PART 2.] 
kin.[) : Gold-fields of S. - E. Wynad. 
37 
It is much more difficult to say anything as to their depth in the underlie. Very many show 
by their outcrop on the hills and valleys that they are 300 or 400 feet in depth. The Hudia- 
betta Reef, on the edge of the ghats, gives indications of being 1,300 yards down its underlie ; 
while there is slight evidence that some of the reefs west of this show down in the low 
country. On the other hand, two large reefs, as they run south of the Nadgani-Giidalur 
road, are not seen in the deep trenches, and it is difficult to say whether they are covered up 
or have actually thinned out. 
The thickest actual section is 15 feet in the quarries of the Skull Reef, though there 
must be greater thicknesses than this close by. A good average thickness in most of the 
reefs may be taken as from 4 to 9 feet. The thickness of the leaders naturally varies 
very much. They appear to run generally up to 2 feet or so; but there is one under the 
Dunbar Reef which is 6 to 8 feet in thickness. 
A very common feature in the outcrop of the big ‘ ledges 1 is, that they show strong on 
the higher parts of the ridges and hillocks traversed by them, and thinner or not at all in 
the saddles. This at first sight points to a probable thinning out in depth ; hut there is the 
view that the higher ground is more open to denudation while the saddles would to some 
extent be covered up by debris of the country rock, and their slopes are not so steep as 
those of the ridges; the outcrops, too, are deceptive, for they are often encumbered with big 
lumps of fallen quartz. Indeed, the masses of fallen quartz are in some places so largo and 
so tumbled together down the western slopes of the grassy hills that they give the appearance 
of stone in situ. 
The rock of the Wynad, or as it would he termed in mining regions the 1 country rock,’ 
is gneiss, belonging to the Mdest known series in India, termed 
Rock of the country. variously the Crystalline, Gneissic, or the Metamorphic, series ; 
Gneiss - and is of very variable constitution in different parts of the coun¬ 
try. Ordinarily, there is a massive foliated quartzo-felspathic, or 
quartzo-hornblendic variety, with intercalations of micaceous and taleose schists; but all 
these are, except in the hill-ridges, generally weathered or decomposed into a more or less 
tough clayey rock, granular and friable with the undecomposed quartz, dark red and brown 
from the hornblendic and chloritic constituents, or white, pale colored, and cheesy, or soap3' 
from the felspatliic, micaceous, and taleose ingredients of the original rock. There is a large 
quantity of ferruginous matter distributed through the gneiss in the form of minutes granules 
or crystals of magnetic iron; and in one particular baud in the Marpanmudi ridge, as 
laminse of gray hsomatite. Hence the red and brown colors of much of the decomposed 
rock; and also its occasional lateritoid character : while at every working of the surface 
soils or the river sands by the Pannirs there is the unfiiiliug accompaniment of black 
iron sand. 
The strike of the foliation, or indeed of the lamination and the bedding of the gneiss, 
is usually east-nortli-east, west-south-west, the dip being mostly at high angles to the south¬ 
ward ; except in the Vellaramulla and Sultan’s Battery country, when a west-north-west, 
east-south-east foliation is prevalent with some folding, and even reduplication of the beds. 
In South-east Wynad four belts of gneiss are recognizable. Along and south of the 
Several bands of gneiss. Nadgani-Giidalur high road there is the northern edge of the 
highly syenitoid and quartzose gneiss of the Oucliterlony valley 
and the Nilgiris. North of this and striking about east-north-east, west-south-west, is a 
highly felspathic band with two minor belts of chloritic gneiss. In this, the Dayvallah zone, 
there is very little true massive rock until—still going north—the conspicuous and pic¬ 
turesque serrated and lofty ridge of Marpanmudi and the Needle Rock is reached. Here 
