330 GREAT SERPENTINE BELT OF NEW SOUTH WALES, vii , 



trict. We must conclude, therefore, that considerable repetition 

 by strike-faulting is present, though admitting that the sequence 

 from east to west is, in the main, an ascending one in the time- 

 scale. 



We shall now endeavour to trace through from the Tamworth 

 to the Nundle District, several horizons already recognised in 

 the succession of Middle Devonian strata. 



The Nemingha Limestone. — The main limestone of the Loom- 

 berah District is clearly a continuation of the mass of limestone 

 which runs through Beedles Freehold and the Gap at Nemingha 

 (6, pp. 587-9), and then commences by the eastern corner of 

 Portion 60,* Parish of Loomberah, appearing from beneath the 

 river-alluvium, and running thence to the south-east through 

 Portions 59, 58, and 57. It is a brecciated pink limestone asso- 

 ciated, in Portion 59, with a small amount of very ferruginous, 

 more or less brecciated keratophyre or porphyritic andesite, lying 

 on the eastern side of the limestone; and, to the west, is an intru- 

 sion of porphyritic dolerite with phenocrj^sts of labradorite. The 

 outcropping mass of limestone is 77 yards wide, but it is impos- 

 sible to determine the thickness of the limestone owing to the 

 absence of any evidence of the angle of dip, though adjacent 

 rocks dip at high angles. It is broken by cross-faults, throwing 

 it for short distances. In Portion 58 (Mr. David Carter's pro- 

 perty), the limestone has been duplicated by a fault or faults, 

 and a short band of the same horizon occurs four hundred yards 

 north-east of the main zone. The eastern mass is the more 

 clearly exposed, and covers an area four hundred yards long by 

 sixty yards in width. Both bands of limestone have a western 

 wall of keratophyre-breccias, ferruginous rocks apparently greatly 

 altered by percolating solutions (the Nemingha Red Breccia). 

 Both masses of limestone, for the most part, lie in ploughed 

 land, and, in the boulders of limestone brought to the surface, a 

 large series of fossils was obtained, which confirm the correla- 

 tion of this limestone with the Nemingha horizon. These were 



* Unless otherwise stated, all references to Portion-numbers in the 

 sequel refer to Portions of the Parisli of Loomberah. 



