Redeposited conglomerates in a miocene flysch sequence at Blackmount, Western Southland, New Zealand

Abstract

Carter, R.M. and Norris, R.J., 1977. Redeposited conglomerates in a Miocene flysch sequence at Blackmount, western Southland, New Zealand, Sediment. Geol., 18: 289--319.The Middle Miocene Monowai Formation represents a gravel delta that prograded south into a flysch basin complex developed along the Moonlight Tectonic Zone, southern New Zealand. The delta-slope environment was characterized by a conglomeratic sequence up to 500 m thick. Most of the gravel was moved downslope by mass-transport processes. A complete spectrum exists from synsedimentary slide sheets (up to 10 m thick and 100 m long) that retain pre-sliding sedimentary structures, to more mature mass-transported sediment types in which all original structures have been destroyed. The most distal deposits include ungraded homogeneous pebble conglomerates up to 3 m thick. Some of the more mature redeposited conglomerate--sand--mud units (X--Y--Z sequences) are between 2 and 10 m thick; they comprise a basal X-division of bouldery conglomerate, a middle Y-division of pebbly mudstone or pebbly sandstone, and an upper Z-division of hydroplastically folded mudstone. Though X--Y--Z sequences may have been deposited from very proximal turbidity or fluxoturbidity currents, inertia-flow emplacement seems more likely. An inertia-flow mode of emplacement also seems most probable for the other redeposited sediment types described from the Monowai Formation.

Transpressional development of the Australia‐Pacific boundary through southern South Island, New Zealand: Constraints from Miocene‐Pliocene sediments, Waiho‐1 borehole, South Westland

“…Can any constraints be put on the distance and direction of sedimentary transport between source area and deposition site? It is clear from studies in western Southland (e.g., Carter & Norris 1977;Turnbull et al 1993;Manville 1994), that transport of conglomerate clasts during the Miocene took place over distances of >150 km, and therefore care must be taken when trying to separate tectonic from sedimentary transport (Sutherland 1995c (Cutten 1979), South Westland (Sutherland 1995b), and western Southland (Carter & Norris 1977;Turnbull et al 1993;Manville 1994) contain relatively high proportions of metagreywacke clasts. The metagreywacke clasts in these sediments have compositions that span the QFL fields of several different basement terranes (e.g., Fig.…”

“…4), but highly lithic metagreywack o compositions characteristic of the Caples Terrane are mo-t common ( Fig. 4; Carter & Norris 1977;Cutten 1979;Manville 1994). This suggests that middle-late Miocene erosion southeast of the Alpine Fault was concentrated i n regions where metagreywacke basement rocks (Caples Terrane rock types in particular) were exposed.…”

“…Norris .v Turnbull (1993) suggested that middle-late Miocene up lilt of Caples Terrane rocks was related to a restraining herd geometry associated with the transfer of dextral slip from the eastern margin of Fiordland to the Alpine Fault. The very low concentration of Fiordland-derived material (gneissic and amphibole-bearing plutonic detritus) in middle-late Miocene sediments deposited both east (western Southland; Carter & Norris 1977;Manville 1994) and weM (Westland Basin) of Fiordland, indicates that Fiordland was low lying or submerged during the middle-late Miocene. The common occurrence of metagreywacke clasts in middlelate Miocene sediments in the Westland Basin suggests that there was no continuous drainage divide along Fiordland, and that middle-late Miocene river systems or submarine canyons were transporting pebble-sized metagreywacke material westward across Fiordland.…”

Synsedimentary seismotectonic features in Triassic and Cretaceous sediments of the Intrasudetic Basin (U Devíti křížů locality) – regional implications

“…Such phe nom ena are usu ally con sid ered as seis mic phe nomena sensu lato. Some au thors have in di cated the re la tion ship be tween injectites and synsedimentary faults (e.g., Carter and Norris, 1986;Vanneste et al, 1999;Neuwerth et al, 2006;Moretti and Sabato, 2007;Mazumder et al, 2009;Bonini, 2009). Anal o gous lac co lite struc tures have been ob tained in soil (sed iment) fluidization mod el ling in con di tions of cy clic over bur den (shocks) (e.g., Rodrigues et al, 2009;Bu reau et al, 2014).…”

Sedimentology and stratigraphy of Prospect Formation, Te Anau Basin, western Southland, New Zealand

“…The top of the unit is everywhere unconformably overlain by Quaternary fluvioglacial gravels. Prospect Formation has previously been excluded from the Waiau Group on the basis of its largely nonmarine nature and basal unconformity (Carter & Norris 1977;Turnbull & Uruski 1993). It is here proposed that Prospect Formation in the Te Anau Basin be combined with its inferred distal equivalents, the marine Rowallan Sandstone and Te Waewae Formation in the Waiau Basin (previously included in the Waiau Group on the basis of their marine nature), to form the Wilderness Group (Fig.…”