5<S GEOLOGY OF LOWER MESOZOlC ROCKS OF QUEENSLAND, 



Lower Mesozoic rocks, both in Western Queensland and in New 

 South Wales. At some places, there is a very great thickness 

 of Cretaceous and possibly Cainozoic strata overlying the Lower 

 Mesozoic rocks; e.g., in South Australia, the bore at Goyder's 

 Lagoon struck water bearing strata at 4, 700 feet, and the Patcha- 

 warra bore was abandoned at a depth of 5,458 feet, being still 

 in the Cretaceous rocks. 



Palaeontological proof of the age of the water-bearing strata 

 in the bores is not often forthcoming, but, in a number of cases 

 in New South Wales, records have been made, e.g., (a) in the Bul- 

 yeroi bore, 60 miles W. by S. of Moree, Lower Cretaceous rocks 

 with marine fossils were passed through down to 520 feet, and 

 then shales, sandstones, and coal-seams with fossil plants: (b) in 

 the Wallon bore, 20 miles N. by W. of Moree, Lower Cretaceous 

 rocks with marine fossils were encountered dow^n to 1,500 feet; 

 at 1,630 feet, fragments of Tceuiopteris spatnlata [7'. Baiiiti'eei] 

 were obtained, and water was struck at 2,330 feet; (c) in the 

 Coonamble bore, both T(vniopteris sjmtulata [7'. Daiiitreei\ and 

 Thlniifeldia odoiitopteroides were obtained. These are not all of 

 the recorded occurrences. 



The Walloon Series (or its equivalents) is considerably thicker 

 than the Ipswich or Bundamba Series. In AVestern Queens- 

 land (Roma District), the map and sections prepared by Messrs. 

 Saint-Smith and Thom show a width of outcrop of about 60 

 miles, and dips of the order of 3 or 4 degrees; the dips are small, 

 but, if the average dip be only 2 degrees, the thickness repre- 

 sented is about 11,000 feet. En the Maryborough District, the 

 thickness of the Tiaro Series has been estimated at 12,000 feet 

 by Messrs. Blake and Bryan. 



if) Artesian IFa^er. —A general consideration of the Lower 

 Mesozoic rocks of Queensland would not be complete without 

 some reference to the question of artesian water. This question 

 has been the subject of considerable controversy between the 

 exponents of the two theories as to the origin of the water, 

 known respectively as the '^ Meteoric" Theory, and the "Plu- 

 tonic" Theory. Suffice it to state, that there seems now to be 

 no reasonable doubt that a large portion of the water is of 



