Aspects of New Zealand Sedimentafion and Tectonics

Home , Bounty Trough, Hikurangi Margin, Hikurangi Trench, Puysegur Trench

Aspects of New Zealand Sedimentaon and Tectonics

Kathleen M. Marsaglia! California State University Northridge! [email protected]! and! Carrie Bender, Julie G. Parra, Kevin Rivera, Adewale Adedeji, Dawn E. James, Shawn Shapiro, and Alissa M. DeVaughn (California State University Northridge)! Mike Marden (Landcare), Nick Mortimer (GNS). ! J.P. Walsh (East Carolina University), Candace Martin (Otago U.),! Lionel Carter (NIWA, Victoria U.)! ! Acknowledgments • C. Alexander, B. Gomez, S. Kuehl, A. Orpin, and A. Palmer • Funded by NSF GEO-0119936 & GEO-0503609 hp://ocean.naonalgeographic.com

Image from CANZ (1996)

New Zealand vs. “Zealandia”

(see Mormer, 2004; Gondwana Research) OVERVIEW of TALK • General overview of NZ Paleozoic to Cenozoic(meta)sedime ntary units emphasizing convergent margin history

• North Island Cenozoic – sedimentary record of Oligo-Miocene subducon incepon and Hikurangi margin development

Youngest sediments and oldest sedimentary rocks related to subducon

New Zealand Basement Rocks (Mormer, 2008) Image from NIWA Modern Continental Margin Example of Subduction Inception South Island, NZ North (Sutherland et al., 2006) Island

Solander Island ”Arc”?

South Island

Puysegur Trench Solander Small-scale Islands Version of Upli/erosion what Puysegur then Quaternary Ridge may have subsidence looked like

Beehive Island New Zealand Basement Rocks (Mormer, 2008)

Nelson Q-map by See GeoPRISMS White Paper by Pound et al. on Takaka Terrane Raenbury et al. (1998) 200 Ma Triassic/Jurassic

Gondwana (Antarca/Australia) 250 Ma Permian

100-55 Ma to schist Late Cretaceous/ Early Terary Zealandia Tectonic History • Acve-margin subducon in Permian (older?) • Followed by riing and passive-margin formaon in Cretaceous • Acve ( subducon and transform) margin in Illustraons by G. Cox from Coates (2002) Cenozoic (complex The Rise and Fall of the Southern Alps evoluon) Rangitata R.

Waitaki R. upper Clutha River Clutha R.

Bounty/Canterbury Sedimentary Coates (2002) System: SOURCE

upper Clutha River

Rangitata River

Coates (2002) CM BT

Passive Margin History preserved in Bounty Trough (BT)and Canterbury Margin (CM) but with Alpine Fault Influence Image from CANZ (1996) Canterbury Stragraphy: 3. Miocene - Recent (MR) Post-ri, Cretaceous to Recent Regression first-order, tectonically- • Regression in late Oligocene or controlled, transgressive- early Miocene: iniaon of Alpine regressive cycle. Fault movement increased sediment supply. • Upli of the Southern Alps accelerated at ∼8-5 Ma or ∼10-8 Ma indicang an increased component of convergence. • This transpression led to a further ri increase in sediment supply to the offshore basin. MR O 2. Oligocene Highstand (O) CP Marshall Paraconformity Iniaon of strong ocean currents MR O 1. Cret.-Paleogene (CP) CP Transgression Summary from C. Fulthorpe DWBC

11.0-3.5 Ma hiatus at Site 1122 during me of Alpine upli and sealevel lowstand Cause(s)? Submarine erosion (DWBC) & decrease in sediment input owing to onshore ﬂuvial drainage disrupon and LAKE formaon

Marsaglia et al. (2011; Geosphere) Subducon iniaon in Oligocene/ Miocene in Northern North Island ulmately evolving into modern Hikurangi Subducon Zone Image from CANZ (1996) Late Oligocene (c. 25 Ma) paleogeography Evidence for upli and exposure from King et al. (1999) (islands)… 1) During subducon iniaon? Unknown? 2) During allochthon emplacement? Ihungia Igneous Conglomerate?

Alternate view No land area during Late Oligocene Timing of Events

Northland Arc Magmasm

Max. Marine

Ma Inundaon Northland Allochthon Emplacement Pre-TVZ? Subducon

Iniaon? V Miocene volcanic centers Allochthon-related igneous rocks

Ihungia Ophiolite part of allochthon Outcrops arguably obducted during process of subducon ! Observations of Ihungia igneous conglomerate:! ! Ø In Lower Tolaga Group Ø Occurs as isolated, small outcrops (<1km2) Ø Adjacent to faulted(?) contacts with allochthon Ø 10-15m thick conglomeratic intervals Ø Outer shelf to slope deposits Ø Channelized, discontinuous Ø Normal grading, NW source Ø Wood and plant debris Ø Associated with mélange, debris ﬂows & sedimentary breccia

Map simpliﬁed from Mazengarb and Speden (2000) Gravel Clast Counts (n=100)

DS short axis DI intermediate axis DL long axis

Serpenne Metamorphic

Volcanic Sandstones Contain Serpennite Sedimentary Clasts! Serpenne

0.5 mm 0.5 mm Matakaoa Submarine Instability Complex Joanne et al. (2010) (slump / debris avalanche / debris ﬂow)

B secon

MDA = Matakoa Debris Avalanche

? Ao5cm 34

Ihungia re-entrant explains: > Nature of contact > Distribuon of gravel > Debris ﬂows / breccia beds > Distribuon of mélange > Large block of allochthon > Oﬀshore seismic character > Distribuon of Miocene seep imestones in this basin Hikurangi Convergent Margin

• The Cretaceous Hikurangi oceanic plateau, part of the Paciﬁc Plate, is being subducted beneath the eastern North Island, New Zealand at the Hikurangi Trough. Waipaoa River Sedimentary System • Convergence rates range from 4-6 cm/yr in the north to 2-4 cm/yr at southern end.

• The northern Hikurangi margin is relavely sediment-starved, with <1km of sediment blankeng the incoming Hikurangi plateau.

• Oﬀshore tectonics are dominated by subducon erosion and seamount subducon.

Adapted from Barnes et al. (2010) Adapted from Barnes et al. (2010) SOURCE Waipaoa Sedimentary System

SINK Mazengarb and Speden (2000) TARNDALE SLIP

Very Fine

Very Coarse F Mazengarb and Speden (2000) L Poverty Shelf - Sink/Source/Transfer zone? mud, sand, and gravel

Mud

Coastal cliﬀ erosion of Miocene sedimentary rocks

•Narrow sandy beaches

Parra et al. (2012; Sedimentary Geology) Poverty Slope & Hikurangi Trough: WSS SINK Poverty NIWA Shelf Short Piston Adedeji (in prep) Core Adedeji Poverty (in prep) Shelf

RV Marion Adedeji Dufresne (in prep) Long Piston Cores

Poverty Shelf Mixed Waipaoa River

modiﬁed from Alexander et al. (2010) Eﬀects of Seamount Subducon - Seismic Interpretaon by Pedley et al. (2010) Parra et al. (2012)

• Gravel made up of Torlesse lithologies.

•No Torlesse exposed in Waipaoa River Basin or on anclines.

• Torlesse gravel implies WSS not a closed system

Torlesse gravel Sandy low tombolo on beaches in connecng Mahia Hawke’s Bay Peninsula to mainland

5 cm

Hawke Bay Torlesse Beach Gravel

Parra et al. (2012) Di/Dl

Poverty Shelf Box-core Gravel

Ds/Di Did lowstand river system extend from Hawke Bay across or around Mahia Peninsula to Poverty Shelf? Probably… System not closed!

Torlesse outcrop

mp mp Parra et al. (2012)

Paquet et al. 2009 Image from CANZ (1996)

Taranaki Basin (Courtesy of NZPAM.)

Clasc provenance reﬂects change from Cretaceous ried margin to Miocene/ Recent retroarc foreland basin Image from CANZ (1996) Thank you for your aenon

Quesons? Waipaoa Sedimentary System: Drivers, processes and responses (Carter et al., 2010, Marine Geology v.270)

Modiﬁed from Carter et al. (2010)

Taupo Waipaoa Poverty Hikurangi Magmac arc River Bay, Shelf, Slope Trench Pedley et al. (2010) Note modern Lake & terrace coastline used! deposits

LAKE

Oﬀshore implicaons: sediment derived from upli, decrease river input, lake oulow deposit(s)? Moki Interval (14 Ma) Paleogeography

Submarine fan sinks

Source(s)? Onshore ﬂuvial drainage?

(courtesy of P. King, GNS) Doran (in prep.)

Ihungia Clast Geochemistry! > Basaltic andesite to gabbro > Mainly tholeiitic & subalkalic > Trace element composition: a) intermediate between MORB & arc basalt with mild slab ﬂuid signature b) unlike Hikurangi Plateau, Cret. MORB and Northland Arc c) similar to Tangihua & Matakaoa Ign.

Matakaoa Tangihua Igneous Igneous Rocks

Rocks V Miocene volcanic rocks Allochthon-related igneous rocks Concentraon of Miocene seep limestones in Ihungia ‘basin’

Nyman et al. (2010) Saether et al. (2010)

Sand/Sandstone Detrital Modes Similar to those from Cyprus!

(Matakaoa) Cyprus beach & stream sand from Garzan et al. 2000

Geological Map of Cyprus Geological Survey Dept., Cyprus (1995)

S Kouris River

S Rangitata R. Waitaki R. Bounty Channel & Fan ODP Site 1122 Clutha R. ODP Site 1122 50 km

~4500 m water depth levee

Mean value

Pleistocene to Miocene Individual samples 620 m

Conclusion: Shapiro et al. (2007) Clutha River is the main source of sand GSA Spec. Pap. 420 delivered to Bounty Fan

Late Oligocene (c. 25 Ma) paleogeography from King et al. (1999)

Alternate view: No land area during Late Oligocene Taranaki Basin - many

Waipaoa - one

Canterbury/Bounty - a few

Image from CANZ (1996)

Waipaoa SS! Focus Site! (actively deforming! forearc)!

New paradigm for modeling sediment producon, transport & depo- sion; closed systems allow for sediment budget calculaons. Embraced by the Petroleum Indus.

HIKURANKI REENTRANT STUDIES

1) Source-to Sink in Poverty Summary Reentrant Modern Waipaoa Sedimentary System (WSS) Source ( River) to Sink (Poverty re-entrant & Hikurangi Trench) 2) Ihungia Miocene Reentrant Miocene Subducon & Forearc Development Reentrants Ihungia Conglomerate 3) IODP Drilling Proposal Seamount subducon. slow- slip events, reentrant sedimentaon and tectonics

Deposional model must explain: > Subaerial indicators (clast shape, wood debris) > Limited sedimentary structures > Northwestern(?) source from deeper (mantle?) levels > Associaon with mélange, debris ﬂows & sedimentary breccia > Gravel-sized clasts in deep water > Limited occurrence > Contact with allochthon (normal fault, sheared, vs. unconformity)