.10 ~
t04
10 2
E
~- 0.t
..._1
.,uC
"-" t05
t.t.J
~0 4
iO 3
t0 2
ARKOSIC
UNAFFE
FELDSP
RATION]
ARKOSI(
TES AFF
BY FELl
KAnl IN
SA!
RAIN SIZE
cr
~2.7 >~r ~,"MED,UM
/.,
~ FINE,
',',~ ~vERY
.//)
/~2 FINE
L,}
,,,
|
CHANNE
AN
CREVAS
COAS
BARR
l/S S /
/
ARENIT
CTED Bh
AR ALTE
ARENI-I
ECTED/
~S_~AR/
rlON r
ES
/
~,M.
/ ~.~z~ ~ E
(
~l"
MIOCENI
CANIC-L
ARENIT
( JAPAN,
6ooo ')
L FILLS
D
SE
SPl AYR._
I'AL
IER
ESTIMATE[
INITIAL Pt
DIAGENES
)SITION
IS
s
'/
/
: VOL-/
,~H,~/
~oo-I/,
l/
t0
20
",/,,~ gVF.
I
E/ /i/
M. 1
E
|
"'I" M.
i/
9
|
0.t
.,.
0
t0
20
30
40
50 0
30
40
50
POROSITY % BV
Fig. 8.18. Illustrations of the changes in porosity and permeability for sandstones of different mineralogical
composition and for different burial depth. (From Nagtegaal, 1978, courtesy of the Geological Society of London.) (A) Reference grid for porosity and permeability values of various grain size and sorting mixes of unconsolidated clay-free sands. (B) Porosity/permeability plots for Miocene quartz arenites at 11,800-12,000 ft
(3596-3657 m) burial, (12 samples) Niger delta. (C) Porosity/permeability plots for arkosic arenites with and
without feldspar kaolinisation, at 9,000-10,000 ft (2743-3047 m) (20 samples) and 10,000-11,000 ft (30483352 m) (34 samples) burial, respectively. Jurassic sands, North Sea. (D) Porosity/permeability plots for Miocene volcanic lithic arenites (greywackes, according to many classifications) at 5000-6000 ft (1524-1828 m)
burial (18 samples), Japan.