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Regional economic impacts of changes in electricity rates resulting from Western Area Power Administration`s power marketing alternatives
This technical memorandum describes an analysis of regional economic impacts resulting from changes in retail electricity rates due to six power marketing programs proposed by Western Area Power Administration (Western). Regional economic impacts of changes in rates are estimated in terms of five key regional economic variables: population, gross regional product, disposable income, employment, and household income. The REMI (Regional Impact Models, Inc.) and IMPLAN (Impact Analysis for Planning) models simulate economic impacts in nine subregions in the area in which Western power is sold for the years 1993, 2000, and 2008. Estimates show that impacts on aggregate economic activity in any of the subregions or years would be minimal for three reasons. First, the utilities that buy power from Western sell only a relatively small proportion of the total electricity sold in any of the subregions. Second, reliance of Western customers on Western power is fairly low in each subregion. Finally, electricity is not a significant input cost for any industry or for households in any subregion
Spectral and stratigraphic mapping of hydrated sulfate and phyllosilicate-bearing deposits in northern Sinus Meridiani, Mars
We present detailed stratigraphic and spectral analyses that focus on a region in
northern Sinus Meridiani located between 1°N to 5°N latitude and 3°W to 1°E longitude.
Several stratigraphically distinct units are defined and mapped using morphologic
expression, spectral properties, and superposition relationships. Previously unreported
exposures of hydrated sulfates and Fe/Mg smectites are identified using MRO CRISM and
MEX OMEGA nearâinfrared (1.0 to 2.5 ”m) spectral reflectance observations. Layered
deposits with monohydrated and polyhydrated sulfate spectral signatures that occur in
association with a northeastâsouthwest trending valley are reexamined using highresolution
CRISM, HiRISE, and CTX images. Layers that are spectrally dominated by
monohydrated and polyhydrated sulfates are intercalated. The observed compositional
layering implies that multiple wetting events, brine recharge, or fluctuations in evaporation
rate occurred. We infer that these hydrated sulfateâbearing layers were unconformably
deposited following the extensive erosion of preexisting layered sedimentary rocks and
may postdate the formation of the sulfateâ and hematiteâbearing unit analyzed by the MER
Opportunity rover. Therefore, at least two episodes of deposition separated by an
unconformity occurred. Fe/Mg phyllosilicates are detected in units that predate the sulfateand
hematiteâbearing unit. The presence of Fe/Mg smectite in older units indicates that the
relatively low pH formation conditions inferred for the younger sulfateâ and hematitebearing
unit are not representative of the aqueous geochemical environment that prevailed
during the formation and alteration of earlier materials. Sedimentary deposits indicative of
a complex aqueous history that evolved over time are preserved in Sinus Meridiani, Mars
Volatile and Organic Compositions of Sedimentary Rocks in Yellowknife Bay, Gale crater, Mars
HâO, COâ, SOâ, Oâ, Hâ, HâS, HCl, chlorinated hydrocarbons, NO and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. HâO/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbonates and combustion of organic materials are candidate sources for the COâ. Concurrent evolution of Oâ and chlorinated hydrocarbons suggest the presence of oxychlorine phase(s). Sulfides are likely sources for S-bearing species. Higher abundances of chlorinated hydrocarbons in the mudstone compared with Rocknest windblown materials previously analyzed by Curiosity suggest that indigenous martian or meteoritic organic C sources may be preserved in the mudstone; however, the C source for the chlorinated hydrocarbons is not definitively of martian origin
A Habitable Fluvio-Lacustrine Environment at Yellowknife Bay, Gale Crater, Mars
The Curiosity rover discovered fine-grained sedimentary rocks, inferred to represent an ancient lake, preserve evidence of an environment that would have been suited to support a Martian biosphere founded on chemolithoautotrophy. This aqueous environment was characterized by neutral pH, low salinity, and variable redox states of both iron and sulfur species. C, H, O, S, N, and P were measured directly as key biogenic elements, and by inference N and P are assumed to have been available. The environment likely had a minimum duration of hundreds to tens of thousands of years. These results highlight the biological viability of fluvial-lacustrine environments in the post-Noachian history of Mars
Elemental Geochemistry of Sedimentary Rocks at Yellowknife Bay, Gale Crater, Mars
Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from approximately average Martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved indicating arid, possibly cold, paleoclimates and rapid erosion/deposition. Absence of predicted geochemical variations indicates that magnetite and phyllosilicates formed by diagenesis under low temperature, circum-neutral pH, rock-dominated aqueous conditions. High spatial resolution analyses of diagenetic features, including concretions, raised ridges and fractures, indicate they are composed of iron- and halogen-rich components, magnesium-iron-chlorine-rich components and hydrated calcium-sulfates, respectively. Composition of a cross-cutting dike-like feature is consistent with sedimentary intrusion. Geochemistry of these sedimentary rocks provides further evidence for diverse depositional and diagenetic sedimentary environments during the early
history of Mars
The Petrochemistry of Jake_M: A Martian Mugearite
âJake_M,â the first rock analyzed by the Alpha Particle X-ray Spectrometer instrument on the
Curiosity rover, differs substantially in chemical composition from other known martian igneous
rocks: It is alkaline (>15% normative nepheline) and relatively fractionated. Jake_M is
compositionally similar to terrestrial mugearites, a rock type typically found at ocean islands and
continental rifts. By analogy with these comparable terrestrial rocks, Jake_M could have been
produced by extensive fractional crystallization of a primary alkaline or transitional magma at
elevated pressure, with or without elevated water contents. The discovery of Jake_M suggests that
alkaline magmas may be more abundant on Mars than on Earth and that Curiosity could encounter
even more fractionated alkaline rocks (for example, phonolites and trachytes)
X-ray Diffraction Results from Mars Science Laboratory: Mineralogy of Rocknest at Gale Crater
The Mars Science Laboratory rover Curiosity scooped samples of soil from the Rocknest aeolian
bedform in Gale crater. Analysis of the soil with the Chemistry and Mineralogy (CheMin) x-ray
diffraction (XRD) instrument revealed plagioclase (~An57), forsteritic olivine (~Fo62), augite,
and pigeonite, with minor K-feldspar, magnetite, quartz, anhydrite, hematite, and ilmenite.
The minor phases are present at, or near, detection limits. The soil also contains 27 ± 14 weight
percent x-ray amorphous material, likely containing multiple Fe^(3+)- and volatile-bearing phases,
including possibly a substance resembling hisingerite. The crystalline component is similar to
the normative mineralogy of certain basaltic rocks from Gusev crater on Mars and of martian
basaltic meteorites. The amorphous component is similar to that found on Earth in places
such as soils on the Mauna Kea volcano, Hawaii
Mineralogy of a Mudstone at Yellowknife Bay, Gale Crater, Mars
Sedimentary rocks at Yellowknife Bay (Gale Crater) on Mars include mudstone sampled by the Curiosity rover. The samples, John Klein and Cumberland, contain detrital basaltic minerals, Ca-sulfates, Fe oxide/hydroxides, Fe-sulfides, amorphous material, and trioctahedral smectites. The John Klein smectite has basal spacing of ~10 Ă
indicating little interlayer hydration. The Cumberland smectite has basal spacing at ~13.2 Ă
as well as ~10 Ă
. The ~13.2 Ă
spacing suggests a partially chloritized interlayer or interlayer Mg or Ca facilitating H_2O retention. Basaltic minerals in the mudstone are similar to those in nearby eolian deposits. However, the mudstone has far less Fe-forsterite, possibly lost with formation of smectite plus magnetite. Late Noachian/Early Hesperian or younger age indicates that clay mineral formation on Mars extended beyond Noachian time
Global Distribution of Stratified Deposits on Mars
This study uses the highest available resolution imagery of the Martian surface obtained by the Mars Reconnaissance Orbiter (MRO) High-Resolution Imaging Science Experiment (HiRISE) to create a global inventory of stratified deposits on Mars. Deposits are categorized as sedimentary or volcanic based on a set of distinguishing orbital outcrop parameters including albedo, weathering style, layer thickness, and proximity to known volcanic source regions. Deposits are also classified according to geomorphic setting. This study shows that stratified deposits are ubiquitous on Mars, suggesting that a record of surface processes potentially spanning four billion years is preserved. This global inventory will aid in understanding the occurrence and diversity of sedimentary depositional processes through time and across the surface of Mars