The 55- to 60-ka Te Whaiau Formation: a catastrophic, avalanche-induced, cohesive debris-flow deposit from Proto-Tongariro Volcano, New Zealand

2001 ◽  
Vol 63 (8) ◽  
pp. 509-525 ◽  
Author(s):  
Jérôme A. Lecointre ◽  
Vincent E. Neall ◽  
Cleland R. Wallace ◽  
Warwick M. Prebble
Keyword(s):  
New Zealand ◽  
Debris Flow ◽  
Debris Flow Deposit ◽  
Flow Deposit

Complex internal architecture of a debris-flow deposit revealed using ground-penetrating radar, Cass, New Zealand

2013 ◽  
Vol 69 (1) ◽  
pp. 26-38 ◽  
Author(s):  
Colette C.A. Starheim ◽  
Christopher Gomez ◽  
Justin Harrison ◽  
Claire Kain ◽  
Nicholas J. Brewer ◽  
...  
Keyword(s):  
New Zealand ◽  
Debris Flow ◽  
Ground Penetrating Radar ◽  
Debris Flow Deposit ◽  
Flow Deposit ◽  
Ground Penetrating ◽  
Internal Architecture

The cohesive Naranjo debris-flow deposit (10 km3):

2002 ◽  
Vol 117 (1-2) ◽  
pp. 213-235 ◽  
Author(s):  
L Capra ◽  
J.L Macı́as
Keyword(s):  
Debris Flow ◽  
Debris Flow Deposit ◽  
Flow Deposit

Huge, CO2-charged debris-flow deposit and tectonic sagging in the northern plains of Mars

Geology ◽  
2001 ◽  
Vol 29 (5) ◽  
pp. 427 ◽  
Author(s):  
Kenneth L. Tanaka ◽  
W. Bruce Banerdt ◽  
Jeffrey S. Kargel ◽  
Nick Hoffman
Keyword(s):  
Debris Flow ◽  
Northern Plains ◽  
Debris Flow Deposit ◽  
Flow Deposit

scholarly journals Stratigraphy, facies architecture and emplacement history of the c. 3.6 ka B.P. Ngatoro Formation on the eastern flanks of Egmont Volcano, western North Island, New Zealand

2021 ◽  
Author(s):  
◽  
Benjamin John Dixon
Keyword(s):  
New Zealand ◽  
Debris Flow ◽  
Mass Flow ◽  
Extended Phase ◽  
Facies Architecture ◽  
Eruptive Event ◽  
Central Java ◽  
Flow Deposit ◽  
History Of ◽  
Mass Flows

<p>The Ngatoro Formation is an extensive volcaniclastic deposit distributed on the eastern lower flanks of Egmont Volcano, central North Island, New Zealand. Formally identified by Neall (1979) this deposit was initially attributed to an Egmont sourced water-supported mass flow event c. 3, 600 ¹⁴C years B.P. The Ngatoro Formation was subsequently described by Alloway (1989) as a single debris flow deposit closely associated with the deposition of the underlying Inglewood Tephra (c. 3,600 ¹⁴C yrs B.P) that had laterally transformed into a hyperconcentrated- to- flood flow deposit. Such water-supported mass flows have been well documented on volcanoes both within New Zealand (i.e. Mt Ruapehu) and elsewhere around the world (i.e. Mt Merapi, Central Java and Mt St Helens, Washington). This thesis comprises field mapping, stratigraphic descriptions, field and laboratory grain size and shape analysis, tephrochronology and palaeomagnetic analysis with the aim of refining the stratigraphy, facies architecture and emplacement history of the c. 3,600 ¹⁴C yrs B.P. Ngatoro Formation.  This study has found that the Ngatoro Formation has a highly variable and complex emplacement history as evidenced by the rapid textural changes with increasing distance from the modern day Egmont summit. The Ngatoro Formation comprises two closely spaced mass flow events whose flow and emplacement characteristics have undergone both proximal to distal and axial to marginal transformations. On surfaces adjacent to the Manganui Valley on the deeply incised flanks of Egmont Volcano, the Ngatoro Formation is identified as overbank surge deposits whereas at the boundary of Egmont National Park it occurs as massive, pebble- to boulder-rich debris flow deposits. At intermediate to distal distances (17-23 km from the modern Egmont summit) the Ngatoro Formation occurs as a sequence of multiple coalescing dominantly sandy textured hyperconcentrated flow deposits. The lateral and longitudinal textural variability in the Ngatoro Formation reflects downstream transformation from gas-supported block-and-ash flows to water-supported debris flows, then subsequently to turbulent pebbly-sand dominated hyperconcentrated flows.  Palaeomagnetic temperature estimates for the Ngatoro Formation at two sites (Vickers and Surrey Road Quarries, c. 10 km from the present day Egmont summit) indicate clast incorporation temperatures of c. 300°C and emplacement temperatures of c. 200°C. The elevated emplacement temperatures supported by the Ngatoro Formation’s coarse textured, monolithologic componentry suggest non-cohesive emplacement of block-and-ash flow debris generated by the sequential gravitational collapse of an effusive lava dome after the paroxysmal Inglewood eruptive event (c. 3,600 ¹⁴C yrs B.P.). The occurrence of a prominent intervening paleosol between these two events suggest that they are not part of the same eruptive phase but rather, the latter is a product of a previously unrecognised extended phase of the Inglewood eruptive event. This study recognises the potential for gravitational dome collapse, the generation of block-and-ash flows and their lateral transformation to water-support mass flows (debris, hyperconcentrated and stream flows) occurring in years to decades following from the main eruptive phase. This insight has implications with respect to the evaluation of post-eruptive hazards and risk.</p>

Sign in / Sign up

Export Citation Format

Share Document