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M.C. Reheis

Publications and source records attributed to M.C. Reheis.

At least 19 recordsLinked to original sources
USGS2019

Late Quaternary paleohydrology of desert wetlands and pluvial lakes in the Soda Lake basin, central Mojave Desert, California (USA)

Sediment cores taken near extant springs along the western margin of Soda Lake playa, as well as from the playa center, reveal dramatic hydrologic changes that occurred in the central Mojave Desert during the late Quaternary. Results of stratigraphic, chronologic, physical, chemical, and microfossil analyses of seven cores, ranging in length from 5 to 23 m, help refine the timing and character of the final stages of pluvial Lake Mojave during the late Pleistocene and define distinct periods of wetland development in the early and late Holocene. Evidence shows that an incipient lake occupied the central Soda Lake basin by at least 25.0 ka (ka = thousands of calibrated 14 C years before present), and a fully developed Lake Mojave was present between 20.5 and 12.8 ka, before receding and ultimately yielding to playa conditions by 11.0 ka. Organic-rich “black mats” appear in several cores along the playa margin between 10.7 and 9.0 ka, suggesting that spring-fed wetlands persisted in this area long after the lake had regressed. The basin remained relatively dry throughout most of the Holocene until wetland ecosystems expanded along the margins between 0.73 and 0.18 ka, coincident with part of the Medieval Climate Anomaly and Little Ice Age. Overall, our results demonstrate that buried sediments surrounding extant and extinct springs can be used to reconstruct past hydrologic conditions in desert environments on a variety of spatial and temporal scales, and provide important baseline information for effective management of limited desert resources.

California↗
USGS2017

Rates of soil development from four soil chronosequences in the southern Great Basin

Four soil chronosequences in the southern Great Basin were examined in order to study and quantify soil development during the Quaternary. Soils of all four areas are developed in gravelly alluvial fans in semiarid climates with 8 to 40 cm mean annual precipitation. Lithologies of alluvium are granite-gneiss at Silver Lake, granite and basalt at Cima Volcanic Field, limestone at Kyle Canyon, and siliceous volcanic rocks at Fortymile Wash. Ages of the soils are approximated from several radiometric and experimental techniques, and rates are assessed using a conservative mathematical approach. Average rates for Holocene soils at Silver Lake are about 10 times higher than for Pleistocene soils at Kyle Canyon and Fortymile Wash, based on limited age control. Holocene soils in all four areas appear to develop at similar rates, and Pleistocene soils at Kyle Canyon and Fortymile Wash may differ by only a factor of 2 to 4. Over time spans of several millennia, a preferred model for the age curves is not linear but may be exponential or parabolic, in which rates decrease with increasing age. These preliminary results imply that the geographical variation in rates within the southern Great Basin-Mojave region may be much less significant than temporal variation in rates of soil development. The reasons for temporal variation in rates and processes of soil development are complexly linked to climatic change and related changes in water and dust, erosional history, and internally driven chemical and physical processes. ?? 1991.

Quaternary Research↗
USGS2009

Compositions of modern dust and surface sediments in the Desert Southwest, United States

Modern dusts across southwestern United States deserts are compositionally similar to dust-rich Av soil horizons (depths of 0-0.5 cm and 1-4 cm at 35 sites) for common crustal elements but distinctly different for some trace elements. Chemical compositions and magnetic properties of the soil samples are similar among sites relative to dust sources, geographic areas, and lithologic substrates. Exceptions are Li, U, and W, enriched in Owens Valley, California, and Mg and Sr, enriched in soils formed on calcareous fan gravel in southeast Nevada. The Av horizons are dominated by dust and reflect limited mixing with substrate sediments. Modern dust samples are also similar across the region, except that Owens Valley dusts are higher in Mg, Ba, and Li and dusts both there and at sites to the north on volcanic substrates are higher in Sb and W. Thus, dust and Av horizons consist of contributions from many different sources that are well mixed before deposition. Modern dusts contain significantly greater amounts of As, Cd, Cr, Cu, Ni, Pb, and Sb than do Av horizons, which record dust additions over hundreds to thousands of years. These results suggest that modern dust compositions are influenced by anthropogenic sources and emissions from Owens (dry) Lake after its artificial desiccation in 1926. Both modern dusts and Av horizons are enriched in As, Ba, Cu, Li, Sb, Th, U, and W relative to average crustal composition, which we interpret to indicate that the geologic sources of dust in the southwestern United States are geochemically distinctive.

Journal of Geophysical Research F: Earth Surface↗
USGS2009

Geology and geomorphology of Bear Lake Valley and upper Bear River, Utah and Idaho

Bear Lake, on the Idaho-Utah border, lies in a fault-bounded valley through which the Bear River flows en route to the Great Salt Lake. Surficial deposits in the Bear Lake drainage basin provide a geologic context for interpretation of cores from Bear Lake deposits. In addition to groundwater discharge, Bear Lake received water and sediment from its own small drainage basin and sometimes from the Bear River and its glaciated headwaters. The lake basin interacts with the river in complex ways that are modulated by climatically induced lake-level changes, by the distribution of active Quaternary faults, and by the migration of the river across its fluvial fan north of the present lake. The upper Bear River flows northward for ???150 km from its headwaters in the northwestern Uinta Mountains, generally following the strike of regional Laramide and late Cenozoic structures. These structures likely also control the flow paths of groundwater that feeds Bear Lake, and groundwater-fed streams are the largest source of water when the lake is isolated from the Bear River. The present configuration of the Bear River with respect to Bear Lake Valley may not have been established until the late Pliocene. The absence of Uinta Range-derived quartzites in fluvial gravel on the crest of the Bear Lake Plateau east of Bear Lake suggests that the present headwaters were not part of the drainage basin in the late Tertiary. Newly mapped glacial deposits in the Bear River Range west of Bear Lake indicate several advances of valley glaciers that were probably coeval with glaciations in the Uinta Mountains. Much of the meltwater from these glaciers may have reached Bear Lake via groundwater pathways through infiltration in the karst terrain of the Bear River Range. At times during the Pleistocene, the Bear River flowed into Bear Lake and water level rose to the valley threshold at Nounan narrows. This threshold has been modified by aggradation, downcutting, and tectonics. Maximum lake levels have decreased from as high as 1830 m to 1806 m above sea level since the early Pleistocene due to episodic downcutting by the Bear River. The oldest exposed lacustrine sediments in Bear Lake Valley are probably of Pliocene age. Several high-lake phases during the early and middle Pleistocene were separated by episodes of fluvial incision. Threshold incision was not constant, however, because lake highstands of as much as 8 m above bedrock threshold level resulted from aggradation and possibly landsliding at least twice during the late-middle and late Pleistocene. Abandoned stream channels within the low-lying, fault-bounded region between Bear Lake and the modern Bear River show that Bear River progressively shifted northward during the Holocene. Several factors including faulting, location of the fluvial fan, and channel migration across the fluvial fan probably interacted to produce these changes in channel position. Late Quaternary slip rates on the east Bear Lake fault zone are estimated by using the water-level history of Bear Lake, assuming little or no displacement on dated deposits on the west side of the valley. Uplifted lacustrine deposits representing Pliocene to middle Pleistocene highstands of Bear Lake on the footwall block of the east Bear Lake fault zone provide dramatic evidence of long-term slip. Slip rates during the late Pleistocene increased from north to south along the east Bear Lake fault zone, consistent with the tectonic geomorphology. In addition, slip rates on the southern section of the fault zone have apparently decreased over the past 50 k.y. Copyright ?? 2009 The Geological Society of America.

Special Paper of the Geological Society of America↗
USGS2009

Allogenic sedimentary components of Bear Lake, Utah and Idaho

Bear Lake is a long-lived lake filling a tectonic depression between the Bear River Range to the west and the Bear River Plateau to the east, and straddling the border between Utah and Idaho. Mineralogy, elemental geochemistry, and magnetic properties provide information about variations in provenance of allogenic lithic material in last-glacial-age, quartz-rich sediment in Bear Lake. Grain-size data from the siliciclastic fraction of late-glacial to Holocene carbonate-rich sediments provide information about variations in lake level. For the quartz-rich lower unit, which was deposited while the Bear River fl owed into and out of the lake, four source areas are recognized on the basis of modern fluvial samples with contrasting properties that reflect differences in bedrock geology and in magnetite content from dust. One of these areas is underlain by hematite-rich Uinta Mountain Group rocks in the headwaters of the Bear River. Although Uinta Mountain Group rocks make up a small fraction of the catchment, hematite-rich material from this area is an important component of the lower unit. This material is interpreted to be glacial fl our. Variations in the input of glacial flour are interpreted as having caused quasi-cyclical variations in mineralogical and elemental concentrations, and in magnetic properties within the lower unit. The carbonate-rich younger unit was deposited under conditions similar to those of the modern lake, with the Bear River largely bypassing the lake. For two cores taken in more than 30 m of water, median grain sizes in this unit range from ???6 ??m to more than 30 ??m, with the coarsest grain sizes associated with beach or shallow-water deposits. Similar grain-size variations are observed as a function of water depth in the modern lake and provide the basis for interpreting the core grain-size data in terms of lake level. Copyright ?? 2009 The Geological Society of America.

Special Paper of the Geological Society of America↗
USGS2008

Compositional trends in aeolian dust along a transect across the southwestern United States

Aeolian dust strongly influences ecology and landscape geochemistry over large areas that span several desert ecosystems of the southwestern United States. This study evaluates spatial and temporal variations and trends of the physical and chemical properties of dust in the southwestern United States by examining dust deposited in natural depressions on high isolated surfaces along a transect from the Mojave Desert to the central Colorado Plateau. Aeolian dust is recognized in these depressions on the basis of textural, chemical, isotopic, and mineralogical characteristics and comparisons of those characteristics to the underlying bedrock units. Spatial and temporal trends suggest that although local dust sources are important to the accumulated material in these depressions, Mojave Desert dust sources may also contribute. Depth trends in the depressions suggest that Mojave sources may have contributed more dust to the Colorado Plateau recently than in the past. These interpretations point to the important roles of far-traveled aeolian dust for landscape geochemistry and imply future changes to soil geochemistry under changing conditions in far-distant dust source areas. Copyright 2008 by the American Geophysical Union.

Journal of Geophysical Research F: Earth Surface↗
USGS2006

A 16-year record of eolian dust in Southern Nevada and California, USA: Controls on dust generation and accumulation

An ongoing project monitors modern dust accumulation in the arid southwestern United States to (1) determine the rate and composition of dust inputs to soils and (2) relate dust accumulation to weather patterns to help predict the effects of climate change on dust production and accumulation. The 16-year records of 35 dust-trap sites in the eastern Mojave Desert and southern Great Basin reveal how generation and accumulation of dust, including the silt-clay, carbonate, and soluble-salt fractions, is affected by the amount and seasonal distribution of rainfall and the behavior of different source types (alluvium, dry playas, and wet playas). Accumulation rates (fluxes) of the silt-clay fraction of dust, including carbonates, range from about 2-20 g/m2/yr. Average rates are higher in the southern part of the study area (south of latitude 36.5??N) and annually fluctuate over a larger range than rates in the northern part of the area. Sites throughout the study area show peaks in dust flux in the 1984-1985 sampling period and again in 1997-1999; northern sites also show increased flux in 1987-1988 and southern sites in 1989-1991. These peaks of dust flux correspond with both La Nina (dry) conditions and with strong El Nino (wet) periods. The accumulation rates of different components of mineral dusts fluctuate differently. For example, soluble-salt flux increases in 1987-1988, coincident with a moderate El Nino event, and increases very strongly in 1997-1999, overlapping with a strong El Nino event. Both of these high-rainfall winters were preceded and accompanied by strong summer rains. In contrast, little or no change in soluble-salt flux occurred during other periods of high winter rainfall but little summer rain, e.g. 1992-1995. The differences between northern vs. southern sites and between sites with playa dust sources vs. alluvial dust sources indicate that regional differences in the response of precipitation and vegetation growth to ENSO influence and differences in the response of source types control dust production and accumulation. A major factor is the hydrologic condition of surface sediments. The silt-clay and soluble-salt fluxes increased during the El Nino events of 1987-1988 and 1997-1998 at sites close to "wet" playas with shallow depths to groundwater (<10 m), consistent with the concept that active evaporative concentration of salts disrupts surface crusts and increases the susceptibility of surface sediment to deflation. The silt-clay flux also increased during drought periods (1989-1991, 1995-1997) at sites downwind of alluvial sources and "dry" playas with deeper groundwater (<10 m). These increases are probably related to the die-off of drought-stressed vegetation on alluvial sediments, and in some cases to local runoff events that deliver fresh sediment to playa margins and distal portions of alluvial fans. ?? 2006 Elsevier Ltd. All rights reserved.

Journal of Arid Environments↗
USGS2005

Late Quaternary eolian and alluvial response to paleoclimate, Canyonlands, southeastern Utah

In upland areas of Canyonlands National Park, Utah, thin deposits and paleosols show late Quaternary episodes of eolian sedimentation, pedogenesis, and climate change. Interpretation of the stratigraphy and optically stimulated luminescence ages of eolian and nearby alluvial deposits, their pollen, and intercalated paleosols yields the following history: (1) Eolian deposition at ca. 46 ka, followed by several episodes of alluviation from some time before ca. 40 ka until after 16 ka (calibrated). (2) Eolian deposition from ca. 17 ka to 12 ka, interrupted by periods of pedogenesis, coinciding with late Pleistocene alluviation as local climate became warmer and wetter. (3) A wetter period from 12 to 8.5 ka corresponding to the peak of summer monsoon influence, during which soils formed relatively quickly by infiltration of eolian silt and clay, and trees and grasses were more abundant. (4) A drier period between ca. 8.5 and 6 ka during which sheetwash deposits accumulated and more desertlike vegetation was dominant; some dunes were reactivated at ca. 8 ka. (5) Episodic eolian and fluvial deposition during a wetter, cooler period that began at ca. 6 ka and ended by ca. 3-2 ka, followed by a shift to drier modern conditions; localized mobilization of dune sand has persisted to the present. These interpretations are similar to those of studies at the Chaco dune field, New Mexico, and the Tusayan dune field, Arizona, and are consistent with paleoclimate interpretations of pollen and packrat middens in the region. A period of rapid deposition and infiltration of eolian dust derived from distant igneous source terranes occurred between ca. 12 and 8 ka. Before ca. 17 ka, and apparently back to at least 45 ka, paleosols contain little or no such infiltrated dust. After ca. 8 ka, either the supply of dust was reduced or the more arid climate inhibited translocation of dust into the soils. ?? 2005 Geological Society of America.

Geological Society of America Bulletin↗
USGS2003

Multiple oxygen and sulfur isotopic analyses on water-soluble sulfate in bulk atmospheric deposition from the southwestern United States

Sulfate is a major component of bulk atmospheric deposition (including dust, aerosol, fog, and rain). We analyzed sulfur and oxygen isotopic compositions of water-soluble sulfate from 40 sites where year-round dust traps collect bulk atmospheric deposition in the southwestern United States. Average sulfur and oxygen isotopic compositions (δ 34 S and δ 18 O) are 5.8 ± 1.4 (CDT) and 11.2 ± 1.9 (SMOW) (n = 47), respectively. Samples have an oxygen 17 anomaly (Δ 17 O), with an average value of 1.0 ± 0.6‰. Except for a weak positive correlation between δ 18 O and Δ 17 O values (r 2 ≈ 0.4), no correlation exists for δ 18 O versus δ 34 S, Δ 17 O versus δ 34 S, or any of the three isotopic compositions versus elevation of the sample site. Exceptional positive Δ 17 O values (up to 4.23‰) are found in samples from sites in the vicinity of large cities or major highways, and near-zero Δ 17 O values are found in samples close to dry lakes. Comparison of isotopic values of dust trap sulfate and desert varnish sulfate from the region reveals that varnish sulfate has average isotopic values that are ∼4.8‰ lower for δ 18 O, ∼2.1‰ higher for δ 34 S, and ∼0.3‰ lower for Δ 17 O than those of the present-day bulk deposition sulfate. Although other factors could cause the disparity, this observation suggests a possibility that varnish sulfate may have recorded a long-term atmospheric sulfate deposition during the Holocene or Pleistocene, as well as the differences between sulfur and oxygen isotopic compositions of the preindustrial bulk deposition sulfate and those of the industrial era.

Journal of Geophysical Research D: Atmospheres↗
USGS2002

Drainage reversals in Mono Basin during the late pliocene and Pleistocene

Mono Basin, on the eastern flank of the central Sierra Nevada, is the highest of the large hydrographically closed basins in the Basin and Range province. We use geomorphic features, shoreline deposits, and basalt-filled paleochannels to reconstruct an early to middle Pleistocene record of shorelines and changing spillways of Lake Russell in Mono Basin. During this period of time, Lake Russell repeatedly attained altitudes between 2205 and 2280 m-levels far above the present surface of Mono Lake (~1950 m) and above its last overflow level (2188 m). The spill point of Lake Russell shifted through time owing to late Tertiary and Quaternary faulting and volcanism. During the early Pleistocene, the lake periodically discharged through the Mount Hicks spillway on the northeastern rim of Mono Basin and flowed northward into the Walker Lake drainage basin via the East Walker River. Paleochannels recording such discharge were incised prior to 1.6 Ma, possibly between 1.6 and 1.3 Ma, and again after 1.3 Ma (ages of basaltic flows that plugged the paleochannels). Faulting in the Adobe Hills on the southeastern margin of the basin eventually lowered the rim in this area to below the altitude of the Mount Hicks spillway. Twice after 0.76 Ma, and possibly as late as after 0.1 Ma, Lake Russell discharged southward through the Adobe Hills spillway into the Owens-Death Valley system of lakes. This study supports a pre-Pleistocene aquatic connection through Mono Basin between the hydrologically distinct Lahontan and Owens-Death Valley systems, as long postulated by biologists, and also confirms a probable link during the Pleistocene for species adapted to travel upstream in fast-flowing water.

Geological Society of America Bulletin↗
USGS2001

Asian dust events of April 1998

On April 15 and 19, 1998, two intense dust storms were generated over the Gobi desert by springtime low-pressure systems descending from the northwest. The windblown dust was detected and its evolution followed by its yellow color on SeaWiFS satellite images, routine surface-based monitoring, and through serendipitous observations. The April 15 dust cloud was recirculating, and it was removed by a precipitating weather system over east Asia. The April 19 dust cloud crossed the Pacific Ocean in 5 days, subsided to the surface along the mountain ranges between British Columbia and California, and impacted severely the optical and the concentration environments of the region. In east Asia the dust clouds increased the albedo over the cloudless ocean and land by up to 10–20%, but it reduced the near-UV cloud reflectance, causing a yellow coloration of all surfaces. The yellow colored backscattering by the dust eludes a plausible explanation using simple Mie theory with constant refractive index. Over the West Coast the dust layer has increased the spectrally uniform optical depth to about 0.4, reduced the direct solar radiation by 30–40%, doubled the diffuse radiation, and caused a whitish discoloration of the blue sky. On April 29 the average excess surface-level dust aerosol concentration over the valleys of the West Coast was about 20–50 μg/m 3 with local peaks >100 μg/m 3 . The dust mass mean diameter was 2–3 μm, and the dust chemical fingerprints were evident throughout the West Coast and extended to Minnesota. The April 1998 dust event has impacted the surface aerosol concentration 2–4 times more than any other dust event since 1988. The dust events were observed and interpreted by an ad hoc international web-based virtual community. It would be useful to set up a community-supported web-based infrastructure to monitor the global aerosol pattern for such extreme aerosol events, to alert and to inform the interested communities, and to facilitate collaborative analysis for improved air quality and disaster management.

Journal of Geophysical Research D: Atmospheres↗
USGS1999

Elemental analyses of modern dust in southern Nevada and California

Selected samples of modern dust collected in marble traps at sites in southern Nevada and California (Reheis and Kihl, 1995; Reheis, 1997) have been analyzed for elemental composition using instrumental neutron activation analysis (INAA) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) and inductively coupled plasma mass spectroscopy (ICP-MS). For information on these analytical techniques and their levels of precision and accuracy, refer to Baedecker and McKown (1987) for INAA, to Briggs (1996) for ICP-AES, and to Briggs and Meier (1999) for ICP-MS. This report presents the elemental compositions obtained using these techniques on dust samples collected from 1991 through 1997. The dust-trap sites were established at varying times; some have been maintained since 1984, others since 1991. For details on site location, dust-trap construction, and collection techniques, see Reheis and Kihl (1995) and Reheis (1997). Briefly, the trap consists of a coated angel-food cake pan painted black on the outside and mounted on a post about 2 m above the ground. Glass marbles rest on a circular piece of galvanized hardware cloth (now replaced by stainless-steel mesh), which is fitted into the pan so that it rests 3-4 cm below the rim. The 2-m height eliminates most saltating sand-sized particles. The marbles simulate the effect of a gravelly fan surface and prevent dust that has filtered or washed into the bottom of the pan from being blown back out. The dust traps are fitted with two metal straps looped in an inverted basket shape; the top surfaces of the straps are coated with a sticky material that effectively discourages birds from roosting.

California, Nevada↗
USGS1996

Kinematics of the Eastern California shear zone: Evidence for slip transfer from Owens and Saline Valley fault zones to Fish Lake Valley fault zone

Late Quaternary slip rates and satellite-based geodetic data for the western Great Basin constrain regional fault-slip distribution and evolution. The geologic slip rate on the Fish Lake Valley fault zone (the northwest extension of the Furnace Creek fault zone) increases northward from about 3 to 5 mm/yr, in agreement with modeled geodetic data. The increase coincides with the intersections of the Deep Springs fault, connected to the Owens Valley fault zone, and of other faults connected to the Saline Valley fault. The combined geologic and geodetic data suggest that (1) the northwest-striking faults of the Eastern California shear zone north of the Garlock fault are connected by north- to northeast-striking normal faults that transfer slip in a series of right steps, and (2) the amount and distribution of slip among the many faults of this broad, complex plate boundary have changed through time.

Geology↗
USGS1995

Quaternary soils and dust deposition in southern Nevada and California

Eolian dust constitutes much of the pedogenic material in late Pleistocene and Holocene soils of many arid regions of the world. Comparison of the compositions and influx rates of modern dust with the eolian component of dated soils at 24 sites in southern Nevada and California yields information on (1) the composition and influx rate of dust in late Pleistocene and Holocene soils, (2) paleoclimate and its effects on the genesis of aridic soils, especially with regard to dustfall events, (3) the timing and relative contribution of dust from playa sources versus alluvial sources, and (4) the effects of accumulation of dust in soil horizons. The <2 mm fractions of A and B horizons of soils formed on gravelly alluvial-fan deposits in the study area are similar to modern dust in grain size, content of CaCO 3 and salt, major oxides, and clay mineralogy; thus, they are interpreted to consist largely of dust. The major-oxide compositions of the shallow soil horizons are nearly identical to that of the modern dust, but the compositions of progressively deeper horizons approach that of the parent material. The clay mineralogy of modern dust at a given site is similar to that of the Av horizons of nearby Holocene soils but is commonly different from the mineralogies of deeper soil horizons and of the Av horizons of nearby Pleistocene soils. These results are interpreted to indicate that dust both accumulates and is transformed in Av horizons with time. Changes in soil-accumulation rates provide insights into the interplay of paleoclimate, dust supply, and soil-forming processes. Modern dust-deposition rates are more than large enough to account for middle and late Holocene soil-accumulation rates at nearly all sites. However, the early Holocene soil-accumulation rates in areas near late Pleistocene pluvial lakes are much higher than modern rates and clearly indicate a dust-deflation and -deposition event that caused rapid formation of fine-grained shallow soil horizons on uppermost Pleistocene and lower Holocene deposits. We interpret late Pleistocene soil-accumulation rates to indicate that dust-deposition rates were low during this period but that increased effective moisture during the late Wisconsinan favored translocation of clay and CaCO 3 from near the surface to deeper in the soil profile. Pre–late Pleistocene rates are very low in most areas, mainly due to a pedogenic threshold that was crossed when accumulations of silt, clay, and CaCO 3 began to inhibit the downward transport of eolian material, but in part due to erosion.

Geological Society of America Bulletin↗