Geology of the Mercury Bay area : sheets T11BD & part U11, scale 1:50 000

(Inc. GST)
(Ex. GST)
Write a Review

Skinner, D.N.B. 1995 Geology of the Mercury Bay area : sheets T11BD & part U11, scale 1:50 000. Lower Hutt: Institute of Geological & Nuclear Sciences. Institute of Geological & Nuclear Sciences geological map 17 56 p. + 1 fold. map

Abstract: The Mercury Bay map region consists of a Neogene volcanic sequence, part of the Coromandel Volcanic Zone, of andesite, dacite, rhyolite, and minor basalt. A small area of late Jurassic sedimentary basement is exposed in the north. Both andesitic and rhyolitic rocks host epithermal vein systems, but recorded production of gold-silver bullion amounted to only 190 kg. The Jurassic rocks (Manaia Hill Group) are thinly bedded siltstones and mudstones of a very low grade lithic-volcanic to lithic-feldspathic greywacke suite, altered to prehnite-pumpellyite facies (zeolite and quartz-prehnite subfacies). Although the earliest volcanism of the Coromandel Volcanic Zone, in the north of the Coromandel Peninsula, commenced about 18 Ma ago, eruptions in this map region commenced with late Mid Miocene (c. 13 Ma) to early Late Miocene (c. 11 Ma) Kuaotunu Subgroup andesites and dacites of Coromandel Group. From oldest to youngest, these comprise Matarangi Andesite, Te Tutu Andesite, Mahinapua Andesite, and Maumaupaki Formation. (auth)

Shipping Cost:
Calculated at Checkout
400.00 Grams