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S. S. Howe

Publications and source records attributed to S. S. Howe.

13 recordsLinked to original sources
USGS2012

Mineralogy and geochemistry of a sediment‐hosted hydrothermal sulfide deposit from the Southern Trough of Guaymas Basin, Gulf of California

Samples dredged from a 15‐m‐high hydrothermal mound atop the flat turbidite pond in the Southern Trough of Guaymas Basin consist of pyrrhotite‐rich massive sulfide, barite, barite + calcite, talc, and opaline silica as well as substrate material composed of fossiliferous, clay‐rich ooze. An 11‐m‐long sediment core taken near the dredge site shows increasing hydrothermal alteration with depth; anhydrite‐filled fractures near the base of the core appear to be channels for hydrothermal discharge. Oxidation of the sulfide‐rich samples to an assemblage of geothite, lepidocrocite, and amorphous Fe oxyhydroxide is ubiquitous. Compared to other massive sulfide deposits on sediment‐starved oceanic ridges, the hydrothermal deposit dredged in Guaymas Basin has a high pyrrhotite/pyrite ratio, a low Zn sulfide and combined ore metal (Cu + Zn + Pb + Ag + Cd) content, and a greater abundance of sulfate, carbonate, and silicate phases. Venting hydrothermal solutions are alkaline with moderately high p H; high Ca, Ba, and SiO 2 content; low ƒS 2 and ƒo 2 ; and very low transition metal content. Disequilibrium assemblages of pyrrhotite and sulfate minerals form during rapid mixing of this evolved vent fluid with ambient bottom waters at the discharge site. Talc is formed at a temperature near 270°C by mixing or entrainment of Mg‐rich bottom water or pore fluid with upwelling hydrothermal fluid that is saturated with silica. Calcite may precipitate from the alkaline, Ca‐rich fluid during degassing of CO 2 . The minimum temperature range for sulfide and nonsulfide deposition is approximately 190°–326°C. The composition of hydrothermal deposits, vent solutions, and altered sediment requires that circulating fluids evolve during deep penetration into the basaltic basement complex, further interaction with the organic‐and carbonate‐rich sediment pile, and near‐surface mixing with ambient seawater. Although the stable assemblage albite‐epidote‐clinochlore present at depth in the sediment pile requires very low dissolved Mg and Fe in the altering fluid, the addition of Mg to deeply buried sediment indicates significant recharge of the system by Guaymas Basin bottom water.

Southern Trough of Guaymas Basin↗
USGS2007

Holocene sea-level oscillations and environmental changes on the Eastern Black Sea shelf

A multi-proxy study of four sediment cores from the Eastern (Caucasian) Black Sea shelf revealed five transgressive-regressive cycles overprinted on the general trend of glacioeustatic sea-level rise during the last 11,000??14C yr. These cycles are well represented in micro-and macrofossil assemblages, sedimentation rates, and grain size variations. The oldest recovered sediments were deposited in the Neoeuxinian semi-freshwater basin (??? 10,500-9000??14C yr BP) and contain a Caspian-type mollusk fauna dominated by Dreissena rostriformis. Low ??18O and ??13C values are measured on this species. The first appearance of marine mollusks and ostracodes from the Mediterranean is established in this part of the Black Sea at ??? 8200??14C yr BP, i.e., about 1000-2000??yr later than the appearance of marine microfossils in the deeper part of the sea. The Early Holocene (Bugazian to Vityazevian) condensed section of shell and shelly mud sediments with at least two hiatuses represent a high-energy shelf-edge facies. It contains a transitional assemblage representing a mixture of Caspian and Mediterranean fauna. This pattern suggests a dual-flow regime via the Bosphorus after 8200??14C yr BP. Caspian species disappear and oligohaline species decrease in abundance during the Vityazevian-Prekalamitian cycle. Later, during the Middle to Late Holocene, low sea-level stands are characterized by shell layers, whereas silty mud with various mollusk and ostracode assemblages rapidly accumulated during transgressions. Restricted mud accumulation, as well as benthic faunal composition and abundance, suggest high-energy and well-ventilated bottom water during low sea-level stands. A trend of 18O enrichment in mollusk shells points to an increase in bottom-water salinity during the Vityazevian to Kalamitian transgressions (??? 7000 to 5700??14C yr BP) due to a more open connection with the Mediterranean, while a pronounced increase in polyhaline species abundance is established during the Kalamitian to Djemetean transgressions (??? 6400 to 2700??14C yr BP). However, the composition of the faunal assemblage indicates that bottom-water salinity never exceeded modern values of 18-20??psu. ?? 2006 Elsevier B.V. All rights reserved.

Palaeogeography, Palaeoclimatology, Palaeoecology↗
USGS2005

Water resources data, North Carolina, water year 2004. Volume 2: Ground-water records

Water-resources data for the 2004 water year for North Carolina consist of records of stage, discharge, water quality for streams; stage and contents for lakes and reservoirs; precipitation; and ground-water levels and water quality of ground water. Volume 1 contains discharge records for 217 gaging stations; stage and contents for 58 lakes and reservoirs; stage only records for 22 gaging stations; elevations for 9 stations; water quality for 39 gaging stations and 5 miscellaneous sites, and continuous water quality for 35 sites; and continuous precipitation at 127 sites. Volume 2 contains ground-water-level data from 161 observation wells, ground-water-quality data from 38 wells, continuous water quality for 7 sites and continuous precipitation at 7 sites. Additional water data were collected at 51 sites not involved in the systematic data-collection program, and are published as miscellaneous measurements in Volume 1. The collection of water-resources data in North Carolina is a part of the National Water-Data System operated by the U.S. Geological Survey in cooperation with State, municipal, and Federal agencies.

North Carolina↗
USGS2004

Water resources data, North Carolina, water year 2003. Volume 2: Ground-water records

Water-resources data for the 2003 water year for North Carolina consist of records of stage, discharge, water quality for streams; stage and contents for lakes and reservoirs; precipitation; and ground-water levels and water quality of ground water. Volume 1 contains discharge records for 213 gaging stations; stage for 61 gaging stations; and continuous precipitation at 118 sites. Volume 2 contains ground-water-level data from 143 observation wells and ground-water-quality data from 72 wells. The collection of water-resources data in North Carolina is a part of the National Water-Data System operated by the U.S. Geological Survey in cooperation with State, municipal, and Federal agencies.

North Carolina↗
USGS2003

Water resources data, North Carolina, water year 2002. Volume 2: Ground-water records

Water-resources data for the 2002 water year for North Carolina consist of records of stage, discharge, water quality for streams; stage and contents for lakes and reservoirs; precipitation; and ground-water levels and water quality of ground water. Volume 1 contains discharge records for 211 gaging stations; stage and contents for 62 lakes and reservoirs; stage for 20 gaging stations; water quality for 52 gaging stations and 7 miscellaneous sites, and continuous water quality for 30 sites; and continuous precipitation at 109 sites. Volume 2 contains ground-water-level data from 143 observation wells and ground-water-quality data from 72 wells. Additional water data were collected at 85 sites not involved in the systematic data-collection program, and are published as miscellaneous measurements in Volume 1. The collection of water-resources data in North Carolina is a part of the National Water-Data System operated by the U.S. Geological Survey in cooperation with State, municipal, and Federal agencies.

North Carolina↗
USGS1997

Hydrogeologic framework and ground-water resources at Seymour Johnson Air Force Base, North Carolina

A preliminary hydrogeologic framework of the Seymour Johnson Air Force Base was constructed from published data, available well data, and reports from Air Base files, City of Goldsboro and Wayne County records, and North Carolina Geological Survey files. Borehole geophysical logs were run in selected wells; and the surficial, Black Creek, and upper Cape Fear aquifers were mapped. Results indicate that the surficial aquifer appears to have the greatest lateral variability of clay units and aquifer material of the three aquifers. A surficial aquifer water-level surface map, constructed from selected monitoring wells screened exclusively in the surficial aquifer, indicates the general direction of ground-water movement in this mostly unconfined aquifer is toward the Neuse River and Stoney Creek. However, water-level gradient data from a few sites in the surficial aquifer did not reflect this trend, and there are insufficient hydrologic and hydrogeologic data to determine the cause of these few anamalous measurements. The Black Creek aquifer underlies the surficial aquifer and is believed to underlie most of Wayne County, including the Air Base where the aquifer and overlying confining unit are estimated from well log data to be as much as 100 feet thick. The Black Creek confining unit ranges in thickness from less than 8 feet to more than 20 feet. There are currently no accessible wells screened exclusively in the Black Creek aquifer from which to measure water levels. The upper Cape Fear aquifer and confining unit are generally found at depths greater than 80 feet below land surface at the Air Base, and are estimated to be as much as 70 feet thick. Hydrologic and hydrogeologic data are insufficient to determine localized surficial aquifer hydrogeology, ground-water movement at several sites, or hydraulic head differences between the three aquifers.

Open-File Report↗
USGS1986

Geochemical and fluid zonation in the skarn environment at the tomboy-minnie gold deposits, Lander County, Nevada

The Tomboy—Minnie gold deposits are related to the middle Tertiary porphyry copper system centered at Copper Canyon. Gold-silver ores in the deposits occur mostly in a pyrrhotite- and pyrite-rich basal 30-m-thick sequence of altered calcareous conglomerate belonging to the Middle Pennsylvanian Battle Formation. The entire mineralized system contained at least 3.3 million troy oz gold before large-scale mining operations began. Alteration in the Tomboy—Minnie deposits includes actinolite- and chlorite-dominant assemblages, in marked contrast to the skarn, potassic, and phyllic assemblages characterizing the copper-gold-silver deposits of the system. Introduction of gold occurred penecontemporaneously with replacement of early diopside-alteration assemblages by actinolite and chlorite. Metals are zoned strongly in the Copper Canyon system: the West and East ore bodies occur in a copper-gold-silver zone that is followed outward by a gold-silver zone which includes the Tomboy deposit and in turn, is succeeded by a lead-zinc-silver zone. Locations of drill holes that have Au/Ag assay ratios of ⩾ 1 clearly outline the Tomboy—Minnie deposits within an area of rocks with Au/Ag ratios of ≈ 0.5. Fluid-inclusion studies suggest wide variations in temperature and chemistry prevailed in the fluids associated with mineralization at the Tomboy. Early fluids associated with diopsidequartz assemblages probably were dominantly CaCl 2 -rich brines and were boiling at temperatures higher than 500°C. These fluids were progressively enriched in sodium and potassium over time, and during the hydrosilicate stages, temperatures probably ranged from 320 to 500°C at the time actinolite formed, and from 220 to 320°C at the time chlorite was dominant. Sulfur isotopic data suggest that sulfur, mostly from a magmatic or deep-seated crustal source, was transported by hydrothermal fluids as aqueous H 2 S with a δ 34 S of about . 4 ± 1‰ ">

Journal of Geochemical Exploration↗