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COMMONWEALTH OF AUSTRALIA
DEPARTMENT OF NATIONAL DEVELOPMENT
BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS
Record No. 1969 /27
Mellong Well
Petrological Study of (A.O.G) No.1
Sydney Basin N.S.WI
by
S.J. Mayne
The information contained in this report has been obtained by the Department of National Development as part of the policy of the Commonwealth Government to assist in the exploration· and development of mineral resources. It may not be published in any form or use in 11 company prospectus or statement without the permission in writing of the Director, Bure~u of Mineral Resources, Geology and Geophysics.
Record No. 1969 /27
Petrological Study of Mellong No.1 Well (A.O.G)
Sydney Basin N.S.W.
by
S.J. Mayne
The information contained in this report has been obtained by the Department of N~tional Development as part of the policy of the Commonwealth Government to assist in the exploration and development of mineral resources. It may not be published in any form or use in a company prospectus or statement without the permission in writing of the Director, Bureau of Mineral Resources, Geology and Geophysics.
,. ,
RECORDS NO. 1969/21
PEI'ROLOGICAL STUDY OF MELLONG (A.O.G.) NO. I WELL
SYDNEY BASIN, NEW SOUTH WALES
by
S.J. MAYNE
,.
PErROLooICAL STUDY OF MELLONG (A.O.G.) NO. I WELL SYDNEY BASIN, NEW SOUTH WALES
GENERAL INFORMATION
G&)LooY
UNIT Me 1
UNITS Me 2-7
UNIT Me 2
UNIT Me 3
UNIT Me 4
UNIT Me 5 UNIT Me 6
UNIT Me 7 UNIT Me 8
T ABLE OF CONTENTS
Provenance and Environment
Comparison with Mt. llirwin
Comparison with Grose River District
Palaeontology
Permo-Triassic Boundary
Summary
References
Appendix
TEXT FIGURES
FIGURE 1: Summary of Petrological Results
FIGURE 2: Comparison of B. M.R. units with company interpretation
FIGURE 3: Comparison of Grose River, Mellong and Mt. Murwin
PLATES
Page
1
2-13 ~
3-5 3
3
4
4
4-5
5 5-6
6-7
7-8
8-9
9 9-10
10
10-11
12-13
PLATE 1A: Petrographic Well Log O' - 1700' (End of Report)
PLATE 1B: Petrographic Well Log 1700' - 2970' (End of Report)
MELLONG. No.1 WELL
Summary ·of PetrologicQ'·" Results
u (/) . CD
(J) :IE <l I
N Q:: CD
I-- Z
. . .. . '. '.' . ••• 1 ": · , ,
; -'.>: : It) ,. ',;
CD : 00, :: •• :::
~ ",:: \ : ",' .' '.
',' . . , • "I • j '.
',' ..... ",
: : : '. 'eo··:
i,.
· ... ': ;', ~,a..:,....;',...:..j' 2000
Z
.,....... ,0 •
'.'~.~.': · ... CD •••••• :. · ... '. eD :-:-::'. :E '.", :..:.:,', .. ' . : ",' .
-. '-. .--' j
<l II) CD • Q)CD_'
~ :E 2 ., Q:: • 3000 w Il.
: ~ .
· .. DELTAIC
I.
',,' .
,
----
DELTAIC
SANDSTONE
j ,'" y. ' •. : •• 0'; ,.1.,
.' .
/. I
!
I' .
. 1
\ .
. /
SA N1)STONE , A RIo(OSf
OR
GRANITE
SANDSiONc.
ARKOSf
OR GRANITE
Fig.1
B.MR Petroleum' explorofion. Fsbtuory 9 ro accompany Record x AUS-I-69
,-
GENERAL INFORMATION
Well Data
Well Name ani Number:
Operating Company:
Location:
Date Drilled:
Elevation:
Total Depth:
Rig Type:
Logs Run:
Hydrocarbon Shows:
Water Testing:
Mellong No. 1
Australian Oil and Gas Corporation
Latitude 330 00'25" South
Longitude 150041' 36" East
3 miles south-east of the Township of
Putty, in the County of Hunter.
1 :250,000 Sheet Singleton 'j .). 9
, . . ...
196-3/64
Ground 1146' a.s.l.
Collar 1149' a.s.l.
2970' Percussion.
Gamma-r a3. Resistivity and Self
Potential logs were run by the N.S.W.
Department of Mines.
Two gas shows, too small to be measured
by the standard equipment, were detected
between 1830' - 1836' and 2045' - 2050'.
Water was encountered at several
horizons (see p.2, 4, 5,).
Summary of Major Reference
penetrated:
The well was drilled in the period 20.11.1963 - 29:2.1964, and
Triassic ( 0' - 370' ( 370' - 2480'
Permian 2480' - 2970'
(Hawkesbury Sandstone) (Narrabeen Group)
("Upper Coal Measures")
The well was located on the crest of a small closed anticline with a north
south trending axis, in the Sydney Basin. It was drilled in the hope of finding
commercial quantities of gas in a dominantly sand sequence of the Narrabeen
Group. These sandstones were mostly "tight", but evidence of porosity and ,
perm~abili ty was afforded by at least seven water horizons and two gas horizons .•
New isopach data obtained show that the Narrabeen thins to the north and. north
west.
The presence of white tuffaceous shales in the uppermost "Upper
Coal Measures" resemble occurrences near Newcastle and Burr ago rang. These beds
ma3 prove to be good marker beds for the "Upper Coal Measures" in the Sydney Basin.
The Company did not attempt a correlation with the defined units of
other areas.
Cuttings I
Coresl
2.
Material Available for Stud.Y . .
0' to 2910' (total depth) at 10' intervals.
Nil.
Methods Used
All samples were examined with a low-power binocular microscope,
and thin sections were made from chosen intervals and examined under a
petrological microscope. Eight units were distinguished on lithological
characteristics and on log features.
Pettijohn's classification of sedimentary rocks (1951) was used.
GEOLOGY
The uppermost rocks penetrated by the well are a distinctive
sandstone 360'deep. They cannot be subdivided readily, and so constitute
a single major unit, Me 1.
Unit Me 1
Characteristicsl This unit extends from the surface to 360' and apart from a
thin sil ty l~er at about 285' consists of ortho quartzite. The quartz grains
are subangular to angular, Qolourless,dominantly medium-grained but ranging
from very fine to coarse. Crystal faces are often present. Graphite is
alw~s present but varies from rare to common.
The orthoquartzite occurs in two types, the common or normal
Hawkesbury Sandstone, and a dark brown ferruginous variety.
(a) The normal orthoquartzite consists of rather closely
packed quartz grains with occasional feldspars (including
plagioclase and microcline), chert liths, white mica, and
kaolin as an interstitial cement.
Whi teand colourless pebbles of quartz up to 15 mm occur
spor adic ally.
(b) The ferruginous orthoquartzite shows a disrupted framework
of irregular quartz grains, many of which are shattered
by a sub-parallel system of cra:cks. Limonite (goethite)
occupies the interstices, opening up m~ of the cracks in
the quartz grains, and constituting up to 3~ of the total
rock. There are a few feldspar grains and flakes of white
mica.
This ferruginous sandstone occurs as bands in the normal
sandstone.
Fresh water flowed at 100 gph from the very bottom of Me 1.
,.
3.
Major Unit Me 2 to Me 1
This sequence is 2120' thick, extending from 360' to 2480'. It
consists of sandstone» and siltstone and shale: the pelitic grades dominate
in both the upper and IO'l'ler horizons, whilst the sandstone predominates in
the middle horizons.
The sandstone, which falls in the category of protoquartzite,
contains a distinctive component of grains of coloured che;rt, especially green
and reddish brown, which mc\y be up to 15 mm in size. Chert gravel is more
common in the lower levels than in the higher.
The pelitic rocks are mostly sandy Siltstone, sometimes verging
on the very-fine-sandstone border, but also include the so-called "chocolate"
or "red" shales frequently found elsewhere in the upper Narrabeen sequence.
Siderite occurs throughout this sequence: sometimes it is
coarse enough to be seen by thenaked eye, and often it is partly altered to
limonite.
Unit Me 2
Characteristics: This unit is 210' thick, extending from 370' to 580'. It
consists of 5~ siltstone interlaminated with 43% quartz greywacke. The
siltstone ranges in, colour from "red" or "chocolate" to brown and pale grey.
It is probably mottled as some chips show irregular colour boundaries. It
consists of kaolin, illite, limonitized siderite, traces of chert and from 10%
to 15% angular quartz and feldspar grains, some small carbonaceous flakes which
at times may be in just sufficient quantity to impart a slight fissility, and
occasional small grains of zircon and tourmaline.
The quartz greywacke consistf! of aboll-t 401» subangular quartz grains
and 401» rounded chert li ths, and the rest an infilling ot kaolin, illite and
limonitic siderite. There is no graphite.
Unit Me 3
Characteristics: This is an orthOquartzite 110' thick (from 580' - 690'). The
quartz is clear, colourless and medium/coarse grained at the top of the unit and
fine to medium grained at the bottom. There is a cement of white kaolin and \
siderite, and sporadic quartz gravel up to 10 mm, but no chert or graphite.
Unit Me 4 Characteristics: This sequenoe is 140' thick (from 690' - 830') and consists
{I
of interlaminated fine siltstone like that in Me 2, sandy siltstone and very
subordinate protoquartzite. The sandy siltstone consists of a fairly equi
granula,.r mosaic of somewhat irregularly-shaped grains of quartz and feldspar,
with illite, siderite, zircon, tourmaline and a few small ohert grains.
Fresh water is recorded as having flowed at 600 gph from 595'
in Me 3, ani at 150 gph from 785' in Me 4.
Unit Me 5
Characteristics: This unit is 1~010' thick, extending from 830' to 1840'. It
is essentially a sandstone unit, with a spa,.rse development of very thin and
widely separated siltstone l~ers. The gamma ray log supports the identification
of this sequence of rocks as a unit.
The sandstone samples oonsist only of disaggregated sand, indioating
a rather friable rock with little effeotive oementing material. There is a
goodly proportion, up to 30%, of multi-ooloured chert grains of all sizes up to
10 rom. It is probable that the rock is a protoquartzite~ verging on an ortho
quartzite, with siderite qnd white kaolin binding material.
The porous and p~rmeable nature of the sandstone is further indicated
by the following records of underground water produced from the well:-
fCeSh water f'lowLt8 at 800 gph from 960' - 970' <I ? " 1,009 ' I'! 650 " 1,265' 11 300 11 1,660'
Unit Me 6
Charaoteristios: This unit is 460' thiok, extending from 1840' to 2300'. Lithologioally it is dominantly a medium-grained sandstone with thin variegated
sil tstone bands well distributed throughout. Multiooloured chert gravel is
common, and there are two very thin coal l~ers. The geop~sioal logs reveal
this unit clearly, especially the break at 2300'.
The sandstone is a medium-grained proto quartzite tending towards
subgreywacke. It oonsists of a rather tightly-fitting framework of rounded
chert and devitrified volcanio ash grains, subangular quartz and feldspars up
to 7% of the total, and fairly oommon siderite oement.
At the top of the unit there was a small gas show and another
at 2050'. Both yielded less than 500 cu. ft .. / daJ', and were the only occurrences
of ~drocarbons in the Mellong well.
At 1869' there was a small flow of water with an unusually high
sodium. .. bicarbonate content.
Unit Me 1
Characteristics: This unit is 180' thick, extending from 2300' to 2480'.
All three geophysical logs confirm its existence. Lithologically it consists
of sandstone and siltstone similar to those described above. It differs from
Me 6 by having a higher percentage of shaley members and by a markedly less
amount of multicoloured chert grains, and from Me 8 by the virtual absence of
coaly material.
Unit Me 8
The rocks below 2480' constitute a major unit which cannot
readily be subdivided.- The frequent occurrence of coal confers upon it the
designation of "Coal Measures". It is quite likely that they represent cyclical
deposits as envisaged by F.W. Booker. The upper 200' are more arenaceous than
the lower intervals and thus form a transition zone into the overlying deposits
of the Narrabeen Group.
Unit Me 8
Charaoteristicsl This unit is at least 490'thick, extending from 2480' to
total depth at 2910'. Its identity is quite clearly revealed on the wire-line
logs, which indicate a shale":'rich sequence containing coal seams and sandstone.
Unfortunately, an accurate representation of the lithology cannot be obtained
from the Cl.1ttings because of such trouble at the well as caving, mixing and
insufficient recovery. It seems reasonable to interpret the wire-line logs as
showing coal occurrences as in the following table, which also shows coal as it
is recorded in the cuttings.
Coal Seams Coal Seams 'Ii of (as interpreted from logs) (as indicated in cuttings) sample
1. 2480' 2480'
2. 2520' 2510~ - 2530' 10
3. 2540' 2510' - 2580' 20
4- 2605' 2620' - 2630' 10
5. 2650'
6.
6. 2610' - 2680' 2100' - 2130' 10% 2130' - 2150' 1r$ (cavings)
1· 2110' 2180' - 2190' 5% 8. 2195' 2800' - 2820"' 1~
9. 2815' 2820' - 2880' trace 2910' 2920' 3ato
10. 2935~ 2940' - 2970' 1r$
The coal is mainly a hard. bituminous type, but there is no firm
evidence for its existing in other than thin seams. The occurrences at 2600' and
2610' m~ be from 5' to 10' thick. The co al is associated with black carbonaceous
shale and this material m~ in fact constitute some of the supposed coal
occurrences. Films of calcite and ankerite have been detected associated with the
coal. The other pelitic rocks present are greyish or brownish siltstones
similar to those encountered higher up the borehole. The sandstones, too, are
protoquartzites similar to those already described in unit Me 2.
Perhaps the most noteworthy rock present is a whitish-grey very
fine-grained devitrified vo~canic ash or crystal vitric tuff. The sample from
2640' - 2650' consists largely of this material, and pieces of it are fairly
Common throughout the remainder of the sequence. It is unfortunately impossible
to decide if these come from earlier-formed l~ers of ash or whether they are merely
cavings from the interval 2640' - 2650'. The rock consists of a very finEi-grained
mosaic of devitrified glass and shards with a sprinkling of fresh-looking
feldspars (? Oligoclase) and quartz. Carbonate grains are present, and a few
zircons. X-r~ examination reveals the presence of montmorillonite.
Provenance, and Environment of Deposition: The rocks encountered in the Mellong • • I '
borehole (likewise those in the Mt. Murwin borehole) were probably all deposited
during one major sedimentary episode, with no breaks of great significance. They
vary in type from shale and. mudstone to gravel beds, or sandstone with. abundant
gravel content, and these . all seem to be intimately associated. Even the cuttings
show siltstone with medium sandstone, or sandstone with large gravel pebbles in
the one small .rock fragment.
It is envisaged that during Permo-Triassic times a number of short
rapidly flowing streams descended from the. uplands enclosing the Sydney Basin
area of deposition. Loss of energy resulting from decrease in gradient brought
about the deposition of coarser material in 101'1 angle alluvial fans, levees and
deltaic structures in the basin. In riverine swamps ad'jacent to the levees and.
in the ponds and. lagoons of the del tar-areas fine-grained material settled, and
naturally such places were favourable sites for the collection of plant debris
which was later coalified.
In these deltaic areas, maintained by the vigorous inflowing
streams, there was a fairly high degree of impermanence of features, even
though the overall pattern remained over a vast length of time (from the
middle Permian to the middle Triassic). Such events as the breaching of
levees, the prograding of deltas, the blocking of distributaries on one
alluvial fan by the encroachment of a neighbouring fan, the action of waves
along a lake- (or sea- ) shore would all have combined to give the intimate
interrelationship of events and deposits to which cuttings bear witness.
The major coal-zones maJ" however be indicators of a basic process
of cyclic sedimentation, as visualized by Booker (1951).
The area of provenance is assumed to have been the nearby (60 to
80 miles) uplands of Older Palaeozoic sediments and Middle Palaeozoic igneous
intrusions which had been upraised in the Devono-Carboniferous orogenies.
Because of Mellong's comparative proximity to the western margin of the Basin
there is a higher percentage of arenaceous material in the deposits, whilst
. fine and coaly material occurs in thinner and more erratic la\Yers than in
more eastern localities. The well-known folding in the northern coalfields of
N.S.W. ma\Y well have been associated with the erosion of primary chert beds
laid down during the Permo-Carboniferous, the debris of which, transported by
turbulent streams, provided such a notable proportion of the Narrabeen sediments.
It is very likely that much of the sediments is reworked debris from till and .... outwash plains formed du~ing the Permo-Carboniferous ice-age which was, in the
Permo-Triassic, still dperative or only recently over.
There is the possibility of the. at present unknown, eastern
boundary region of the Sydney Basin having contributed materialcto the sediments
of-the Mellong Area. In particular, none of the Permian volcanoes, whose ashes
. are so widespread, has ever been located: they ma\Y have been situated in this
lost land - which. could (by invoking Continental drift) have been New Zealand.
Comparison with Mt. Mlrwin A.O.G. NO.1: The closeness of the Mt. Mlrwin
section to that of Mellong invites a comparison between them. There is a
considerable stratigraphic Similarity, as can be seen from Plate 3.
~ .. ' ,
, ,
,', ":'., I
" ,
, ' , '
" ,., ~, .
" '
..... "
. ~ ..
. . ... ;! '. ~ .
.' , ""
. .." : ........ '\' " ,I"
.. . '. ' .. - '-, . Fig,2
" . .. , . ,(- .. . . " COMPARISON OF B.M.R. UNITS
: ' , WITH ..
COMPANY INT£RPRETATION , .'
"
B.M.R. UNITS BOUNDARY COMPANY AiO.G.', DEPTHS
, , ; MAJOR MINOR -(ft.)
, FORMATION GROUP' A'GE
"
, " J , ,-HAwKESBURY, I "
Me, , Me I " SANDSTONE -,', .. , , , ,
" .. , ' I
360 \ I I '" ! " " .. , '
" \ L,', :
Me2 ',' . i" " .. z "
" ... ;., U 581 w " -' " w - en
, ,
Me3 ,', en , , m . i .. ~' .
Me2 " ,. <t ..
; « -.... - 690 ", I a:: " " a:: M e7 .. -
I-;;", I a:: " l, '" Me4 " , . ,~. , "
, -- <t " " , ' -,
830' .,,'.\ - Z "
, Me5
2375 1840
, ,,' --..
'" " CJ)-.. , --. w MeG
I -- .. a:: -I-- ' W
.-
" .J ::> .. 2300" I- CJ) Z CJ) <{ <t , , « w' -Me7 U :E ~ !; "
Il:: 2480 w
L1J \ .. - Z ~ Q.,
Me8 Mee <{ 0 , U : ,
2970 B,M.R, Petroleum Explorotlon, Februaryl969 !o accompony Record1969/27 X AUS-I-70
8. Me 1 corresponds with MM 1 (both are Hawkesbury Sandstone)
Me 2, 3, 4 " " MM2 and MM3
Me 5 " " MM4
Me6 ani 7 " MM5
Me8 " " MM 6, 7, 8. (Newcastle Coal Measures)
The major unit Me 2 - 7 is 2120' thick, and the equivalent major unit MM 2 - 5
is 2215' thick.
The stratigraphic differences are:
(a) Me 2,3:~ 4.·tu'.e clearly distinguishable, whereas MM2 and 3
are distinguished on statistical grounds only. Me 2 is
thinner than MM2 + MM 3.
(b) Me 5 on the other hand is thicker than MM 4.
(c) The arrangement of coal seams is different, but this mqy
be more apparent than real, as Me is based on log-data,
whilst MM is based merely on cuttings samples.
Li thologically, Me 1 differs from MM 1 only in containing graphite.
This mineral is w~dely distributed in the Hawkesbury Sandstone and its apparent
absence from MM 1 is probably only fort~itous.
"Red Beds" are· more pronounoed in Me 2 ani 4· than in MM 2 - 3.
Coloured chert pebbles and grains are, if any thing, more abundant
in Mellong than in Mt. Murwin, and the former is distinctly more arenaoeous than
the latter.
Devitrified voloanio ash is a more proI!linent component of the
lithology of Me 8 than of the equivalent beds MM 6 - 7 - 8.
Comparison with the Grose River Distriot I The beds of the Narrabeen Group at
Mellong also resemble closely those of the Narrabeen Group at Grose River, as
desoribed by Crook (1956). The Grose River sequenoe is as follows:
Hawkesbury Sandstone
Burralow Formation
Grose Sandstone
450' thiok (including the Tabarag
Sandstone Member, 80' thick and 130' above
the base of the Burralow). Grey shale and
red-brown ol~stone.
700' thiok composed of massive labile to
sub-labile sandstone with some beds of
shale and siltstone
Caley Formation
9. 150' thiok of sub-labile sandstone,
silty mudstone and shale.
It may be seen (Pl. 3) that Me 3 corresponds to the Tabarag
Sandstone MeP,lber of the Burralow Formation, and that Me 2 and Me 4 correspond
to the overlying and underly~ng shaley zones of the Formation. Me 5 is the
muoh thicker equivalent of the Grose Sandstone and Me 6 and Me 7 are the muoh
thioker equivalent of the Caley Form~tion.
It is reasonably oertain, therefore, that the Narrabeen Group
of the Sydney Basin is divisible into three formations (the Caley, Grose aqd
Burralow) rather than into two (the Clifton Sub-Group and the Gosford
Formation) as in the eastern part of the Basin.
Palaeontologya Palaeontologioally, there is little material available.
Dr. E. Kemp has examined a few cuttings for spores and has reported (personal
oommun~oation) that:
(i) the interval 2840' - 2850' contains spores diagnos~tio
of the palynologioal unit P3b - 4 of Evans. Within this
unit Evans inoluded the Newoastle and Tomago Coal Measures
am the Mulbring Siltstone. The type of spore suggested
a depositional site olose to the site of growth of the
parent plants.
(ii) P4 type l;Ipores w.ere also tound in the intervals 2580' -
2590'; 2510' - 2520'; 2460' - 2470'.
(iii) The interval 2360' - 2370' yielded forms whioh, if the
outtings were not oavings from higher levels, suggest
the inComing of Triassio elements.
(lv) From the interval 2510' - 2520' there oomes a shred of
evidenoe, in the form of an aori taroh alga, that braokish
water :i,.nfluenoes may have penetrated as far as the
Mellong region at the very olose of the Permian.
The Perm-Triassio Boundarya The Company ohose to place this boundary at 2480'
on the Ii thologioal grounds that here was the virtual end. of the Coal Measures.
/'
I I i 1
; .i
Fig 3
GROSE RIVER MELLONG ·MT MURWIN
Mel . .' ::.': MM I HAWKESBURY
w z
UJ 0 (/J .... o (/J a:: a (!) ~ ,
(/J
.... ,. '.' ...
f-:.-_-.-:- ------
Me2
• . . . . --'--::-=~:--- 1-:-:,...,.......,....-1 ~ ..... : •.• :.;.: •.. : TABARAG, .:.::: .:-: •.•••.• Me3
SANPSTONE
'::-.':;~: :".::';~-::" M 4 _,_._. _______ ._._. e ::'°:°,';. . .... ~
• 0° •• :
• : '; .: : : • °0 .: :. " ." .. ' '. '.' . . :.... :.::::<.:' . ', .....
• " '0 • .. '.' : " : ',' .:.: ; : '. ' .. : .. ~ .. ~ :. <, : ....
',' " . • '0 •• :
: ~ : .. :: :.' ~ ••••••• 0. '0.·· ., • .• !.
: ..... :.:.:; Me5
1 '.\\:::./ . : " . :.:. ~ . ; 0
1• '. '0' : ....... " .
CALEV FORMATION ~~:'.~f~ ~ . en _.-
. . ~ UJ •• . o . 0: • ., .
(!)...J:l '-_ X ~ en •• .... 0 ~ JU::E _
. '-
'- ' ~- .......
.i .
. 1··· . '.' .; o. '0' ••••• I,
I" ••• ... , · .... :.::': ".: .: "0
..... ~:'~ ; : : :. . ..••...• i'. :~: :'.: Me6 . , •• 0
0
.. :: .. ~.o ,,-.,~
'0 " •
" .------.. .-- .-:'-MeS -. ..
MM2
::: : .... :..'. MM3 ,'.', ' .. ,0.' ;
' .. ~ .. ' . · .. . · " ... ' • "0· • · " .' . · ... "
• .: 0" :','
' ..
· ... • ,0 " · . ~ : : .. ' ....
:. ',', .. : . ~ " .. . ... · .. ' ' . . .... . · ... .
· " '. ~:: ..
0° ,'- •• ' •
~~~,'. · ... . . .... :":', .-:--- . . . · . : :: ~ . ... ~. '.:: : :. ':' : -. -r-: · .' . :. "'-'
MM4
MM5
•. _ MM6-6 .- . . '- ""T
8. M..R. Pelroleum ExploroilonJ:'ehruory 1969 To (Jccompony Record 1969/2"
lLJ ..J .... VI ~ U
~ z
t
z UJ w m ~ a:: a:: ~
z
!
" ...J <X 0 U
VI W 0: :l en· <X w ::E
X AUS-I-71
. , .
10.
Rocks with lower Triassic affinities occur at 2370' and of
definite upper Permian age at 2460'.
The palynological unit Tr1 a which succeeds P4 in other localities
is now considered to be of uppermost Permian age. It is likely that the
Mellong unit Me 7 includes this palynological unit Tr1a, and that the Permo
Triassic boundary there lies at about 2400'.
The Permo-Triassic boundary at Mellong, as at Mt. Murwin, appears • .< - - ••
to be undistinguished by ~ noteworthy lithological feature and to be well
above the younge"st coal ·seam of the Newcastle Coal Measures.
Summary: The section consists of 27~O' of sediments that appear to be all of
non-marine origin, although there is a suggestion of a slight brackish-water
influence at 2510'. It is postulated that all the sediments represent the
accumulations of the varied micro-environments of a deltaic plain, over which
slight amounts of volcanic ash settled from time to time.
I
Eight units have been separated out on litho1ogical and geophysical
grounds, but there is no reason to doubt the essential conformity of the
sediments of these units which range in time from the upper Permian to the
middle Triassic.
There is a strong stratigraphic resemblance petween the beds at
~llong and those at Mt. Mui'win and in ~he Grose River District. The Narrabeen
Group units in particular can be arranged in the same three formations as exist
at Grose River.
The somewhat scanty information afforded by spores indicates that
the Permo-Triassic boundary is at 2400', some 80' above the horizon commonly
chosen, i.e. the upper limit end of the significantly large coal horizons.
AUSTRALIAN OIL AND GAS CORPORATION,
BOOKER, F. VI 0'
References
1964 Mellong No. 1 Well, Sydney BaSin,
N.S.W. Final Report.
1957 Studies in Permian Sedimentation
in the Sydney Basin. N.S.W. Dept.
of Mines Tech. Reports,vol. 5
1957·
11.
CROOK, K.W.A.,
PEl'TIJOHN, F ..J. .• ,
1956 The Stratigraphy and Petrology
of the Narrabeen Group in the
Grose River District.
1957
Jour. and Proc. Roy. Soc. N.S.W.
Vol. 90, Part II, 1956.
Sedimentary Roc~,New York,
Harper.
12.
APPENDIX·
Pa~nology of Cuttings from Mellong (A.O.G.) NO.1 Well,
Sydney Basin, N.S.W.
Cuttings from five intervals were examinEd by Dr. E. Kemp
(B.M.R.) who recovered the following forms:
1. From interval 2840' - 2850':
Dalhuntyispora parvi thola (very well preserved, ;common)
Cirratriradites sp.
Acanthotriletes cf. filiformis II terete angulatus
Leiotriletes directus
Punctatispori tes sp.
Parasacci tes sp. (rare)
Gnetaceaepollenites sinuosus
Striatopodooarpidites of. pantii
cf. Fimbraesporites sp.
Taeniaesporites sp. (Triassic form, m~ be oaving contaminant)
Dalhuntyispora parvithola and Gnetaoeaepollenites sinuosus are diagnostic of
palynologioal unit P3b-4 of Evans.
2. From interval 2580' - 2590':
Protohaploxypinus limpidus
Leiotriletes direotus
Acanthotriletes sp.
3. From interval 2510' - 2520':
Striatopodocarpites oancellatus
Protohaploxypinus limpidus
Vitreisporites pallidus
Marsupipollenites triradiatus
Microbaoulispora sp. indet.
Lophotriletes sp.
4. From interval 2460' - 2470':
Striatopodooarpites oanoellatus II sp.
Falcisporites sp. (a Triassio form)
13. Protohaplo~inus limpidus
II sp.
:. Vitreisporites palUdus
Lophotriletes sp.
Apiculatisporis filifo~~s
Veryhachium sp. (a 'non-freshwat!=lr acritarch alga)
5. From interval 2)60' - 2310' s"
Falcisporites ap.
? Taeni"aesporites ap.
Reticuloidosporites sp. indet.
Leiotriletes direotus
WELL NAME,No. MellongNolBore ELEVATION (A.SU SAMPLE STORAGE
OPERA.TING Co. \USTRALIAN OIL&CASCORP.LTD.: Ground Level 1146; fl. :BM.R.,Canberra PETROGRAPH Ie WELL LO G
WELL LOCATION .C~lla~ Dalum,1149'nsl.ft
Lal.: 330 00'?1" .S .• Long.: 1 S0041' 36" E.. Ba sin SYDNEY BASI.:.
S I a Ie IIE'I/ "O~'I'I! W AL.ES
Te n e men t No .. P.E.L.No. 103,N.S.W.Minp.3 Dept.
1250.000 Sheel No.S 1/56-5
200
000
1200
1300
1400
1500
1600
I , I
I I t-t !
t I
I r
.. M R ".fro/,um Exploratio" Ja"uary /966.
HYDROCARBON SYMBOLS
~ Show of all
e Trace of all
.tJ:. Show of QOs
-0 Trace of Oos
o Fluorescenc,
MISCELLANEOUS
Intervol ond Num ber
of Formation T.~t
No sample available
tram int.rval
'00
Geology by.
ZOO fI
DESCRIPTIONS OF
CUTTI N G S
Description ® reter!; to litnolotjllcol
palfern@ 01 correspondrnQ depth)
PALl VtLLOW .. ME1)IUM·'.AIN[D SANDSToNt
WITH CL[Alit SU .... MGULA .. QUA'RTZ IN
WHITE IiI~T1!Il\.5I'A1!SE hlUSCOVITE ANl>
IOlIAl'HITE.l>151'ns[]) ltDUN:PEl> _1I.TZ
• TIIl~"K' OF MOW .. F'(1tWUGINOU,
SANDSTONE
• ... OWN ,,,TS'Tg,,,, -NIT" &1try MOTTLIMe;
"ALE ""LLOW M(~IIJM TO '1"[" '''''INI' cauAIT1 SAM'D5ToN£ WITIo4 WMr1"r ([ .. , .. T.
3,5 AS A.O~C
.. A' ... .ao-vll'
4 AS AJI,ovE
ME llONG (A,O.G.) No 1
S.J.Moyne
[JiJhon oxide
EJVO!CaniC5
o
,-::r .'
'.'
.. ,."
1°,,°6' 1 BreCCia to conolomerot. LITHOLOGICAL SYMBOLS
E2J ....... Quortz sand ,Iondstone ~ Cool
~t~~~ ~- Siltstone ---1 '-'-'I } ~ - - Snole ond mudstone '-~'- Cloystone
{ ~ , c , Calcirudite
E2i9 Llm.stone ____
~ ~ ~ ~ Calcorenit.
~ Dolomlt. ~ Calcilutite ~ ~~
DESCRIPTION
OF
INTERPRETED
LITHOLOGY
Rock Nome
(attrr Prttljohn ,1957)
OIITHOQUARTZ ITE l'ALE BUFF.MlJ)lUhI'GRAINE\),
"RAINS SUIII\NGULAR,SOMC WITH C1l'fS'Al '1'(15. LENSES OF CMltSER 5A~ /'til> IIOIII6l£l) "I.I.tIlTZ
PEpLE5 II' TO "mm. IHTERSTITIAl WHITE C.LAY OCCASIONAL CllAINS OF FELlISMR SHREOS of WHITt hllCA AND RAU BLEBS 6,. GRAPHITE. I~RE'ULAR U"oNIT[-IIICH MilliS •
I .. TIIl.CDDI:P 5ILTaTON£ AND NOTOQYA1tTZIT'1
702 .... TIIE XQUEIICE IS SILTSTONE 302" . . I'IIOTO ....... TZITE T .. JlLTSTONE CONSISTS ., ISZ ..... RTZ,S2 r£LIIIM. IN A MATRIX", li:AOLU ... S'W'CIT£. CA_ACEOUS rU"(I:5, SlKRITE UAN.,,,. TO LltrAONtTI, AIQ) aA"£ 11.'OMS. THI .... crrOQUA.T&ITC COIIIlfiTS "~"_,,,~.~ __ • ...., ~~,::l=~<"nT .... U.
-nt~ SILTSTONE AMP PIlOTO ....... TZ,ITI" AS A"'V[, TIll 5A_ SlL T5TOOl[ _ ..... E"e"'UANULAI. _$~I~ ... ...,A"RTJ, NG nL»,p,A. "RAINS"" TO -Ii ..... , ",,""Ttl IIMaITE/UMOHITf, ~ .... c.MfaT Z.Iyt,COM NO TOUlilMALUIE
"ROToaUAltT'1ITE WITH IlL T,ToN' .... RTINU
""OTOQ."AIlT~IT •• A5 AaOVl, WITH NICH CO,.ToN"T t:'F 01'01» AIiP •• AV[l·IIZfP I;IIA"'S tlf Co\'OURl"'D c,HE1I:T.
BM.R. UNITS
z o ;::: !!, a: u
'" .., o
W Z 0 .-(J) Q
Z « tn
Plale
lA
Q.
:> 0 .., a: ", ", . ..
U
o
0::: (/')
z
<
X AUS -1- 60A
•
FO S S I LS
'900
3000
00
00
00 !
! i
8.M.R p,frol.um E,cplorofton Jonuory 1968.
DES C R I PTI 0 N S 0 F
CUTTIN GS
Descrlpflon ® refers to IIfholo91COI
POflern@ 01 corresDondlnc;J depth)
4 MEDIUM-_RAIN(D QUARTZ CHERT SANDSTONE
........ ilL TSTOOI[ WITH "'Uhl'" SANDSTONr
n.;A(..[ 011 COAL WITH SMiIT"( 'ILTn'ONE ... ,...
ME»"J'" SAUSTDNE.
COAL.
COAL
WMIf!$H "o~('''M'' ASif
C..E ..... I.IlO~1'4 AO"LAC,tl. c~eus 5ttAt.1
COAL.
'INTEIltL""'IMATtD $.AMJ"( "LTSTC",'/
"IM£ ...... pM('pt\J1'IA ~D:!ioTON[J "I.("'t,
ANP (.A~NAc.[I1I1~. 5HAL£i, C_AL
AIIID "'" .. TI'>" "."'ANle A ....
..... ·.it ... ·x:.
.. '!-'
DESCRIPTION
OF
INTERPRETED
LITHOLOGY
IIiTEItIl[DDED 'ItOTOQUAItTZITE AND SILtSTONE
1151 OF THIS SUUENCE CONSISTS OF PROTOQUA"T:t In: (AS A1!OIIE)
IS Z CON 51 5TS or GR£Y-BaOWN SILTSTONE {fI5 ~CNI:) WITH OCCIlSIOtIAL COALY
PARTIN,S.
,OZ Dr THIS SEQUENCE COI/SISTS Dr acy O,.TE:N CARAOHACCOUS IILTSTON[
40l COOISISTS OF PIIIQTOQUARTZITE (liS
.-.:>vc) WIT1-I NO (""RSE CHERT (;I/\'N5 .
II EN T I TlV[ success ... , IW COAL,
CII~AC[OIl5 SIL TST_ All'
PtlOT04llUAilT ZITf ; SOMf PAU: artY D£v,T"'rl£JI VOLCANIC '"'Sit
B.M.R. UNITS
QJ
o
&oJ ... ..
u
z ~
~ 0:: I.J.J
a.
XAU5-1-60B
Recommended