Geology, micropaleontology and geochemistry of permian sediments at Meyers Pass, South Canterbury, New Zealand / by Phil Ford.

Ford, Philip Barry.

In this report, emphasis is placed on defining lithologies and their extent, along with geochemical consideration of the sedimentary rocks and their metamorphic equivalents. Torlesse sedimentary rocks in the Meyers Pass area are mapped. Paleontological methods and biostratigraphy nave also received much attention. Atomodesmatinid bivalve macrofossils, redeposited in flysch, and. Permian conodonts (Neogondelella and Xaniognathus) in an allochthonous block of siliceous pelagite, are recorded. Conglomerates are largely composed of acid extrusive and hypabyssal clasts dominating sedimentary clasts, all in a matrix of similar derivation and including plentiful rip-up clasts of a finer nature. Isoclinal folding of siltstone/fine sandstone and pelagite in an allochthonous block is noted as being inconsistant with the degree of deformation in other mapped areas. The allochthonous block was deformed during accretion, while all sediments were later deformed by a regional metamorphic event. The sedimentary assemblage is consistant with tectonic accretion along an active continental margin, with the acid igneous fraction derived of subduction related plutonic activity. The dominance of extrusive types within this acid fraction, and minor amount of burial metamorphic types may indicate a young or newly reactivated subduction complex. No true acid plutonics are present as clasts in the conglomerates. Tectonic considerations relevant to incorporation of the Torlesse sediments into the New Zealand geotectonic framework are considered.

xi, 180 leaves : ill. (some col.), maps (some col.) ; 30 cm.

1995Ford

POLYGON ((170.753682231000084 -44.708638358999963,170.753463203000024 -44.714017662999936,170.748205876000043 -44.713903039999934,170.725562236000087 -44.71340173699997,170.715766650000091 -44.713354789999983,170.715308649000121 -44.722231465999982,170.702876873000037 -44.72206889399996,170.702689695000117 -44.730748310999957,170.670184109000047 -44.730199597999956,170.670464972000104 -44.712492133999945,170.703099966000082 -44.712949031999983,170.703593806000072 -44.700332404999983,170.704150882000022 -44.686154998999939,170.691761635000034 -44.685744285999931,170.691908952000063 -44.681218773999944,170.692059052000104 -44.676702313999954,170.692865618000042 -44.676727253999957,170.704444967000086 -44.677067963999946,170.704737933000047 -44.677078222999967,170.705681334000019 -44.650259349999942,170.730798192000066 -44.650664750999965,170.732490595000058 -44.605436076999979,170.770174484000108 -44.606261490999941,170.768255261000036 -44.651085049999949,170.756050174000052 -44.650666619999981,170.753682231000084 -44.708638358999963))