Si  search
USEsilicon
Si-32  search
BTisotopes
 .radioactive isotopes
 ..Si-32
BTsilicon
 .Si-32
RTaccelerator mass spectroscopy
SNThis term has multiple hierarchies.
sial  search
USEgranitic layer
Siam  search
USEThailand
Sian China  search
USEXi'an China
Sibay Russian Federation  search
BTCommonwealth of Independent States
 .Russian Federation
 ..Bashkortostan Russian Federation
 ...Sibay Russian Federation
SNTown in the Southern Urals in Bashkortostan in SE European Russian Federation. Before 1993, Sibay Russian Republic was also used. This term has multiple hierarchies.
Siberia  search
BTAsia
 .Siberia
RTRussian Federation
 Kazakhstan
 Siberian Platform
 Russian Far East
 Central Asia
 Baikal rift zone
 Baikalian Phase
 Beringia
 Ob River
 Russian Pacific region
 Khatanga Basin
 Moty Formation
 Omolon Block
 Popigay Structure
 Tunguska Basin
 Tunguska Syneclise
 West Sib
SNRegion in Asia extending from the Urals to the Pacific Ocean, and from the Arctic Ocean to the Chinese and Mongolian borders and including N Kazakhstan. Indexed with former Soviet republics as applicable.
Siberia-Soviet Far East  search
USERussian Far East
Siberian fold belt  search
BTAsia
 .Siberian fold belt
NTBaikal region
 Sayan
RTRussian Federation
 Altai Mountains
 Tuva Russian Federation
SNAdded to Thesaurus in 1981.
Siberian Lowland  search
BTAsia
 .West Siberia
 ..Siberian Lowland
UFWest Siberian Basin
 West Siberian Lowland
 West Siberian Plain
RTRussian Federation
 Kazakhstan
 Ob-Irtysh Interfluve
 Megion Field
 Urengoy Field
SNRegion comprising the West Siberian Plain which extends from the Urals in the W to the Yenisei River in the E, and from the Kara Sea in the N to the Kazakh Hills in the S. Also search Siberian. This term has multiple hierarchies. Indexed with former Sovie
Siberian Platform  search
BTCommonwealth of Independent States
 .Russian Federation
 ..Siberian Platform
BTAsia
 .Siberian Platform
NTAldan Shield
 Anabar Shield
 Angara-Lena Basin
 North Siberian Plain
 Tunguska
 Vilyuy Syneclise
 Yakutia region
 Yenisei Ridge
UFCentral Siberian Plateau
 West Siberian Platform
RTUdachnaya Pipe
 Siberia
 Bazhenov Formation
 Mir Pipe
SNRegion comprising the Central Siberian Plateau which lies between the Yenisei River on the W, and the Lena River on the E. Also search Siberian. This term has multiple hierarchies.
Sibiu Romania  search
BTEurope
 .Southern Europe
 ..Romania
 ...Transylvania
 ....Sibiu Romania
SNCity and county in S Transylvania.
Sibley County Minnesota  search
BTUnited States
 .Minnesota
 ..Sibley County Minnesota
Sichuan Basin  search
BTAsia
 .Far East
 ..China
 ...Sichuan Basin
UFSzechwan Basin
RTSichuan China
SNSW China. Added to Thesaurus in 1993.
Sichuan China  search
BTAsia
 .Far East
 ..China
 ...Sichuan China
NTPanxi Rift
UFSichuan Sheng
 Szechuan China
RTWufeng Formation
 Yangtze Platform
 Chongqing China
 Yangtze Three Gorges
 Xichang China
 Qinghai-Xizang Plateau
 Luoquan Formation
 Xianshuihe fault zone
 Sanjiang
 Sichuan Basin
SNProvince, SW China. In 1997, the eastern part became the Chonqqing independent municipality.
Sichuan Sheng  search
USESichuan China
Sicilia Italy  search
USESicily Italy
Sicilian  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Cenozoic
 ...Quarternary
 ....Pleistocene
 .....Upper Pleistocene
 ......Sicilian
SNEurope.
Sicily Italy  search
BTEurope
 .Southern Europe
 ..Italy
 ...Sicily Italy
NTCaltanissetta Italy
 Ciminna Basin
 Enna Italy
 Lipari Islands
 Madonie Mountains
 Messina Italy
 Mount Etna
 Nebrodi Mountains
 Palermo Italy
 Pantelleria
 Peloritani Mountains
 Syracuse Italy
 Trapani Italy
 Ustica Island
UFSicilia Italy
RTMediterranean region
 Mediterranean Sea
 Calabrian Arc
SNIsland in Mediterranean Sea and autonomous region.
Sicker Group  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Paleozoic
 ...upper Paleozoic
 ....Sicker Group
RTPermian
 Pennsylvanian
 British Columbia
 Vancouver Island
SNVancouver Island, British Columbia. Pennsylvanian? to Permian. Added to Thesaurus in 1989.
side-looking airborne radar  search
USESLAR
side-scanning methods  search
RTacoustical methods
 GLORIA
 methods
 radar methods
 SAR
 geophysical methods
 SLAR
 sonar methods
SNAdded to Thesaurus in 1981.
sideraerolite  search
USEstony irons
Siderian  search
BTChronostratigraphic Units
 .Precambrian
 ..Proterozoic
 ...Paleoproterozoic
 ....Siderian
siderite  search
BTcarbonates
 .siderite
UFchalybite
RTiron ores
 iron minerals
siderite (meteorite)  search
USEiron meteorites
siderolite  search
USEstony irons
siderophile elemen  search
siderophile elements  search
RTchalcophile elements
 chemical elements
 cobalt
 gold
 iron
 lithophile elements
 nickel
 phosphorus
 platinum
SNChemical elements which tend to concentrate in metallic phases of meteorites. Also, an element possessing weak affinity for sulfur and oxygen.
siderophyre  search
BTmeteorites
 .stony irons
 ..siderophyre
SNAdded to Thesaurus in 1984.
Sidhi India  search
BTAsia
 .Indian Peninsula
 ..India
 ...Madhya Pradesh India
 ....Sidhi India
SNVillage and district in E Madhya Pradesh, central India.
Sidobre Massif  search
BTEurope
 .Western Europe
 ..France
 ...Central Massif
 ....Sidobre Massif
BTEurope
 .Western Europe
 ..France
 ...Tarn France
 ....Sidobre Massif
SNIn S Central Massif NE of Castres. Also search Sidobre. This term has multiple hierarchies.
Siebengebirge  search
BTEurope
 .Central Europe
 ..Germany
 ...North Rhine-Westphalia Germany
 ....Siebengebirge
BTEurope
 .Central Europe
 ..Germany
 ...Westerwald
 ....Siebengebirge
SNHills in the Westerwald on right bank of Rhine River SSE of Bonn. This term has multiple hierarchies.
Siedlce Poland  search
BTEurope
 .Central Europe
 ..Poland
 ...Siedlce Poland
UFSyedlets Poland
SNProvince and city in E Poland.
Siegenian  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Paleozoic
 ...Devonian
 ....Lower Devonian
 .....Siegenian
SNEurope. Above Gedinnian, below Emsian.
siegenite  search
BTsulfides
 .siegenite
RTlinnaeite
Siena Italy  search
BTEurope
 .Southern Europe
 ..Italy
 ...Tuscany Italy
 ....Siena Italy
SNCity and province in S central Tuscany.
Sierozems  search
BTsoils
 .Sierozems
UFCerozem
 Gray desert soil
 Gray earth
 Serozem
RTsoil group
 Zonal soils
Sierra Ancha  search
BTUnited States
 .Arizona
 ..Gila County Arizona
 ...Sierra Ancha
SNRidge in E central Arizona.
Sierra Blanca  search
RTLincoln County New Mexico
 Otero County New Mexico
 Sangre de Cristo Mountains
 New Mexico
SNRange in Otero and Lincoln counties in S central New Mexico. Indexed with counties and mountains as applicable.
Sierra County California  search
BTUnited States
 .California
 ..Sierra County California
SNNE California.
Sierra County New Mexico  search
BTUnited States
 .New Mexico
 ..Sierra County New Mexico
NTTruth or Consequences New Mexico
RTBlack Range
 Caballo Mountains
 Jornada del Muerto
 Orogrande Basin
 San Andres Mountains
SNSW New Mexico.
Sierra de Gador  search
BTEurope
 .Southern Europe
 ..Iberian Peninsula
 ...Spain
 ....Andalusia Spain
 .....Almeria Spain
 ......Sierra de Gador
SNRange in SE Spain.
Sierra de Gredos  search
BTEurope
 .Southern Europe
 ..Iberian Peninsula
 ...Spain
 ....Sierra de Gredos
RTAvila Spain
 Caceres Spain
 Toledo Spain
 Madrid Spain
SNRange W of Madrid in W central Spain.
Sierra de Guadarrama  search
BTEurope
 .Southern Europe
 ..Iberian Peninsula
 ...Spain
 ....Sierra de Guadarrama
RTAvila Spain
 Old Castile Spain
 Segovia Spain
 New Castile Spain
 Madrid Spain
SNRange N of Madrid separating Old Castile from New Castile.
Sierra de Juarez  search
RTBaja California
 Baja California Norte Mexico
 Chiapas Mexico
 Chihuahua Mexico
 Oaxaca Mexico
SNMountain range, N Baja California, Mexico. Also mountain ranges in southern and central Mexico. May also occur in other locations. Indexed with Mexican states or other location as applicable. Added to Thesaurus in 1985.
Sierra de la Demanda  search
BTEurope
 .Southern Europe
 ..Iberian Peninsula
 ...Spain
 ....Sierra de la Demanda
RTOld Castile Spain
 Burgos Spain
 La Rioja Spain
 Iberian Mountains
SNRange of the Cordillera Iberica in Old Castile in N Spain.
Sierra de los Filabres  search
BTEurope
 .Southern Europe
 ..Iberian Peninsula
 ...Spain
 ....Andalusia Spain
 .....Almeria Spain
 ......Sierra de los Filabres
RTNevado-Filabride Complex
SNRange in W central Almeria Province, SE Spain.
Sierra de los Organos  search
BTCaribbean region
 .West Indies
 ..Antilles
 ...Greater Antilles
 ....Cuba
 .....Pinar del Rio Cuba
 ......Sierra de los Organos
SNRange in W Pinar del Rio, W Cuba.
Sierra de Perija  search
BTSouth America
 .Andes
 ..Sierra de Perija
RTColombia
 Venezuela
 Eastern Cordillera
 Zulia Venezuela
SNRange of the Andes on the Colombia-Venezuela border. Indexed with countries as applicable. Added to Thesaurus in 1985.
Sierra de Ronda  search
USESerrania de Ronda
Sierra Gorda  search
BTMexico
 .Guanajuato Mexico
 ..Sierra Gorda
RTSierra Madre Occidental
SNE range of S Sierra Madre Occidental in central Mexico.
Sierra Leone  search
BTAfrica
 .West Africa
 ..Sierra Leone
SNFormer British colony and protectorate. Became independent in 1961.
Sierra Leone Rise  search
BTAtlantic Ocean
 .North Atlantic
 ..Sierra Leone Rise
RTLeg 41
 DSDP Site 13
 Equatorial Atlantic
 DSDP Site 366
 ODP Site 668
 ODP Site 665
 ODP Site 666
 ODP Site 667
SNSW of West Africa in NE Equatorial Atlantic. Added to Thesaurus in 1981.
Sierra Madre  search
RTLuzon
 Mexico
 North American Cordillera
 California
 Sierra Madre del Sur
 Sierra Madre Occidental
 Sierra Madre Oriental
 Sierra Madre Range
SNChief Mexican mountain system extending 1500 miles SE from U.S. border including 3 separate ranges which enclose the great central plateau. Before 1978, this term also included the Sierra Madre Range of Wyoming. Also used for ranges on Luzon, Philippines
Sierra Madre del Sur  search
BTMexico
 .Sierra Madre del Sur
RTGuerrero Mexico
 Mexican volcanic belt
 Sierra Madre
 Oaxaca Mexico
SNCoastal range in SW Mexico. Indexed with Sierra Madre and Mexican states as applicable.
Sierra Madre Occidental  search
BTMexico
 .Sierra Madre Occidental
RTChihuahua Mexico
 Sonora Mexico
 Jalisco Mexico
 Mexican volcanic belt
 Colima Mexico
 Durango Mexico
 Nayarit Mexico
 Zacatecas Mexico
 Sierra Madre
 Sierra Gorda
SNRange running for 700 miles parallel to the Pacific Ocean. Indexed with Mexican states and Sierra Madre as applicable.
Sierra Madre Oriental  search
BTMexico
 .Sierra Madre Oriental
RTTamaulipas Mexico
 Coahuila Mexico
 Hidalgo Mexico
 Puebla Mexico
 Sierra Madre
 Nuevo Leon Mexico
 Veracruz Mexico
 San Luis Potosi Mexico
SNRange running parallel to the Gulf of Mexico. Indexed with Mexican states and Sierra Madre as applicable.
Sierra Madre Range  search
BTUnited States
 .Wyoming
 ..Sierra Madre Range
RTSierra Madre
 Mullen Creek-Nash Fork shear zone
SNRange in Continental Divide, S Wyoming, just W of North Platte River. Also search Sierra Madre AND Wyoming.
Sierra Morena  search
SNA valid term through mid-1978. See Betic Cordillera.
Sierra Nevada  search
RTCascade Range
 Long Valley Caldera
 Melones Fault
 Mount Lyell
 Nevadan Orogeny
 North American Cordillera
 California
 Sonoma Orogeny
 Spanish Sierra Nevada
 Table Mountain
 White Mountain
SNMountain range in E California. Search Sierra Nevada AND California. May also occur in other locations. After 1981, see Spanish Sierra Nevada if applicable. Indexed with states or regions and mountains as applicable.
Sierra Nevada Batholith  search
BTUnited States
 .California
 ..Sierra Nevada Batholith
SNE central California. Added to Thesaurus in 1981.
Sierra Nevada de Santa Marta  search
BTSouth America
 .Colombia
 ..Sierra Nevada de Santa Marta
RTSanta Marta Colombia
SNMountain range in N Colombia on Caribbean coast.
Sierra Pena Blanca  search
BTMexico
 .Chihuahua Mexico
 ..Sierra Pena Blanca
SNChihuahua, N Mexico. Added to Thesaurus in 1989.
Sierras Australes  search
BTSouth America
 .Argentina
 ..Buenos Aires Argentina
 ...Sierras Australes
UFSouthern Ranges, Buenos Aires
SNGroup of mountain ranges in S Buenos Aires Province, E Argentina. Also index individual ranges if available. Added to Thesaurus in 1995.
Sierras Pampeanas  search
USEPampean Mountains
Sierrita Mountains  search
RTArizona
 Pima County Arizona
SNS Arizona. Location of porphyry copper deposits. Indexed with counties or region as applicable.
Sifton Basin  search
BTCanada
 .Western Canada
 ..British Columbia
 ...Sifton Basin
SNN British Columbia. Also search Sifton.
Sigillaria  search
BTPlantae
 .Pteridophyta
 ..Lycopsida
 ...Sigillaria
SNGenus.
Sigma Mine  search
BTCanada
 .Eastern Canada
 ..Quebec
 ...Sigma Mine
RTmines
 Abitibi Belt
 gold ores
 Val d'Or Quebec
SNGold ores. Val d'Or, SW Quebec. Added to Thesaurus in 1989.
signal distortion  search
RTdistortion
 elastic waves
 seismology
SNAdded to Thesaurus in 1981.
Signal Hill Formation  search
BTronian
 .Signal Hill Formation
RTCanada
 Newfoundland Island
SNUnconformably underlies Random Formation and overlies Avalonian Formation.
signal to noise ratios  search
USEsignal-to-noise ratio
signal-to-noise ratio  search
UFsignal to noise ratios
RTseismology
 geophysical methods
 geophysical surveys
 seismic methods
 seismograms
 stacking
 noise
 signals
SNAdded to Thesaurus in 1981.
signals  search
RTfilters
 noise
 signal-to-noise ratio
 geophysical methods
 seismology
 teleseismic signals
Signy Island  search
BTAntarctica
 .South Orkney Islands
 ..Signy Island
RTAtlantic Ocean
SNOne of the South Orkney Islands SE of the Falkland Islands. This term has multiple hierarchies.
Sigsbee Deep  search
BTAtlantic Ocean
 .North Atlantic
 ..Gulf of Mexico
 ...Sigsbee Deep
RTCampeche Scarp
 DSDP Site 3
 Mississippi Fan
 DSDP Site 91
SNIn SW central part of Gulf of Mexico. Before 1993, also search Mexico Basin AND Gulf of Mexico.
Sikhote Alin  search
USESikhote-Alin Range
SNA valid term through 1976.
Sikhote-Alin Range  search
BTCommonwealth of Independent States
 .Russian Federation
 ..Sikhote-Alin Range
BTAsia
 .Sikhote-Alin Range
UFSikhote Alin
RTRussian Far East
 Khabarovsk Russian Federation
 impact features
 Primorye Russian Federation
SNMountain range in Primorye and Khabarovsk krays along the Japan Sea and the Tatar Strait. Before 1977, also search Sikhote-Alin. This term has multiple hierarchies.
Sikkim India  search
BTAsia
 .Indian Peninsula
 ..India
 ...Sikkim India
RTHimalayas
 Lesser Himalayas
 Siwalik System
 Siwalik Range
SNBecame an associated Indian state on Sept. 7, 1974.
Sila Massif  search
BTEurope
 .Southern Europe
 ..Italy
 ...Calabria Italy
 ....Sila Massif
RTApennines
 Southern Apennines
SNIn the Southern Apennines forming central part of toe of the Italian boot.
silcrete  search
BTsedimentary rocks
 .chemically precipitated rocks
 ..silcrete
RTterrigenous materials
 duricrust
Silesia  search
BTEurope
 .Central Europe
 ..Silesia
RTGermany
 Poland
 Czech Republic
 Moravia
 Lower Silesia
 Upper Silesia
SNRegion in E central Europe lying mostly in SW Poland. It comprises both Upper and Lower Silesia plus small areas in E Germany and N Moravia. Indexed with countries as applicable.
Silesian  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Paleozoic
 ...Carboniferous
 ....Silesian
Silesian Basin  search
USESilesian coal basin
Silesian coal basin  search
BTEurope
 .Central Europe
 ..Poland
 ...Silesian coal basin
UFSilesian Basin
RTcoal fields
 Wroclaw Poland
 Katowice Poland
 Lower Silesia
 Upper Silesia
 Upper Silesian coal basin
SNIn Lower Silesia in Wroclaw Province, and in Upper Silesia in Katowice Province. Indexed with provinces as applicable.
silexite  search
SNAs of 1981, no longer a valid term for GeoRef. Use quartzolite (for the igneous rock) or chert as applicable.
silica  search
RTabrasives
 glass materials
 Ottawa Sand
 sand
 sands
 silica minerals
 silicates
 siliceous composition
 silicic acid
 silicon
SNAs of 1985, no longer considered a commodity term (list C). Used for silicon dioxide.
silica group  search
USEsilica minerals
silica minerals  search
BTsilicates
 .framework silicates
 ..silica minerals
NTagate
 amethyst
 carnelian
 chalcedony
 chrysoprase
 coesite
 cristobalite
 hyalite
 jasper
 keatite
 lechatelierite
 melanophlogite
 moganite
 onyx
 opal
 quartz
 smoky quartz
 stishovite
 tridymite
UFsilica group
RTsilica
silicate glass  search
SNAs of 1998, not a valid term for GeoRef. Use (volcanic glass or glasses) AND (silicates or siliceous composition). For natural glasses which are not volcanic, glass materials is be used. See silicate melts if applicable.
silicate melts  search
BTmelts
 .silicate melts
RTpetrology
 magmas
 geophysics
 phase equilibria
 liquid phase
SNAlso search silicates and melts.
silicate minerals  search
USEsilicates
silicate rocks  search
RTpetrology
 rocks
 siliceous composition
 standard materials
silicates  search
NTaluminosilicates
 asbestos
 barium silicates
 borosilicates
 chain silicates
 chlorophaeite
 framework silicates
 iron silicates
 magnesian silicates
 orthosilicates
 ring silicates
 sheet silicates
UFsilicate minerals
RTsilica
 minerals
 clay mineralogy
 silicon
SNIn indexing, use this term only for broad treatments of the entire class of minerals; otherwise, use a narrower term, e.g. orthosilicates, ring silicates, chain silicates, etc.
siliceous composition  search
RTclastic rocks
 composition
 insoluble residues
 jasperoid
 sedimentary rocks
 sediments
 silica
 silicate rocks
 siliceous sinter
 siliciclastics
SNBefore 1978 also search siliceous in combination with specific sediment type. Also search siliceous rocks.
siliceous earth  search
SNUse diatomaceous earth or diatomite as applicable.
siliceous rocks  search
SNA valid term through 1977. After 1977, use siliceous composition.
siliceous sinter  search
BTsedimentary rocks
 .chemically precipitated rocks
 ..siliceous sinter
RTsiliceous composition
 sintering
SNAlso search sinter AND siliceous.
silicic acid  search
UFhydrated silica
 silicic acids
RTsilica
 acids
SNSiO
silicic acids  search
USEsilicic acid
silicic composition  search
USEacidic composition
siliciclastic rocks  search
USEsiliciclastics
siliciclastics  search
UFsiliciclastic rocks
RTsedimentary rocks
 clastic sediments
 sediments
 clastic rocks
 siliceous composition
SNAdded to Thesaurus in 1989.
silicides  search
BTalloys
 .silicides
NTferrosilicon
RTmoissanite
silicification  search
UFsilification
RTsedimentation
 processes
 metasomatism
 diagenesis
 fossilization
 chertification
silicified wood  search
USEfossil wood
Silicispongiae  search
BTInvertebrata
 .Porifera
 ..Silicispongiae
UFNoncalcarea
Silicoflagellata  search
BTInvertebrata
 .Protista
 ..Silicoflagellata
NTDictyocha
 Distephanus
RTmicrofossils
SNIndexed with microfossils if applicable.
silicon  search
NTSi-32
UFSi
RTsilica
 silicates
 chemical elements
 moissanite
 ferrosilicon
silicon carbide  search
SNNot a valid term for GeoRef. As of 1993, see carborundum for economic papers or carbides or moissanite, for minerals. Before 1993, also search carborundum.
silicon dioxide  search
SNNot a valid term for GeoRef. For geochemistry, see silica. Use specific silica minerals (list L) name if applicable or see commodity terms (list C).
silification  search
USEsilicification
Siljan  search
BTEurope
 .Western Europe
 ..Scandinavia
 ...Sweden
 ....Siljan
RTSiljan Ring
SNLake in central Sweden. Also used for possible meteor crater before 1993.
Siljan Ring  search
BTEurope
 .Western Europe
 ..Scandinavia
 ...Sweden
 ....Siljan Ring
RTimpact features
 Gravberg Well
 Siljan
SNImpact crater containing the lake, Siljan in central Sweden. Site of several deep drilling boreholes. Before 1993, also search Siljan. Added to Thesaurus in 1993.
sillimanite  search
BTsilicates
 .orthosilicates
 ..nesosilicates
 ...sillimanite
UFfibrolite
RTandalusite
 kyanite
 sillimanite deposits
SNAs of 1981, use sillimanite deposits for sillimanite as a commodity.
sillimanite deposits  search
RTceramic materials
 sillimanite
SNMay be used as a commodity term with ceramic materials.
sillimanite gneiss  search
BTmetamorphic rocks
 .gneisses
 ..sillimanite gneiss
sills  search
BTintrusions
 .sills
RTdikes
Silo Field  search
RTLaramie County Wyoming
 oil and gas fields
 Taylor County Texas
SNIn Laramie County, SE Wyoming. Also in Taylor County, Texas. Also occurs in other locations. Indexed with counties or region as applicable. Added to Thesaurus in 1995.
silt  search
BTsediments
 .clastic sediments
 ..silt
UFsilts
RTsand
 alluvium
 clay
 overbank sediments
 terrigenous materials
 loam
 mud
 loess
 siltation
 siltstone
siltation  search
RTdeposition
 dredging
 maintenance
 reservoirs
 settling
 silt
 sedimentation
 waterways
SNAdded to Thesaurus in 1982.
siltite  search
USEsiltstone
silts  search
USEsilt
siltstone  search
BTsedimentary rocks
 .clastic rocks
 ..siltstone
UFsiltite
RTsilt
 terrigenous materials
 mudstone
 metasiltstone
Silurian  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Paleozoic
 ...Silurian
NTLlandovery
 Wenlock
 Ludlow
 Priduli
 Aberystwyth Grits
 Bass Islands Dolomite
 Clinch Sandstone
 Crab Orchard Formation
 Fusselman Dolomite
 Henryhouse Formation
 Lower Silurian
 Middle Silurian
 Perry Mountain Formation
 Rockwood Formation
 Sangerville Formation
 Scandian Orogeny
 Upper Silurian
 Vassalboro Formation
 Waterville Formation
UFGothlandian
 Gotlandian
RTEllis Bay Formation
 Broken River Formation
 Dalradian
 Berwick Formation
 Merrimack Group
 Henderson Gneiss
 Downtonian
 range
 New York City Group
 Peel Sound Formation
 Hanson Creek Formation
 Hunton Group
 Hidden Valley Dolomite
 Kittery Formation
 Madrid Formation
SNAbove Ordovician, below Devonian.
silvanite  search
USEsylvanite
silver  search
BTmetals
 .silver
UFAg
RTargentite
 silver ores
 native elements
 chalcophile elements
 heavy metals
 electrum
SNChemical element. Use silver ores for silver as a commodity.
Silver Bow County Montana  search
BTUnited States
 .Montana
 ..Silver Bow County Montana
NTButte Montana
SNSW Montana.
Silver City Nevada  search
BTUnited States
 .Nevada
 ..Lyon County Nevada
 ...Silver City Nevada
SNHamlet in W Nevada.
Silver City New Mexico  search
BTUnited States
 .New Mexico
 ..Grant County New Mexico
 ...Silver City New Mexico
SNTown in SW New Mexico.
silver ores  search
BTmetal ores
 .silver ores
RTacanthite
 argentite
 native elements
 silver
 Sullivan Mine
 Leadville mining district
 tetrahedrite
 Equity Mine
 freibergite
 Kamioka Mine
 Kidd Creek Mine
 nuggets
 Toyoha Mine
 Summitville Mine
 San Juan mining district
 stephanite
 Temagami Mine
SNCommodity. See List C.
Silver Peak Mountains  search
BTUnited States
 .Nevada
 ..Esmeralda County Nevada
 ...Silver Peak Mountains
SNSmall range in W Esmeralda County in SW Nevada. Also search Silver Peak.
Silverton Caldera  search
BTUnited States
 .Colorado
 ..San Juan County Colorado
 ...Silverton Caldera
RTSan Juan Mountains
SNNear town of Silverton in San Juan County in San Juan Mountains of SW Colorado. Also search Silverton.
Silvretta Group  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Paleozoic
 ...Silvretta Group
RTSwitzerland
 Tyrol Austria
SNAlso search Silvretta.
sima  search
USEbasaltic layer
simazine  search
BTpesticides
 .herbicides
 ..triazines
 ...simazine
RTpollutants
 toxic materials
Simbirsk Russian Federation  search
USEUlyanovsk Russian Federation
Simcoe County Ontario  search
BTCanada
 .Eastern Canada
 ..Ontario
 ...Simcoe County Ontario
NTBorden Ontario
SNS Georgian Bay, S Ontario.
Simferopol Ukraine  search
BTEurope
 .Ukraine
 ..Crimea Ukraine
 ...Simferopol Ukraine
SNCity in the S central Crimea, S Ukraine. This term has multiple hierarchies.
Simi Hills  search
BTUnited States
 .California
 ..Ventura County California
 ...Simi Hills
SNIn Ventura County NW of Los Angeles. Indexed with county or region as applicable.
Simi Valley California  search
BTUnited States
 .California
 ..Ventura County California
 ...Simi Valley California
SNCity in S California.
simians  search
BTChordata
 .Vertebrata
 ..Tetrapoda
 ...Mammalia
 ....Theria
 .....Eutheria
 ......Primates
 .......simians
NTCercopithecidae
 Platyrrhina
 Pongidae
similar folds  search
BTfolds
 .similar folds
UFshear folds
 slip folds
RTconcentric folds
 shear
SNBefore 1978, also search shear folds. Before 1993, also search slip folds. Before 1978, also search similar and folds.
Simla Hills  search
BTAsia
 .Indian Peninsula
 ..India
 ...Himachal Pradesh India
 ....Simla Hills
BTmalayas
 .Kumaun Himalayas
 ..Simla Hills
SNHill and mountain area of the outer Kumaun Himalayas around Simla in Himachal Pradesh. This term has multiple hierarchies.
Simla India  search
BTmachal Pradesh India
 .Simla India
SNTown and hill resort in S Himachal Pradesh, N India.
Simleu Basin  search
BTEurope
 .Southern Europe
 ..Romania
 ...Transylvania
 ....Simleu Basin
SNIn Bihor Mountains near town of Simleu Silvaniei in NW Transylvania. Also search Simleu.
Simplon region  search
BTEurope
 .Simplon region
RTSwitzerland
 Italy
 Piemonte Italy
SNIncludes Simplon Pass, Simplon Road, and Simplon Tunnel area. Also search Simplon. Indexed with Italy and/or Switzerland.
Simpson County Kentucky  search
BTUnited States
 .Kentucky
 ..Simpson County Kentucky
Simpson County Mississippi  search
BTUnited States
 .Mississippi
 ..Simpson County Mississippi
Simpson Desert  search
RTAustralia
 Northern Territory Australia
 Queensland Australia
 South Australia
SNPrimarily in SE Northern Territory. Indexed with Northern Territory Australia and/or states as applicable.
Simpson Field  search
RTAlaska
 Nebraska
 North Slope
 oil and gas fields
SNNorth Slope, Alaska. Also one in Nebraska. Search in conjunction with appropriate state. Indexed with counties and/or states as applicable. Added to Thesaurus in 1989.
Simpson Group  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Paleozoic
 ...Ordovician
 ....Middle Ordovician
 .....Simpson Group
RTOklahoma
 Bromide Formation
SNComprises Joins, Oil Creek, McLish, Tulip Creek, Bromide, and Corbin Ranch formations. Central and S Oklahoma.
SIMS  search
USEsecondary ion mass spectroscopy
simulation  search
RTanalog simulation
 bottom-simulating reflectors
 computer animation
 data processing
 digital simulation
 DRAINMOD
 general circulation models
 laboratory studies
 mathematical geology
 mathematical models
 models
 modern analogs
 MODFLOW
 MODPATH
 sandbox models
 SUTRA
Sinai  search
UFSinai Peninsula
RTEgypt
 Israel
 Gavish Sebkha
 Sinai Egypt
 Solar Lake
SNPeninsula extending from the Mediterranean Sea to the Red Sea. It is bounded on the W by the Suez Canal and the Gulf of Suez, and on the E by Israel and the Gulf of Aqaba. Coextensive with the Egyptian governorate. As of 1993, see Sinai Egypt for the gove
Sinai Egypt  search
BTAfrica
 .North Africa
 ..Egypt
 ...Sinai Egypt
RTGavish Sebkha
 Sinai
 Solar Lake
SNGovernorate, NE Egypt, coextensive with the Sinai Peninsula. Indexed with Middle East and/or Sinai.
Sinai Peninsula  search
USESinai
Sinaia Romania  search
BTEurope
 .Southern Europe
 ..Romania
 ...Walachia
 ....Prahova Romania
 .....Sinaia Romania
RTBucegi Mountains
SNTown and health resort at SE foot of Bucegi Mountains of the Transylvanian Alps in Prahova County.
Sinaloa Mexico  search
BTMexico
 .Sinaloa Mexico
NTMazatlan Mexico
RTGuerrero Terrane
 Rivera Plate
SNState in W Mexico.
Sind Pakistan  search
BTAsia
 .Indian Peninsula
 ..Pakistan
 ...Sind Pakistan
NTChor Pakistan
 Hyderabad Pakistan
RTNari Series
SNProvince in SE Pakistan. Also search Sindh.
Sinemurian  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Mesozoic
 ...Jurassic
 ....Lower Jurassic
 .....Sinemurian
BTChronostratigraphic Units
 .Phanerozoic
 ..Mesozoic
 ...Jurassic
 ....Lower Jurassic
 .....lower Liassic
 ......Sinemurian
SNEurope. Above Hettangian, below Pliensbachian.
Singapore  search
BTAsia
 .Far East
 ..Singapore
RTASEAN
 West Pacific Ocean Islands
SNIsland republic and city off the southern tip of the Malay Peninsula.
Singhbhum Granite  search
BTChronostratigraphic Units
 .Precambrian
 ..Archean
 ...Singhbhum Granite
RTIndia
 Bihar India
 Orissa India
 Singhbhum India
SNAlso search Singhbhum.
Singhbhum India  search
BTAsia
 .Indian Peninsula
 ..India
 ...Bihar India
 ....Singhbhum India
NTSini India
RTSinghbhum Granite
SNDistrict, Chota Nagpur division, S Bihar.
Singhbhum shear zone  search
BTAsia
 .Indian Peninsula
 ..India
 ...Singhbhum shear zone
RTBihar India
 Orissa India
SNIndexed with states as applicable.
single domains  search
BTmagnetic domains
 .single domains
SNAdded to Thesaurus in 1981.
single-crystal method  search
RTcrystal growth
 crystal structure
 methods
 minerals
 powder method
 X-ray analysis
SNBefore 1978, search single crystal.
Singleton Coal Measures  search
RTAustralia
 Carboniferous
 New South Wales Australia
 Permian
 Permian-Triassic boundary
 Triassic
SNE New South Wales. Indexed with age as applicable.
Sini India  search
BTAsia
 .Indian Peninsula
 ..India
 ...Bihar India
 ....Singhbhum India
 .....Sini India
SNVillage in Singhbhum District. Site of limestone quarries for Jamshedpur iron and steel works.
Sinian  search
BTChronostratigraphic Units
 .Precambrian
 ..Proterozoic
 ...Sinian
NTDengying Formation
 Doushantuo Formation
 Nantuo Formation
 upper Sinian
 Wumishan Formation
RTEocambrian
SNChina. Added to Thesaurus in 1985.
Sinjar Formation  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Cenozoic
 ...Paleogene
 ....Sinjar Formation
RTPaleocene
 lower Eocene
 Middle East
 Iraq
SNPaleocene-lower Eocene. In the Jabel Sinjar Mountains. Indexed with ages as applicable.
sink holes  search
USEsinkholes
sinkholes  search
BTsolution features
 .sinkholes
UFsink holes
RTgeomorphology
 geologic hazards
 karst
 dolines
 potholes
Sinkiang  search
SNNot a valid term for GeoRef. See Xinjiang China.
Sinkiang China  search
USEXinjiang China
Sinkiang Uighur China  search
USEXinjiang China
Sinkiang Weiwu'er Zizhiqu China  search
USEXinjiang China
sinking  search
SNUse land subsidence for geotechnical studies, or subsidence for large, regional tectonic subsidence or sinking slabs. Also see submergence, underground streams.
sinking (currents)  search
USEdownwelling
sinks  search
RTchemical reactions
 geochemistry
SNSubstance used to dissipate heat or remove fluids during a chemical reaction. For the solution feature, use sinkholes.
sinnerite  search
BTsulfides
 .sinnerite
Sino-Korean Paraplatform  search
USESino-Korean Platform
Sino-Korean Platform  search
BTAsia
 .Far East
 ..Sino-Korean Platform
UFSino-Korean Paraplatform
RTChina
 Korea
SNIndexed with regions as applicable. Added to Thesaurus in 1989.
sinter  search
SNA valid term through 1977. After 1977, use siliceous sinter.
sintering  search
RTdeformation
 diffusion
 meteorites
 phase equilibria
 refractory materials
 siliceous sinter
SNAdded to Thesaurus in 1985.
sinuosity  search
RTchannels
 fluvial features
 meanders
 streams
Sioux County Iowa  search
BTUnited States
 .Iowa
 ..Sioux County Iowa
SNNW Iowa.
Sioux County Nebraska  search
BTUnited States
 .Nebraska
 ..Sioux County Nebraska
SNExtreme NW Nebraska.
Sioux County North Dakota  search
BTUnited States
 .North Dakota
 ..Sioux County North Dakota
SNS North Dakota.
Sioux Quartzite  search
BTChronostratigraphic Units
 .Precambrian
 ..Sioux Quartzite
RTIowa
 Nebraska
 Minnesota
 South Dakota
SNHas been correlated with Baraboo Quartzite in Wisconsin. NW Iowa, SW Minnesota, NE Nebraska, and SE South Dakota.
Siphonaptera  search
BTInvertebrata
 .Arthropoda
 ..Mandibulata
 ...Insecta
 ....Pterygota
 .....Neoptera
 ......Endopterygota
 .......Siphonaptera
UFSiphonapteroida
SNOrder.
Siphonapteroida  search
USESiphonaptera
Sipunculoida  search
BTInvertebrata
 .Vermes
 ..Sipunculoida
Siqueiros fracture zone  search
BTPacific Ocean
 .North Pacific
 ..Northeast Pacific
 ...Siqueiros fracture zone
RTEquatorial Pacific
 DSDP Site 427
SNNear E end of Clipperton fracture zone. This term has multiple hierarchies. Added to Thesaurus in 1985.
SIR  search
SNNot a valid term for GeoRef. See Shuttle Imaging Radar if applicable.
Sir Darya  search
USESyr Darya
Siracusa  search
SNNot a valid term for GeoRef. See Syracuse Italy.
Sirenia  search
BTChordata
 .Vertebrata
 ..Tetrapoda
 ...Mammalia
 ....Theria
 .....Eutheria
 ......Sirenia
SNOrder.
Siret River  search
BTEurope
 .Siret River
UFSereth River
 Siretul River
RTRomania
 Ukraine
 Moldavia
 Romanian Plain
 Moldavian Platform
SNRises on the E slopes of the Carpathians in the Ukraine and flows SE into the Danube River just N of Galati. Also search Siret. Indexed with Moldavia and/or Romania; and/or Ukraine.
Siretul River  search
USESiret River
Sirius Group  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Cenozoic
 ...Neogene
 ....Pliocene
 .....Sirius Group
RTAntarctica
 Victoria Land
 Beardmore Glacier
SNDrift, Beardmore Glacier area, Antarctica. Age has been considered uncertain. Also search Sirius Formation and Antarctica. The Permian Sirius Formation occurs in Australia.
Sirohi India  search
BTAsia
 .Indian Peninsula
 ..India
 ...Rajasthan India
 ....Sirohi India
SNTown in SW Rajasthan.
Sirte Basin  search
BTAfrica
 .North Africa
 ..Libya
 ...Sirte Basin
UFSyrte Basin
SNOn the Gulf of Sidra in N Libya. Also search Sirte.
Sisian Armenia  search
BTEurope
 .Armenia
 ..Sisian Armenia
SNVillage in S Armenia. This term has multiple hierarchies.
Siskiyou County California  search
BTUnited States
 .California
 ..Siskiyou County California
NTMedicine Lake Highland
 Mount Shasta
RTMarble Mountains
 Preston Peak
 Trinity Complex
 Medicine Lake
SNN California.
Sisquoc Formation  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Cenozoic
 ...Neogene
 ....Sisquoc Formation
RTPliocene
 California
 upper Miocene
SNUpper Miocene to Pliocene. S California. Indexed with ages as applicable. Added to Thesaurus in 1985.
site evaluation  search
USEsite exploration
site explo  search
site explora  search
site exploration  search
UFsite evaluation
 site investigation
 site selection
RTland subsidence
 dams
 slope stability
 engineering geology
 rock mechanics
 permafrost
 geologic hazards
 soil mechanics
 reservoirs
 marine installations
 feasibility studies
 foundations
 explosions
 highways
 nuclear facilities
 exploration
 railroads
 trenching
 tunne
SNBefore 1978, also search site selection. Collection of data about and testing of, surface and subsurface materials (including physical properties, distribution, and geologic structure) at a site, to prepare suitable design for an engineering structure or
site investigation  search
USEsite exploration
site location maps  search
BTmaps
 .site location maps
UFlocation maps
 sample location maps
RTindex maps
SNAdded to Thesaurus in 1989.
site selection  search
USEsite exploration
sites, archaeological  search
USEarchaeological sites
sites, landing  search
USElanding sites
Sitka Sound  search
BTUnited States
 .Alaska
 ..Southeastern Alaska
 ...Sitka Sound
RTAlexander Archipelago
 Gulf of Alaska
SNOn W side of Baranof Island in SE Alaska. Entrance to Sitka from Gulf of Alaska. Also search Sitka.
Sivamalai  search
BTAsia
 .Indian Peninsula
 ..India
 ...Tamil Nadu India
 ....Coimbatore India
 .....Sivamalai
SNA hill in the Coimbatore District in E Tamil Nadu, S India.
Sivapithecus  search
BTChordata
 .Vertebrata
 ..Tetrapoda
 ...Mammalia
 ....Theria
 .....Eutheria
 ......Primates
 .......simians
 ........Pongidae
 .........Sivapithecus
RTDryopithecus
 Proconsul
 Ramapithecus
SNGenus. Also search Ramapithecus which is often included within this group.
Sivash  search
BTEurope
 .Ukraine
 ..Crimea Ukraine
 ...Sivash
UFPutrid Sea
SNSalt lagoons and marshes in N and NE Crimea. This term has multiple hierarchies.
Siw  search
Siwalik Formation  search
USESiwalik System
Siwalik Group  search
USESiwalik System
Siwalik Hills  search
USESiwalik Range
Siwalik Range  search
BTAsia
 .Siwalik Range
UFSiwalik Hills
 Siwaliks
RTIndia
 Pakistan
 Himalayas
 Nepal
 Sikkim India
SNRange of foothills parallel with the main Himalayan system and extending 1000 miles SE from N Punjab in Pakistan to Sikkim. Also search Siwalik. Indexed with Sikkim India and countries as applicable.
Siwalik Sandstone  search
USESiwalik System
Siwalik Series  search
USESiwalik System
Siwalik System  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Cenozoic
 ...Siwalik System
UFSiwalik Formation
 Siwalik Group
 Siwalik Sandstone
 Siwalik Series
RTPliocene
 Pleistocene
 Miocene
 India
 Pakistan
 Burma
 Chinji Formation
 Sikkim India
SNMiddle Miocene-Pleistocene. Extends beyond limits of Siwalik Range to include parts in Baluchistan and North-West Frontier Province in Pakistan, Tipam Series in Assam, and Irrawaddy Series in Burma. Includes Lower (Kamlial and Chinji), Middle (Nagri and D
Siwaliks  search
USESiwalik Range
Sixes River  search
BTUnited States
 .Oregon
 ..Curry County Oregon
 ...Sixes River
SNN Curry County in SW Oregon. Flows into the Pacific Ocean.
Siyeh Formation  search
USEHelena Formation
size  search
UFbody size
RTmorphology
 ore bodies
 scale factor
 size distribution
 reserves
 resources
SNUsed as a general term. Use grain size or size distribution or see scale factor if applicable. From 1981-1997, not a valid term for GeoRef. For paleontology, search in combination with body part or taxonomic class.
size analysis  search
SNA valid term through mid-1978. Now use granulometry.
size distribution  search
RTdistribution
 grain size
 granulometry
 power law
 sedimentary rocks
 sediments
 size
 textures