Page 68 - Sumatra Geology, Resources and Tectonic Evolution

GRANITES 55

I I I I I i
96OE 98 ,~ 102 ~' 104"-' 106" t 08 ~
\X "}
~ ~""S i k u I e h.,._.._~
- 6<,N
BANDA ACEIt
~.
o
, , ,{JL.~ Batholith o ~
\ q l
GeuXfit'~eu~ ~ ~ _ ~ . . Kuantan-Dungun
Granodiorite\'~ ;~ ?LSerbadjadl
.... i i
~\. L
4 o
Unga MALAY
Diorite ~ .... PENINSULA
,,[,u,on,

2 c' i ~' HataPang'x~-N-'~
Sibolg,~
Batholith,
~~ RIAU
'
Muarasipongi
-~Rokan
ISLANDS
L., "~ \~X "? .... Siabu
-- 0 < (~ Ombilill Sulit Air"[
G ran itel~.~J)te.~ ),,Sijunjung
;ingkep
~anjung ~; "~lsahanU~'\"-P'---~ -
,Gadang <,,, \
_North O JAMB.]
I~IL Bungo Batholith ~:
- 2~ VOLCANIC ARC PROVINCE ~I'L~ South .
Biotite-hornblende diorites~,~ BANGKA
tonalites, granodiorites and ~~ BILLITON
i ................................
monzogranites of Volcanic
Arc affinity, l-Types F
Age range 203-5 Ma ranjong'
MAIN RANGE PROVINCE Pandang'-~'---'-
-4'~ Biotite monzogranites of BENGKUI.U Pluton 4 ~ --
l ~,, J Post-collisional affinity S-Types ~.e Garba
l "~ J Some tin-associated "--. LIN Batholith
Age range 247q43 Ma
Padean oguru
EASTERN PROVINCE
*/Jatibaru
Biotite and biotite-hornblende % rbamba "X>~.~'~ On~;~Sulan T~
~
n
g
Pluton ~
monzogranites of post-collisional BANDAR LAMPUNG
_6 ~ [--~ and crustal I-Types v,/
Age range 264-216 Ma tti
0 100 200 300 400 500km
96" 98 ~ 100 ~ 102 ~ 104 ~
1 .................. i .................. l .......................... I
. . . . . . . . ...... l ........
Fig. 5.1. The granites of Sumatra, the Malay Peninsula and the Tin islands of Bangka and Billiton. Data from Beddoe-Stephens et al. (1987), Clarke & Beddoe-Stephens
(1987), Cobbing et al. (1986, 1992), Sato (1991), McCourt & Cobbing (1993), Gasparon & Varne (1995). Broken line shows the eastern limit of the Western Province
Granites in Sumatra.

In Peninsular Malaysia the Eastern Granite Province is separated for the Tiga Puluh region, Clarke & Beddoe-Stephens (1987) for
by the Bentong-Raub Line from the Main Range Province, where the Hatapang Granite, Sato (1991) for three I-type and S-type
the ages of the granites are generally younger, ranging from 207 to plutons in central Sumatra, Gasparon & Varne (1995) for selected
230 Ma (Late Triassic) (Figs 5.1 & 5.3) although some granites, plutons of mainly volcanic arc character from the whole island,
especially in the Tin Islands, have given Late Permian ages, e.g. McCourt & Cobbing (1993) who provided a complete data set
the Belinyu and Penangas quoted above (Cobbing et al. 1992). of their collection for the southern half of Sumatra, and
Although a great deal of work has been done on the granites of McCourt et al. (1996) giving selected data from that data set. It
Sumatra only six studies have provided sufficient detail of their is however useful to interpret the ages and affinities of other gran-
geological, geochemical and isotopic features for useful compari- ites in Sumatra within the framework provided by these recent
son. These are the publications of Beddoe-Stephens et al. (1987) studies, using the field and petrographic characteristics provided
for the Muarasipongi Batholith, Schwartz & Surjono (1990a) by earlier studies.