20 MADAGASCAR 
places where the rock became visible it was granite or 
quartz with good-sized masses of rose quartz. The case 
is quite diherent on the western side, on the geological 
conditions of which we have been informed principally 
by Grandidier and Gautier. From Nossi-Be, where num- 
mulitic limestones occur, there begins a broad strip of 
mesozoic (calcareous and Jurassic) and eocene rocks which 
surrounds the granitic high land on the west, bends 
round on the south and extends as far as Fort Dauphin. 
The stratification of these sedimentary rocks does not 
appear to have suffered any disturbance. In the num- 
mulitic limestones of the eocene period are found al- 
Geological Section from Majunga to Suberbieville (after Leon Suberbie). 
I. Recent alluvial formations. 2. Early alluvial deposits. 3. Calcareous rocks. 
4. Jurassic rocks. 
veolina, nummulites and Velates ScJmiicleliana. As can be 
seen in the accompanying diagram the Jurassic deposits and 
calcareous strata in Bembatoka Bay reach from Majunga 
to Suberbieville, but are broken through here and there 
by masses of basalt. In the south-west, in the valley 
of the River St. Augustine, are found strata rich in fos¬ 
sils, which probably belong to the lower greensand. 
Richardson found ammonites, terebratulas, turitellas and 
petrified echinoderms. 
E. Suesz remarks concerning the geologic past of the 
island, that India, Madagascar and South Africa bear the 
marks of having been once united into a single table¬ 
land. A rupture from India took place during or after 
the lias period, and from South Africa some time earlier 
