Krasnozems of Innisfail — Monteith 
375 
33-36 inches. As above with gravelly "stone" 
line consisting of "cuirasse.” 
36 inches. Similar to 8-33 inch layer. 
The soil contains an amount of clear euhedral 
quartz with some stone lines of basaltic and 
nonbasaltic origin, and occurs generally over 
steep hills. Field observations, therefore, seemed 
to indicate that the soil was of mixed origin, 
containing colluvial materials derived from 
basaltic and nonbasaltic sources. 
Daradgee Series ( McA-voy Farm ) 
0-8 inches. Yellow-red (dry) 3YR 4/8, dark 
red-brown (moist) 2.5YR % clay loam. Mod- 
erate line granular structure. Friable consistence 
when moist. 
8-44-)- inches. Dusky-red (moist) lOR % 
grading to dark red (moist) lOR 3/6 clay 
loam. Fragmental, firm consistence when moist. 
This soil appears at elevations of approxi- 
mately 50-80 ft above sea level and is associated 
with upper-level river terraces. In some areas it 
occurs as a band of uniform width between the 
river terraces and Pin Gin or Eubenangee soils. 
These field observations seemed to indicate that 
the soil had an alluvial origin. 
Mundoo Series ( Grima Farm ) 
0-8 inches. Yellow-red (dry) 5YR 4/6, dark 
red-brown (moist) 2.5YR % loam. Apedal, 
friable with some gravel plentiful, fine, eu- 
hedral, clear quartz. 
8-30 inches. Dark red (moist) lOR 3/6, 
gravelly loam. Fragmental, firm consistence 
when moist, some gravel and plentiful fine, 
euhedral clear quartz. 
30-42 inches. Similar to 8-30 inch layer, but 
plentiful gravel. 
42-)- inches. Similar to 8-30 inch layer. 
The main features of the Mundoo series are 
the abundance of clear quartz throughout the 
profile and the occurrence of scattered, discon- 
tinuous "cuirasse” layers. The soil forms a 
gently sloping dissected plain and can be traced 
under the olivine basalt flow. It could be hy- 
pothesised from field observations that this soil 
was of nonbasaltic origin which had undergone 
a laterization process, had been covered by a 
basalt flow, and later was exposed. 
Crook and McGarity (1955) have described 
the presence of considerable quantities of clear, 
high-temperature, euhedral quartz in some 
krasnozem soils of the Lismore area. They con- 
cluded that the quartz was derived from 
rhyolitic tuffs. In the case of the Mundoo soil, 
quartz could be derived from quartz rhyolite 
of the Upper Paleozoic Glen Gordon volcanics. 
However, as the nearest outcrop is 26 miles to 
the southwest, it is difficult to attribute the 
origin of quartz to this source, even though 
there is no other satisfactory explanation. 
LABORATORY METHODS 
Soil samples from pit profiles were air dried 
and passed through a 2-mm sieve. Air drying 
was used because field moisture contents were 
in the order of 25-40% by weight and indi- 
cated that allophane was not present. 
After treatment with H 2 0 2 , "free” iron was 
extracted, using the dithionite method (Jack- 
son, 1956:57). The clay (< 2ji) fraction was 
separated by centrifugation and the silt and 
sand fractions by sieving. X-ray diffraction pat- 
terns were obtained on oriented clay samples 
which were washed to remove excess salts. The 
heavy and light mineral fractions were sepa- 
rated by flotation in bromoform, using the silt 
size samples. These fractions were dried and 
weighed separately, then mounted in Canada 
balsam for microscopic investigations. The per- 
centage of tourmaline and zircon was estimated 
by counting mineral grains in the heavy frac- 
tion. Differential thermal analysis was carried 
out on air-dried samples ground to pass through 
a 70-mesh sieve, using 0.4-grn samples with a 
heating rate of approximately 10 C per minute. 
Samples were treated with hot 0.5N sodium 
hydroxide and were analysed again on the DTA 
apparatus to distinguish the goethite from the 
gibbsite peak. 
RESULTS AND DISCUSSION 
The table shows marked differences in 
mineralogical properties among the four soil 
series. 
Light /Heavy Mineral Ratio 
Because most of the light fraction is quartz 
and the heavy fraction is magnetite the light/ 
