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Geological and other Reports

“Copy of Letter of Rev. W. B. Clarke

“Copy of Letter of Rev. W. B. Clarke

“St. Leonards, Sydney, January 5th, 1864.

My Dear Mr. Crawford,

“Your last parcel did not reach me till some days after the mail started again. What with that and the delay in working up the “black stuff,” respecting which I did not like to report finally, till I had laid my views before two excellent mineral analysis, one in Victoria and the other at the Mint here, you have I fear waited with some im patience from week to week. But this sort of work takes time, and halt work is none.

“Revolving your map as you have explained it and taking the section from W to E. into consideration, I see no help for the fate of the disputed rocks but this. Either the main ranges are of one, or of more than one epoch. If the latter, how are we, on the supposition of an independent coal formation, to account for the occurrence of the carbonaceous beds on both sides of the anticlinal of Tararua, with parallel strike and dips; and would not any coal formation be unconformable* to the other rocks if they are older? You have plenty of evidence as to the existence of igneous rocks, of probably, several ages in that chain. You give prominence to jasperoid masses which testify to transmutation. My notes on the specimens show that there have been dislocation and upheaval. Then you have, certainly, evidence of the intrusion at some time or another of porphyry. In all these respects but the strike and dip, I see a great conformity with the Eastern side of Haast's great fissure in Nelson; and the ranges there may agree with yours. But Hochstetter has an idea of a shifting of these ranges to the eastward

* Not necessarily unconformable.—J.C.C.

They do not, but lie to the westward of ours.—J.C.C.

page 13 in Wellington and Auckland. Could your ranges be really different from those in the Middle Island; i.e., more to the east, and covered or only occasionally appearing in Canterbury? I have laid down your colouring on the small map of Petermann, and it looks as if your Rimutaka ranges crossed to Cape Campbell, and the Aorangi ranges struck out for the Christchurch country; in which case the Nelson ranges would appear again on the east side of Taupo Lake, where you have a patch of a similar formation. If this is the case all your formation in the heart of the ranges may be of different general age to the West Nelson country; and therefore we need not look to that for comparison. Nevertheless, there are in some of your younger igneous rocks resemblances to some of Haast's. But then again where are the well developed secondary rocks which undoubtedly exist in Nelson, if not in Canterbury? All you have are the patches of vegetable tissue in the plant beds and the Theca? or Dentalium in No. 39, for I have seen no other fossil in any of your collections.§ The supposed graphite would naturally point to old Silurian rocks rather than to young secondary, or upper Palæozoic. But whether they are lower or upper does not appear. The Makara rocks look marvellously like upper Silurian.* In that case you will have probably very little gold; and as certainly no regular coal formation, though the carbonaceous matter is quite in agreement with experience.

“I think you will have to find out by further researches to the N.E. whether the formations are one or several, and if there is any unconformable deposit over the vertical beds, of a coal age.

“I wish I could enlighten you thereon, but at present you have sent me nothing which agrees altogether with our coal formation here, except as I have before mentioned. My idea once was that coal beds might exist on your West Coast, but the study of your map shows me, that if so, they underlie the tertiaries.

“I learnt lately that the Whangaroa and Aotea tertiaries on your West Coast (i.e., of North Island) are perhaps Eocene like those of Cape Farewell in the Middle Island and about the Waikato. The younger, or sub-appennine beds, occur in your Island about the N. of Auckland, Whanganui, Hawke's Bay and in the Middle Island about Nelson, &c.

“I always believed that the order was from E. to W. in point of age, and Haast tells me Zittel's views confirm that idea. The elevation of the islands has gone on from W. to E. as Haast shows,** which quite agrees with the tertiary arrangement. He says further that he is obliged to include among the Eocene tertiaries some deposits which Hochstetter and others considered Cretaceous.

“Believe me,
“Yours very truly,

(Signed) “W. B. Clarke.”

The continuation of the whole breadth of our ranges from Terawiti to Cape Palliser, may easily be traced across the Strait and carried South until the corresponding rocks are found skirting the Canterbury Plains. A graceful curve must be allowed, not a rigid straight line. There is no necessity to suppose a lateral shift.—J.C.C.

The fossil is evidently crushed, but it shows an irregular kind of opening at the upper end. It is, however, arched like Dentalium, though slightly I do not see the slit at the lower end which usually occurs in Dentalium. It is nevertheless apparently open at both ends, as in Dentalium.

§ I have not sent any tertiary rocks or fossils to Mr. Clarke. Our secondary rocks to the westward are either wanting, or they lie below the tertiaries. To the Eastward see my remarks on East Coast.—J.C.C.

* Note—You should search Belmont for fossils.

This is just what I have been unable to find, unless the Porirua beds should prove to be such, but Belmont is about in their line of strike, and the Theca? or Dentalium there conflicts with the Phyllotheca? of Porirua.—J.C.C.

** I do not quite understand this, and therefore I may be wrong in thinking it erroneous.—J.C.C.