250 THE GEOLOGY OF THE MALAY PENINSULA. 
In Sumatra the granite is mostly syenitic, and whether it was 
intruded in Palaeozoic or Mesozoic times is not yet known. In 
ne Malay Peninsula there are two. distinct facies, a tin-bearing 
granite, and a hornblende-granite with associated syenite, the latter 
being found in the Benom Range. This hornblende-granite agrees 
with the hornblende-granites found in Sumatra, and elsewhere in 
the Archipelago, and there is no evidence of it being younger or 
older than the tin-bearing granite. 
Sedimentary strata of Cretaceous age are known in Borneo, 
Java, Sumatra, and smaller tislands of the Dutch Hast Indies, but 
all of the northern part of the area was a land surface subject to: 
erosion, and no deposition was taking place there. 
In Borneo certain strongly folded shallow-water sandstones and 
marls contain foraminifera, of which one species Orbitolina, makes 
it certain that the deposits are Cretaceous (Cenomanian). In Java. 
there is a series of serpentinous, mica-, chloritic, and clay-schists 
containing limestone bands, which, in one place, contained Orbi- 
tolina, the fossil characteristic of the Cretaceous beds in Borneo. 
These limestones are nearly always granular and crystalline, with- 
out fossils. The schists are traversed by thin quartz-veins, and 
they are penetrated also by dykes of quartz-porphyry, gabbro and 
dolerite. 
Cretaceous rocks are found in the Arakan Yoma of Burma, and 
along the same line of strike, to the south, in the Andaman Islands. 
Marine limetones occur at the base, while the upper part of the 
series consists of shallow-water and estuarine deposits. Besides 
the granite intrusion, masses of serpentines of Cretaceous age are 
known, an these are penetrated by veins of the semi-precious mine- 
ral jadeite. . 
Tertiary. 
In our area, as in Europe, there is a blank between the upper 
Cretaceous and the overlying Eocene deposits, which is marked by 
an abrupt change in the nature of the fauna, rather than by a sharp- 
ly marked stratigraphical break. The igneous activity in Cretace- 
ous times was the forerunner of earth-movements which continued 
during Tertiary times, affecting both the lower and upper Tertiary, 
aithough they were much stronger in the north, and in the 
Andaman Islands, than in the Malay Peninsula and in the Hast 
Indies. 
In the Northern Shan States there is no trace of the marine 
Tertiary rocks which are so well developed in the plains of Lower 
and Upper Burma, so it is clear that, when the Tertiary sea extend- 
ed over what is now the valley of the Irrawaddy, the Shan Plateau 
had already been raised above its waters. 
Tertiary of Burma. 
In Burma the Tertiary beds are represented by the following 
series: 
Jour. Straits Branch 
