382 Transactions. —Geology. 
Madrepore Limestone.—At Reefton a limestone occurs, chiefly composed 
of large madrepore corals, which if cut and polished would afford a most 
beautiful ornamental stone. 
Lithographic Limestone.—A stone suitable for most classes of lithographic 
work has been found in considerable quantities at the Abbey Rocks, West- 
land, and again at Amuri Bluff; but at the latter locality it is too much 
traversed by joints to be of any value. 
Chalk.—Dr. Hector mentions (Trans. N.Z, Inst., vol. ii., p. 178) the 
occurrence of chalk with flints on Campbell Island, and during 1880 a 
deposit of chalk, not less than 100 feet thick, was discovered at West 
Oxford, Canterbury, of which Dr. Hector says (Geol. Rep., 1879-80, p. xviii.) : 
** The samples of chalk obtained have more perfectly the mineral character 
and texture of English chalk than any previously discovered in New Zea- 
land. The rock is pure white, fine-grained, and soft enough to be used for 
ihe manufacture of crayons. 
* Its composition as determined by analysis is as follows :— 
.. 89:26 
Caleie carbonate v X 
Magnesic carbonate .. ea ie 1:84 
Ferrie oxide .. s dx traces 
Silica .. = a vd (v 10700 
Water.. fe ae ‘i ae 0:21 
100:00." 
Stalactites and. Stalagmites occur in all the many limestone caves of New 
Zealand, some of them being of great size and beauty. Of these the caves 
at Whangarei, Waipu, Collingwood, and Mount Somers are well known for 
the variety in form and size in which these deposits of lime occur. 
Travertine.—Dr. v. Haast mentions (Jurors’ Rep. N.Z. Ex., 1865, 
p. 256) a deposit of travertine from calcareous waters at the Weka Pass, 
and it occurs on a small scale in many localities, but no large deposits are 
known.* 
Limestone occurs very widely distributed throughout New Zealand in all 
degrees of purity and texture from a marl with 4 or 5 per cent. of carbonate 
of lime to a limestone which is nearly pure. Hydraulic varieties also exist, 
and at Mahurangi a deposit of this sort has been worked for some time 
past. 
Aragonite, Ca G, is by no means of so common occurrence as calcite, but 
has still been found in a few localities. Dr. Hector mentions it (Jurors' 
Rep. N.Z. Ex., 1865, p. 266) in cavities in basaltic rocks at Dunedin, and 
* A remarkable deposit of this mineral oceurs on the Alfred River, a branch of the 
Maruia River, in terraces which are in the aggregate about 400 feet in height. They are 
chiefly composed of moss which has been petrified by the calcareous waters, and are now 
partially clothed by a fresh growth of this moss, 
