minerals sir jero Flashcards
what is the same skeme of boundstone in folks?
biolithite
pink-coloured titanite)
greenovite
a deep-violet omphacitic clinopyroxene)
violan
most important and famous Mn occurrence of the Piemonte nappe
belongs to the lower part of the Piedmont Jurassic ophiolitic nappe, of oceanic origin
Praborna
synonym of aluminoceladonite)
leucophyllite
ntermediate between leucophyllite (now a synonym of aluminoceladonite) and muscovite.
Alurgite
manganandalusite, is a Mn-rich variety of andalusite, with deep green colors.
viridine
an be accompanied by lizardite which can form the major component in pseudomorphs after orthopyroxene.
Antigorite
forms as a retrograde product rimming relict orthopyroxenes and olivine, and as an accessory mineral in cordierite-bearing gneisses and schists.
retrograde metamorphic mineral derived from ultramafic rocks along with serpentinite.
formed by the breakdown of talc in ultramafic rocks in the presence of water and carbon dioxide as a prograde metamorphic reaction.
product of metamorphism of magnesium-rich rocks,
anthophyllite
etamorphic assemblages of ultramafic rocks containing anthophyllite are indicative of at least
greenschist facies metamorphism
A fibrous variety of Brucite is called
nemalite
common low-temperature hydrothermal mineral in metamorphosed limestones and chlorite schists and is often found serpentinized dunites.
common alteration product of periclase, which is commonly formed in metamorphosed dolomites.
brucite
the lilac miracle of Siberia”
main mineralogical discovery of the second half of the 20th century”
charoite
Chlorites end members
Clinochlore: (Mg5Al)(AlSi3)O10(OH)8
♦ Chamosite: (Fe5Al)(AlSi3)O10(OH)8
♦ Nimite: (Ni5Al)(AlSi3)O10(OH)8
♦ Pennantite: (Mn,Al)6(Si,Al)4O10(OH)8
Manganese-rich chloritoid is known as
ottrelite
magnesium-rich variety is called
sismondine
formed by the reaction of copper hydroxy carbonate with siliceous acid according to the reaction:
chrysocolla
Fe-rich cordierite
sekaninaite
characterized by hexagonal rings of six silicate tetrahedral (Si6O18)12-, where one-half of the oxygen ions of each SiO4 tetrahedron are bridging oxygens shared with adjoining tetrahedral in the ring.
Cordierite
cordierite may well persist as an important mineral in various mineral associations until sediments are literally fused to glass
buchite rocks)
high-grade rock cordierite is present
indialite (the high grade polymorph)
The alteration product is usually a fine-grained, yellow-greenish aggregate (Chlorite+biotite+muscovite) called
Pinite.
Al2O3
corundum
padparadscha
corundum-pink orange
why is the ruby red?
caused by minor amounts of trivalent Cr replacing Al in the crystal structure.
(also know as disthene)
Barrowian type.
kyanite
kyanite cleavage
(100) and (010) very good
occurs in boron-rich volcanic and sedimentary rocks which have undergone high grade metamorphism. found in metamorphosed anorthosite complexes.
kornerupine
variety of kyanite rich in graphite inclusions
Reticite or “raethicite”
occurrence to blueschist facies meta-ironstones
Deerite
fibrous aluminium boro-silicate mineral, it crystallizes in the orthorhombic system and typically forming fibrous aggregates of slender prismatic crystals.
occurs in high temperature aluminium rich regional metamorphic rocks, those resulting from contact metamorphism and also in boron rich pegmatites.
dumortierite
what are under epidotes?
allanite
pistacite
zoisite
piemontite
also known as “orthite”
one of the most common rare earth minerals
horium and uranium, in amounts up to 5 ThO2 and 0.5 U3O8 wt.% respectively, are present in the majority of this mineral
often occurs in the metamict state due to the destruction of the crystalline structure by the bombardment of α (alfa) particles emitted by the radioactive constituents.
Can alter into epidote; during weathering it is replaced by carbonate and limonite
allanite
crystal system of epidote
monoclinic
he non-metamict allanites are distinguished from other epidotes by their
brownish colour,
orthorhombic varieties of epidote
Zoisite Ca2Al3O(SiO4)(SiO7)OH
♦ Thulite Ca2(Al,Fe3+, Mn3+)3O(SiO4)(SiO7)OH
Monoclinic varieties:
Clinozoisite Ca2Al3O(SiO4)(SiO7)OH
♦ Pistacite Ca2Fe3+Al2O(SiO4)(SiO7)OH
♦ PiemontiteCa2(Al,Fe3+,Mn3+)3O(SiO4)(SiO7)OH
♦ Allanite (Ca,Ce,La)2(Al,Fe3+,Fe2+)3O(SiO4)(SiO7)OHOH
♦ Tawmawite Ca2(Al,Fe3+,Cr3+)3O(SiO4)(SiO7)OH
♦ Hancockite (Ca,Pb,Sr)2(Al,Fe3+)3O(SiO4)(SiO7)OH
forms complete solid solution with all compositions of the clinozoisite-epidote series and differs from it by the presence of Manganese.
common occurrence is in schists of low-medium grade regional metamorphism in association with chlorite, quartz and sericite.
Piemontite
known as saualpite
zoisite
Even very minor Mn3+ produces intense pink color, forming the poorly defined variety of zoisite
thulite
most common occurrence of Zoisite
schists and granulites of medium-grade regional metamorphism
Zoisite is a common hydrothermal product of Ca-Rich plagioclase where it appears in a fine-grained mass, in association with muscovite, calcite or chlorite, called
saussurite
describe a pyroxene from an augite syenite-limestone
used to describe the Al-rich and Na-poor pyroxenes commonly found in metamorphosed limestone and dolomites.
Fassaite
what is the solid solution of glaucophane
Glaucophane-riebeckite-crossite series
ow essentially complete solid solution among three end-member compositions, Pyrope-Almandine-Spessartine;
Pyralspite garnets
iron-aluminium garnet with the formula Fe3Al2(SiO4)3
occurs in metamorphic rocks like mica schists
Almandine:
magnesium aluminium silicate with the formula Mg3Al2(SiO4)3, though the magnesium can be replaced in part by calcium and ferrous iron.
indicator mineral for high-pressure rocks. The garnets from mantle-derived rocks, peridotites, and eclogites commonly contain this mineral
Pyrope
manganese aluminium garnet, Mn3Al2(SiO4)3.
occurs most often in granite pegmatite and allied rock types and in certain low grade metamorphic phyllites.
spessartine
aluminium in Y site
Pyralspite garnets
calcium in X site
Ugrandite group
xtensive solid solution exist among the three and-members of the ugrandite garnet.
Uvarovite: Ca3Cr2(SiO4)3
* Grossular: Ca3Al2(SiO4)3
* Andradite: Ca3Fe2(SiO4)3
calcium-iron garnet, Ca3Fe2(SiO4)3,
“emerald of the Urals”
found both in deep-seated igneous rocks like syenite as well as serpentines, schists, and crystalline limestone
pale to deep brown
Andradite
(yellow or green) andradite
topazolite
(green) andradite
demantoid
black andradite
melanite
calcium-aluminium garnet with the formula Ca3Al2(SiO4
found in contact metamorphosed limestones with vesuvianite, diopside, wollastonite and wernerite.
pale yellow
Grossular
calcium chromium garnet with the formula Ca3Cr2(SiO4)3 emerald-green
Uvarovite
spinel that occurs in high-grade metamorphosed iron rich argillaceous sediments as well as in mafic and ultramafic igneous rocks
Hercynite
stubby and prismatic, and usually have a rectangular cross section.
Hedenbergite
calcium aluminium garnet series with formula: Ca3Al2(SiO4)3-x(OH)4-x with hydroxide (OH) partially replacing silica SiO4.
common mineral in rodingites,
Hydrogrossular
endmembers of the hydrogarnet family
(grossular, hibschite, and katoite)
type locality for the minerals deerite, howieite, and zussmanite
Laytonville quarry
n = 2, named from the Greek word meaning “a grain” alluding to the granular texture of the material as it occurs in aggregate form; humite
Chondrodite
consists of four polysomatic series (a series of minerals composed of the same structurally or chemically distinct layers in different ratios or different sequences).
Humites
piedra de ijada” which means “stone of the side”
believed to cure kidney stones if it was rubbed against the side of the afflicted person’s body
Jadeite
lapis nephriticus
nephrite
only in metamorphic rocks and is most common as a monomineralic rock.
Jadeite
contains chains of edge-sharing Al(O,OH)6 octahedra parallel to c axis.
metamorphic mineral typical of the blueschist facies
Lawsonite
forms by high grade metamorphism of high silica quartz rich rocks and in pegmatites
Lazulite
Lazulite is in a solid solution series with the mineral
scorzalite
ranges from the magnesium rich lazulite to the iron rich scorzalite.
lazulite-scorzalite series
lazurite-calcite-pyrite rock
Lapis Lazuli
banded iron formations of northern Minnesota. low grade metamorphic banded iron formations
Minnesotaite
rests unconformably on granite, greenstone, and other rocks of the Archean (greater than 2.4 billion years old) Superior Province, which constitutes the bedrock in most of northern Minnesota.
Animikie Group
extends for 190 km across northern Minnesota (Fig.1). It is separated from the correlative, 1.9 Ga Gunflint Formation of Ontario by the intrusion of the 1.1 Ga Duluth gabbro, which developed a spectacular contact aureole within these iron formations.
Biwabik Iron Fromation
muscovite form a continuous series with celadonite and aluminoceladonite; intermediates are known as the variety
phengite and K-deficient variants as illite.
Large alkalis (Rb and Cs) and some alkaline earths (Ca, Sr, Ba) may appears as minor impurities replacing K, Ba-rich muscovite is called
oellacherite
Na my replaces K in Muscovite to form a distinct minerals called
paragonite
olivine group contains manganese
tephroite
calcium-manganese
glaucochroite),
calcium-magnesium
monticellite
calcium-iron
kirschsteinite
forsterite + quartz
orthopyroxene
410 km olivine transforms into
wadsleyite
at about 520 km depth, wadsleyite transforms into
ringwoodite,
depth of about 660 km, ringwoodite decomposes into silicate
perovskite (Mg,Fe)SiO3 and ferropericlase
most characteristic of oxidation, deuteric alteration or weathering.
Iddingsite and bowlingite alteration
appears as reddish-brown replacement of olivine, along fracture, rims, or complete replacement.
appears optically homogeneous, with high relief, and high interference colors.
Iddingsite
fine-grained aggregate containing smectite, goethite, chlorite, calcite, silica, talc.
Bowlingite
also characteristic of volcanic or shallow intrusion, this fine-grained aggregate tends to be isotropic. Probably contain limonite, chlorite and serpentine.
Chlorophaeite:
clinopyroxene solid solution of jadeite (25%-75%), augite (25%-75%), and aegirine (0%-25%).
occurs in eclogite xenoliths from kimberlite as well as in crustal rocks metamorphosed at high pressures.
Omphacite
complex inosilicate mineral of the amphibole group.
solidus temperature of the lherzolite
main water-storage site in the uppermost mantle, however it becomes unstable at depths greater than 90 km.
Pargasite
forms complete solid solution with all compositions of the clinozoisite-epidote series and differs from it by the presence of manganese.
Piemontite
solid solution of pyrite (incomplete) Ni-isomorph
vaesite (NiS2) and cattierite (CoS2)
occurs as stalactite masses. found in Cape of Good Hope in South Africa
Prehnite
nesosilicate containing both independent SiO4- tetrahedral and Si2O76- units cross-linking octahedral chains occupied by metals.
occurs as amygdaloidal and fracture fillings in basaltic and gabbroic rocks in metamorphic terranes
Pumpellyite
stable below 573°C
(α)-Quartz:
stable from 573 to 870°C
(β)-Quartz
never stable, exists metastably below 117°C
(β)-Tridymite
stable from 867°C to 1470°C
(α)-Tridymite:
never stable, exists metastably below 267°C
(α)-Cristobalite
stable from 1470°C to 1723°C
(β)-Cristobalite:
high-pressure phase found in meteor impact craters, stable at pressures of 2-3GPa and from 700 to 1700°C
Coesite
high-pressure phase found in meteor crater, stability field unknown.
Stishovite:
natural form of silica that lacks a definitive crystal structure. It is amorphous and considered a natural glass, and is scientifically classified as a mineraloid. lightning strike or during high pressure shock metamorphism due to meteorite impact and is a common component of a type of glassy ejecta called tektites.
Lechatelierite
high-pressure, low-temperature polyOF RHODONITEmorph.
pyroxmangite
greyish-brown variety containing as much as 20% of calcium oxide is called
bustamite
zinciferous variety containing 7% of zinc oxide
fowlerite
polymorphs of the TiO2
rutile
brookite
anatase
(sometimes known by the obsolete name “octahedrite”), a tetragonal mineral of pseudo-octahedral habit.
Anatase
an orthorhombic mineral
Brookite
rutile also solid solution with
tapiolite
“blauer Diamantspath (saphirin)”
high-temperature minerals of regional metamorphism ore contact metamorphism.
characteristic of the granulite-amphibolite facies and silica poor, Mg-rich rocks
Sapphirine
Sapphirine remains stable up to pressures of about 17-25 Kbar and up to temperatures of 1000°C; Beyond that limit, Sapphirine dissociates in
pyrope, spinel and corundum
Scapolite
Meionite: Ca4(Al2Si2O8)3(CO3,SO4)
Marialite: Na4(AlSi3O8)3Cl
roup of aluminosilicate minerals that includes meionite, marialite and silvialite assive specimens often exhibit a wood-grain or fibrous texture which facilitates their identification.
Scapolite
members of the serpentine group
repeated two-layer arrangement of one tetrahedral (SiO4) and one octahedral (Mg(OH)2) laye
Antigorite - (Mg,Fe)3Si2O5(OH)2
Chrysotile - Mg3Si2O5(OH)4
Lizardite - Mg3(Si2O5)(OH)4
derived from dunites, peridotites and other ultramafic-mafic rocks
Serpentine
A common variety of sillimanite is known as
fibrolite,
twinned, six-sided crystals that sometimes intersect at 90 degrees to form a cross (an intersection angle of 60 degrees is more common
consist basically of layers Al2SiO5 (kyanite composition) and layers of AlFe2O2(OH)2 alternating parallel to (010).
may alter to sericite, chlorite and limonite
Staurolite
With increasing metamorphic grade, staurolite becomes
almandine and kyanite or sillimanite:
a common mineral in low-grade metagreywackes and blueschist-facies rocks, as well as in metamorphosed iron formations.
Stilpnomelane
(also known as lavulite)
rare pink to purple cyclosilicate
Sugilite
he ratio of talc and kyanite is dependent on aluminium content, with more aluminous rocks favoring production of kyanite. Such rocks are typically white, friable, and fibrous, and are known
whiteschist.
mineral rich in barium and occurring in brownish red radially fibrous aggregates in metamorphic contact rocks
taramellite
also known as rosaline, is a a pink variety of zoisite, frequently manganian
Thulite
very rare mineral found in the Murun Massif
occurs as an accessory mineral in potassic feldspar metasomatites at the contact with limestones.
derived from its composition: titanium (Ti), sodium (Na) potassium (K) and silicon (Si).
Tinaksite
Mesozoic K-alkaline intrusions are abundant at the Aldan shield and they are distributed in the northern part with a strike roughly parallel to the NE-SW trending Mongolia-Okhotsk orogenic belt
Murun Complex
borosilicate and belong to the axinite group. manganese-bearing ophiolites that have been metamorphosed as well as in quartz veins running through chert in greenschist facies.
Tinzenite
series name for a group of isostructural minerals, all with the same structure but different chemistry. They are named for their respective enrichment in either iron, magnesium and manganese, except for the iron manganese intermediate
Axinite
The axinite group includes:
Axinite-(Fe) or ferroaxinite, Ca2Fe2+Al2BOSi4O15(OH)
Axinite-(Mg) or magnesioaxinite, Ca2MgAl2BOSi4O15(OH)
Axinite-(Mn) or manganaxinite, Ca2Mn2+Al2BOSi4O15(OH)
Tinzenite, Ca2Mn2+4Al4B2Si8O302.
orthosilicate with independent SiO4 tetrehedra united by Ti4+ in octahedral coordination and Ca2+ in sevenfold coordination. Al3+ or Fe3+ may partially replace Ti4+ and are most common impurity.
associated with chlorite
titanite
has a greater presence of magnesium over iron compared to actinolite
result of contact metamorphism of calcium and magnesium rich siliceous sedimentary rocks and in greenschist facies metamorphic rocks derived from ultramafic or magnesium carbonate bearing rocks.
tremolite
consists of six-fold rings of silicon tetrahedra stacked with BO3 groups between the rings that form columns parallel to the c axis distinguished from biotite and hornblende by the absence of cleavage
tourmaline
hyacinthus dictus octodecahedricus
hyacinte du Vesuve”
closely resembles that of garnet
common mineral in skarns formed during contact or regional metamorphism of limestones; in garnetized gabbros, mafic and ultramafic rocks, and serpentinites.
Vesuvianite or idocrase
Violet clinopyroxenes from the manganese deposit of Praborna, near St. Marcel occur in two different varieties: euhedral crystals grown in vugs and massive lamellar to fibrous aggregates. The deep violet colour, occasionally shading to blue, is presumably due to the presence of both Mn3+ and Mn2+ ions. makita pud sa praborna mine
violan
who discovered palladium (1804) and rhodium (1809) and invented the reflecting goniometer (1809).
William Hyde Wollaston Norfolk,
a calcium inosilicate mineral. It forms when impure limestone or dolostone is subjected to high temperature and pressure sometimes in the presence of silica-bearing fluids as in skarns or contact metamorphic rocks. Associated minerals include garnets, vesuvianite, diopside, tremolite, epidote, plagioclase feldspar, pyroxene and calcite.
Wollastonite
In the progressive metamorphism of siliceous dolomites, the early stages of the sequence are
talc-tremolite-diopside-forsterite-wollastonite-periclase-monticellite,
mposed of coarse interlocking, often curved, flakes of talc with interstitial patches of quartz, exhibiting strain shadows; large irregularly margined grains of yoderite enclose random flakes of talc and some quartz. A constant feature is the presence within each yoderite grain of relicts of kyanite.
he quartz-yoderite-kyanite-talc schist of Mautia hills
associated with deerite, in riebeckite-garnet-stilpnomelane metachert from the Franciscan formation of California
Zussmanite
Monomineralic coronas are also known as
moats
polymineralic ones composed of an intergrowth of small elongate new grains are known as
symplectitic coronas.
he structure of lamellar or vermicular fine-grained intergrown material is known as
symplectite.
metamorphic rock texture comprising of equigranular, interlocking, randonly orientated platy, tabular, prismatic or elongate minerals.
similar to a granoblastic texture.
Decussate (or diablastic) texture
crystal lattice which contains a large number of similar dislocations can be slightly bent; as a result, the crystal does not extinguish homogeneously as observed with crossed polars; this effect is known as
undulose extinction.
crystals deformed at low temperature by intracrystalline deformation are lamellae with a high optical relief which usually have a distinct preferred orientation, known as
deformation lamellae
characterized by phyllosilicate-rich (P) domains, in which phyllosilicates deï¬ne the overall cleavage, separated by quartz and feldspar-rich (QF)domains
most common type of cleavage in multiply deformed, intermediate to high-grade metapelitic rocks
created when an earlier foliation is folded (crenulated) on a meso- to microscale. An already established tectonic foliation can be affected by a later cleavage (S2 or higher) if the orientation of the ISA (Instantaneous Stretching Axes) changes locally or regionally at some point during the deformation, or if a later cleavage-forming deformation phase occurs.
series of microfolds at the centimeter scale or less with parallel axial surfaces.
crenulation cleavage
a grade of coal that has properties between those of bituminous coal and anthracite an
also known as thermal coal, is used in power stations to generate electricity
steam coal
german of lignite
flame coal
gas flame coal
gas coal
fat coal
forge coal
non baking coal
anthracite
braunkohle
flammkohle
gasglammhohle
gashkohle
fettkohle
fettkohle
esskohle
magerkohle
anthrazit
lignin content of plants may fall within the
range of
10–35%
woody material the lignin may be within the narrower
range of
25–30% w/w
protein content of grasses has been assigned
to fall within the range of
15–20%
cellulose (carbohydrate) content of grasses falls in the range
of
20–55%
complex, 3-dimensional
polymer rich in aromatic (benzene) rings
lignin,
When the pH of the medium is sufficient (pH = ∼4), these bacteria die. The product
at this stage is a gel-like material called
Gytta (sometime referred to as proto-coal).
(the
non-hydrocarbon species in coal, i.e., nitrogen-, oxygen-, and sulfur-containing
species)
heteroatom species
oxygen content of coal ranges from a high of 20–30% by weight for a lignite
1.5–2.5% by weight for an anthracite.
thiophene ring system.
important sulfur types
aryl sulfides,
alkyl sulfides, and acyclic sulfides
occur in coal to the extent of several parts per million and, on
combustion of the coal a varying quantity of these elements are released or retained in
the ash
Arsenic and selenium
represent the macrostructure of coal and are,
in fact, descriptive of the coal
Lithotypes
The organic constituents in coal and non-coal organic-rich rocks
are termed macerals
Macerals
oxidized, with fire thought to be the primary cause
of their formation.
Inertinite macerals
products of such
oxidation and, in most coals, are the most abundant inertinite macerals.
fusinite and semifusinite
product of the oxidation of plant secretions
Secretinite
riginated as a secondary maceral from the breakdown of hydrogen-rich liptinite.
Micrinite
consists predominantly of inertinite and also contains impurities such as kaolin
(as well as other clays), pyrite, and carbonate minerals
Fusite
(which also contains exinite in addition to vitrinite) is more
commonly found as thick bands in clarains but does not occur in many other coals;
clarite may also contain inorganic impurities such as clay, pyrite, and carbonates
clarite
composed predominantly of exinite and inertinite a
Durite
indicates that the durite is relatively
rich in exinite
(durite E)
indicates the durite to be relatively rich in
inertinite.
(durite I)
Liptobiolithic (non-banded)
Boghead Algal debris present
Cannel Spore debris present
High hydrogen content
Sapropelic
Black, vitreous
Vitrain
Charcoal-like
Fusain
Nonstriated
Durain
Striated, glossy
Clarain
Low hydrogen content
Humic (banded)
Anthraxylon absent
Non-banded coal
> 30% w/w opaque matter
Splint coal
20–30% w/w opaque
Semi-splint coal
<20% w/w opaque matter
Bright coal
Anthraxylona present Opaque matter present
Banded coal
A mass of recently accumulated to partially carbonized plant
debris that is not classed as coal; an organic sediment that
has a carbon content <60% w/w on a dry ash-free basis.
Peat
The lowest rank of coal (also called brown coal), which may
contain recognizable plant structures; the heating value is
<8300 Btu/lb on a mineral matter free basis and a carbon
content from 60% to 70% w/w on a dry ash-free basis.
Lignite
Coal with a carbon content on the order of 71–77% w/w on a
dry ash-free basis) and a heating value between 8300 and
13,000 Btu/lb on a mineral matter free basis; on the basis of
heating value, this coal is subdivided into sub bituminous
A, sub bituminous B, and sub bituminous C coals
Sub Bituminous
Coal with a carbon content on the order of 77% and 87% w/w
on a dry ash-free basis and a heating value that is much
higher than lignite or sub bituminous coal; on the basis of
volatile matter production, bituminous coal is subdivided
into low volatile bituminous coal, medium volatile
bituminous coal, and high volatile bituminous coal; often
referred to as soft coal (in relation to anthracite).
Bituminous
The highest rank of coal with a carbon content greater than
87% w/w on a dry ash-free basis and the highest heating
value per pound on a mineral matter free basis; often
subdivided into semi-anthracite, anthracite, and
meta-anthracite on the basis of carbon content and hard
coal (in relation to bituminous coal)
Anthracite
hazardous air pollutants (HAPs)
e antimony (Sb), arsenic (As), beryllium (Be), cadmium
(Cd), nickel (Ni), lead (Pb), selenium (Se), mercury (Hg), cobalt (Co), chromium
(Cr), and manganese (Mn), with chlorine (Cl) and the radionuclides, thorium (Th)
and uranium (U),
increase in volume of
the coal when it is heated in the absence of air;
vitrinite maceral
group is the main contributor to the swelling properties.
Free-swelling index (FSI)
how the coal behaves as the different macerals melt, devolatilize, and resolidify at different temperatures during
the carbonization process
- Gieseler plastometer
determine the proportions of coke or char (carbonaceous solids), tar (organic liquids), liquor (ammonia-rich solutions), and
gas produced when the coal is carbonized (heated in the absence of air)
Gray-King assays
indicates the ease with which
the coal can be ground to fine powder
Hardgrove grindability index
indicates the amount of heat liberated per unit of mass of combusted coal; this is a rank-related parameter but is
also dependent on the macerals in the coal and mineral composition
Heating value (calorific value)
provides information on the caking properties of the
coal; the index is derived from the strength or cohesion of the coke produced in
the crucible, as evaluated by a subsequent tumbler test.
Roga index
First appearance of lignified land plants
Late Silurian
Large, diverse flora of spore-dispersing
plants, including ferns and slender
trees with varying amounts of
branching and leaf development
Carboniferous
Seed-fern flora (glossopteris) flourishes
all over Gondwanaland
Permian
Seed-bearing plants flourish, with
conifers and cycadophytes prominent
Triassic and Jurassic
Flowering plants evolve (Angiosperms)
Cretaceous
Essentially modern flora in most
respects
Late Cretaceous
Grasses and sedges appear
Tertiary
name given to a once-existing supercontinent comprising what are now South
America, Africa, India, Australasia, and Antarctica.
aGondwanaland
