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About the Fields in the Index to Marine and Lacustrine Geological Samples Database


*=mandatory field

Sample Information (sampling event: core, grab, dredge, drill hole)

  • Facility Abbreviation - entered at NGDC, up to ten alphanumeric characters
  • NGDC Institution Code - entered at NGDC, two digit integer
  • NGDC Ship Code - entered at NGDC, two digit integer
  • *Ship/Platform - from institution, maximum 30 alphanumeric characters
  • *Cruise Identifier - from institution, maximum 30 alphanumeric characters
  • *Sample Identifier - from institution. Unique within a cruise (for a sampling device), maximum 30 alphanumeric characters
  • Date Sample Collected - form YYYYMMDD
  • Date Sample Collection Ended (if not same as above) - form YYYYMMDD
  • *Latitude/Longitude (maximum five decimal places; - = South or West):
    • Latitude - form +/-DD.DDDDD
    • Longitude - form +/-DDD.DDDDD
  • Ending Latitude/Longitude (if applicable)
    • Latitude - form +/-DD.DDDDD
    • Longitude - form +/-DDD.DDDDD
  • Alternative Latitude/Longitude Form
    (deprecated/please use decimal degrees, if possible):
    • Latitude whole degrees - form DD
    • Latitude whole minutes - form MM
    • Latitude decimal minutes - form MM
    • North or South - N or S
    • Longitude whole degrees - form DDD
    • Longitude whole minutes - form MM
    • Longitude decimal minutes - form MM
    • East or West - E or W
  • Lat/Lon type flag - 1 digit, m=minutes; d=decimal degrees
  • Water Depth - corrected meters, no decimal, 5 digit integer. (beginning depth for dredges
  • Ending Water Depth (dredges only) - corrected meters, no decimal, 5 digit integer.
  • *Sampling Device (see device list)
  • Storage Method (see storage list)
  • Core Length - 6 digit integer total length in centimeters
  • Core Length mm - 2 digit integer additional precision in millimeters
  • Core Diameter - 3 digit integer, in centimeters (round to nearest whole centimeter and place real value in comments field, if necessary).
  • Core Diameter mm - 2 digit integer, additional precision in millimeters
  • Principal Investigator (last name, first name of P.I.) up to 26 characters
  • Physiographic Province (see province terms)
  • Lake Name
  • IGSN (obtain from SESAR or add later)
  • Leg - leg within cruise, or alternate/standard leg identifier
  • Sample Comments - up to 2000 characters of comments pertaining to entire sample, do not use nonstandard characters
  • Publish - "Y" added at NGDC after entry approved for publication by repository
  • Previous State - internal NGDC field
  • Objectid - internal NGDC field (may change)
  • Shape - added by NGDC, computed from Lat/Lon
  • Show Sample - added by NGDC, internal link
  • IMLGS - unique sample identifier within the IMLGS, does not change

Interval/Subsample Information

  • Interval (3-digit integer, '001') 1st interval/subsample or rock within a core or dredge)
  • Depth to Top of Interval - 6 digit integer, centimeters
  • Depth to Top of Interval mm - 2 digit integer, additional precision, millimeters
  • Depth to Bottom of Interval - 6 digit integer, centimeters
  • Depth to Bottom of Interval mm - 2 digit integer, additional precision, millimeters
    • (if a point sample, enter same depth for top and bottom of interval)
  • Primary Lithologic Composition for Interval (see composition list).
    For unconsolidated sediment. Also see ternary diagram below. (also see alternative unconsolidated sediments "rock lithologies")
    small ternary sediment composition classification diagram.
    The "dominant" component is determined by plotting the percentages of material from the major component categories (calcareous, biosiliceous, and terrigenous) on the ternary diagram. For example, a sediment sample with 10% calcareous material, 35% biosiliceous material, and 55% total terrigenous components would plot as shown on the ternary diagram above and have a classification of "biosiliceous." The major category is further refined by determining if any single component comprises 50% or more of the category selected from the ternary diagram. If a single component does make up 50% or more of the category selected, choose the value for that component from the vocabulary list as the primary composition. If no component makes up 50% or more of the category, then choose the value of the major category (calcareous, biosiliceous, or terrigenous.
  • Primary Texture (see texture list).
    small ternary sediment texture classification diagram.
    Select appropriate term from the ternary diagram above by plotting weight percentages of end-member textural elements, or choose from the textural terms list.
    "primary" texture is the texture associated with the primary composition.
  • Secondary Lithologic Composition for Interval (see composition list)
    Composition of a second lithology that is common but lessser than the primary lithologic composition.
  • Secondary Texture (see texture list) Texture associated with secondary composition.
  • Other Components: No importance implied by order.
  • Description of Interval - up to 2000 characters, do not use nonstandard characters
  • Age of Interval (see geologic age terms)
  • Absolute Age, Top of Interval - up to 50 characters
  • Absolute Age, Bottom of Interval - up to 50 characters
  • Bulk Weight (kg, format 9999.999) weight applies to rock or interval, if only one rock or interval entered for sample, weight applies to entire sample.
  • Rock Lithology (see lithology terms)
    this field may also be used to describe unconsolidated sediments from the new descriptors provided for this field - do not use these descriptors in the previously described primary/secondary/components fields
  • Rock Mineralogy (see mineralogy terms)
  • Rock Weathering and Metamorphism (see weathering/metamorphism terms)
  • Rock Glass remarks and MN/Fe oxide coating (see remarks/coating terms)
  • Color - up to 30 characters (deprecated, originally a translation of Munsell code)
  • Flag for material exhausted, no longer available ("X")
  • Comments on Interval (up to 255 characters)
  • IGSN - IGSN of individual interval/subsample
  • Parent IGSN - IGSN of parent sample to which interval/subsample belongs
  • Parent IMLGS - added by NGDC, same as IMLGS of parent sample
  • Publish - added by NGDC when interval/subsample record approved by repository for publication

  • Note: there are other fields in the IMLGS data tables reserved for specific data types/sources.

Controlled Vocabularies

(*=mandatory field):
  • Sampling device * (historic code):
    • core (undifferentiated)
    • core, box (G)
    • core, camera mounted (H)
    • core, dart (N)
    • core, free-fall (E)
    • core, gravity (D)
    • core, hand-held (J)
    • core, kastenlot (P)
    • core, multicorer (O)
    • core, piston (C)
    • core, piston(giant) (V)
    • core, submersible mounted (I)
    • core, vibrating (F)
    • corer, trigger wt. (T)
    • downhole coring (X)
    • dredge (undifferentiated)
    • dredge, rock (R)
    • drill (undifferentiated)
    • drill, rock (L)
    • drill, sediment (K)
    • grab (A)
    • grab, ROV (Y)
    • probe (W)
    • suspended sediment (M)
    • trap, sediment (S)
    • trawl (3)
    • unknown device (U)
  • Storage method (historic code):
    • frozen (A)
    • refrigerated (B)
    • room temperature, dry (D)
    • room temperature, moisture sealed (C)
  • Lithologic composition (historic code): (see ternary diagrams)
    • Calcareous
      • calcareous, algae (L)
      • calcareous, biogenic (B)
      • calcareous, coral (G)
      • calcareous, foraminifera (C)
      • calcareous, nannofossils (E)
      • calcareous, nonbiogenic (A)
      • calcareous, oolites (I)
      • calcareous, ostracods (J)
      • calcareous, pteropods (D)
      • calcareous, shells (F)
      • calcareous, spines (H)
    • Biosiliceous
      • siliceous (M)
      • siliceous, diatoms (O)
      • siliceous, radiolaria (N)
      • siliceous, sponge spicules (P)
    • Terrigenous
      • terrigenous (Q)
      • terrigenous clastic sedimentary rock (4)
    • Additional components
      • clay minerals (+)
      • fish teeth (Y)
      • glauconite (W)
      • iron or iron oxide (U)
      • manganese (S)
      • opaques (*)
      • phosphate (T)
      • plant debris (X)
      • pyrite or marcasite (V)
      • zeolites (Z)
  • Textural Terms: (see ternary diagrams)
    • gravel (A)
    • gravelly mud (D)
    • gravelly sand (E)
    • mud or ooze (F)
    • muddy gravel (B)
    • muddy sand (H)
    • sand (I)
    • sandy gravel (C)
    • sandy mud or ooze (G)
  • Additional Textural Terms for Volcanic Sediments and Authigenic Components:
    • ash (J)
    • breccia (K)
    • crusts (P)
    • dolomite (K)
    • glass shards (M)
    • lapilli (L)
    • nodules (N)
    • slabs (O)
    • volcanics (R)
  • Rock Descriptors: (deprecated, use rock lithology below.
    (originally used in place of textural term, with blank composition)
    • allogenic limestone (5)
    • authigenic limestone (6)
    • chert or porcelanite (7)
    • erratic rock (9)
    • evaporite (8)
    • metamorphic rock (3)
    • plutonic igneous rock (2)
    • terrigenous clastic sedimentary rock (4)
    • volcanic igneous rock (1)
  • Geologic Ages:
    • unknown (00)
    • Quaternary (10)
      • Holocene (11)
      • Pleistocene (12)
        • Pleistocene, Late (13)
    • Tertiary (20)
      • Pliocene (21)
      • Miocene (22)
      • Oligocene (23)
      • Eocene (24)
      • Paleocene (25)
    • Cretaceous (30)
      • Cretaceous, Late (31)
      • Cretaceous, Middle (32)
      • Cretaceous, Early (33)
    • Jurassic (40)
      • Jurassic, Late (41)
      • Jurassic, Middle (42)
      • Jurassic, Early (43)
    • Pre-Jurassic (50)
      • Triassic (51)
      • Permian (52)
      • Pennsylvanian (53)
      • Mississippian (54)
      • Devonian (55)
      • Silurian (56)
      • Ordovician (57)
      • Cambrian (58)
      • Precambrian (59)
  • Physiographic Province:
    • abyssal hills (11)
    • abyssal plain (10)
    • apron, archipelagic (09)
    • axial valley (16)
    • basin, small ocean (21)
    • beach (38)
    • canyon or channel, mid-ocean (26)
    • canyon, submarine (25)
    • channel, river or stream (31)
    • delta or cone (24)
    • estuary (39)
    • fjord (40)
    • fracture zone (19)
    • harbor, shallow bay (23)
    • lagoon (32)
    • lake (33)
    • lake, inland fresh water (22)
    • lake, salt water inland (28)
    • marginal plateau or borderland (07)
    • paleochannel (34)
    • paleoestuary (41)
    • paleolake (35)
    • plateau, oceanic (27)
    • reservoir (36)
    • ridge crest (14)
    • ridge flank (15)
    • rise or ridge, aseismic ocean (13)
    • rise, continental (06)
    • rise, insular (05)
    • sea, marginal (20)
    • seamount or seamount province (12)
    • shelf, continental (02)
    • shelf, insular (01)
    • slope, continental (04)
    • slope, insular (03)
    • sound (29)
    • strait (30)
    • terrestrial, undifferentiated (42)
    • trench, continental margin (18)
    • trench, insular (17)
    • unspecified (08)
    • wetland (37)
  • Rock Lithology:
    igneous:
    • intrusive/plutonic
      • igneous (intrusive/plutonic) (0)
      • igneous (intrusive/plutonic), anorthosite (0E)
      • igneous (intrusive/plutonic), clinopyroxenite (0Q)
      • igneous (intrusive/plutonic), diorite (0X)
      • igneous (intrusive/plutonic), dunite (0J)
      • igneous (intrusive/plutonic), gabbro (0A)
      • igneous (intrusive/plutonic), gabbro, ferro (0D)
      • igneous (intrusive/plutonic), gabbro, olivine (0B)
      • igneous (intrusive/plutonic), gabbro, quartz (0C)
      • igneous (intrusive/plutonic), granite (0T)
      • igneous (intrusive/plutonic), granodiorite (0U)
      • igneous (intrusive/plutonic), harzburgite (0K)
      • igneous (intrusive/plutonic), hornblendite (0O)
      • igneous (intrusive/plutonic), lherzolite (0M)
      • igneous (intrusive/plutonic), metagabbro (0H)
      • igneous (intrusive/plutonic), monzonite (0Y)
      • igneous (intrusive/plutonic), norite (0G)
      • igneous (intrusive/plutonic), orthopyroxenite (0R)
      • igneous (intrusive/plutonic), peridotite (0I)
      • igneous (intrusive/plutonic), pyroxenite (0N)
      • igneous (intrusive/plutonic), serpentinite (0S)
      • igneous (intrusive/plutonic), syenite (0Z)
      • igneous (intrusive/plutonic), tonalite (qtz diorite) (0V)
      • igneous (intrusive/plutonic), tondhjemite (0W)
      • igneous (intrusive/plutonic), troctolite (0F)
      • igneous (intrusive/plutonic), websterite, olivine (0P)
      • igneous (intrusive/plutonic), wehrlite (0L)
    • hypabyssal
      • igneous (hypabyssal) (1)
      • igneous (hypabyssal), aplite (1P)
      • igneous (hypabyssal), diabase (1A)
      • igneous (hypabyssal), diabase, aphyric (1B)
      • igneous (hypabyssal), diabase, cpx-phyric (1I)
      • igneous (hypabyssal), diabase, ol-cpx phyric (1H)
      • igneous (hypabyssal), diabase, ol-pg phyric (1E)
      • igneous (hypabyssal), diabase, ol-pg-cpx phyric (1F)
      • igneous (hypabyssal), diabase, olivine phyric (1C)
      • igneous (hypabyssal), diabase, pg-cpx phyric (1G)
      • igneous (hypabyssal), diabase, plagioclase phyric (1D)
      • igneous (hypabyssal), diorite porphyry (1M)
      • igneous (hypabyssal), granite porphyry (1K)
      • igneous (hypabyssal), granophyre (1L)
      • igneous (hypabyssal), lamprophyre (1O)
      • igneous (hypabyssal), metadiabase (1J)
      • igneous (hypabyssal), pegmatite (1N)
    • extrusive/volcanic
      • igneous (extrusive/volcanic) (2)
      • igneous (extrusive/volcanic), andesites (2P)
      • igneous (extrusive/volcanic), basalt (2A)
      • igneous (extrusive/volcanic), basalt, aphyric (2B)
      • igneous (extrusive/volcanic), basalt, clinopyroxene phyric (2I)
      • igneous (extrusive/volcanic), basalt, ol-cpx phyric (2H)
      • igneous (extrusive/volcanic), basalt, ol-pg phyric (2E)
      • igneous (extrusive/volcanic), basalt, ol-pg-cpx phyric (2F)
      • igneous (extrusive/volcanic), basalt, olivine phyric (2C)
      • igneous (extrusive/volcanic), basalt, pg-cpx phyric (2G)
      • igneous (extrusive/volcanic), basalt, pillow (2J)
      • igneous (extrusive/volcanic), basalt, plagioclase phyric (2D)
      • igneous (extrusive/volcanic), basalt, vesicular (>10% vesicles) (2K)
      • igneous (extrusive/volcanic), basanite (2Z)
      • igneous (extrusive/volcanic), dacites (2Q)
      • igneous (extrusive/volcanic), hyaloclastites (2M)
      • igneous (extrusive/volcanic), latite (2T)
      • igneous (extrusive/volcanic), leucitite (2Y)
      • igneous (extrusive/volcanic), metabasalt (2O)
      • igneous (extrusive/volcanic), nephelinite (2X)
      • igneous (extrusive/volcanic), obsidian/quenched basalt-glass (2N)
      • igneous (extrusive/volcanic), phonolite (2U)
      • igneous (extrusive/volcanic), pumice/scoria (2L)
      • igneous (extrusive/volcanic), rhyolite (2R)
      • igneous (extrusive/volcanic), sheet flow basalt (2*)
      • igneous (extrusive/volcanic), tephrite (2W)
      • igneous (extrusive/volcanic), trachybasalt (2V)
      • igneous (extrusive/volcanic), trachyte (2S)
  • sedimentary:
    • pyroclastic
      • sedimentary (pyroclastic) (3)
      • sedimentary (pyroclastic), agglomerates (bombs)(>32mm diam) (3G)
      • sedimentary (pyroclastic), breccia, pillow (3K)
      • sedimentary (pyroclastic), hyaloclastite (3I)
      • sedimentary (pyroclastic), loose glass fragments (3J)
      • sedimentary (pyroclastic), tuff (3A)
      • sedimentary (pyroclastic), tuff, ash (<4mm diam. clasts) (3E)
      • sedimentary (pyroclastic), tuff, crystal (crystal clasts) (3C)
      • sedimentary (pyroclastic), tuff, lithic (rock clasts) (3D)
      • sedimentary (pyroclastic), tuff, vitric (glass clasts) (3B)
      • sedimentary (pyroclastic), volcanic breccia (blocks)(>32mm) (3H)
    • detrital/fragmental or clastic
      • sedimentary (detrital/fragmental or clastic) (4)
      • sedimentary (detrital/fragmental or clastic), arkose (4M)
      • sedimentary (detrital/fragmental or clastic), breccia (4E)
      • sedimentary (detrital/fragmental or clastic), breccia, hyaloclastite/palagonite (4F)
      • sedimentary (detrital/fragmental or clastic), breccia, intraformational (sed rocks in same matrix) (4H)
      • sedimentary (detrital/fragmental or clastic), breccia, serpentinite (4G)
      • sedimentary (detrital/fragmental or clastic), breccia, tectonic (4I)
      • sedimentary (detrital/fragmental or clastic), calcarenite (4X)
      • sedimentary (detrital/fragmental or clastic), calcilutite (4Y)
      • sedimentary (detrital/fragmental or clastic), calcirudite (4Z)
      • sedimentary (detrital/fragmental or clastic), claystone (4T)
      • sedimentary (detrital/fragmental or clastic), conglomerate (4A)
      • sedimentary (detrital/fragmental or clastic), greywacke (4N)
      • sedimentary (detrital/fragmental or clastic), greywacke, arkosic (4O)
      • sedimentary (detrital/fragmental or clastic), greywacke, lithic (4P)
      • sedimentary (detrital/fragmental or clastic), greywacke, sandy (4R)
      • sedimentary (detrital/fragmental or clastic), greywacke, volcanic (4Q)
      • sedimentary (detrital/fragmental or clastic), marl (4W)
      • sedimentary (detrital/fragmental or clastic), mudstone (lutite) (4V)
      • sedimentary (detrital/fragmental or clastic), oligomictic conglomerate (clasts of one lithology) (4B)
      • sedimentary (detrital/fragmental or clastic), orthoquartzite (4K)
      • sedimentary (detrital/fragmental or clastic), polymictic conglomerate (variable clast lithology) (4C)
      • sedimentary (detrital/fragmental or clastic), sandstone, lithic (containing rock fragments) (4L)
      • sedimentary (detrital/fragmental or clastic), sandstone/arenite (4J)
      • sedimentary (detrital/fragmental or clastic), shale (4S)
      • sedimentary (detrital/fragmental or clastic), siltstone (4U)
      • sedimentary (detrital/fragmental or clastic), tillite (4D)
    • chemical
      • sedimentary (chemical) (5)
      • sedimentary (chemical), Mn/Fe nodules (5K)
      • sedimentary (chemical), Mn/Fe oxide crusts and nodules (5J)
      • sedimentary (chemical), amorphous silica (tube worm tests) (5W)
      • sedimentary (chemical), anhydrite (5E)
      • sedimentary (chemical), calcite (assoc with sulfide chimney) (5V)
      • sedimentary (chemical), chalcopyrite (5T)
      • sedimentary (chemical), chert/porcelanite (5A)
      • sedimentary (chemical), dolomite/dolostone (5I)
      • sedimentary (chemical), gypsum (5D)
      • sedimentary (chemical), iron ore (5O)
      • sedimentary (chemical), iron stone (5N)
      • sedimentary (chemical), jasper (5B)
      • sedimentary (chemical), limestone (5F)
      • sedimentary (chemical), limestone, lithographic (5G)
      • sedimentary (chemical), phosphorite crusts (5L)
      • sedimentary (chemical), phosphorite nodules (5M)
      • sedimentary (chemical), pyrite/marcasite (5S)
      • sedimentary (chemical), salt (5C)
      • sedimentary (chemical), sphalerite/wurtzite (5U)
      • sedimentary (chemical), sulfide "dust" (5R)
      • sedimentary (chemical), sulfide chimney (fragment) (5Q)
      • sedimentary (chemical), sulfide chimney (whole specimen) (5P)
      • sedimentary (chemical), travertine (5H)
    • organic
      • sedimentary (organic) (6)
      • sedimentary (organic), chalk (6A)
      • sedimentary (organic), coal (6K)
      • sedimentary (organic), coquina (fossiliferous limestone) (6B)
      • sedimentary (organic), diatomites (chert) (6G)
      • sedimentary (organic), dolomite/dolostone (6E)
      • sedimentary (organic), iron ore (6J)
      • sedimentary (organic), iron stone (6I)
      • sedimentary (organic), limestone (6C)
      • sedimentary (organic), limestone, lithographic (6D)
      • sedimentary (organic), peat (6L)
      • sedimentary (organic), phosphorite (6H)
      • sedimentary (organic), radiolarites (chert) (6F)
  • metamorphic:
    • metamorphic (metamorphosed) (7)
    • metamorphic (metamorphosed), amphibolite (7U)
    • metamorphic (metamorphosed), blastomylonite (7V)
    • metamorphic (metamorphosed), cataclastite (7X)
    • metamorphic (metamorphosed), eclogite (7P)
    • metamorphic (metamorphosed), gneiss (7K)
    • metamorphic (metamorphosed), gneiss, augen (7M)
    • metamorphic (metamorphosed), gneiss, banded (7L)
    • metamorphic (metamorphosed), granulite (7Q)
    • metamorphic (metamorphosed), greenstone (7D)
    • metamorphic (metamorphosed), hornfels (7S)
    • metamorphic (metamorphosed), marble (7O)
    • metamorphic (metamorphosed), metabasalt/greenstone (7A)
    • metamorphic (metamorphosed), metadiabase/greenstone (7B)
    • metamorphic (metamorphosed), metagabbro/greenstone (7C)
    • metamorphic (metamorphosed), migmatite (7R)
    • metamorphic (metamorphosed), phyllite (7I)
    • metamorphic (metamorphosed), quartzite (7N)
    • metamorphic (metamorphosed), rodingite (7G)
    • metamorphic (metamorphosed), schist (7J)
    • metamorphic (metamorphosed), serpentinite (7E)
    • metamorphic (metamorphosed), skarn (7T)
    • metamorphic (metamorphosed), slate (7H)
    • metamorphic (metamorphosed), soapstone (7F)
    • metamorphic (metamorphosed), tectonite (7Y)
    • metamorphic (metamorphosed), ultramylonite (7W)
  • unconsolidated material:
    • sediments (unconsolidated) (8)
    • sediments (unconsolidated), clay, calcareous (1-30% biogenous matter-calcareous) (8B)
    • sediments (unconsolidated), clay, siliceous (1-30% biogenous matter-siliceous) (8D)
    • sediments (unconsolidated), clay, unfossiliferous (8A)
    • sediments (unconsolidated), coral (8N)
    • sediments (unconsolidated), crabs (+/- vent origin) (8S)
    • sediments (unconsolidated), glacial erratics (8M)
    • sediments (unconsolidated), gravel (8L)
    • sediments (unconsolidated), lutite (unconsolidated) (8I)
    • sediments (unconsolidated), ooze, calcareous (>30% biogenous matter) (8C)
    • sediments (unconsolidated), ooze, calcareous-siliceous (8F)
    • sediments (unconsolidated), ooze, siliceous (>30% biogenous matter) (8E)
    • sediments (unconsolidated), sand (8K)
    • sediments (unconsolidated), sand, calcareous (forams/pteropods) (8G)
    • sediments (unconsolidated), sea cucumbers (8U)
    • sediments (unconsolidated), shell fragments (tests) (8P)
    • sediments (unconsolidated), shell/coral hash (8H)
    • sediments (unconsolidated), silt (8J)
    • sediments (unconsolidated), sponge (8O)
    • sediments (unconsolidated), urchins (8T)
    • sediments (unconsolidated), vent clams (8Q)
    • sediments (unconsolidated), vent worm tests (8R)
  • Rock Mineralogy:
    • major minerals
      • alkali feldspar (K-spar) (E)
      • amphibole (amph) (D)
      • feldspathoids (f) (G)
      • olivine (ol) (B)
      • plagioclase (pg) (A)
      • pyroxene (opx/cpx,px) (C)
      • quartz (q) (F)
    • minor minerals
      • biotite (H)
      • garnet (J)
      • muscovite (I)
      • spinel (K)
    • mineral combinations
      • olivine + pyroxene (O)
      • plagioclase + amphibole (N)
      • plagioclase + olivine (L)
      • plagioclase + pyroxene (M)
      • plagioclase+olivine+pyroxene (P)
    • matrix cements
      • matrix cement Mn/Fe oxides (T)
      • matrix cement calcite (Q)
      • matrix cement lithified sediment (U)
      • matrix cement silica (S)
      • matrix cement zeolite (R)
    • clast mineralogy
      • clasts, basalt (V)
      • clasts, metamorphic (W)
      • clasts, plutonic (X)
      • clasts, sedimentary (Y)
      • xenoliths (Z)
  • Rock Weathering/Metamorphism
    • weathering
      • weathering - fresh (0)
      • weathering - light (1)
      • weathering - moderate (2)
      • weathering - heavy (3)
      • weathering - heavy, very (4)
    • metamorphism
      • metamorphism - amphibolite (8)
      • metamorphism - granulite (9)
      • metamorphism - greenschist (7)
      • metamorphism - hydrothermal (5)
      • metamorphism - serpentinized (*)
      • metamorphism - zeolite (6)
  • Rock Glass Remarks & Mn/Fe Oxide
    • no glass (0)
    • some samples exhibit fresh glass (1)
    • >50% samples exhibit fresh glass (2)
    • some samples exhibit palagonitized glass (3)
    • >50% samples exhibit palagonitized glass (4)
    • notable Mn/Fe oxide coatings (5)
    • some samples with fresh glass & Mn/Fe oxide coatings (6)
    • >50% of samples exhibit fresh glass & Mn/Fe oxide coatings (7)
    • some samples exhibit palagonitized glass & Mn/Fe oxide coatings (8)
    • >50% of samples exhibit palagonitized glass & Mn/Fe oxide coatings (9)
    • thin Mn/Fe oxide (a)

How to Cite:

Curators of Marine and Lacustrine Geological Samples Consortium (2013). The Index to Marine and Lacustrine Geological Samples (IMLGS). National Geophysical Data Center, NOAA. doi:10.7289/V5H41PB8 [date of access].

More About Evolution of the IMLGS Database

The Index to Marine and Lacustrine Geological Samples database (IMLGS) (also known as the Core Curators' database) was designed by a group of curators of marine geological samples in cooperation with the National Geophysical Data Center beginning in 1977.

The data fields/forms have undergone subsequent changes, including modification in 1991 to include more detailed information about rock dredges. In May, 1996 additional terms were added, some new fields were added, and some fields were expanded. In 1998/99 some rock descriptors were removed from the "texture" field, since they are now available in the rock lithology field. During 2000/2001 two new devices were added.

Recent additions to the database include an IGSN number and a "standard" (usually MGDS, USGS, or SIO Explorer standard) cruise/leg to facilitate links to corresponding information at participating insitutions, the USGS InfoBank, the MGDS, and the SIO Explorer.

Learn more about the IMLGS.

Standard Entry Template(s)

Data may be provided on a standard spreadsheet template (uses codes/expands the codes to terms before entry into the database), or in any convenient form - please contact NGDC for your options.

Maintaining Organization:


US Department of Commerce
National Environmental Satellite, Data, and Information Service
National Oceanic and Atmospheric Administration
US National Geophysical Data Center (NGDC)
and collocated
World Data Service for Geophysics, Boulder

Please direct questions to:


Carla Moore
National Geophysical Data Center
NOAA E/GC3
325 Broadway
Boulder, CO 80305
Phone: 303-497-6339
FAX: 303-497-6513