Habitat preference of Himalayan musk deer (Moschus leucogaster Hodgson, 1839) at Lapchi of Bigu Rural Municipality, Gaurishankar Conservation Area

The Himalayan musk deer (Moschus leucogaster) is an endangered species listed in the IUCN Red List and Appendix I of CITES. It is widely but discontinuously distributed in Nepal. A Pellet sign survey was carried in April 2019 in Lapchi valley of Gaurishankar Conservation Area (GCA) in Nepal to assess the habitat preference of Himalayan musk deer. A total of 11 transects of 16348 m length and 10 m wide was surveyed. Seven Parameters: Elevation, Aspect, ground cover, distance from the water source, crown cover, rock exposure, and distance from settlement/cow sheds were recorded from the location where pellet (toilet) of musk deer were recorded to extrapolate the probable habitat map. We recorded a total of 157 musk deer pellet groups in the study area14.27 ± 2.91. The study concluded that the 38.4% (26.5 km2) area of Lapchi valley is the probable habitat of musk deer. The c2 – test suggested that the distribution of musk deer is significantly associated with elevation and aspect of the location. Musk deer mostly preferred habitat between 3600-4000 m elevations, with North-West aspect, ground cover less than 25%, and canopy cover between 25%-50%. Musk deer signs were recorded in areas with rock exposure ranging from as low as less than 25%. Distance from the water source and human settlement affect the distribution of musk deer. The indirect signs were higher near water sources and far from human settlement.

Paleomagnetism from multi-orogenic terranes is "not a simple game": Pyrenees' Paleozoic warning

Paleomagnetism is a versatile tool in the Earth sciences: it provides critical input to geological time scales and plate tectonic reconstructions. Despite its undeniable perks, paleomagnetism is not without complications. Remagnetizations overprinting the original magnetic signature of rocks are frequent, especially in orogens which tend to be the areas with better rock exposure. Unraveling the magnetic history of the rocks is a complicated task, especially in areas that underwent several orogenic pulses. In turn, constraining the timing of remagnetization represents an opportunity to solve post-magnetization structural and tectonic kinematics. Here, we evaluate the magnetization history of Silurian-Devonian carbonates from the Axial Zone of the Pyrenees. The Pyrenees are a multi-orogenic mountain belt where Silurian-Devonian rocks have seen the Variscan collision (late Paleozoic), the opening of the Atlantic / Bay of Biscay (early Cretaceous) and the Alpine orogeny (late Cretaceous to Miocene). Our results show widespread remagnetization(s) carried by magnetite and pyrrhotite in the Silurian-Devonian series of the Pyrenees. The majority of the samples show a post-folding but pre-alpine tilting magnetization. Considering the equatorial inclinations found in such samples, we suggest that they likely acquired their magnetization during the late Carboniferous and early Permian times. Two of the studied sites (located at the western Axial Zone) were subsequently remagnetized at the end of the Alpine orogeny. The paleomagnetic results constrained that the Variscan orogeny was responsible for the main folding event affecting Paleozoic rocks in the Axial Zone, whereas the Alpine orogeny produced the large-scale thrusting and antiformal stacking of these units. In addition, we observed a general clockwise rotational pattern which could be related with the formation of the Cantabrian Orocline and/or rotations associated with the Alpine orogeny. The Silurian-Devonian carbonates are thus useful to understand the tectonic evolution of the Pyrenean mountain range after a systematic combination of paleomagnetism with structural and petrological observations. In contrast, the secondary character of magnetization and complications associated with the Variscan tectonics indicate that a reassessment of Siluro-Devonian poles from the Variscan elsewhere in Europe might be appropriate.

About this title - The Geology and Tectonics of the Jabal Akhdar and Saih Hatat Domes, Oman Mountains

The geology of the Oman Mountains, including the Jabal Akhdar and Saih Hatat domes, is extraordinarily well-exposed and diverse, spanning a geological record of more than 800 Ma. The area is blessed with first-class outcrops and is well known in the geological community for its ophiolite. The Oman Mountains have much more to offer; including, Neoproterozoic diamictites (“Snowball Earth”), fossil-rich Permo-Mesozoic carbonates and metamorphic rocks. The arid climate and deep incision of wadis allow for nearly complete rock exposure which can be investigated in all three dimensions. The diverse geology is also responsible for the breathtaking landscape. New roads and the nature of the friendly Omani people make fieldwork unforgettable.This Memoir provides a thorough state-of-the-art overview of the geology and tectonics of the Southeastern Oman Mountains, and is accompanied by an over-sized geological map and a correlation chart.

A new, more accurate, and easier to use Jacob's staff

ABSTRACT A new Jacob's staff using 3D printed brackets, a laser pointer, and an iOS app is described here. The staff offers improved accuracy of sighting, especially in situations where the rock exposure is not in the direction of dip, or where a lateral offset in a stratigraphic section is needed. Although the Jacob's staff will also work with a pocket transit or other inclinometer, the iOS app makes it easier to simultaneously maintain the correct dip angle and direction of the staff. The laser pointer substantially reduces error in sighting. The availability and low cost of 3D printing make this staff more accessible than similar apparatuses that require machined or welded metal parts. Field tests by students demonstrate greater accuracy than a traditional Jacob's staff combined with a transit.

Mapping surface rock exposures to enhance geohazard susceptibility assessment: a random forest approach

<p>We present the approach taken to map surface rock exposures in upland areas of Scotland. This has been carried out as a means of enhancing the mapping of superficial sediment thickness which has important applications including the assessment of potential geohazard susceptibility. The presented study includes selected test cases that have been constructed prior to scaling up the approach to upland areas across Great Britain (GB).</p><p>The presence of rock at surface acts as a marker of locations with minimal superficial sediment cover (essentially a zero depth). The thickness of superficial sediments across GB are currently estimated based on borehole records which range in both quality and coverage, with limited data particularly for upland regions. Superficial sediment thickness is an integral factor for assessing geohazard processes including landslides. Therefore, by improving datasets detailing rock at surface, we can enhance superficial sediment thickness estimates and enhance the variable inputs to the models used to assess geohazard susceptibility.</p><p>The GB landscape has been subject to a range of different environmental processes through time with its current topography being the subject of glacial erosion through to marine incursions. However, these patterns are not uniform and this results in a range of landscapes. The resulting domains are an important consideration when attempting to model the relationship between the presence and absence of natural rock exposures.  With a wealth of information available across GB including high resolution topography, the resulting (often scale-dependent) geomorphometric derivatives, geological datasets as well as satellite imagery, we are able to consider a range of possible relationships that might exist. We combine these datasets coupled with field validation of rock absence/presence to train a random forest classifier for specific domains with the aim being to identify a way of modelling rock exposure in areas of limited data availability as is the case for many upland areas.</p><p>The methodology and results of the approach for specific process domains will be presented with a specific focus on the Glen Gyle catchment, at the head of Loch Katrine (the primary water reservoir for the city of Glasgow) in the Trossachs National Park, Scotland. This is an area that has been subject to recent landslides which have affected local properties and infrastructure.</p>

Landscape Arch, Delicate Arch, and Double Arch in Arches National Park, Southeastern Utah

Arches National Park in southeastern Utah has the greatest concentration of natural rock arches in the world. The park is located in a geologic region called the Paradox fold and fault belt in the northern Paradox Basin and showcases spectacular and classic Colorado Plateau geology with its colorful sedimentary rocks, ancient sand dunes, cliffs, domes, fins, and pinnacles, as well as the arches. The arches in the park and the surrounding region were formed by a unique set of circumstances involving Middle Pennsylvanian (about 308 million years ago [Ma]) to Late Triassic (200 Ma) movement of subsurface salt layers, Middle Pennsylvanian to Late Cretaceous (about 70 Ma) deposition, and Tertiary and Quaternary (23 Ma to the present) folding, faulting, erosion, and salt dissolution. Massive, hard, brittle sandstones jointed by folding, resting on or containing soft layers or partings, and located near fold structures such as salt-cored anticlines undergoing dissolution, and a dry climate, all favor the formation of arches. Rarely do all these phenomena occur in one place, but they do in Arches National Park.The Natural Arch and Bridge Society (NABS) stated, “A natural arch is a rock exposure that has a hole completely through it formed by the natural, selective removal of rock, leaving a relatively intact frame.” They also make it clear that a natural bridge (which is at least partially formed by flowing water) is one type of natural arch (NABS website) (see A Bit of Perspective, below, for more explanation). Using their own criteria, Stevens and McCarrick (1988) catalogued over 2000 natural arches in Arches National Park; most have unique characteristics that could qualify them as geosites. However, the three most famous arches in the park, and perhaps the world, are Landscape Arch, Delicate Arch, and Double Arch, and thus these were selected as the geosites for this paper.

Dynamics of Abies Nephrolepis Seedlings in Relation to Environmental Factors in Seorak Mountain, South Korea

We present novel evidence of environmental drivers of seedling density in Abies nephrolepis, an alpine and subalpine tree species. Continuous monitoring of natural conditions is required to understand forest ecosystem dynamics. We investigated Abies nephrolepis seedling dynamics in relation to biotic and abiotic factors. The survey, which included the measurement of trees and seedlings, was carried out from March to October in 2016 and 2018. Monitoring sites in the coniferous forests of Seorak Mountain were divided into 27 quadrats. We analyzed relationships using simple and multiple linear regression. The majority of Abies nephrolepis individuals had a diameter at breast height less than l0 cm, and the number of seedlings increased over the study period. This reflects survival and growth due to successive annual mast seeding events. Aspect direction (R2 = 0.201, p < 0.05), rock exposure (R2 = 0.364, p < 0.001), canopy openness (R2 = 0.322, p < 0.05), herbaceous cover (R2 = 0.268, p < 0.01), and basal area (R2 = 0.199, p < 0.05) show significant linear relationships with seedling density. Seedling density was positively related to rock exposure, canopy openness, and species richness, and there was a negative relationship between herbaceous cover and basal area (p < 0.0001). The relative importance of predictor variables was as follows: Rock exposure (40.3%), canopy openness (30.2%), basal area (13.9%), herbaceous cover (11.5%), and species richness (4.1%). Seedling density was most strongly influenced by the presence of large rocks, which provide shelter from harsh winds and a substrate for moss. We conclude that appropriate canopy openness creates a synergistic relationship. We found a positive association between the Abies nephrolepis seedling density in subalpine forests and certain physical environmental factors. Therefore, environmental gradients about the roles of rocks and canopies apply, even in this habitat.

Sporadic sampling, not climatic forcing, drives observed early hominin diversity

The role of climate change in the origin and diversification of early hominins is hotly debated. Most accounts of early hominin evolution link observed fluctuations in species diversity to directional shifts in climate or periods of intense climatic instability. None of these hypotheses, however, have tested whether observed diversity patterns are distorted by variation in the quality of the hominin fossil record. Here, we present a detailed examination of early hominin diversity dynamics, including both taxic and phylogenetically corrected diversity estimates. Unlike past studies, we compare these estimates to sampling metrics for rock availability (hominin-, primate-, and mammal-bearing formations) and collection effort, to assess the geological and anthropogenic controls on the sampling of the early hominin fossil record. Taxic diversity, primate-bearing formations, and collection effort show strong positive correlations, demonstrating that observed patterns of early hominin taxic diversity can be explained by temporal heterogeneity in fossil sampling rather than genuine evolutionary processes. Peak taxic diversity at 1.9 million years ago (Ma) is a sampling artifact, reflecting merely maximal rock availability and collection effort. In contrast, phylogenetic diversity estimates imply peak diversity at 2.4 Ma and show little relation to sampling metrics. We find that apparent relationships between early hominin diversity and indicators of climatic instability are, in fact, driven largely by variation in suitable rock exposure and collection effort. Our results suggest that significant improvements in the quality of the fossil record are required before the role of climate in hominin evolution can be reliably determined.

Intentional, dual purpose of ancient wine presses as cisterns for runoff water harvesting in drylands

Rock-quarried wine presses were prevalent across the Mediterranean Basin throughout ancient times and particularly during the Late Roman and Byzantine ages. Archeological surveys have uncovered many presses across Israel. Overall, a ratio of ~5 m−1 has been recorded between treading floor area (in m2) and volume of collecting vat (in m3). A recent survey of two presses located at the transition zone between the semi-arid northern Negev, Judean Lowlands, and Southern Hebron Hills of Israel revealed a considerably smaller ratio between the treading floor and collecting vat. In addition, extensive rock exposures were located around the treading floors of the two presses. A 3D laser scanning revealed that the surrounding rock exposure formed a drainage network which flows to the treading floor. Moreover, indications for light modifications of the surrounding rock exposure were recorded for the two presses. In one of the presses, this modification was indicated by remnants of ancient plaster, which were found filling several gaps in the surrounding rock exposure. It is suggested that the purpose of the plaster was for allowing hydrological connectivity between the upslope and downslope edges of these gaps. In the second press, this modification included the chiseling of adjacent bedrock, for the purpose of, it is suggested, channeling runoff water to the treading floor. The findings suggest the intentional collection of raindrops falling on the surrounding rock exposure, together with those falling on the treading floor, which were drained as runoff into the collecting vat. The collected runoff could be used for domestic consumption in this dryland region, augmenting the provision of water for the local populations during the agricultural off-season.