Kathleen Nicoll
University of Utah, Geography, Faculty Member
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Western Desert of Egypt, Arid environments, Climate Change, Fluvial Geomorphology, Soil Science, Quaternary geochronology, and 36 moreQuaternary Sedimentology and Geomorphology, Sedimentology, Quaternary Geology, Geoarchaeology, Middle Eastern Archaeology, Earth Sciences, Prehistoric Archaeology, Middle Stone Age (Archaeology), Landscapes in prehistory, African prehistory, African Middle Stone Age, Geography, Archaeology, Paleoenvironment, Societal Collapse, Near Eastern Archaeology, Mediterranean prehistory, Neolithic Archaeology, Middle Paleolithic, Great Basin Archaeology, Displaying Levallois technique lithic industry from the United States, Gpr, Remote Sensing, Cemetery, Prehistory, Adaptation, Desertification, Middle Holocene, Civilisation, Social Complexity, Geomorphology, Geomorphology and Active tectonics, Environmental Sustainability, Anatolian Archaeology, Turkey, and Israel edit
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The papers uploaded to this site are offered for fair use. for further information please see www.kathleennicoll.com... moreThe papers uploaded to this site are offered for fair use.
for further information please see www.kathleennicoll.com
or contact via email on kathleen.nicoll<that "at" symbol>gmail.com
I most often post updates to facebook, either on my own page or that for the Archaeological Geology Division of the Geological Society of America (GSA). The latter is shared with the Geoarchaeology Interest Group of the Society for American Archaeology (SAA). edit
Analysis of multi-temporal satellite images from 1980 to 2019, complemented by geomorphic mapping and field study, indicate that "loose sand" extraction of Sakarya River deposits from the Adapazarı Plain of NW Turkey significantly... more
Analysis of multi-temporal satellite images from 1980 to 2019, complemented by geomorphic mapping and field study, indicate that "loose sand" extraction of Sakarya River deposits from the Adapazarı Plain of NW Turkey significantly intensified during the last decade, and mining operations have caused complete and irreversible alteration of floodplain habitat in a total area amounting to ~970 hectares. Our reconstructions estimate the total amount of mined material over a 40-year period since 1980 as ~50 million m 3 , amounting to ~80 million tonnes of fluvial sand. These sand mine operations, like most around the world, are highly disruptive and destructive but remain unregulated, and neither extractions or environmental impacts are reported or monitored. Our independent study is first to directly assess sand extraction in altering the natural geomorphic setting of the Sakarya River and describe economic, environmental, and social impacts of mining operations. The high demand for loose sand used in cement and concrete infrastructure correlates with changes in Turkey's political economy, which increasingly focused on construction during the last quarter of the 20th century. Extractive sand mining in this region has caused substantial land loss, soil erosion and water table alterations, which have made agricultural land unsuitable for cultivation, and even destroyed most of the farmland supporting the villages, eliminating the traditional farming practiced for millennia. Continuous mining operations cause constant noise, heavy vehicle traffic and pollution. Furthermore, sand removal from the Sakarya river environment has significantly diminished sediment transport offshore to its delta in the Black Sea; the lower sediment yield diminishes coastal beach nourishment and is accelerating coastal land erosion regionally. The Sakarya case study we describe illustrates the need for (1) improved oversight of human agency that destroys riverine settings; and (2) regulations regarding long term environmental and social impacts of sand mining.
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First scientifically documented by the British explorer and soldier Ralph Alger Bagnold, the Selima Sand Sheet is an extensive low-relief area located within the modern hyperarid core of the Eastern Sahara. Field survey and trenching... more
First scientifically documented by the British explorer and soldier Ralph Alger Bagnold, the Selima Sand Sheet is an extensive low-relief area located within the modern hyperarid core of the Eastern Sahara. Field survey and trenching reveal a surface mantle of near 'pinstripe" laminated aeolian sands that comprise active chevron (or zibar) bedforms, which are apparent on satellite datasets. These active sands cover Quaternary paleosols with morphostratigraphic characteristics that reflect differing degrees of soil development over time as a function of in situ weathering of quartz parent materials, addition of silts and clays via illuviation and eluviation processes, the precipitation of carbonates, rubification, and bioturbation by plants and insects. A relative chronostratigraphy is inferred from the associated archaeological (Neolithic) and historical materials (Late Historic to World War II), and absolute ages for these deposits are provided by optical dates using single aliquot regeneration techniques (SAR). Constraining the timing of aeolian sedimentation provides a basis for reconstructing paleoenvironmental changes and pedogenesis over Late Quaternary timescales in this region of northeast Africa. Accretion of the sand sheet was episodic and occurred during time periods of enhanced aeolian activity at ~20-14 and ~5-3 ka years ago. Late Pleistocene deposition of the sand sheet was out-of-phase with the widely recognized period of rainwater-fed "pluvial" playa lake formation and wadi river drainage alluviation documented in the Sahara, which resulted from enhanced monsoonal rains associated with the orbitally-forced precessional insolation maximum in the Northern Hemisphere. Enhanced bioturbation processes associated with wet phases during the Holocene have completely obliterated most primary sedimentary structures in the Pleistocene-aged sand sheet, resulting in the development of a cohesive, coarse sand and granule-dominated deposit exhibiting incipient prismatic soil structural development. The younger sand sheets dating to the Late Holocene (~4-3 ka years ago) preserve primary sedimentary structures (e.g. planar laminations), and increasing amounts of cohesion and structure with age. Reconstructing the maximum estimated accumulation rates, and assuming approximately uniform rates of sedimentation across the Selima Sand Sheet area, sediment storage within the sand sheet may be on the order of ~7 km 3 /1000 years during the time period that has elapsed since the mid-Holocene onset of arid conditions.
full citation: Nicoll, K., 2023. Sand, wind, paleosols, war: Late Quaternary aeolian dynamics in the Selima Sand Sheet Region, Darb el Arba'in Desert, Southern Egypt. Quaternary International 657:37-49 https://doi.org/10.1016/j.quaint.2023.02.002
full citation: Nicoll, K., 2023. Sand, wind, paleosols, war: Late Quaternary aeolian dynamics in the Selima Sand Sheet Region, Darb el Arba'in Desert, Southern Egypt. Quaternary International 657:37-49 https://doi.org/10.1016/j.quaint.2023.02.002
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Abstract Kiseiba Oasis and depression are located in southern Egypt between the Selima Sand Sheet to the west and the Nile to the east, an important area that hosted Late Cenozoic drainage, Middle Pleistocene lakes, and numerous... more
Abstract Kiseiba Oasis and depression are located in southern Egypt between the Selima Sand Sheet to the west and the Nile to the east, an important area that hosted Late Cenozoic drainage, Middle Pleistocene lakes, and numerous Paleolithic and Neolithic cultural sites. A synthesis of orbital data, field surveying and near-surface stratigraphy provides new insights into the Quaternary history of this region. Shuttle Imaging Radar data show a complex of fluvial channels that are due to stringers of surficial fluvial lag, subsurface fluvial deposits, and areas of deep alluvium. Three topographic surfaces are described: 1) the Atmur El-Kibeish, above 230 m elevation, which displays a linear pattern of light radar returns, possibly formed from northeast drainage; 2) the Acheulean Surface, at 200 m elevation, that has dark radar patterns resulting from thick alluvium bounded by pebble sand and calcrete strata, and 3) the Kiseiba Surface, below 190 m, that has a complex series of surface and subsurface fluvial and aeolian sediments. Initial drainage from the Early through Middle Pleistocene was to the northeast, which may have lasted through the Last Interglacial. Later reworking of sediments during the Last Glacial Maximum and the Holocene resulted in topographic inversion, with any subsequent local drainage on the Kiseiba Surface to the southwest, towards the Kiseiba Scarp.
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Geology, Geophysics, Ground Penetrating Radar (GPR), Arid environments, Neolithic Archaeology, and 13 moreEgypt, Aeolian Geomorphology, Ground Penetrating Radar, Saharan Archaeology, Fluvial Geomorphology, Kharga Oasis, Quaternary, Sahara, Acheulean, Synthetic Aperture Radar, Middle Pleistocene, Western Desert of Egypt, and Aeolian Sand
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Journal ArticleDunes and stratified eolian sedi-ments are a significant component of the postglacial landscape across the mid-continent. During the 1970s, a benchmark study in north-central Minne-sota inferred a period of eolian activity... more
Journal ArticleDunes and stratified eolian sedi-ments are a significant component of the postglacial landscape across the mid-continent. During the 1970s, a benchmark study in north-central Minne-sota inferred a period of eolian activity 8,000 ? 5,000 years ago (i.e., the Altithermal Hypsithermal periods), based upon radiocarbon dates on charcoal and organic material preserved within paleosols developed in dunes [1]. We revisited a classic local-ity at Lake Winnibigoshish (N 47?27'; W 94?12'), and sample other dune-forms to hypothesis-test whether eolian landform development occurred dur-ing the middle Holocene. Optical luminescence techniques can better resolve Minnesota's eolian chronologies by directly dating the emplacement of bed forms; sediments are typically oxidized and lack preserved organic materials suitable for 14C dating
Petrography and palynology of Late Oligocene and Middle Miocene coals in the
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Geography, Human Geography, Geology, Zagros Mountains, Maps, and 3 moreKarst, Tigris River, and Folding
Located in the Great Basin Desert within the North American continental interior, the Great Salt Lake (GSL) is a remnant of freshwater Palaeolake Bonneville, and today is the fourth largest perennial and closed basin lake in the world.... more
Located in the Great Basin Desert within the North American continental interior, the Great Salt Lake (GSL) is a remnant of freshwater Palaeolake Bonneville, and today is the fourth largest perennial and closed basin lake in the world. More than a century of study on the Pleistocene megalake and its modern hypersaline environment (latitude 40.7° to 41.7°N, longitude 111.9° to 113.1°W) has significantly contributed to what we know about lake systems, sediments, and Quaternary climate change. Ongoing geolimnological work on GSL is lively and diverse; there is much progress, this review paper highlights select key themes of interest. Some recent studies aim to quantify hypersaline lake water properties and hydrodynamics in context of human activities (e.g., pressures from transportation, mining, development), as science-informed monitoring and managing GSL waters has become a greater priority for extractive industries, resource managers, environmentalists, and regulating officials. Copious research leverages new technologies and methods to identify and describe microbes living in the GSL and its brine, including halophiles, halobacteria, fungi, and viruses. The GSL’s self-sustaining microbial ecology drives the high productivity of the lake, which has cascading global impacts for millions of migratory birds that stop at this oasis to feed. Furthermore, the question of what extremophiles live in each niche of the modern saline ecosystem in relation to salts and carbonate organosedimentary sedimentary systems is broadly relevant for understanding the deep rock record, the nature of early Earth evolution, and for astrobiological prospection as we aim to find life on other planets.
Annotated review summarizing the cool papers presented at INQUA, presented as full papers in this volume.
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Archaeology, Geology, Geomorphology, Geoarchaeology, GeoArcheology, and 10 moreLandscape Archaeology, Quaternary Geology, Quaternary, Quaternary Sedimentology and Geomorphology, Quaternary environments, Quaternary Science, Quaternary environmental change, Geoarchaeology and Paleoenvironmental Reconstructions, Quaternary Geoarchaeology, and Landscape and Land-use-history
We present an overview of selected papers published since 2000 that interpret Late Quaternary multi-proxy palaeoclimate records from Turkey and the surrounding region of the Near-Middle East and Mediterranean region. Existing records in... more
We present an overview of selected papers published since 2000 that interpret Late Quaternary multi-proxy palaeoclimate records from Turkey and the surrounding region of the Near-Middle East and Mediterranean region. Existing records in Turkey are rather limited in their resolution, and the locations studied thus far reflect a limited spatial and temporal distribution. Because Turkey is a very large country with numerous mountains that affect local weather conditions and create complex feedbacks, it is difficult to correlate trends across the broad landscape, and beyond. Published instrumental records are too short, and most palaeoclimate proxy records, including many lakes studied in Cappadocia and Konya, are low resolution. The Anatolian peninsula is sensitive to spatial and temporal shifts in the configuration, strength and persistence of global circulation patterns affecting the Mediterranean climate zone, including the mid-latitude westerlies, the continental climate system anc...
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Elinor Wight Gardner (1892–1981) was the first female geologist who worked and published as a geoarcheologist. During her career, she worked in arid lands of North Africa, Mediterranean and the Near East, and was regarded as a pioneering... more
Elinor Wight Gardner (1892–1981) was the first female geologist who worked and published as a geoarcheologist. During her career, she worked in arid lands of North Africa, Mediterranean and the Near East, and was regarded as a pioneering geoscientist who made important contributions in multiple fields, including archeology, geomorphology, paleontology and Quaternary science. Despite her ground-breaking work at many archeological sites, Gardner’s impact has been largely unrecognized. Few details are known about her personal life; she was a private and reserved person who left limited first-hand accounts of her opinions and motivations. Gardner worked with charismatic figures such as her life-long friend and primary collaborator, the archeologist Gertrude Caton Thompson (1888–1985). This biography synthesizes primary sources and draws insights about Gardner’s character from her bibliography, publications and notebooks, and mentions by contemporary peers. Much attention has focused on ...
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Archaeology, Geology, Quaternary Geology, Egypt, Middle Stone Age (Archaeology), and 15 moreQuaternary, Pergamon, Lakes, Quaternary Sedimentology and Geomorphology, Quaternary environments, Calcareous Tufa, Tufa, Travertine and Tufa formation, Oasis, Nile River Basin, Western Desert of Egypt, Quaternary Geoarchaeology, Nile Basin, Sub Saharan Africa, and Egyptian Oasis and Caravan Routes
Abstract Ahora Gorge is a 400 m deep canyon located along the North Eastern flank of Mt. Ararat (Turkey), a compound volcanic complex covered by an ice cap. In the past, several diarists and scientific authors reported a calamitous event... more
Abstract Ahora Gorge is a 400 m deep canyon located along the North Eastern flank of Mt. Ararat (Turkey), a compound volcanic complex covered by an ice cap. In the past, several diarists and scientific authors reported a calamitous event on July 2, 1840, when a landslide triggered by a volcanic eruption and/or an earthquake obliterated several villages located at the foot of the volcano. The reasons and effects of this Ahora Gorge Catastrophe (AGC) event have been obscure and ambiguous. To reappraise the 1840 catastrophe and the geomorphic evolution of the Ahora Gorge, we used high-resolution satellite images, remote sensing thermal data supplemented by observations collected during two field surveys. According to our interpretation, an earthquake in 1840 triggered an abrupt volcanic eruption, which caused the consequent rapid melting of glacial ice and mountain snow. This event produced significant mud and ice flow along the Ahora Gorge that inundated the villages downslope. The flooding, which we interpret as a lahar, deposited a wide alluvial fan at the foot of the volcano. Today, an elongated landform present within the Ahora Gorge has alternately been interpreted as a landslide deposit. Our multi-data integrated analysis and ground-based observations demonstrate that this feature is an unmapped glacier. The shape of the landform coupled with ASTER thermal satellite data and ground-based observations reveal that a debris-covered glacier (DCG) formed soon after the catastrophic lahar. Our discovery of the Ahora Gorge Glacier in context of a reappraisal of the Ahora Gorge Catastrophe demonstrates the contribution of glaciers in shaping the landscape near ice-capped volcanoes. Moreover, our data underscore the importance of being more aware of the potential future geo-hazards posed by Mount Ararat, particularly where glaciers are still present along several valleys and seismically-induced lahar events might occur.
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Geology and Geomorphology
Abstract Though southern Egypt is currently hyperarid, relict freshwater carbonate deposits called tufas near Kurkur (region centered at 23° 54′ N, 32° 19′ E) indicate that ambient rainwater-fed alkaline springs formerly sourced drainages... more
Abstract Though southern Egypt is currently hyperarid, relict freshwater carbonate deposits called tufas near Kurkur (region centered at 23° 54′ N, 32° 19′ E) indicate that ambient rainwater-fed alkaline springs formerly sourced drainages in the Sinn El-Kaddab or Eocene scarp, and precipitated carbonate tufa deposits at waterfall cascades, pools, and streams. Petrographic analysis enables the reconstruction of a variety of vegetated microenvironments during Quaternary time. The Kurkur tufas are very porous rocks with an abundance of fossil plant casts and molds making up the petrofabrics at the macroscale. The tufas also preserve laminations of successive generations of calcified remains of microbes visible at the microscopic scale. Original carbonate framework architectures are massive carbonate structures to the decameter scale, with characteristic highly porous and permeable rock fabrics, including vegetation-rich phytoherms and stromatolite forms. The tufas are relatively pristine, preserving their original rock textures with minimal post-depositional alteration. Structural controls affecting the development of tufa deposits near Kurkur include fissure, cracks and fault planes that would have enhanced groundwater recharge and emergence of carbonate-saturated springs from perched aquifers above the Nubian Aquifer System during periods of greater effective rainfall in the past when the water table was significantly higher. The Kurkur tufas are relict archives from phases when groundwater discharge supported comparatively more vegetation than the modern day, and spring flows sustained baseflow in the Wadi Kurkur tributary of the Upper Nile. Episodes of tufa deposition along now-defunct tributaries therefore reflect phases of a more integrated Nile drainage system.
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Archaeology, Prehistoric Archaeology, Geology, Geomorphology, Geoarchaeology, and 12 moreGeoArcheology, Coastal Geomorphology, Quaternary Geology, OSL dating, Quaternary Sedimentology and Geomorphology, Quaternary geochronology, Great Basin Archaeology, Coastal geoarchaeology, Geoarchaeology and Paleoenvironmental Reconstructions, Quaternary Geoarchaeology, Great Basin hunter-gatherers, and Elsevier
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Geography, Archaeology, Near Eastern Archaeology, Earth Sciences, Climate Change, and 15 moreEnvironmental Archaeology, Mediterranean prehistory, Climate Change Adaptation, Levantine Archaeology, Cypriot Archaeology, Mediterranean archaeology, Abrupt Climate Change, Near East, North Africa, North African Archaeology, Mesopotamia, History and archaeology, Middle Holocene, Abrupt Drying, and Eastern Mediterranean
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Egyptology, Earth Sciences, Geology, Geoarchaeology, GeoArcheology, and 15 moreEgyptian Archaeology, Egypt, Quaternary, Late Pleistocene to Early Holocene, Ancient Egypt, Quaternary environments, Hydroclimatology, Holocene, History and archaeology, Quaternary environmental change, Geoarchaeology and Paleoenvironmental Reconstructions, Nile River Basin, Floodplains, Quaternary Geoarchaeology, and Paleochannels
Remote sensing datasets enable planetary volcanologists to extract information regarding eruption processes. Long-lived effusive eruptions at sites such as Kilauea Volcano (HI) provide opportunities to collect rich observational data... more
Remote sensing datasets enable planetary volcanologists to extract information regarding eruption processes. Long-lived effusive eruptions at sites such as Kilauea Volcano (HI) provide opportunities to collect rich observational data sets, including detailed measurements of topography and extrusion rates, that allow comparisons between lava flow surface morphologies and emplacement conditions for use in interpreting similar morphological features associated with planetary lava flows. On Mars, the emplacement of basaltic lava flows is a volumetrically and spatially important process, creating both large-scale and small-scale surface morphologies. On Earth, low effusion rate eruptions on relatively horizontal slopes tend to create inflated lava flows that display hummocky topography. To better understand the processes involved in creating observed surface characteristics, we repeatedly measured the surface topography of an actively flowing and inflating basaltic unit within the Pu'...
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... Geomorphic evi-dence of former glaciation is preserved at large impact basins (eg, Argyre basin—Kargel and Strom, 1992; Banks et al., 2008) and at volcanoes (eg, Arsia ... Opal mound sinter records the history of springs such as... more
... Geomorphic evi-dence of former glaciation is preserved at large impact basins (eg, Argyre basin—Kargel and Strom, 1992; Banks et al., 2008) and at volcanoes (eg, Arsia ... Opal mound sinter records the history of springs such as Roosevelt Hot Springs, Utah (Lynne et al., 2007). ...
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The integration of high-resolution archaeological, textual, and environmental data with longer-term, low-resolution data affords greater precision in identifying some of the causal relationships underlying societal change. Regional and... more
The integration of high-resolution archaeological, textual, and environmental data with longer-term, low-resolution data affords greater precision in identifying some of the causal relationships underlying societal change. Regional and microregional case studies about the Byzantine world—in particular, Anatolia, which for several centuries was the heart of that world—reveal many of the difficulties that researchers face when attempting to assess the influence of environmental factors on human society. The Anatolian case challenges a number of assumptions about the impact of climatic factors on socio-political organization and medium-term historical evolution, highlighting the importance of further collaboration between historians, archaeologists, and climate scientists.
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Late Antique and Byzantine History, Late Antique and Byzantine Studies, Bioarchaeology, Geoarchaeology, Anatolian Studies, and 15 moreEnvironmental History, Anatolian Archaeology, Late Antique Archaeology, Byzantine Studies, Late Antiquity, Byzantine History, Byzantine Archaeology, Applied Economics, Interdisciplinary History, Anatolia, Byzantium, Ancient Anatolia, Climate history, Ephesos, and Historical Studies
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Genetics, Geology, Sedimentology, Stratigraphy, Sequence Stratigraphy, and 12 morePaleoclimate, Sedimentary geology and stratigraphy, Seasonality, Jurassic Stratigraphy, Paleosols, Regime change, Upper Jurassic, Fluvial Sedimentology, Sedimentary Geology, Colorado Plateau, Unconformities, and Contextual Information
... Images Images, Journal/Book title, Volume, Issue, Page, Search tips. ... Since the archaeology of this region is poorly known, these cultural assemblages enable initial correlations across ... Indian Ocean, either associated with... more
... Images Images, Journal/Book title, Volume, Issue, Page, Search tips. ... Since the archaeology of this region is poorly known, these cultural assemblages enable initial correlations across ... Indian Ocean, either associated with ridging along the east coast or a deep low over the interior ...
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Management, Geology, Geomorphology, Fire Ecology, Arid Land Ecology, and 15 moreArid environments, Disturbance Ecology, Aeolian Geomorphology, Planning, Landscapes, Evaporites, Cenozoic, Distribution of rubber cultivation in relation to landscape attributes, Phanerozoic, Mobilization, Eolian dust, Aeolian sedimentology, Lac, Evaporite, and Playa
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Geology, Geomorphology, Renewable Energy, Climatology, Energy, and 15 moreMorphology, Aeolian Geomorphology, Communication Networks, Interpretation, Greater Southwest, Control Systems, Mediterranean Area, Direction, North America, Great Basin, Sediment Transport, Laser Communication Networks, Electrical Power Distribution, High Deserts and Rain shadow Mountains, and Great Basin of US
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Earth Sciences, Geology, Geoarchaeology, Egyptian Archaeology, Middle Stone Age (Archaeology), and 8 moreDevelopment in the Middle East and North Africa, Middle to Upper Paleolithic Transition, Sudanese Archaeology, Mediterranean and North Africa, North African prehistory (Archaeology), Palaeolithic, History and archaeology, and African Middle Stone Age
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Paleobiology, Earth Sciences, Geology, Paleontology, Biogeochemistry, and 15 moreGeoarchaeology, Palaeolithic Archaeology, Palaeontology, Late Palaeolithic, Palaeolithic, Calcareous Tufa, Raman, Environmental Radioactivity, History and archaeology, An, LIBS, African Middle Stone Age, Radon, Isotope Geochronology, and Hydrothermal Sinter
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... Fifth, in all of these Operations micro-archaeological samples were taken to better recover artefacts from everyday life in the ancient city. ... in the lower town (see below), in 2004 we decided to test a new technique of geophysical... more
... Fifth, in all of these Operations micro-archaeological samples were taken to better recover artefacts from everyday life in the ancient city. ... in the lower town (see below), in 2004 we decided to test a new technique of geophysical mapping using an electrical resistance meter in the ...
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Assessing the “human footprint” on the landscape since prehistory requires some comparison of the degree and pace of such changes, and the cause-and-effect, as well as the ability to resolve the anthropogenic signal from from patterns of... more
Assessing the “human footprint” on the landscape since prehistory requires some comparison of the degree and pace of such changes, and the cause-and-effect, as well as the ability to resolve the anthropogenic signal from from patterns of “natural” environmental variation. The deep archaeological record provides valuable insights regarding the timeframe prior to the European industrial revolution; studies at specific localities may help resolve differences between anthropogenically-mediated changes and “natural” climatic changes. Results of various archaeological and palaeoecological archives across the Fertile Crescent indicates that rapid changes on landforms and biota have occurred since the beginnings of agriculture and urbanization. Work at key localities suggests that periods of imperialism such as the Neo-Assyrian 9th century BCE are synchronous with sediment disturbances and deforestation in southeastern Turkey. New findings from geomorphic and archaeological survey and inves...
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Although the extrusion of pahoehoe lava flows is one of the most dominant planetary surface-forming processes in the solar system, emplacement models remain controversial, and affect our ability to understand the implications of... more
Although the extrusion of pahoehoe lava flows is one of the most dominant planetary surface-forming processes in the solar system, emplacement models remain controversial, and affect our ability to understand the implications of continental effusive eruptions. To study the detailed growth patterns of an actively inflating hummocky pahoehoe field in Hawaii, we used a Riegl LMSZ420i ground-based light detection and ranging (LiDAR) system that captures topographic data at unprecedented resolutions and speed, and co-registers the x, y and z coordinates with the RGB values of true color high-resolution (12 megapixel) photographs from an externally-mounted camera. Over a 3-day period (February 21-23, 2007) we acquired 4 surveys of surface topography over a ~200 x 200 m area within the Pu'u O'o flow field that contained actively inflating pahoehoe flows emplaced over older, hummocky pahoehoe lavas. Total scan times ranged from 6 to 19 minutes, with topographic points collected at a 0.05-0.08 degree spacing. Each scan obtained between 1.6 and 5.1 million x, y, and z data points. We acquired topographic data at a rate of 12,000 points/second, permitting repeatable digital elevation model (DEM) generation with 5mm accuracy. We differenced successive DEMs generated from our topographic data to determine the magnitude and patterns of growth. We documented uneven rates of inflation over the area, ranging from less than 0.5 m to 3.9 m, with several tumuli forming over the 3-day time period. These results are the first detailed measurements that help us constrain the movement of lava between upper and lower flow crusts.
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Introduction: The hypersaline Great Salt Lake (GSL) of northern Utah, USA is a critical regional ecosystem that has not been examined in detail from a geobiological perspective. There are presently only a handful of studies on the biota... more
Introduction: The hypersaline Great Salt Lake (GSL) of northern Utah, USA is a critical regional ecosystem that has not been examined in detail from a geobiological perspective. There are presently only a handful of studies on the biota of this shallow water closed-lake system [1]. Despite interest from industries mining the salt and harvesting the brine shrimp, relatively little is known about the lake‘s geochemistry, microbial diversity, metabolic activity, and mineralogy, and how these relate together with processes of biosedimentation and fossil preservation. Objectives: We study the composition, architecture, and preservation of modern GSL microbial communities present using genomic (DNA sequencing) and microscopic techniques (SEM, EDAX). Initial Results: Our examination of various sedimentary facies sampled in the modern GSL (figure 1) indicates that microbial communities occur in many of its environments. Microbial communities in the GSL are found in microbial mats, crusts, t...
We present the geomorphological map of the northwestern part of the Kurdistan Region of Iraq, where the landscape expresses the tectonic activity associated with the Arabia-Eurasia convergence and Neogene climate change. These processes... more
We present the geomorphological map of the northwestern part of the Kurdistan Region of Iraq, where the landscape expresses the tectonic activity associated with the Arabia-Eurasia convergence and Neogene climate change. These processes influenced the evolution of landforms and fluvial pathways, where major rivers Tigris, Khabur, and Great Zab incise the landscape of Northeastern Mesopotamia Anticlinal ridges and syncline trough compose the Zagros orogen. The development of water and wind gaps, slope, and karsts processes in the highlands and the tilting of fluvial terraces in the flat areas are the main evidence of the relationship between tectonics, climate variations and geomorphological processes. During the Quaternary, especially after the Last Glacial Maximum, fluctuating arid and wet periods also influenced local landforms and fluvial patterns of the area. Finally, the intensified Holocene human occupation and agricultural activities during the passage to more complex societi...
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The Great Basin physiographic province is the largest desert region in the USA, and a known source area for windblown dusts, including aerosols, black carbon, nutrients, and mineral particles. However, surprisingly little is known about... more
The Great Basin physiographic province is the largest desert region in the USA, and a known source area for windblown dusts, including aerosols, black carbon, nutrients, and mineral particles. However, surprisingly little is known about dust composition, atmospheric loading and fluxes from sources to sinks. Within this semi-arid region, intermountain cyclonic storms and aeolian dynamics are important drivers of dust entrainment and transport. Since the 1930s, Utah newspapers have reported spring cold front passages after dust storms that caused it to “rain mud.” Various studies on the prevailing winds and synoptic meteorological conditions relate seasonal development of strong intermountain cyclones with elevated wind speeds and dust storm events. The peak frequency of dust event days (DEDs) typically occurs during the spring months when ‘Hatu winds’ blow from the south. The highest frequencies of dust storms occur in March and April, with a secondary peak in September.
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FOR SURFACE PROCESSES ON MARS. Marjorie A. Chan, Kathleen Nicoll, Paul W. Jewell, Timothy J. Parker, Bruce G. Bills, Chris H. Okubo, and Goro Komatsu. University of Utah, Department of Geology and Geophysics, 115 S. 1460 E. Rm. 383 FASB,... more
FOR SURFACE PROCESSES ON MARS. Marjorie A. Chan, Kathleen Nicoll, Paul W. Jewell, Timothy J. Parker, Bruce G. Bills, Chris H. Okubo, and Goro Komatsu. University of Utah, Department of Geology and Geophysics, 115 S. 1460 E. Rm. 383 FASB, Salt Lake City, UT 84112-0102, marjorie.chan@utah.edu, University of Utah, Department of Geography, Salt Lake City, UT 84112, Jet
Propulsion
Laboratory,
California
Institute
of
Technology,
Pasadena,
CA
91109, U.S. Geological Survey, Flagstaff, AZ 86001, International Research School of Planetary Sciences, Università d’Annunzio, Viale Pindaro 42, 65127 Pescara, Italy.