■'"'^'•"1 Siii:akshy. /?('rcji/ Tvnvevtin Foyniatimis, Yasx. ic 



192.) J .1 -T 



NOTES ON THE OCCURRENCE OF RECENT TRAVERTIN 

 FORMATIONS IN OAKY AND RAVENSVVOOD 

 CREEKS, NEAR VASS, NEW SOUTH WALES. 



By a. J. Shearsby, FT^.M.S. 



(Communicated by F. Chapman, AT. .8.) 



{Read before the Field Naturalists' Club of Victoria, i8th March, 1920.) 



[Note by F. C. — A few months ago Mr. A. J. Shearsby was 

 good enough to send me the photographs here reproduced, 

 together with some notes on the formation of the travertin. 

 Recognizing the value to geologists of Mr. Shearsby's observa- 

 tions, I wrote to him for permission to present them to the 

 Field Naturalists' Club of Victoria, which he readily granted. 

 I have appended a few notes of my own regaiding similar 

 occurrences in the geological series.] 



Massive travertin in Oaky Creek, portion 65, parish of Taemas, 

 near Yass (fig. i) :— " This is typical of the deposit forming 

 and already formed at Oaky Creek. All the ' rock ' here shown 

 is travertin. Even the foreground on which the log is lying 

 is solid stuff, on which the grass and watercress, &c., grows 

 profusely for a while, and is then coated over with the cal- 

 careous material, thus adding to the thickness of the already 

 massive travertin. 



" The man in the centre of the picture will give an idea of 

 the tiiickness of the deposit. Note also the oak trees 

 [Cas'iarina) growing out of it at the top. The roots are 

 responsible for a further thickening of the deposit (see fig. 3)." 



Stalactitic travertin formed on moss, Oaky Creek, Taemas 

 (fig. 2) : — " This photograph shows a little grotto in the face 

 of fig. I, but about 20 feet to the right. Note the stalactitic 

 formation of the travertin. All of these stalactites are formed 

 on a matri.x of moss, which keeps on growing outwards and 

 downwards as the stalactites thicken with the calcareous 

 deposit, and in time join up to each other and form a solid 

 mass. The deposit here is very rapid in growth, and in at least 

 four instances the calcareous water may be noted pouring in 

 a continuous stream from the stalactities. The foreground of 

 the photograph is a matted mass of grass in various stages of 

 ' petrifaction ' (incrustation). A two-foot rule folded to one 

 foot is standing to tlie left to give an idea of proportion." 



Travertined roots of oaks {Casiiarina), Oaky Creek (lig. 3) : — 

 " This adjoins lig. 2, and shows the roots of the Casiianna 

 being rapidly thickened and cemented together by a calcareous 

 spring. The loots, which form only a small central portion of 

 the thick pendants shown, are at present alive, and will later 

 on send out fresh rootlets, whirli, in turn, will he covered up. 



