caverns National Park were collected and inventoried. A total of 41 bryophyte species were found including 38 moss species in eight families, and three liverwort species in two families. No hornworts were found. The liverwort Riccia atromarginata Levier is reported new for New Mexico. We provide the first photographs of Mannia paradoxa Schuster, collected by Schuster at the park in 1982. Since water is a limiting factor for life in much of the park, we initially assumed that the many natural springs in the area would provide the most diverse habitats. In fact, the seasonally flooded arroyos and north-facing limestone cliffs together proved to have more bryophyte diversity than the springs. A brief biography of Gilford J. Ikenberry is included.

A World Below by Wesley King

Reviewed by: A World Below by Wesley King Wesley Jacques King, Wesley A World Below. Wiseman/Simon, 2018 [272p] Trade ed. ISBN 978-1-4814-7822-9 $17.99 E-book ed. ISBN 978-1-4814-7824-3 $10.99 Reviewed from galleys R Gr. 6-9 When Mr. Baker’s eighth-grade AP class travels to Carlsbad Caverns National Park on a field trip, Eric, the quietest in the class, believes having his mother along as chaperone will be a nightmare. Worried that his whole world might figuratively fall apart as his mom starts showing interest in his crush, Silvia, he’s startled when it literally does: a sudden earthquake rips the ground from underneath him and drops him and Silvia into the Midnight Realm, a land completely untouched by sunlight, inhabited by the descendants of indigenous peoples who have lived in fear of surface-dwellers for generations. Eric, Silvia, and the Midnight King Carlos embark on journeys of self-discovery as they navigate the darkness of the caves and confront what lurks in the metaphorical shadows cast by their respective fathers (Eric was abandoned by his, Silvia’s father ignores her anxiety issues, and Carlos the boy king struggles with the influence of his royal father). This underground adventure features plenty of strange creatures, clever uses of science, and an appreciation for New Mexico’s geological and historical heritage (though there are some colonialist echoes in Eric and Silvia’s education of the Midnight Realmers, despite the fact that Eric is biracial and Silvia is Latina). This richly imaginative field trip gone bad or amazing—depending on how you look at it—is a sharp meditation on the seemingly universal difficulties of being young, smart, and uncertain. Copyright © 2018 The Board of Trustees of the University of Illinois

Genomic characterization of eight Ensifer strains isolated from pristine caves and a whole genome phylogeny of Ensifer (Sinorhizobium).

A total of eight Ensifer sp. strains were isolated from two pristine cave environments. One strain was isolated from a cave water pool located in the Wind Cave National Park, South Dakota, USA and the remaining seven strains were isolated from Lechuguilla Cave of Carlsbad Caverns National Park, New Mexico, USA. Whole genome sequencing and comparative genomic analyses of the eight isolates compared to various type strains from the genera Ensifer and Sinorhizobium demonstrates that although members in these genera can be phylogenetically separated into two distinct clades, the percentage of conserved proteins (POCP) between various type strains from Ensifer and Sinorhizobium are consistently higher than 50%, providing strong genomic evidence to support the classification of the genera Ensifer and Sinorhizobium into a single genus.

Roving with a Digital Visual Library: Increased Learning Opportunities at Carlsbad Caverns National Park

At Carlsbad Caverns National Park, park rangers blended traditional personal interpretation with technology to showcase park-based research and to advance science literacy among visitors. Interpreters and Scientists Working on Our Parks (iSWOOP) provided interpreters with professional development and a selection of visualizations from scientists’ research on Brazilian free-tailed bats and their habitat at Carlsbad Caverns. After using tablets containing these visualizations for informal interpretive interactions, the interpreters responded to an open-ended survey. The authors examined interpreters’ responses, finding that interpreters regarded tablets as helpful in accomplishing several interpretive goals, especially in particular locations. Interpreters were strategic in initiating and sustaining interactions. Visitors’ reactions were positive; nevertheless, there were challenges indicating that this new form of interpretation is worthy of further research.

A brief history of exploration in Lechuguilla Cave in New Mexico, USA

Lechuguilla Cave, a complex three-dimensional cave with a single known entrance, is located in remote desert terrain in Carlsbad Caverns National Park, in southeastern New Mexico, USA. The Guadalupe Mountains there contain uplifted limestone and dolomite rock in the Permian-age Capitan Reef complex. Hundreds of caves have been found in this region, but Lechuguilla Cave greatly exceeds the size of all others known. It was only a small pit mined for bat guano in the early twentieth century. In the 1970s the Cave Research Foundation performed digs at the bottom, where profuse air movement had been noted in the debris. This work ceased but another team of cavers visited in 1984, hearing and feeling the significant air, and began a digging project approved by the Park. The cavers dug into continuing passage in 1986. It was explored in three major branches, generally trending west/southwest to east/northeast, parallel to the reef face, with north-south connections along deep rift features. Depositional and corrosional events during sulfuric-acid speleogenesis created remarkable speleothems and speleogenesis, and the cave has often been called “the Jewel of the Underground”. The rapidly growing cave passed 80 km of surveyed length by 1990. Within the first ten years of exploration, 28 large-scale expeditions led to the cave reaching 113 km in length. From 1997 to 2013, 109 additional kilometers were mapped with smaller teams of up to 12 cavers per expedition. Exploration and mapping is now done in three to five expeditions per year, and recent work has focused on climbs and smaller leads such as tight crawls and fissures that were previously passed. Significant discoveries continue to be found using these techniques. The cave reaches a depth of 475 m and has been mapped to over 222 km in length. Exploration to the extreme ends is efficiently done with multi-day expeditions, using established camps in each branch. Cavers from the United States and dozens of other countries have been involved in this mapping project. The cave now has more than 35,000 survey stations, and the complexity of the maze of passages creates significant challenges for cartographers. Based on ever-present airflow and porosity of the bedrock, it is expected that this cave will continue to surprise and delight explorers and speleo-scientists in the future.

A record of wet glacial stages and dry interglacial stages over the last 560 kyr from a standing massive stalagmite in Carlsbad Cavern, New Mexico, USA

Abstract A horizontal core through a large, standing, stalagmite in Carlsbad Caverns National Park, New Mexico, USA, provides a radiometrically dated record of wetter glacial stages and drier interglacial stages over the last 560 kyr. The stalagmite, the Texas Toothpick, is about 7 m tall and about 3 m wide at its base. Two cores through the stalagmite reveal five distinct matching layers, and the best estimates from twenty U–Th ages indicate that those layers were deposited during MIS 6, 8, 10, 12, and 14, the five glacial periods ending with the Penultimate Glacial Maximum (PGM). Stable isotope data, measurements of remanent magnetism, and petrographic observations combine to suggest that conditions during glacials, the periods in which deposition took place, were significantly wetter than today. On the other hand, the stalagmite's hiatuses seemingly represent conditions during interglacials similar to or drier than today. These results combine with modern climatological observations to suggest 100-kyr-scale alternation between wetter conditions with an increased proportion of winter rainfall from a Pacific source during glacials to drier conditions with largely summer rainfall derived from the Gulf of Mexico during interglacials. The length and continuity of the results confirm that the pattern of wetter glacials and drier interglacials, known previously from studies isolated in time, existed across all of at least the last six glacial cycles. Simple monotonic extrapolation of these findings from cooler wetter glacials of the past and warmer drier interglacials like the present to a warmer climate expected in the coming century suggests that groundwater in the already dry southwestern United States may become even more scarce.

Whole-Genome Sequences of Five Oligotrophic Bacteria Isolated from Deep within Lechuguilla Cave, New Mexico.

Here, we report the whole-genome sequences and annotation of five oligotrophic bacteria from two sites within the Lechuguilla Cave in the Carlsbad Caverns National Park, NM. Three of the five genomes contain an acyl-homoserine lactone signal synthase ortholog (luxI) that is involved in cell-to-cell communication via quorum sensing.

The Transport of Nonindigenous Microorganisms Into Caves by Human Visitation: A Case Study at Carlsbad Caverns National Park

A series of atmospheric investigations was conducted in Carlsbad Cavern to determine if human visitation is a possible cause for the contamination of the cave system with non-indigenous microorganisms. In 2004, site-specific culture-based data demonstrated that Staphylococcus spp. colony-forming units (CFUs) were the most prevalent members of the atmospheric community along the paved visitor trail (avg. 18.8% of CFU), while Knoellia spp. CFUs dominated off-trail locations (40.1% of CFU). Fungal culture data revealed that Penicillium and Aspergillus were prevalent in the Lunch Room where food is stored, sold, and consumed. Ubiquitous genera such as Cladosporium and Alternaria were prevalent near the Natural Entrance of the cave, and the general trend was a decrease in fungal CFUs with progression into the cave system, except for the area near the Lunch Room. Management practices such as prohibition of crumb-generating types of foods could be considered to protect cave health. In 2009, nonculture-based analyses demonstrated that Enterobacteriaceae were the dominant microbiota at sites along the descent trail and within the Lunch Room. Dominance of Enterobacteriaceae has not been previously demonstrated in caves. Either they are naturally occurring indigenous members, or their presence is a marker of anthropogenic contamination.

Delineating the Rattlesnake Springs, New Mexico Watershed using Near-Surface Geophysical Techniques

We used a combination of ground conductivity, DC resistivity and precision gravity surveys in an effort to characterize the watershed of Rattlesnake Springs, New Mexico. The Springs serve as the domestic water source for Carlsbad Caverns National Park. Our results confirm previous geological studies that suggested ground water flows into the Springs from a number of sources. Gravity, resistivity and conductivity studies indicate that fine grained clays, possibly related to a collapsed karst feature, located to the north and northwest of the Springs serve as a barrier to fluid flow and may be responsible for the Springs' current location. Gravity data also suggest that north-south and west-northwest oriented fractures within the underlying gypsum bedrock serve as conduits to funnel ground water from the south and southwest. These fracture directions are consistent with fracture systems observed to the north within the limestone of the Guadalupe Escarpment, suggesting the fracture system resulted from regional tectonism.

The Lepidoptera of White Sands National Monument 5: Two new species of Cochylini (Lepidoptera, Tortricidae, Tortricinae)

In 2006, 10-year studies of the moths in two park units of the U.S. National Park Service in southern New Mexico were initiated: White Sands National Monument in Otero County, New Mexico, USA; and Carlsbad Caverns National Park, in Eddy County, New Mexico, USA. Two new species of Cochylini, Eugnosta brownana Metzler &amp; Forbes and Cochylis yinyangana Metzler, are described. Adults and male and female genitalia of both species are illustrated.

New taxa in Aspergillus section Usti

Based on phylogenetic analysis of sequence data, Aspergillus section Usti includes 21 species, inclucing two teleomorphic species Aspergillus heterothallicus (= Emericella heterothallica) and Fennellia monodii. Aspergillus germanicus sp. nov. was isolated from indoor air in Germany. This species has identical ITS sequences with A. insuetus CBS 119.27, but is clearly distinct from that species based on β-tubulin and calmodulin sequence data. This species is unable to grow at 37 °C, similarly to A. keveii and A. insuetus. Aspergillus carlsbadensis sp. nov. was isolated from the Carlsbad Caverns National Park in New Mexico. This taxon is related to, but distinct from a clade including A. calidoustus, A. pseudodeflectus, A. insuetus and A. keveii on all trees. This species is also unable to grow at 37 °C, and acid production was not observed on CREA. Aspergillus californicus sp. nov. is proposed for an isolate from chamise chaparral (Adenostoma fasciculatum) in California. It is related to a clade including A. subsessilis and A. kassunensis on all trees. This species grew well at 37 °C, and acid production was not observed on CREA. The strain CBS 504.65 from soil in Turkey showed to be clearly distinct from the A. deflectus ex-type strain, indicating that this isolate represents a distinct species in this section. We propose the name A. turkensis sp. nov. for this taxon. This species grew, although rather restrictedly at 37 °C, and acid production was not observed on CREA. Isolates from stored maize, South Africa, as a culture contaminant of Bipolaris sorokiniana from indoor air in Finland proved to be related to, but different from A. ustus and A. puniceus. The taxon is proposed as the new species A. pseudoustus. Although supported only by low bootstrap values, F. monodii was found to belong to section Usti based on phylogenetic analysis of either loci BLAST searches to the GenBank database also resulted in closest hits from section Usti. This species obviously does not belong to the Fennellia genus, instead it is a member of the Emericella genus. However, in accordance with the guidelines of the Amsterdam Declaration on fungal nomenclature (Hawksworth et al. 2011), and based on phylogenetic and physiological evidence, we propose the new combination Aspergillus monodii comb. nov. for this taxon. Species assigned to section Usti can be assigned to three chemical groups based on the extrolites. Aspergillus ustus, A. granulosus and A. puniceus produced ustic acid, while A. ustus and A. puniceus also produced austocystins and versicolorins. In the second chemical group, A. pseudodeflectus produced drimans in common with the other species in this group, and also several unique unknown compounds. Aspergillus calidoustus isolates produced drimans and ophiobolins in common with A. insuetus and A. keveii, but also produced austins. Aspergillus insuetus isolates also produced pergillin while A. keveii isolates produced nidulol. In the third chemical group, E. heterothallica has been reported to produce emethallicins, 5'-hydroxyaveranthin, emeheterone, emesterones, 5'-hydroxyaveranthin.

Stratigraphic Response Across a Structurally Dynamic Shelf: The Latest Guadalupian Composite Sequence at Walnut Canyon, New Mexico, U.S.A.

Abstract The uppermost Yates and Tansill formations (Late Permian), as exposed along Walnut Canyon in Carlsbad Caverns National Park, New Mexico, USA, provide a unique opportunity to document the depositional architecture of a progradational, oversteepened, and mechanically failure-prone carbonate platform. Detailed facies mapping permitted critical assessment of depositional processes operating along this structurally dynamic platform margin. At the shelf crest, thick (12 m), vertically stacked fenestral–pisolite–tepee complexes indicate a stable shoreline. Early lithification of sediments and extensive cementation fostered rapid vertical accretion and allowed the shelf crest to easily adjust to base-level oscillations by stepping landward, stepping seaward, or aggrading. This production imbalance—in combination with syndepositional brittle failure and down-to-the-basin tilting(