THE TOURMALINE-BEAEING ROCKS OF THE 

 HEEMSKIRK DISTRICT. 



By G. A. Waller and E. G. Hogg, M.A. 

 [Read 1st December, 1902.] 



The Heemskirk district was visited some weeks ago by one 

 of the authors in the course of his official duties as Assistant 

 Government Geologist. Most of the field observations then 

 made have already been published in the report on the 

 district recently issued by the Mines Department^, but the 

 necessity of writing these reports as soon as possible after 

 the examination of the district in question is completed 

 precludes the possibility of a minute examination into the 

 microscopical character of the rocks prior to publication. 

 In the case of the Heemskirk district, not only are the field 

 observations of more than ordinary interest, but the addi- 

 tional evidence afforded by micro-examination of the rocks 

 is imjDortant. The authors, therefore, think that a short 

 description of the rocks, both as regards their microscopical 

 characters and their field relations, may not be out of place 

 among the proceedings of this Society. It may also be 

 mentioned that, since the publication of the Mines Depart- 

 ment report, other portions of the district have been 

 examined, so that some of the field observations here 

 recorded are published for the first time. 



Mt. Heemskirk is situated on the West Coast of Tas- 

 mania, about 24 miles north of the entrance to Macquarie 

 Harbour. The district may be regarded as extending along 

 the coast from Trial Harbour on the south to Granville 

 Harbour on the north. The major axis of the mountain 

 range runs approximately parallel to, and about 4 miles 

 distant from, the coast. Mt. Agnew is the most southerly 

 and the highest peak of the range, and rises about 2800 

 feet above sea-level. The mountain range is composed 

 almost entirely of granite, which extends along the coast 

 from a little north of Trial Harbour to beyond Granville. 

 To the south and east of the granite the Silurian slates and 

 sandstones outcrop, and these have suffered metamorphism 

 near their contact with the granite. 



* Report on the tin ore deposits of Mt. Heemskirk, by G. A. Waller, 

 Assistant Government Geologist. 



