Gold Hill Research Articles

Mining Charity

Scalding water, plummeting cage elevators, cave-ins, fiery explosions, toxic air. These were among the many hazards of silver ore mining on Nevada’s Comstock Lode in the late 1800s. This article explores the nature of silver mining society in the 1860s and 1870s, focusing on the dangerous conditions in which miners worked in the mineshafts that ran beneath the communities of Virginia City and Gold Hill, Nevada. The material culture and conditions of mining, the article argues, were central to determining the community’s needs and the charitable efforts mounted to address them. Philanthropic work and fundraising for a diverse set of causes—from attending to individuals’ needs to building a hospital to running an orphanage—shaped residents’ social and cultural lives, as well as the built environment in which they lived.

Mark Twain’s Masculinist Fantasy of the West

Abstract In chapter 57 of Roughing It, Mark Twain extols his experience of the West in terms that are at once highly idealized and strangely skewed: “It was a wild, free, disorderly, grotesque society! Only swarming hosts of stalwart men—nothing juvenile, nothing feminine, visible anywhere!” This description, however memorable, is also blatantly false. The 1860 federal census records 111 women in Virginia City and Gold Hill, “83 of whom were living with their husbands . . . and caring for more than 100 children.” Clemens’s cognizance of this fact is reflected in the circumstances of his own brother Orion, who, within a year of their 1861 arrival, was joined in Carson City by his wife and daughter, as well as in his reporting for the Virginia City Enterprise. This article explores the personal and cultural underpinnings of this omission, examining it in relation to conventional nineteenth-century gender hierarchies.

Goldhillite, Cu5Zn(AsO4)2(OH)6⋅H2O, a new mineral species, and redefinition of philipsburgite, Cu5Zn[(AsO4)(PO4)](OH)6⋅H2O, as an As–P ordered species

AbstractPhilipsburgite has been redefined as the intermediate member of the goldhillite–philipsburgite–kipushite isomorphous series with the ideal formula Cu5Zn[(AsO4)(PO4)](OH)6⋅H2O due to the site-selective As–P substitution. The new mineral goldhillite, ideally Cu5Zn(AsO4)2(OH)6⋅H2O [or Cu5Zn(AsO4)(AsO4)(OH)6⋅H2O], is the arsenate end-member of this series. Goldhillite occurs on fracture surfaces in a rock comprised mostly of quartz with iron hydroxides in association with mixite, cornwallite and conichalcite. Goldhillite forms transparent, bright emerald-green, tabular crystals with vitreous lustre, flattened on {100}, up to 1 mm across and in rosettes up to 1.5 mm. The mineral is brittle with uneven fracture and perfect cleavage on {100}; the Mohs hardness is 3.5. The calculated density for the holotype is 4.199 g cm–3. The Raman spectrum is consistent with the presence of H2O-molecules, OH-groups, AsO4 tetrahedra and traces of PO4. Electron microprobe analyses of goldhillite (H2O content based on the crystal structure) provided: CuO 48.91, ZnO 13.18, As2O5 26.06, P2O5 3.25, H2O 8.97, total 100.37 wt.%. The empirical formula for goldhillite based on O = 15 apfu is (Cu4.69Zn1.23)Σ5.92(As0.86P0.18O4)2(OH)5.61⋅H2O. The crystal structures of goldhillite and philipsburgite were determined using single-crystal X-ray diffraction data and refined to R1 = 0.054 (for 2365 I > 2σI reflections) and 0.052 (for 2308 I > 2σI reflections), respectively. Goldhillite is monoclinic, P21/c, a = 12.3573(5), b = 9.2325(3), c = 10.7163(4) Å, β = 97.346(4)°, V = 1212.59(8) Å3 and Z = 4. Philipsburgite is monoclinic, P21/c, a = 12.3095(9), b = 9.2276(3), c = 10.7195(3) Å, β = 97.137(7)°, V = 1208.16(10) Å3 and Z = 4. The strongest lines of the powder X-ray diffraction pattern of goldhillite [d, Å (I, %)(hkl)] are: 4.09 (28)(300), 3.41 (23)(12$\bar{2}$, 221, 311), 2.57 (100)(132, 11$\bar{4}$, 20$\bar{4}$), 2.17 (18)(42$\bar{3}$, 332), 1.95 (22)(432) and 1.54 (20)(13$\bar{6}$, 060). Goldhillite is named after its type locality, the Gold Hill mine, Tooele County, Utah, USA.

Blowing in the late Cenozoic wind—detrital zircon river contributions to an interior Alaska loess deposit

The extensive Interior Alaska loess deposits record glacial advance and retreat over the past 3 Myrs. Refining our understanding of the still-debated origins of this loess will help us refine our understanding of climate patterns since the late Cenozoic. We present here the first detrital-zircon ages from the Gold Hill loess, a well-studied deposit in Fairbanks, Alaska, as well as new detrital-zircon ages from local fluvial sediments. We describe a new statistical approach to quantify the contributions of sediment loads from local rivers to account for the grain-age distributions within the Fairbanks loess. We find that zircons from the 3 Ma base of the loess deposit come mainly from sediments carried by the Tanana and Delta rivers, and Yukon River sediments contributed more zircons over time as this river system developed. This indicates that loess-depositing winds in Interior Alaska came from the east/southeast, a pattern that persists today. Although we cannot exclude other sources, our new statistical approach suggests that a mix of sediments carried from local river deposits can account for almost all of the zircon grains in the Gold Hill loess deposit of interior Alaska.

Update on the Status and Breeding Phenology of the Timberline Sparrow (Spizella breweri taverneri) in Alaska

In July 2020 we located 10 singing Timberline Sparrows [Spizella (breweri) taverneri] in the region of Gold Hill, Nutzotin Mountains, east-central Alaska. All birds were on southeast-facing slopes in the ecotone between subalpine scrub and alpine tundra, to which habitat breeding Timberline Sparrows seem narrowly confined. The population’s estimated density of 0.77 birds/km2 was similar to that at the time of its discovery in 1994. We located the first active nest of the Timberline Sparrow reported for Alaska, ~0.3 m above the ground in a shrubby resin birch (Betula glandulosa). An observation of young fledged on 11 or 12 July 2020 implies egg laying in the third week of June, later than the beginning of the breeding season of Spizella (breweri) breweri.

Remembering Okei (1852–1871): Daughter of Aizu, Pioneer of Gold Hill

This article focuses on the legend of Itō Okei (1852–71), the Aizu native and Boshin War (1868–69) refugee who arrived in California's Gold Country in the fall of 1869. Okei settled in Northern California as part of the Wakamatsu Tea and Silk Colony, a short-lived venture led by the German John Schnell (1834–?) and twenty entrepreneurial samurai and farmers who hoped to support the defeated province through the establishment of an international satellite colony. Serving as a caretaker for Schnell's children, Okei remained in the United States when the venture failed a year later. She died of illness at age nineteen. Okei's short life and tragic death have become symbolic of the life and death of the Wakamatsu colony itself, and her gravesite attracts busloads of tourists annually, including some from Japan. Using theories from the field of memory studies that began in the 1980s, I investigate the historiography of the Wakamatsu colony and Okei's grave as a memory site to reveal a palimpsestuous layering of meaning embedded in both discursive and commemorative work seeking to rehabilitate ethnic and local identities over time. Focusing on how local governments, regional presses, and community organizations have preserved Okei's legacy shows how memory work shapes both local and national narratives, spotlighting the shared terrains of Japanese and Japanese American history.

Our Royal Guest: American Press Coverage of King Kalākaua’s Visit to the United States, 1874–1875

Our Royal Guest: American Press Coverage of King Kalākaua’s Visit to the United States, 1874–1875 Douglas V. Askman (bio) Introduction Less than a year after King Kalākaua ascended the throne of the Hawaiian Islands in February 1874, he departed his kingdom for a trip to the United States. When he arrived in San Francisco at the end of November, Kalākaua became the first reigning monarch to set foot on American soil. The sovereign remained in the United States for over two months, and his visit attracted enormous attention from the American media. It was the first of the king’s three trips to the United States during his reign.1 This article will analyze American press coverage of Kalākaua’s 1874–1875 travels through the United States. The reporting on the king’s visit was frequent, extensive, and generally extremely positive. Kalākaua’s time in the United States created a complimentary impression of the new monarch and served to promote Hawai‘i abroad. The praise given to the king by the press, at times effusive, is in partial contrast to the reaction of American newspapers to Kalākaua’s subsequent journey to the United States in 1881 during his world tour. While there was much complimentary coverage of the world tour in [End Page 131] the American media, it was more mixed than the enormously positive reporting that was seen in 1874 and 1875. Nevertheless, the king’s first trip to the United States as a monarch did engender some negative press coverage. Given the racist attitudes and stereotypes prevalent in the United States at the time, this is not surprising. Indeed, much of the unflattering treatment of Kalākaua in American newspapers was essentially the presentation of repugnant chauvinistic stereotypes, often only a few sentences in length, rather than serious reporting about the king’s visit. Overwhelmingly, Kalākaua created a favorable impression in the American press.2 San Francisco and the Journey to Washington Although the Hawaiian monarch did not arrive in the United States until the end of November 1874, reporting on the king’s trip began significantly earlier. The National Republican, a Washington, DC, newspaper, related towards the end of September that information from Honolulu indicated that “Washington is soon to be honored with the presence of royalty.”3 Other papers remarked that Kalākaua would visit President Ulysses S Grant during his stay and even speculated that the king would travel on to Europe.4 On November 18, the day Kalākaua departed Honolulu for San Francisco on the American naval vessel USS Benicia, the Republican pointed out that the king had always shown an interest in the United States and was a man of “marked intelligence.”5 Several days before Kalākaua landed in California, the Gold Hill Daily News of Gold Hill, Nevada, reported on the upcoming royal visit. The paper pointed out that “doubtless great preparations will be made to receive, in a fitting manner, the first live King who ever honored the United States with his personal presence.” The Daily News also related that the king’s party would occupy a suite of rooms at the Grand Hotel in San Francisco and that two railway companies were providing a special train car to bring Kalākaua from the West Coast to Washington.6 On the night of November 28, 1874, the USS Benicia arrived in San Francisco with the king and his companions on board. Accompanying Kalākaua were his brother-in-law, John O. Dominis, Governor of O‘ahu and wife of the king’s sister Princess Lili‘uokalani, and John [End Page 132] M. Kapena, Governor of Maui. Salutes were fired from the military installations and government ships in the harbor to celebrate the king’s arrival. However, Kalākaua and his associates did not make an appearance until the following day.7 On November 29, the royal party came ashore, accompanied again by gun salutes as they departed the Benicia. When the group reached the dock, they were “greeted with cheers by a crowd of thousands.”8 The mayor of San Francisco, James Otis, and a...

Persistent fine-scale fault structure and rupture development: A new twist in the Parkfield, California, story

We investigate the fine-scale geometry and structure of the San Andreas Fault near Parkfield, CA, and their role in the development of the 1966 and 2004 ∼M6 earthquakes. Long-term surface fault traces indicate that structural heterogeneities associated with secondary reverse and normal fault structures are present at both rupture tips, near Middle Mountain and Gold Hill. Detailed analysis of almost 50 years of high-resolution seismicity reveals a fault plane that has been twisted into a helicoid between Middle Mountain and Gold Hill. Numerical models support our conclusion that this shape is the result of long-term torqueing of a strong stuck patch surrounded by a weak creeping region. The changes in fault friction behavior and related geometric discontinuities act as barriers to rupture propagation of moderate size earthquakes at Parkfield, and as areas of concentrations where rupture initiates. Our study demonstrates also that smooth strike-slip faults with large cumulative offset can form new fault segments at a late stage in their evolution.

Site-selective As–P substitution and hydrogen bonding in the crystal structure of philipsburgite, Cu5Zn((As,P)O4)2(OH)6·H2O

Philipsburgite, Cu5Zn((As,P)O4)2(OH)6·H2O, from the Middle Pit, Gold Hill Mine, Tooele Co., Utah, USA, was studied by single-crystal X-ray diffraction and scanning electron microscopy. The empirical formula of the studied sample is (Cu4.69Zn1.23)(As0.86P0.18O4)2(OH)5.61·H2O, which agrees well with the previous reports on the mineral. Philipsburgite is monoclinic, P21/c, a = 12.385(6), b = 9.261(4), c = 10.770(5) A, β = 97.10(1)o, V = 1225.7(9) A3 (at 100 K), and Z = 4. The crystal structure was refined to R1 = 0.046 for 2563 unique observed reflections with |Fo| ≥ 4σF. The crystal structure of philipsburgite is isotypic to that of kipushite and can be considered as a complex three-dimensional framework consisting of two types of layers stacked parallel to the a-axis. The A-type layer is formed by the edge-sharing Jahn–Teller-distorted Cuφ6 octahedra [φ = O2−, (OH)−, H2O]. Two adjacent octahedral layers are linked via (As2O4) tetrahedra. The B-type layer is built by corner-sharing (ZnO4) and (As1O4) tetrahedra and is formed by the four- and eight-membered tetrahedral rings. The A:B ratio of the A and B layers is equal to 2:1. The hydrogen bonding network in philipsburgite is rather complex and consists of two- and three-center hydrogen bonds. The As1 site accommodates ca. 18% of P and is a preferable position for the P substitution in philipsburgite. The observed selectivity of the As1 site for P may indicate that, for the intermediate compositions with the P:As ratios close to 1:1, there is a fully ordered species with P prevalent at the As1 site and As prevalent at the As2 site. The intermediate composition would, therefore, be Cu5Zn(AsO4)(PO4)(OH)6·H2O and such a mineral can be considered as a separate species, according to the rules of the International Mineralogical Association (IMA). Philipsburgite should be considered as structurally complex with the Shannon information contents of 4.954 bits/atom and 614.320 bits/cell. The obvious reason for the structural complexity of the mineral is its modularity, i.e., the presence of two structurally distinct modules, the octahedral–tetrahedral (A) and tetrahedral (B) layers.

Floodplain storage of sediment contaminated by mercury and copper from historic gold mining at Gold Hill, North Carolina, USA

Previous research on the environmental consequences of mining has shown that metal contaminants can have long-lasting impacts on water quality and aquatic ecosystems because of the remobilization of sediment-associated contaminants that have been stored in floodplains. We examined the magnitude and distribution of mercury (Hg) and copper (Cu) contamination of floodplain deposits associated with nineteenth century gold (Au) mining activities in the Gold Hill mining district, North Carolina. A comparison of post-mining metal concentrations in overbank deposits with sediment quality guidelines indicates that overall about 21% are contaminated above the probable effect concentration (PEC; above which adverse effects are expected to occur more often than not) for both Cu and Hg. The highest contamination occurs upstream near the mine source where 51% of the samples exceed the PEC for Hg and 57% exceed the PEC for Cu. Of the three different methods used to estimate metal mass storage, the most reliable estimate suggests that about 6.8Mg of Hg and 619Mg of Cu currently reside in floodplain deposits within this watershed. Although overbank sediment storage increases downstream and with valley width, about 75% of the Hg and Cu mass are stored in the upstream portion of the watershed. Hg mass storage displays a strong negative relationship with cross-sectional stream power, but the relationship between Cu mass storage and stream power is insignificant. We used vertical changes in overbank metal concentrations and the mining history to estimate a mean sedimentation rate of 2.7cmy−1 during the most intensive period of Au mining at Gold Hill (1842–1856) that is three times the long-term (1842–2007) rate of 0.9cmy−1. Long-term average rates at Gold Hill are comparable to those reported elsewhere in the eastern Piedmont. The downstream increase in long-term rates may indicate a spatial and temporal lag effect where the locus of deposition shifts downstream with time.

The Kamikatsura Event and palaeoclimatic variability recorded in loess deposits at Gold Hill, Alaska

The Kamikatsura Event and palaeoclimatic variability recorded in loess deposits at Gold Hill, Alaska

Kinematics, U-Pb geochronology, and 40Ar/39Ar thermochronology of the Gold Hill shear zone, North Carolina: The Cherokee orogeny in Carolinia, Southern Appalachians

The Gold Hill shear zone is the most prominent pre-Carboniferous structure in the Southern Appalachian peri-Gondwanan tract of Carolinia. Common perception, based on indirect evidence, holds that it is an Acadian, dextral strike-slip shear zone. However, our recent structural and geochronologic studies directed at the shear zone indicate that it is a complex structure in both time and space. Structural studies in central North Carolina kinematically link deformation in the shear zone to regional shortening structures in both the hanging wall and footwall and indicate that there was a sinistral component to the deformation. Collectively, these structures constitute a regional sinistral transpressional system. We obtained nine new U-Pb zircon ages (Ediacaran–Devonian) and 12 new 40 Ar/ 39 Ar muscovite ages (Late Ordovician–Middle Mississippian); these data, in conjunction with the regional geology indicate that the shear zone has ∼12 km of stratigraphic throw and that the main motion on the zone was Late Ordovician. Collectively, geologic relations, structures, and the distribution of 40 Ar/ 39 Ar ages indicate that the shear zone was reactivated in the Late Devonian and the Middle Mississippian. The regional Late Ordovician–Silurian sinistral transpressive system, of which the Gold Hill shear zone is part, represents the most widespread tectonism documented in Carolinia; it overlaps in time with the Ordovician–Silurian Cherokee unconformity in Laurentian strata and Late Ordovician–Silurian suprasubduction-zone magmatism and metamorphism in peri-Laurentian rocks and consequently is considered a manifestation of the Southern Appalachian Cherokee orogeny, marking the accretion of Carolinia to Laurentia.

Douglasien-Provenienzversuch von 1961 in Nordwestdeutschland: Ergebnisse nach 38 Jahren

Douglas-fir provenance trials established 1961 in northwestern Germany: findings at the age of 38 years The Douglas-fir provenance trials established on 14 sites in northwestern Germany in 1961 are the basis for a comparison of 26 North American Douglas-fir provenances. The following assessment criteria were formulated: (1) How do the provenances differ with respect to total volume growth after 38 years? (2) Can climate-induced variations be observed in provenance values? (3) Do provenances differ in regard to branchiness? Because of non-orthogonal trial set-ups and plot-related influences, overall trial sites analysis called for a standardisation of interval-scaled primary data. Relative rank classes were calculated on the basis of a mean plot value. With respect to total volume growth, the provenances Tenas Creek (D47) as well as Molalla (D74) and Timber (D41/59) proved provenances with stable and outstanding productivity. Among the tested local climate elements “long-term annual mean temperature”, “mean annual precipitation” and “height above sea level” only the influence of long-term annual mean temperature is statistically relevant for productivity. Beside hardy ecotypes, which adapt to a wide spectrum of differing plot climates (e.g., Molalla [D74]), there are provenances with poor adaptive capabilities that react sensitively to local climatic conditions (e.g., Salmon Arm II [D46]). For the criterion “fine-branchiness”, the provenances Conrad Creek (D43), Ashford (D67) and Gold Hill (D83) show the best, the provenances Detroit (D76), Carson (D87) and Salmon Arm II (D46) the poorest results.

Metal Contamination from Gold Mining in the Cid District, North Carolina

The purpose of this paper was to assess contamination from 19th century gold (Au) mining in the Cid district, North Carolina. Sediment samples collected from active channel sediments and floodplain cores were analyzed for mercury (Hg), copper (Cu), lead (Pb), and zinc (Zn). Analysis of trace metal concentrations shows that although Hg contamination exists at relatively low levels (i.e., no samples exceeded the probable effect concentration for Hg), the active channel sediments and historical floodplain deposits are contaminated by Hg downstream from all mines in the district. We also found significant contamination by Cu, Pb, and Zn. The use of Hg and other metals as tracers associated with mining activities suggests that long-term rates of floodplain sedimentation in the Cid district (0.3-0.9 cm/yr) were less than half as high as those in the nearby Gold Hill district. This suggests that the intensity of land disturbance in the Cid district was less than in the more intensively mined Gold Hill district.

The Kamikatsura event in the Gold Hill loess, Alaska

[1] As part of a broader geological study of loess/palaesol sequences in Alaska, the paleomagnetism of a section at Gold Hill near Fairbanks has been investigated. Samples were collected at 5 cm intervals through a 5 m loess‐paleosol‐ loess sequence. Detailed alternating field demagnetization of the natural remanent magnetization yields excellent results (average MAD = 2°). The Brunhes‐Matuyama (B‐M) polarity transition is present at the level of the paleosol, which was formedduringOxygenIsotopeStage19.Asystematicperturbation in both declination and inclination occurs ∼1.0–1.5 m belowtheB‐Mboundary.Thecorrespondingvirtualgeomagnetic poles define a track centred on the 60°W meridian from high southerly to equatorial latitudes and back again. This is in very good agreement with results from a sequence of lava flows on the island of Maui that are regarded as a record of the Kamikatsura event. The Alaskan results thus confirm the reality of this geomagnetic feature, and simultaneously provide a firm chronological control point for ongoing geological investigations. Mineral magnetic experiments indicate that the remanence of the Gold Hill loess is dominated by magnetite and/or maghemite, with no subsequent chemical overprinting by hematite and/or goethite. Citation: Evans, M. E., B. J. L. Jensen, V. A. Kravchinsky, and D. G. Froese (2011), The Kamikatsura event in the Gold Hill loess, Alaska, Geophys. Res. Lett., 38, L13302, doi:10.1029/2011GL047793.

Legacy Hg-Cu Contamination of Active Stream Sediments in the Gold Hill Mining District, North Carolina

El propósito de este estudio es evaluar la evolución longitudinal de mercurio (Hg) y cobre (Cu) en sedimentos de canales activos en la parte baja del distrito minero de Gold Hill, en el Piedmont de Carolina del Norte. La minería de oro (Au) y Cu desde 1844 a 1915 produjo Hg (asociados con el procesamiento de Au) y Cu en una cuenca de 254 km 2 . Regresión lineal múltiple se utiliza para cuantificar las tendencias espaciales y geoquímicas en 93 muestras de canales activos, recolectadas en cauces principales contaminados y en localidades en tributarios secundarios. Modelos de regresión simple de dos parámetros combinando los efectos de ambos procesos de dispersión a escala de las cuencas hidrográficas (distancia río abajo) y a escala del alcance del transporte de sedimentos (arena por ciento) explican el 85 por ciento de la variación de Hg y 90 por ciento de la variación de Cu en los sedimentos de canales activos. Las tendencias de contaminación en dos diferentes medios de sedimentos, barra baja y bancos de depósitos de mayor elevación, fueron efectivamente similares cuando la influencia del tamaño del grano local se contabilizó en los modelos de dos parámetros. Modelos geoquímicos de antecedentes explican el 84 por ciento de la variación de Hg y Cu en muestras no contaminadas de tributarios utilizando parámetros relacionados al tamaño de grano, sustratos geoquímicos secundarios, y fuentes de meteorización de minerales. Más del 45 por ciento de la variación de Hg y 20 por ciento de Cu en sedimentos contaminados puede ser explicada a través de parámetros de antecedentes. Firmas geoquímicas difieren entre Hg y Cu en los sedimentos de canales activos debido a variaciones en insumos mineros, trasfondo geoquímico, y las fuentes de contaminación actual.

THE SINGLE-CRYSTAL X-RAY STRUCTURES OF BARIOPHARMACOSIDERITE-C, BARIOPHARMACOSIDERITE-Q and NATROPHARMACOSIDERITE

The crystal structures of two polymorphic forms of bariopharmacosiderite have been determined. Bariopharmacosiderite- C , from Robinson’s Reef, Clunes, Victoria, Australia, (Ba 0.47 K 0.04 Na 0.02 )(Fe 3.97 Al 0.03 )[(As 0.72 P 0.28 )O 4 ] 3 (OH) 4 ·2.52H 2 O, is cubic, space group P 43 m , a 7.942(1) A, Z = 1, R = 0.089. Bariopharmacosiderite- Q , from the Sunny Corner mine, Sunny Corner, New South Wales, Australia, Ba 0.5 Fe 4 (OH) 4 (AsO 4 ) 3 ·6.16H 2 O, is tetragonal, space group P 42 m , a 7.947(1), c 8.049(2) A, Z = 1, R = 0.050. In the cubic polymorph, Ba ions are disordered over all faces of the unit cell, whereas in the tetragonal polymorph, Ba ions are centered on the 001 face. In both cases, the Ba ions are 12-coordinate, with eight bonds to arsenate oxygen atoms; four H 2 O groups complete the coordination sphere, with longer bonds to Ba in the cubic polymorph. Additional H 2 O groups are hydrogen-bonded to each other and to the H 2 O groups that coordinate Ba. Some of these exhibit “zeolitic” behavior. By analogy to the properties of synthetic pharmacoalumite, KAl 4 (AsO 4 ) 3 (OH) 4 · n H 2 O, the cubic polymorph appears to be more stable than the tetragonal one, although two further body-centered polymorphs are known. In addition, the crystal structure of natropharmacosiderite from the Gold Hill mine, Utah, has been determined. Natropharmacosiderite, (Na 0.75 K 0.14 Ba 0.11 ) ∑1.00 Fe 4 (AsO 4 ) 3 (OH) 3.89 O 0.11 ·4H 2 O, is cubic, space group P 43 m , with a 7.928(9) A, Z = 1 and R = 0.0654. The Na position is displaced by ~0.2 A from the Wyckoff 3 c site, and is coordinated by four H 2 O groups and eight oxygen atoms of arsenate groups. A new general formula for “excess cation” pharmacosiderite is proposed, involving deprotonation of bridging hydroxide ions.

Variations of the velocity contrast and rupture properties of M6 earthquakes along the Parkfield section of the San Andreas fault

SUMMARY We investigate the seismic velocity contrast across the San Andreas fault (SAF) in the Parkfield area using fault zone head waves (FZHW) that propagate along the bimaterial fault interface and direct P waves. We systematically analyse large data sets of near-fault waveforms recorded by several seismic networks over the period 1984–2005. Clear FZHW are observed at many stations on the NE side of the fault in the creeping section of the SAF north of Middle Mountain (MM). This indicates the presence of a sharp bimaterial interface and that the NE side of the fault has lower seismic velocities in that region. The obtained P-wave velocity contrast is about 5–10 per cent north of MM, and it systematically decreases to 0–2 per cent near Gold Hill (GH). The along-strike variations of the velocity contrast are consistent with geological observations of a sliver of high-velocity rock immediately to the NE of the SAF near GH, associated with the GH fault, and existing 3-D seismic tomography results. The obtained imaging results offer an explanation for the mixed rupture directions of the M6-type Parkfield earthquakes. The strong velocity contrast around MM is expected to produce a preferred propagation direction to the SE for earthquakes that nucleate near MM (e.g. the 1934 and 1966 Parkfield earthquakes). In contrast, the near-zero velocity contrast and multiple fault branches near GH imply that earthquakes that nucleate near GH (e.g. the 2004 Parkfield earthquake) are not expected to have a preferred propagation direction to the SE, and are likely to propagate in directions that are controlled by other factors such as structural and stress heterogeneities. The observed systematic reduction of the velocity contrast along the SAF from NW of MM to SE of GH provides a dynamic arrest mechanism for earthquakes that nucleate in the northern part of the Parkfield section and propagate to the SE, and a dynamic arrest mechanism for earthquakes that nucleate in the southern section and propagate to the NW.

What are the ODDES? Assessment of Mental Status and Use of the Nursing Process

Authors' Affiliation: Senior Instructor (Dr Meyers); Instructor (Ms Choka), Intercollegiate College of Nursing, Washington State University, Spokane.Judy L. MeyersKatherina P. ChokaCorresponding Author: Dr Meyers, 375 Gold Hill Circle, Sagle, ID 83860 ([email protected]).

BARAHONAITE-(Al) AND BARAHONAITE-(Fe), NEW Ca-Cu ARSENATE MINERAL SPECIES, FROM MURCIA PROVINCE, SOUTHEASTERN SPAIN, AND GOLD HILL, UTAH

The new mineral species barahonaite-(Fe) and barahonaite-(Al), simplified as (Ca,Cu,Na,Fe 3+ ,Al) 12 Fe 3+ 2 (AsO 4 ) 8 (OH) x · n H 2 O and (Ca,Cu,Na,Al) 12 Al 2 (AsO 4 ) 8 (OH) x · n H 2 O, respectively, occur at the Dolores prospect in Murcia Province, southeastern Spain. Barahonaite-(Al) also occurs at the former Gold Hill mine in Tooele County, Utah. The minerals form beads, coalesced beads, and crusts of submillimetric thickness whose surfaces commonly glisten because of the presence of plates, up to 50 μm in diameter (Utah), and razor-thin, tabular, composite crystals, up to 20 μm long (Spain). Barahonaite-(Al) is pale blue, brittle, transparent to translucent, soft, nonfluorescent, and has a white streak and D meas 3.03 g/cm 3 ; barahonaite-(Fe) is similar, but is yellow with a greenish tint and has a white to pale yellow streak. Both minerals are readily soluble in 10% HCl. Barahonaite-(Fe) is biaxial negative, α 1.664(2), β ≈ γ, γ 1.677(2), 2 V meas 45–80°; the indices of refraction of barahonaite-(Al) are α 1.616(2), γ 1.622(2). The compositions for barahonaite-(Fe) and barahonaite-(Al) from Spain, as determined with an electron microprobe, are, respectively, Na 2 O 2.07, 1.65, MgO 0.14, 0.00, CaO 12.96, 15.71, CuO 12.41, 14.59, Al 2 O 3 1.71, 9.52, Fe 2 O 3 13.78, 0.10, SiO 2 0.33, 0.14, P 2 O 5 0.42, 0.35, As 2 O 5 41.18, 42.16, SO 3 0.29, 1.24, Cl 0.91, 0.06, H 2 O (by difference) 14.01, 14.49, which correspond to (Ca 4.95 Cu 3.34 Na 1.43 Mg 0.07 Fe 3+ 1.70 Al 0.72 ) ∑12.21 Fe 3+ 2.00 [(As 0.96 P 0.02 S 0.01 Si 0.01 )O 4 ] 8 [(OH) 6.82 Cl 0.55 ] ∑7.37 ·13.2H 2 O and to (Ca 5.75 Cu 3.77 Na 1.09 Al 1.84 Fe 3+ 0.03 ) ∑12.48 Al 2.00 [(As 0.94 S 0.04 P 0.01 Si 0.01 )O 4 ] 8 [(OH) 7.95 Cl 0.04 ] ∑7.99 ·12.5H 2 O for X O 4 = 8. Indexing of the powder-diffraction patterns gave a 10.161(7), b 22.39(2), c 10.545(10) A, β 93.3(1)° for barahonaite-(Fe), and a 9.964(3), b 22.43(1), c 10.555(6) A, β 92.76(6)° for barahonaite-(Al). The strongest lines in the powder pattern [ d in A( I )( hkl )] are 22.0(100) (010), 11.2(70)(020), 5.068(20)(200), 3.345(20)(023, 310), 2.763(30)(053), 2.659(20)(172), and 2.541(20)(400) for barahonaite- (Fe), and 22.0(100)(010), 11.16(70)(020), 4.983(50)(200), and 3.333(45)(250,113) for barahonaite-(Al). The compositions and X-ray data suggest a possible overall relationship to the smolianinovite group, and a close relationship between attikaite and barahonaite-(Al). The new name barahonaite-(Fe) honors Antonio Barahona (b. 1937) of Madrid, Spain, who collected the original specimens, and barahonaite-(Al) is the Al-dominant analog of barahonaite-(Fe).