244 H. *S'. Suriiniers : 



required to prove their pre'-Devonian age, it ■would be fui-nished 

 by the character of the pebbles, many of which show dimple« 

 caused by intense pressure of one pebble against another during 

 earth movements. If the beds were not in existence prior to 

 the Devonian earth movements, it is extremely difficult to ex- 

 plain the dimpled nature of the pebbles, as there is no e^- 

 dence of subsequent folding in this area. The conglomerate 

 probably formed a shore-line deposit in the Silurian sea, and is 

 part of the same seriesas the Silurian conglomerates near Mansfield. 



The cherts were altered prior to the formation of this eon- 

 glomerate, as fragments of both chert and diabase are found in the 

 conglomerate, and, further, the conglomerate rests uncomfortably 

 on the upturned edge of the sandstones and shales of the trian- 

 gular patch already referred to, lying about three miles north 

 of Tatong. This area is mapped as of Silurian age, but a note 

 on Mr. Howitt's map states that the boundaries between the 

 Silurian and Ordovician beds have not been defined. If the 

 Silurian age of the conglomerates be accepted, these beds would 

 seem to be not younger than Upper Ordovician, as there is a big 

 unconformity between the two. The conglomerate is found in 

 parts directly lestiiig on the sandstone and cliert beds. The 

 cherts and diabase, therefore, are of pre-Silurian age, and the 

 evidence in this area points to the age being Upper Ordovician, 

 rather than pre^Ordovician. The evidence as to age is scanty, 

 as no fossils of any description have been found in the Tatong 

 area, and the nearest fossiliferous beds are some distance to the 

 north-east. 



At Edi and Myrrhee, to the east and north-east of the cherty 

 area, graptolies have been found in the beds containing the tur- 

 quoise deposits. These fossils were submitted by the Mines 

 Department to Mr. Hall, and although they wei-e poorly pre- 

 served, he was able to identify sufficient genera to show that 

 they were alm.ost certainly of Upper Ordovician age. To the 

 north-west, at the Reef Hills, Benalla, sandstones have yielded 

 fossils of Silurian age, and to the south-west are the Silurian 

 sandstimes and limestones of Loyola and the Mansfield area. 



Mr. Howitt has recorded the strike of the Ordovician beds as 

 being N. 40 deg. W., and that of the metamorphic rocks as N. 

 35 dec. W. The strike of the beds in the area north of Tatong 



