SPODDS SPECIAL FIELDTRIP NEW ZEALAND, 2010

Day 3 & 4

Stanford Project on Deepwater Depositional Systems

DEEPWATER DEPOSITS OF THE LOWER MOUNT MESSENGER FORMATION, UPPER MIOCENE,

TARANAKI BASIN

Presented By:

Larisa U. Masalimova Research Advisor:

Donald R. Lowe

Content

• Map of the stops• Outcrops• Architecture• Stop description• Acknowledgements

Map of the stopsLower Mt Messenger Formation

OutcropsMohakatino River

Jam Roll

Rapanui Stream

Tongaporutu River

Potroz Section(won’t be visited)

Waikiekie Stream

Inland section

North

ArchitectureMohakatino Rv Jam Roll

Potroz

Packages in style of depositionThin-bedded complex

Thick-bedded sandstones

MTD

Siltstone package

Siltstone package

4mScale

1. Mohakatino River2. Jam Roll3. Rapanui Stream4. Tongaporutu River5. Inland section6. Waikiekie stream

Stops description

North

Lower Mt Messenger Formation:

1. Mohakatino RiverMain lithofacies:

•Thick-bedded sandstone (S3- Ta), thickness 50 cm to 3 m• Sandstone with plane lamination (Tb) and ripples (Tc)•Thick bioturbated siltstone package with thin ash layers and thin sandstone beds•Thin mud layers (Te) •MTD

Bioturbated siltstone Thin bed of bioturbated sandstone

siltstone

Thick-bedded sandstone

Erosional contact between sandstone & siltstone

N

1. Mohakatino River

• High density turbiduty currents• Energetic flows capable to erode• High rate of sedimentation• Small periods of time between flows

2. Jam Roll

deposits

Main lithofacies: •Mass Transport Deposits•Thick-bedded sandstones•Disturbed siltstone & mudstone

N

Courtesy of Donald Lowe

2. Jam Roll

Siltstone

MTD MTD

Thick-bedded sandstonesKey features:•Sliding blocks, soft sedimentdeformation•Shearing surfaces•Active settings•Slope instabilities & failures

3. Rapanui Stream

Main lithofacies: •Siltstone dominated MTD•Sandstone dominated MTD•Thick-bedded sandstones•Siltstone •Sandstone with thin mudstone beds

Two different MTD broughttogether by fault

Siltstone dominated MTDN

Courtesy of Donald Lowe

3. Rapanui Stream

Sandstone dominated MTD

4. Tongaporutu RiverMain lithofacies:• thick-bedded amalgamated

sandstone• thin-bedded siltstone and sandstone • highly bioturbated thick-bedded siltstone• mud-clast conglomerates

N

4. Tongaporutu River

Finninng Upward

Cross-stratification in thick-bedded sandstones

Key features:•Overall upward fining cycle•compensational style of deposition•Complete cycle of Deposition

5. Inland section

N

6. Waikiekie stream

Channels

Main lithofacies:• thick-bedded sandstones• thin-bedded siltstone and sandstone • highly bioturbated siltstone packages• mud-clast conglomerates•siltstone dominated MTD

Key features:Nested channelsHighly energetic flowsTransition between lower

andUpper Mt. Messenger

Fm.

N

6. Waikiekie streamRotated blocks

Channel

18

SPODDS Students:Jon Rotzien, Lisa Stright .Zane Jobe, Katie Maier, Julie Fosdick,

Anne Bernhardt,Glenn Sharman, Blair Burgreen,

Acknowledgements

Geological and Nuclear Sciences (GNS) in New Zealand

Thank you for your attention!

New Zealand, 2009