n 



various formations, cMefly in connection with fields of coal 

 and lignites, and appears to arise from tlie decomposition or 

 distillation of these strata by subterranean heat." According 

 to the above, and the treatises of other authors upon the origin 

 of petroleum, it is merely the outcome of entombed animal and 

 vegetable decay under certain chemical conditions. If ever 

 such forms were enclosed in our fundamental rocks these con- 

 ditions, or more strictly speaking, metamorphic actions, have 

 long since carried the necessary constituents far beyond the 

 point of ordinary liquefaction. Therefore it would be, under 

 the present state of information, a criminal weakness to offer 

 an inducement that the sought-for treasure is sure to be found 

 in these beds (see Professor Tate's Annual Address to the 

 Eoyal Society of South Australia, 1880-81, pages 124^ and 125). 



BUILDIXG ^IaTEEIAL. 



Qitartzite. — This material is moderately plentiful in Western 

 Barossa. IS'orth of Cockatoo Creek, in Sections 3034 and 3036, 

 abundance of quartzite of medium architectural quality could 

 be obtained ; also a very fair building quartzite — though seem- 

 ingly only fit for rubble work — can be got at Springbett's 

 Quarry, Section 3064. 



Marble. — It is not at all improbable that a marble of 

 very fair architectural properties may be procured in Sections 

 105 and 106. 



Clay -Slate. — Though a considerable quantity of clay- slate of 

 late years has been used in Gawler for building purposes, very 

 little of that material comes from Barossa. 



Brick-Clay. — Ordinary brick of very fair quality has been 

 and is still being manufactured, as occasion requires, from the 

 drift-clays on the flats of the ISTorth and South Para Elvers. 



Sand. — Sand of excellent quality for building purposes is 

 obtained from the bed of the rivers ; and for the use of the iron 

 and brass founder it is procured of very fair quality from the 

 more friable arenaceous beds of the Miocene deposits imme- 

 diately to the east of High-street, and the sandy loams on the 

 banks of the rivers. 



Mortar. — The travertines of Barossa are very much inferior 

 to those of Mudla AVirra for building purposes; therefore the 

 mortar used in Gawler and neighbourhood is chiefly procured 

 from the adjoining Hundred. 



Road Metal. — A considerable part of the road metal used in 

 Gawler is of pebbles from the rivers ; travertine is also used 

 to some extent, and is chiefly obtained from the adjoining 

 Hundreds of Munno Para and Mudla Wirra. In Western 

 Barossa a very fair quartzite metal is obtained from Spring- 

 bett's Quarry, Section 3064 ; likewise from a band situated in 



