MEGMS home page

CoalLog Hatches by Litho_Type and Litho_Qual

Hatch pattern Description
Acid/Felsic Intrusive
(AI)
Any intrusive igneous rock >66 wt.% silica
Alluvium
(AL)
Alluvial deposit (product of river or stream action).
Andesite
(AN)
A basic extrusive igneous rock >65% plagioclase, <20% quartz.
Acid/Felsic Volcanic
(AV)
Any extrusive igneous rock >66 wt.% silica
Brown Coal
(BC)
(Europe) A low-rank coal which is brown or brownish-black, but rarely black. It commonly retains the structures of the original wood. It is high in moisture, low in heat value, and cracks badly upon drying; contains between 10% and 20% water; range from lignite to subbituminous in rank.
Basic/Mafic Intrusive
(BI)
Any intrusive igneous rock 45-52 wt.% silica
Boulders
(BO)
Majority of particles are greater than 200 mm
Boulders
clayey
(BOCL)


Boulders
gravelly
(BOGV)


Boulders
sandy
(BOSA)


Boulders
silty
(BOSI)


Breccia
(BR)
Sedimentary rock mostly composed of angular clasts greater than 2 mm.
Basalt
(BS)
An intermediate extrusive igneous rock >65% plagioclase, <20% quartz.
Basement Undifferentiated
(BU)
Highly folded metamorphic or igneous rocks, overlain by relatively undeformed sedimentary rocks; non-prospective rocks below prospective strata.
Basic/Mafic Volcanic
(BV)
Any extrusive igneous rock 45-52 wt.% silica
Calcite
(CA)
Usually white but can also be colourless, grey, red, green, blue, yellow, brown, orange. White streak, vitreous lustre. Perfect rhombohedral cleavage. Low Mohs hardness (3). Dissolves in cold dilute HCl.
Carbonate
(CB)
Sedimentary rocks composed of >95% calcite or dolomite.
Calcrete
(CC)
(syn: caliche) Carbonate horizon formed in a soil in a semi-arid region by the precipitation of CaCO3 carried in solution, develops over several thousand years with initial stages being nodular, and mature stages massive to laminar.
Conglomerate
(CG)
Sedimentary rock mostly composed of subrounded, subangular, and rounded clasts greater than 2 mm.
Conglomerate
granular
(CGGG)


Conglomerate
granular to cobbly
(CGGO)


Conglomerate
granular to pebbly
(CGGP)


Conglomerate
granular to bouldery
(CGGU)


Conglomerate
cobbly
(CGOO)


Conglomerate
cobbly to bouldery
(CGOU)


Conglomerate
pebbly to cobbly
(CGPO)


Conglomerate
pebbly
(CGPP)


Conglomerate
pebbly to bouldery
(CGPU)


Conglomerate
bouldery
(CGUU)


Chert
(CH)
Chalcedonic nodules or irregular masses that occur in a sedimentary environment, often in association with black shales and spillites.
Chalk
(CK)
Porous, fine grained sedimentary rock composed predominantly of the calcareous skeletons of micro organisms.
Clay
(CL)
Majority of particles are less than 0.002 mm
Clay
gravelly
(CLGV)


Clay
sandy
(CLSA)


Clay
silty
(CLSI)


Coal
(CO)
Carbon rich mineral deposit formed from the accumulation of organic matter and containing less than 50% ash yield on combustion; coal streaks brown (low rank) to black (high rank) when scratched with a metal tool.
Coal
anthracite
(COAN)


Coal
bright with dull bands (60-90% bright coal)
(COBB)


Coal
Interbanded dull and bright (40-60% bright coal)
(COBD)


Coal
bright (>90% bright coal)
(COBR)


Coal
cindered
(COCI)


Coal
undifferentiated
(COCU)


Coal
mainly dull with frequent bright bands (10-40% bright coal)
(CODB)


Coal
dull, conchoidal
(CODC)


Coal
dull (<1% bright coal)
(CODD)


Coal
dull with minor bright bands (1-10% bright coal)
(CODM)


Coal
extremely weathered
(COEW)


Coal
fusainous
(COFU)


Coal
heat affected
(COHA)


Coal
coked
(COKC)


Coal
sapropelic
(COSP)


Coal
stony
(COSY)


Coal
weathered
(COWE)


Claystone
(CS)
Sedimentary rock mostly composed of individual grains or clasts less than 0.002 mm.
Colluvium
(CV)
Weathered rock debris that has moved downhill via creep or surface wash.
Diatomaceous Earth
(DE)
Deposit consisting of diatoms (unicellular algae that can be single, colonial, or filamentous).
Diamictite
(DI)
A type of lithified, matrix supported sedimentary rock that consists of a wide range of unsorted to poorly sorted sediment, such as sand or larger sized particles suspended in a mud matrix.
Dolomite
(DM)
(syn: dolostone) A sedimentary rock composed of >90% dolomite (CaMg(CO3)2, (CaFe(CO3)2, (CaMn(CO3)2).
Dolerite
(DO)
Medium grained basalt/gabbro.
Fault Breccia
(FB)
The assemblage of angular fragments resulting from the crushing, shattering, or shearing of rocks during movement on a fault; a friction breccia. It is distinguished by its cross-cutting relations, by the presence of fault gouge, and by blocks with slickensides; angular to subangular fragments of crushed rock, up to several meters in size, filling a fault.
Fireclay
(FC)
(syn: underclay) A layer of fine-grained (usually clay) lying immediately below a coal seam, the soil in which the coal forming plants were rooted; often siliceous or aluminous; a clay that can withstand high heat without deforming or disintegrating, i.e. kaolin.
Fill/Spoil
(FI)
Any unconsolidated material that has been deposited by equipment or other human activity.
Ferricrete
(FK)
Deposit which can develop into a hardened mass of sesquioxides of iron, especially in subtropical zones.
Fossil Wood
(FW)
Silicified wood; wood that has turned into a rock through fossilization.
Gabbro
(GB)
An intrusive igneous rock composed of plagioclase and pyroxenes.
Granodiorite
(GD)
An intrusive igneous rock >20% quartz, 65-90% plagioclase (normalized).
Gneiss
(GN)
A metamorphic rock displaying gneissose structure (layered/banded generally with dark minerals and felsics).
Granite
(GR)
An intrusive igneous rock >20% quartz, <65% plagioclase, >10% alkali feldspar (normalized).
Gravel
(GV)
Majority of particles are between 2 and 60 mm
Gravel
coarse grained
(GVCC)


Gravel
clayey
(GVCL)


Gravel
fine to coarse grained
(GVFC)


Gravel
fine grained
(GVFF)


Gravel
fine to medium grained
(GVFM)


Gravel
medium to coarse grained
(GVMC)


Gravel
medium grained
(GVMM)


Gravel
sandy
(GVSA)


Gravel
silty
(GVSI)


Igneous Rock, undifferentiated
(IG)
Any igneous rock.
Intermediate Intrusive
(II)
Any intrusive igneous rock 52-66 wt.% silica
Intrusive Rock, undifferentiated
(IN)
Any intrusive igneous rock, e.g. granitoids and gabbros.
Ironstone
(IS)
Iron rich sedimentary rock.
Intermediate Volcanic
(IV)
Any extrusive igneous rock 52-66 wt.% silica
Kaolinite
(KA)
(syn: dickite, nacrite, kaolin) A group of clay minerals belonging to the 1:1 group of phyllosilicates which represent the final product from the chemical weathering of feldspars including low temperature hydrothermal reactions; a rock predominately composed of kaolin minerals.
Cone in Cone Carbonate
(KK)
A secondary structure occurring in marls, limestone, ironstones, coals, etc. It is a succession of small cones of approx. the same size one within another and sharing a common axis.
Core Loss
(KL)
No core recovered for a section
Laterite
(LA)
Weathering product of rock composed of hydrated iron and aluminium oxides and hydroxides, clay minerals, and some silica, formed in humid, tropical areas.
Lignite
(LG)
(USA)~70% carbon, high moisture and volatile content, between peat and bituminous coal in rank; a type of brown coal; contains at least 20% water.
Limonite
(LI)
Secondary weathering mineral from iron, may accumulate to give an iron rich deposit.
Loam
(LO)
Any soil that is a mix of sand, silt, and clay, without a majority of any grain size.
Limestone
(LS)
Sedimentary rocks composed of calcite or dolomite.
Conglomerate (>65% matrix)
(M1)
A rock with clasts >2mm in a finer grained matrix which comprises >65%.
Conglomerate (>65% matrix)
granular
(M1GG)


Conglomerate (>65% matrix)
granular to cobbly
(M1GO)


Conglomerate (>65% matrix)
granular to pebbly
(M1GP)


Conglomerate (>65% matrix)
granular to bouldery
(M1GU)


Conglomerate (>65% matrix)
cobbly
(M1OO)


Conglomerate (>65% matrix)
cobbly to bouldery
(M1OU)


Conglomerate (>65% matrix)
pebbly to cobbly
(M1PO)


Conglomerate (>65% matrix)
pebbly
(M1PP)


Conglomerate (>65% matrix)
pebbly to bouldery
(M1PU)


Conglomerate (>65% matrix)
bouldery
(M1UU)


Conglomerate (35-65% matrix)
(M2)
A rock with clasts >2mm in a finer grained matrix which comprises 35-65%.
Conglomerate (35-65% matrix)
granular
(M2GG)


Conglomerate (35-65% matrix)
granular to cobbly
(M2GO)


Conglomerate (35-65% matrix)
granular to pebbly
(M2GP)


Conglomerate (35-65% matrix)
granular to bouldery
(M2GU)


Conglomerate (35-65% matrix)
cobbly
(M2OO)


Conglomerate (35-65% matrix)
cobbly to bouldery
(M2OU)


Conglomerate (35-65% matrix)
pebbly to cobbly
(M2PO)


Conglomerate (35-65% matrix)
pebbly
(M2PP)


Conglomerate (35-65% matrix)
pebbly to bouldery
(M2PU)


Conglomerate (35-65% matrix)
bouldery
(M2UU)


Conglomerate (<35% matrix)
(M3)
A rock with clasts >2mm in a finer grained matrix which comprises <35%.
Conglomerate (<35% matrix)
granular
(M3GG)


Conglomerate (<35% matrix)
granular to cobbly
(M3GO)


Conglomerate (<35% matrix)
granular to pebbly
(M3GP)


Conglomerate (<35% matrix)
granular to bouldery
(M3GU)


Conglomerate (<35% matrix)
cobbly
(M3OO)


Conglomerate (<35% matrix)
cobbly to bouldery
(M3OU)


Conglomerate (<35% matrix)
pebbly to cobbly
(M3PO)


Conglomerate (<35% matrix)
pebbly
(M3PP)


Conglomerate (<35% matrix)
pebbly to bouldery
(M3PU)


Conglomerate (<35% matrix)
bouldery
(M3UU)


Mud
(MD)
A mixture of silt and clay primarily mixed with water, can contain particles of other dimensions such as sand.
Metamorphic Rock, undifferentiated
(MM)
Any metamorphic rock.
Missing Record
(MR)
No lithology available from historical record
Mudstone
(MS)
Intermediary between claystone and siltstone; any sedimentary rock mostly composed of particles less than 0.02 mm.
Mylonite
(MY)
A metamorphic rock formed by ductile deformation resulting in a fine-grained, dense, hard rock.
Non Coal
(NC)
Not coal, including overburden and interburden
Not Logged
(NL)
Drilled but not logged
No Recovery
(NR)
No returns from drilling
Cobbles
(OB)
Majority of particles are between 60 and 200 mm
Cobbles
clayey
(OBCL)


Cobbles
gravelly
(OBGV)


Cobbles
sandy
(OBSA)


Cobbles
silty
(OBSI)


Oil Shale
(OS)
Any fine grained sedimentary rock that produces substantial quantities of oil when heated.
Old Workings
(OW)
Void caused by mining
Pellet Claystone
(PC)
(syn: kaolinite clayrock, flint clay) A distinctive rock made up of light grey and/or light brown claystone clasts set in a darker, often carbonaceous matrix. Pellets and matrix consist primarily of well crystallised kaolinite.
Peat
(PE)
Unconsolidated but partially compacted accumulation of plant remains in varying states of decomposition, consisting of high moisture and volatile matter content, and ~60% carbon (dry ash free); the precursor to coal.
Phyllite
(PH)
A metamorphic rock displaying schistosity in which very fine phyllosilicates impart a silky sheen to the foliation surface.
Pyrite
(PY)
Pale brass-yellow, tarnishes darker and iridescent. Crystals are usually cubic, faces may be striated, but also frequently octahedral and pyritohedron. Often inter-grown, massive, radiated, granular, globular and stalactitic. Very hard (6-6.5). Metallic lustre. Paramagnetic. Metallic glistening lustre.
Quartzite
(QT)
A metamorphic rock composed predominately of quartz.
Quartz
(QZ)
Colourless/White. No cleavage. Very hard (7). Occurs as drusy, fine-grained to microcrystalline, massive crystals. Conchoidal fracturing. Transparent to nearly opaque. Vitreous lustre but can also be observed as waxy-dull when massive.
Rhyolite
(RH)
An acidic extrusive igneous rock >20% quartz, <65% plagioclase.
Sand
(SA)
Majority of particles are between 0.06 and 2 mm
Sand
coarse grained
(SACC)


Sand
clayey
(SACL)


Sand
fine to coarse grained
(SAFC)


Sand
fine grained
(SAFF)


Sand
fine to medium grained
(SAFM)


Sand
gravelly
(SAGV)


Sand
medium to coarse grained
(SAMC)


Sand
medium grained
(SAMM)


Sand
silty
(SASI)


Silcrete
(SC)
Deposit which can develop into a hardened mass of silica, especially in subtropical zones.
Siderite
(SD)
A carbonate mineral of iron, sometimes of importance as an ore. Crystals typically found as brown to tan rhombohedrons in clusters, faces often curved or composites; more often found as medium to dark brown massive fine grained material or as massive crystalline material with exposed curved cleavage surfaces. Relatively hard (3.75-4.25). Vitreous or silky to pearly lustre. Translucent to subtranslucent. Most often found in bedded sedimentary deposits with a biological component, with shales, clays and coal beds.
Shale
(SH)
Any mudrock that shows fissility.
Silt
(SI)
Majority of particles are between 0.002 and 0.06 mm
Silt
clayey
(SICL)


Silt
gravelly
(SIGV)


Silt
sandy
(SISA)


Slate
(SL)
A very fine grained metamorphic rock with well developed cleavage, cleavage surfaces are dull.
Soil
(SO)
Natural unconsolidated mineral and organic matter occurring above bedrock on the surface of the Earth; any loose, soft, deformable material.
Sandstone
(SS)
Sedimentary rock mostly composed of individual grains or clasts between 0.06 and 2 mm.
Sandstone
coarse grained
(SSCC)


Sandstone
fine to coarse grained
(SSFC)


Sandstone
fine grained
(SSFF)


Sandstone
fine to medium grained
(SSFM)


Sandstone
medium to coarse grained
(SSMC)


Sandstone
medium grained
(SSMM)


Siltstone
(ST)
Sedimentary rock mostly composed of individual grains or clasts between 0.002 and 0.02 mm.
Sedimentary Rock, undifferentiated
(SU)
Any sedimentary rock.
Schist
(SZ)
A metamorphic rock displaying schistosity in which inequant minerals show a preferred orientation.
Talc
(TA)
Light to dark green, brown, white in colour. Almost always in foliated masses, rarely platey to pyramidal crystals. Very soft (1). Waxlike or pearly lustre. Translucent. White to very pearly green streak. Usually found in metamorphic rocks with abundant carbonate minerals associated.
Tuff
(TF)
A sedimentary or igneous rock made of igneous fragments < 2 mm (ash) deposited by pyroclastic or water processes.
Tuff
clay sized
(TFCS)


Tuff
mud sized
(TFMS)


Tuff
sand sized
(TFSS)


Tuff
silt sized
(TFTS)


Tillite
(TI)
A sedimentary rock formed from glacial debris.
Tonstein
(TN)
A compact kaolinite and or smectite rich mudstone which develops as a palaeosol and is frequently found as thin bands within or near coal seams; laterally extensive occurrences are believed to be a product of weathered volcanic ash.
Tar Sand
(TS)
(syn: oil sand) Oil reservoir where the volatiles have escaped and the rock has become impregnated with hydrocarbon residue.
Tuffite
(TT)
A tuff containing 75% to 25% pyroclastic material
Tuffite
clay sized
(TTCS)


Tuffite
mud sized
(TTMS)


Tuffite
sand sized
(TTSS)


Tuffite
silt sized
(TTTS)


Volcanic Breccia
(VB)
A rock made up of pyroclastic fragments that are at least 64 millimeters in diameter.
Void
(VD)
Empty space other than old workings
Volcanic Rock, undifferentiated
(VR)
Any extrusive igneous rock, e.g. rhyolite, andesite, basalts.
Carbonaceous Claystone
(XC)
Sedimentary rock mostly composed of individual grains or clasts less than 0.002 mm. Carbonaceous is an adjective to describe any sedimentary rock that does not have a black streak (streak can be any colour) when scratched with a metal tool, but has coal inclusions; a rock that is >75% ash.
Carbonaceous Shale
(XH)
Any mudrock that shows fissility. Carbonaceous is an adjective to describe any sedimentary rock that does not have a black streak (streak can be any colour) when scratched with a metal tool, but has coal inclusions; a rock that is >75% ash.
Carbonaceous Mudstone
(XM)
Intermediary between claystone and siltstone; any sedimentary rock mostly composed of particles less than 0.02 mm. Carbonaceous is an adjective to describe any sedimentary rock that does not have a black streak (streak can be any colour) when scratched with a metal tool, but has coal inclusions; a rock that is >75% ash.
Carbonaceous Sandstone
(XS)
Sedimentary rock mostly composed of individual grains or clasts between 0.06 and 2 mm. Carbonaceous is an adjective to describe any sedimentary rock that does not have a black streak (streak can be any colour) when scratched with a metal tool, but has coal inclusions; a rock that is >75% ash.
Carbonaceous Sandstone
coarse grained
(XSCC)


Carbonaceous Sandstone
fine to coarse grained
(XSFC)


Carbonaceous Sandstone
fine grained
(XSFF)


Carbonaceous Sandstone
fine to medium grained
(XSFM)


Carbonaceous Sandstone
medium to coarse grained
(XSMC)


Carbonaceous Sandstone
medium grained
(XSMM)


Carbonaceous Siltstone
(XT)
Sedimentary rock mostly composed of individual grains or clasts between 0.002 and 0.02 mm. Carbonaceous is an adjective to describe any sedimentary rock that does not have a black streak (streak can be any colour) when scratched with a metal tool, but has coal inclusions; a rock that is >75% ash.
Coaly Claystone
(ZC)
Sedimentary rock mostly composed of individual grains or clasts less than 0.002 mm. Coaly is an adjective to describe any sedimentary rock that does not have a black streak (streak is usually dark grey to brown) when scratched with a metal tool, but is dark grey to black with coal inclusions; a rock that is between 50-75% ash.
Coaly Shale
(ZH)
Any mudrock that shows fissility. Coaly is an adjective to describe any sedimentary rock that does not have a black streak (streak is usually dark grey to brown) when scratched with a metal tool, but is dark grey to black with coal inclusions; a rock that is between 50-75% ash.
Coaly Mudstone
(ZM)
Intermediary between claystone and siltstone; any sedimentary rock mostly composed of particles less than 0.02 mm. Coaly is an adjective to describe any sedimentary rock that does not have a black streak (streak is usually dark grey to brown) when scratched with a metal tool, but is dark grey to black with coal inclusions; a rock that is between 50-75% ash.
Coaly Sandstone
(ZS)
Sedimentary rock mostly composed of individual grains or clasts between 0.06 and 2 mm. Coaly is an adjective to describe any sedimentary rock that does not have a black streak (streak is usually dark grey to brown) when scratched with a metal tool, but is dark grey to black with coal inclusions; a rock that is between 50-75% ash.
Coaly Sandstone
coarse grained
(ZSCC)


Coaly Sandstone
fine to coarse grained
(ZSFC)


Coaly Sandstone
fine grained
(ZSFF)


Coaly Sandstone
fine to medium grained
(ZSFM)


Coaly Sandstone
medium to coarse grained
(ZSMC)


Coaly Sandstone
medium grained
(ZSMM)


Coaly Siltstone
(ZT)
Intermediary between claystone and siltstone; any sedimentary rock mostly composed of particles less than 0.02 mm. Coaly is an adjective to describe any sedimentary rock that does not have a black streak (streak is usually dark grey to brown) when scratched with a metal tool, but is dark grey to black with coal inclusions; a rock that is between 50-75% ash.