CHAPTER IX. 
THE PEEMO-CARBONIEEEOUS ^YW^'EM.—coniiniied. 
the aTMPIE FOEMATIOlSr OUTSIDE OE THE TYPE DISTEICT— co'nitMMec?. 
HoD&Kiifsojr, Paimeb, Mount Albion, Silveepield, Watsonville, and CniLLAOOE. 
■^’^eas— viz., Hodgkinsoii Gold rield, Horthcote Antimony Mines, Mulgrave Gold Field, 
*‘aliner Gold Field, Cannibal Creek Tin Field, Mitcbell Antimony Mines, Mount Albion 
®'bd Chillagoe Silver Fields, Dry Biver Silver Field, Bebo Gold Field, and Sellbeim Silver 
Field. 
_ The geological position of the Hodgtinson Gold Field has long been a debatable 
,, m my mind, but I can now see my way to include it, at least provisionally, in the 
'^ympie Beds. 
■L This goldfield was described in detail by the Writer in a lieport* accompanied 
^ '^^0 maps. 
qq Tile stratified rocks of the Hodgkinson vary in fineness from shales to 
Boif 5 ^^^‘J'tes. The shales consist of pure blue clay, sometimes (as for instance at the 
Idmi Mine) blackened by carbonaceous matter. The clay is divided into thin 
hy the planes which mark the pauses in the process of deposition. Slaty 
entirely unknown, but it is so rarely met with and so uncertain in its 
prod presumed that pressure of the sort which results in the 
fhe *f*^^**^'^ cleavage has been very feebly exerted in this region. Alternating with 
lestj strata of greywacke, whose materials are essentially the same although 
The component grains or granules of the groywaekes have been partly 
hlejjip ^ basic felspar and partly from a hornblendic rock. The felspatho-horn- 
deriv' 1 contains minute flakes of mica and grains of quartz, both apparently 
thg ^ granitic rock. According to the frequency and size of the quartz grains, 
gradations into grits and conglomerates. The latter, 
®^Udst^^' besides quartz pebbles, pebbles of quartzite or hardened siliceous 
porphyry, lydian-stone, dark shale, and limestone, 
surfj^c ^ '^^’^Mully noting the dip and strike of the strata, wherever they appear at the 
maps ^ gullies or on hilltops, and laying down their direction and degree on the 
^iffere^r clear idea of tho structure of the goldfield has been obtained. The 
^oufid ^ do not present such marked characteristics that they can be traced with 
haveij*^^^ distances, although some of the conglomerates in Glen Mowbray 
Uaturet^v for more than a mile. Conglomerates, however, are from their very 
local oecu^*^^ product of strong currents and powerful attrition — apt to be of very 
‘^’^d Rij the area embraced by tho large map (the neighbourhood of Thornborough 
P^sical^f^ there is a marked connection between the geological structure and 
Il'ich b of the field. This probably holds equally true of the outside districts. 
have neia. xnis prooaoi 
uot yet, however, been mapped. 
a 
Brisbane : by Authority : 1884. 
