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The New Zealand Fossil Record File, an essentially complete compilation of New Zealand's known fossil record, with additional records from parts of Antarctica, SW Pacific, and elsewhere, is, to the best of our knowledge, unique. It has developed collaboratively, with contributions from university, government, industry, and avocational paleontologists and geologists. The distinctive Fossil Record Number has become an icon of New Zealand geological literature since inception of the original paper-based archive in the 1940s. Subsequently, the file has been digitised and currently holds >100,000 locality records and >1,000,000 individual taxonomic identifications spanning numerous plant and animal phyla. These numbers are continually growing. The database contains contextual information on geographic location, collection, stratigraphy and lithology of the fossil localities as well as taxonomic analyses that retain original identifications yet accommodate re-assignments. The data have been widely applied, initially for mapping, establishing age, depositional environment, etc., and more recently including in quantitative biostratigraphy, assessing completeness of the fossil record, understanding biodiversity history, extinction risk assessments, and climate analysis. In this paper, we provide a brief overview of the history of the Fossil Record File, indicate the general nature of the data it contains, and showcase a number of innovative applications of this most valuable resource. [ABSTRACT FROM AUTHOR]

Launched in 2015, the New Zealand volcano supersite provides regular radar acquisitions covering all the major calderas and cone volcanoes which form the Taupō Volcanic Zone (TVZ). This paper documents new InSAR (Interferometric Synthetic Aperture Radar) observation of deformation over the cone volcanoes within the TVZ including the Tongariro Volcanic complex (TVC) and White Island. Observations over White Island support earlier observations indicating that the stability of the crater wall is controlled, at least in part, by the water level in the crater lake with downslope motion of ∼50 mm/yr observed during the latest period of lake drop in early 2019. Deformation over the TVC is dominated by the continued subsidence above the 2012 Te Maari eruption site at rates of ∼30 mm/yr with no evidence of deformation elsewhere. Synthetic models, used to test the potential detectability of magma movement beneath Ruapehu and White Island, suggest that for small volumes (<0.005–0.02 km3), intruded over short periods of time, it would be difficult for InSAR data alone to identify their accumulation. These challenges are not unique to New Zealand's volcanoes and are likely to be faced at other volcanic systems globally. [ABSTRACT FROM AUTHOR]

Two fossil Echinoderms, a starfish (asteroid) and a brittle star (ophiuroid), are described in this paper. They were found in sandstones of Early Cretaceous age in the Te Urewera National Park, East Coast, North Island. The asteroid holotype, EC 192 Paragonaster felli n. sp., is well preserved, except that the disc lacks the integument (i.e. skin). The exposed internal structures, however, are well preserved. Five pointed arms are present, two of which are well preserved for their entire length. Varying lengths of the other three arms are obscured by matrix. The Ophiuroid, EC 194, found with the asteroid, consists of a central pentagonal disc. The mouth is edged by pairs of small triangular oral plates. Four curved arms radiate out from the disc and are distinctly demarcated from the disc. One arm is a stump. The arms are thin, smooth and almost cylindrical. No structure is visible. [ABSTRACT FROM AUTHOR]

In the following paper, we apply digital mapping techniques and tephrostratigraphy to correlate marker horizons across the Whanganui Basin, culminating in a new 1:25,000 geological map of the central Rangitikei. This is achieved by (1) compilation of existing research, (2) correlation of major element glass shard datasets to known eruptive products and (3) completion of a three-year field survey. We update and refine existing stratigraphic correlations, focusing on two critical units within the basin succession; namely the Makirikiri Tuff (1.6 Ma) and Kaimatira Pumice Sand (1 Ma) formations. Okehu Group is proposed to cover all strata from Pakihikura to Potaka pumice. Rewa Pumice is placed within its own formation bridging the Makirikiri Tuff and Kaimatira Pumice Sand formations. Mapping and analysis facilitate placement of Coutts Creek Horizon within Rewa Formation. Sub-aerial surfaces and influxes of greywacke and volcaniclastic detritus from c. 1.6 Ma onward provide evidence for an alluvial plain developing at the foot of the uplifting, paleo-axial range. We suggest uplift in the paleo-axial range occurred contemporaneously with the onset of rhyolitic activity at Mangakino caldera (c. 1.6 Ma) so that the first influxes of fluvial conglomerate and volcaniclastics occur in close proximity within the eastern basin succession. [ABSTRACT FROM AUTHOR]

Numerous igneous bodies within the Deepwater Taranaki Basin are recognised mainly from seismic data and range from Early Cretaceous to Pliocene in age. They were all emplaced within an intra-plate setting but are scattered apparently at random in time and space. This paper describes the occurrences of igneous rocks within the basin as interpreted from seismic data, and discusses their possible origin. There are no indications of hotspot tracks within the Zealandia micro-continent so an alternative origin is sought. Previous authors see the main cause of volcanism as decompression melting due to localised lithospheric detachment and the movement of the Zealandia plate across the mantle as incidental. It is suggested that the movement of the Zealandia lithosphere, in the order of 4000 km to the north-northwest since the Cretaceous, may have caused drag across the asthenosphere, which in turn created transient small-scale convection cells that assisted the process of decompression melting as a modification to the accepted theory. [ABSTRACT FROM AUTHOR]

Understanding the in-situ stress field in the subsurface provides insights on the tectonic processes and seismic hazards of a basin. This paper presents observations and interpretations of present day maximum horizontal stress (SHmax) orientation from well Ranui-2 located in the onshore southern East Coast Basin. Fractures identified in the Ranui-2 image log have been divided into distinct subsets based on fracture orientation. These subsets correspond in a general sense, to changes in lithology in the well, which are associated with changes in formations. Analysis of the image log shows the present day SHmax in the borehole has two primary stress directions, W–E and NW–SE, and most of the fractures strike NE–SW. The change in SHmax occurs at a depth of circa. 1130 m measured depth (918 m true vertical depth subsea), below the depth at which the borehole changes from vertical to ≥10° deviation. When these data are compared to the regional stress field obtained using other stress indicators such as earthquake focal mechanisms, the results are consistent with each other. This study shows that shallow subsurface indications of present-day SHmax in southeastern North Island reflect SHmax orientations from deeper within the subsurface. [ABSTRACT FROM AUTHOR]

This paper synthesises geological and biological data to develop an evolutionary history for the Taieri River that currently follows a circuitous 200 km course as one of the main drainages in Otago. The ancestral Taieri River drained only coastal hills initiated in the Miocene, and much of what is now the upper Taieri catchment flowed into the ancestral Clutha River. Major river reorientation events occurred in the upper half of the catchment because of rise of antiformal fold mountains in the Pleistocene, forming a new divide between the Taieri and Clutha catchments. Coeval incision of a gorge through a volcanic rock barrier connected the upper catchment to the lower Taieri River. The sparse Pleistocene sedimentary record documents these drainage changes via contrasting distribution of distinctive clasts derived from greywacke mountains on the northern edge of the Otago Schist belt. These major capture events are also supported by distributions and genetic divergences of freshwater galaxiid fish species. Erosion during Pleistocene rise of the antiformal mountains caused recycling of placer gold into Clutha tributaries before the Taieri River evolved to its present geometry, thereby limiting the placer gold content of the modern Taieri catchment. [ABSTRACT FROM AUTHOR]

New Zealand has a network of approximately 190 Continuously Operating Reference Stations (CORS) operated by GeoNet, is a project housed within GNS Science. The GeoNet continuous GNSS network (cGNSS) includes the 37 stations that make up the Land Information New Zealand (LINZ) PositioNZ network. These stations are run in partnership by the two agencies. The New Zealand CORS stations make a significant contribution to New Zealand's geospatial infrastructure and to international geodesy. Further, the CORS stations have been used to identify more than 25 slow-slip events (SSEs) associated with the Hikurangi subduction zone, play an important role in volcano monitoring and have the potential to identify tsunamigenic earthquakes. This paper will discuss how the two networks were established, how they have evolved since the first stations were established in 1995 and the significant contribution of the late John Beavan. [ABSTRACT FROM PUBLISHER]

Fragile holoplanktonic gastropods are rare components of the rich and diverse New Zealand Cenozoic molluscan fauna. This paper describes a new species in the extinct genus Gamopleura, G. maxwelli n. sp., from the Late Oligocene Otekaike Limestone, South Canterbury. Its only known congeners are found in Late Oligocene/Early Miocene rocks in southern Europe. [ABSTRACT FROM AUTHOR]

Treatment of acid mine drainage can be accomplished by either active or passive treatment systems. Choice between active and passive treatment and appropriate selection of systems within each category is critical for treatment success. In general, active treatment is more commonly used at operational mines whereas passive treatment is typically considered for closed and abandoned mines. Operational mines often have limited space for remediation systems and have large and fluctuating flow rates with changing drainage chemistry as mining proceeds, factors that are addressed more easily with active than passive treatment. In the long term, passive treatment could offer more economic options than active treatment. Various flow charts have been prepared by previous researchers to help select among the passive systems but little work has been done to help select between active and passive treatment or to select appropriate active treatment systems. Furthermore, the passive treatment flow charts have often not included variables important for application to New Zealand sites: topography, climate and available land area. Very steep topography, dense and often protected vegetation, and a high-rainfall climate may result in acid mine drainage with high flow rates in locations with limited space for remediation. This paper presents flow charts specific to New Zealand which have been prepared to accommodate topography and available land area. [ABSTRACT FROM AUTHOR]

An important component of quantifying seismic hazard and risk in regions such as Wellington is to characterise both the long-term rate of occurrence of the region's major earthquake-generating active faults, as well as potential interactions between faults (e.g., the potential for earthquake triggering). This paper describes paleoseismic data from two trenches (Ohariu Valley) and a natural streambank exposure (Horokiri valley) c. 24 km apart, which constrain the timing and size of recent surface rupture events on the northeast striking Ohariu Fault c. 6 km northwest of Wellington City. One event is recorded at all three sites and radiocarbon age constraints indicate it correlates with the 1050-1000 cal. years BP event previously identified elsewhere along the fault. A younger, smaller (decimetre-scale) event is recorded in one of the Ohariu Valley trenches, and the timing is constrained by two radiocarbon ages to post-310 cal. years BP. This event may either be a small, primary Ohariu Fault rupture, or a triggered event associated with a large earthquake on a nearby fault. If it is a triggered rupture, then a possible mechanism is dynamic triggering associated with one of the recent large-great earthquakes on the Wellington (post-300 yr), Wairarapa (AD1855), or Awatere (AD1848) Faults. Small rupture events do not necessarily contribute to the recurrence interval classification of the Ministry for the Environment Active Fault Guidelines, but they could be important for sensitive structures crossing the fault and for lifelines crossing multiple active faults. [ABSTRACT FROM AUTHOR]

This paper provides a comprehensive description of the plutonic rocks of western Fiordland between Breaksea and Sutherland Sounds. The area is dominated by the Early cretaceous Western Fiordland Orthogneiss (WFO), but also includes smaller bodies of Paleozoic and cretaceous granitoid. Plutonic rocks of western Fiordland intrude metasediments of the Western Province, many of whose age and terrane affinities remain undefined. Paleozoic granitoids in western Fiordland include the Pandora Orthogneiss (c. 500 Ma) and widespread related sills within Paleozoic metasedimentary rocks; the All Round Pluton (c. 340 Ma); the Deas Cove Granite (c. 372 Ma); and possibly the Straight River Granite. The Pandora Orthogneiss is one of the oldest plutons yet found in the Median Batholith. Correlatives include the Jaquiery Granite Gneiss in central Fiordland and orthogneiss in Doubtful Sound. Plutonism of Ross/Delamarian age is therefore widespread in those parts of Fiordland where cambrian or older Western Province metasedimentary rocks form basement. The All Round Pluton and Deas Cove Granite are correlatives of the S-type Ridge and A/I-type Foulwind Suites, respectively. The c. 125-116 Ma WFO includes at least seven major dioritic and monzodioritic plutons in western Fiordland, one in central Fiordland, and one in central Stewart island. Plutons which compose the WFO are distinguished by differences in their age, petrography, structural and metamorphic histories, and geochemistry. The WFO in northern Fiordland and the correlative Walkers Pluton on Stewart island were emplaced in the mid crust (4-9 kbar) at depths comparable with some Separation Point Suite plutons of similar age. WFO plutons in southern Fiordland were emplaced at greater depths (10-18 kbar). WFO plutons have been variably recrystallised to eclogite; omphacite-, garnet-, two-pyroxene-, and hornblende-granulite; and hornblende-amphibolite facies assemblages, reflecting different PTX conditions during metamorphism of each body. Some parts of the WFO remain undeformed and unmetamorphosed. evidence of up to c. 6 kbar loading after emplacement is limited to WFO plutons in northern Fiordland and adjacent country rocks. extensional ductile shear zones previously shown to locally separate the WFO from adjacent rocks are discontinuous later features, commonly localised along earlier intrusive contacts between WFO plutons and metasedimentary country rocks. They do not form a regionally extensive detachment between the upper and lower plates of a metamorphic core complex. The WFO has previously been included in the Separation Point Suite since both units share a high Sr/Y (HiSY) chemistry and were emplaced at broadly the same time. However, the WFO and Separation Point Suite have distinct chemistries. Separation Point Suite rocks generally contain greater Sr, Na, and Al, and have lower Sr/Rb ratios, rare earth element and Y contents, than WFO rocks with comparable amounts of SiO2. Many aspects of the WFO chemistry (aside from its HiSY character) are similar to that of the older Darran Suite rather than the Separation Point Suite. This may reflect a greater amount of partial melting during generation of the SiO2-poor WFO than the SiO2-rich Separation Point Suite. Alternatively it may indicate derivation of the WFO and Separation Point Suite from different sources, albeit at depths greater than those where residual plagioclase is stable. Relatively large variations in the major element chemistry of the Separation Point Suite reflect fractionation and/or accumulation of plagioclase, whereas the more limited variability in the major element chemistry of the WFO reflects minor fractionation and/or accumulation of hornblende and/or clinopyroxene. [ABSTRACT FROM AUTHOR]

The Repongaere Fault is one of a series of active normal faults within the Raukumara Peninsula, eastern North island, New Zealand. These faults appear to form in response to rapid uplift of the Raukumara Range and related extensional strain. however, the activity of these normal faults is poorly constrained. This paper presents new mapping of the active surface trace of the Repongaere Fault, c. 18 km northwest of Gisborne, and the results of two paleoseismic trenches. These results are then used to assess the seismic hazard posed by this fault and impacts on the Waipaoa Sedimentary System in which the fault is situated. active traces can be mapped for c. 4.5 km, but we infer the surface rupture length to be at least 9 km. Tephras within the trenches constrain the timing of the most recent surface rupture event to have occurred during deposition of the Waimihia Tephra (c. 3400 cal. yr BP), and at least one event in the period c. 13 800-5470 cal. yr BP, with single-event displacements of ≥ 0.4-1.1 m. From these data a mean dip-slip rate of c. 0.1 mm/yr and a maximum recurrence interval of 4490-6900 yr, can be calculated. if the Repongaere Fault is representative of other Raukumara Peninsula normal faults, then this relatively low rate of activity supports the interpretation that these faults are not contributing significantly to the deformation of the Raukumara Peninsula. The low rate of activity is also consistent with the very localised evidence for landscape impacts, a calculated moderate Mw of 6.3-6.7, and the fault's location within the lower part of the Waipaoa River catchment. Together, these observations suggest that Repongaere Fault earthquakes have minimal, localised impact on the Waipaoa Sedimentary System. [ABSTRACT FROM AUTHOR]

This paper provides a comprehensive description of all major plutonic rock units in Fiordland between Lakes Poteriteri and Te Anau, and the heads of Doubtful and George Sounds. Plutonic rocks comprise c. 80% of the basement in the area described, the remainder being metasedimentary and metavolcaniclastic rocks. The plutonic rocks, of which c. 50% are granitoids, were emplaced in three phases--at c. 492 Ma, between c. 365 and 318 Ma, and between 168 and 116 Ma. correlatives of the Devonian Karamea Suite emplaced between c. 375 and 367 Ma, and the Triassic to Early Jurassic part of the Darran Suite emplaced between c. 230 and 168 Ma, are not present in the area described here. The strongly deformed Late Cambrian to Early Oordovician Jaquiery Granitoid Gneiss is one of the oldest plutonic rocks yet discovered in New Zealand and is of similar age to plutonic rocks within the Ross and Delamerian Orogens of Victoria Land and South Australia. Rocks emplaced between c. 365 and 318 Ma include Ridge Suite S-type granitoids and closely related S/A-type plutons, Foulwind Suite A-type mafic and granitoid plutons, Tobin Suite I-type granitoids, and several unassigned mafic plutons. Rocks emplaced between 168 and 116 Ma include extensive c. 168-128 Ma old calc-alkaline loSY gabbros, diorites, and granitoids of the Darran Suite, c. 165-135 Ma old hypersolvus perthitic syenogranites and peralkaline granitoids, c. 125 Ma gneissic diorite similar to the Western Fiordland Orthogneiss, and c. 123-116 Ma old quartz diorites and granitoids of the HiSY Separation Point Suite. Plutons from each suite tend to be concentrated in distinct NNE-striking parallel belts up to 20 km wide and 110+ km long. These belts are one of the key features which define the regional structural grain of Fiordland basement geology. Their strike remains constant from the Carboniferous through to the Cretaceous. S, S/A, and A-type plutons of the Carboniferous Ridge and Foulwind Suites are confined to a 125 km long but discontinuous belt in southern and central Fiordland, wholly within the areal extent of early Paleozoic metasedimentary basement. Volumetrically minor Carboniferous Tobin Suite I-type granitoids are confined to the area east of exposed early Paleozoic metasedimentary basement. Much of eastern Fiordland is underlain by an extensive belt of heterogeneous Darran Suite rocks. Darran Suite rocks extend from Stewart Island to the Darran Mountains of northern Fiordland, forming a belt c. 15 km wide and 300 km long. Correlative Darran Suite rocks also occur further west where they intrude early Paleozoic metasediments, indicating that Jurassic to Early Cretaceous arc-related plutonism and volcanism occurred inboard of the edge of early Paleozoic basement in some parts of the Median Batholith. distinctive Jurassic, pink, hypersolvus syenogranite and alkalic granitoids form a narrow discontinuous belt within the wider calcalkaline Darran Suite. Cretaceous Separation Point Suite plutons form two major belts, one in easternmost Fiordland partially covered by Cenozoic sedimentary rocks, and the other stitching inboard and outboard parts of the Median Batholith in central Fiordland. [ABSTRACT FROM AUTHOR]

The late Cretaceous Rakopi Formation (Pakawau Group) represents one of the most important petroleum source rock units and a potential reservoir unit in the highly prospective Taranaki Basin. This paper presents a predominantly outcrop-based study of the sedimentology, petrography, stratigraphy, and depositional environment of the Rakopi Formation in the Paturau River and Pakawau areas of northwest Nelson, southern Taranaki Basin, together with some preliminary insights into the stratigraphic architecture of the Pakawau Group on a more basin-wide scale. The Rakopi Formation is interpreted here as a terrestrial deposit, representing sedimentation in fluvial channels and their associated overbank and levee environments. However, the presence of dinoflagellates, glauconite, and elevated coal seam sulfur contents is evidence for periodic marine influence during deposition. This could be explained by a low-gradient coastal plain paleogeography, crossed by a series of rivers and their associated floodplain deposits, episodically inundated by marine incursions during successive transgressions. A modern analogue setting from the present-day Hauraki Graben, North island, New Zealand, indicates that marine influence within coastal plain systems can extend several tens of kilometres inland. Given such a physiography, relatively small increases in relative sea level could potentially move the shoreline several kilometres or tens of kilometres farther inland, sufficient to introduce the type of marine influence on sedimentation that we suggest for the Rakopi Formation. The results from this study suggest a greater marine influence within the Rakopi Formation, northward into the greater Taranaki Basin, than has previously been recognised. This raises the possibility of both different reservoir facies as well as potentially a greater proportion of marine mudstones, which would have implications for both reservoir and trapping of hydrocarbons. In addition, marine-influenced coaly rocks within the Rakopi Formation are expected to have greater petroleum generative potentials and to be more oil-prone than their fully non-marine counterparts. [ABSTRACT FROM AUTHOR]

This paper provides a first description of all major plutonic rock units between Resolution Island and Lake Poteriteri in southwest Fiordland. Plutonic rocks, of which c. 95% are granitoids, comprise c. 60% of the basement in southwest Fiordland. Approximately 50% of the plutonic rocks were emplaced between c. 355 and 348 Ma, 5% at c. 164 Ma, 25% between c. 140 and 125 Ma, and 20% between c. 125 and 110 Ma. These episodes of plutonism occurred in response to terrane amalgamation, continental thickening, and subduction along the convergent margin of Gondwana. Correlatives of Devonian plutonic rocks which occur in Nelson are absent from the area described here. A wide variety of plutonic rocks were emplaced at c. 355- 348 Ma. These include relatively small plutons of K- and Rb-rich gabbro-diorite and members of at least three distinct suites of granitoids. Plutons of two-mica ± garnet granodiorite, granite, and minor tonalite share affinities with the S-type Ridge Suite and are the most widespread c. 355-348 Ma old granitoids in southern Fiordland. Plutons rich in Ca, Fe and Zr, depleted in K and Na, and containing quartz diorite, tonalite, and minor granodiorite with the unusual assemblage red-brown biotite, garnet ± hornblende ± clinopyroxene also occur widely in southern Fiordland. These plutons are similar to peraluminous A-type granitoids, indicating A as well as I and S-type plutonism occurred in the Western Province at this time. The Newton River and Mt Evans Plutons have no correlatives amongst c. 355-348 Ma granitoids in southern Fiordland, but their chemistry is similar to that of the older Karamea Suite. Three regional-scale metasedimentary units--locally fossiliferous Fanny Bay Group Buller Terrane rocks in southern Fiordland, Edgecumbe and Cameron Group Takaka Terrane rocks in south-central Fiordland, and undifferentiated Deep Cove Gneiss high-grade metasedimentary rocks of western Fiordland--are all stitched by c. 355-348 Ma old plutons, indicating they have been in close proximity since at least c. 355-348 Ma. in south-central Fiordland, c. 355-348 Ma old plutons cut across fabrics defined by upper amphibolite facies mineral assemblages, indicating low pressure/high temperature metamorphism in this area before this time. The c. 164 Ma old leucocratic Lake Mike Granite is a unique pluton in southwest Fiordland with no obvious correlatives. Plutons emplaced between c. 140 and 125 Ma are similar to the Rahu Suite, although isotopic data are required to confirm this correlation. Rahu Suite plutonism may therefore have begun by c. 140 Ma, rather than c. 120 Ma as previously suggested. Plutons emplaced between c. 125 and 110 Ma have high Sr/Y ratios comparable with the Separation Point Suite. They occur in both an outboard location around lake Poteriteri and an inboard location around the western end of Dusky Sound. The c. 115 Ma two-mica garnet granites of the Anchor Island Intrusives #2 probably formed by partial melting of adjacent ortho- and paragneisses, indicating that upper amphibolite facies metamorphism in western Dusky Sound occurred during the early Cretaceous. The Dusky Fault does not pass directly out to the coast through outer Dusky Sound as previously mapped. Instead it merges with the major northeast-striking lake Fraser Fault at Cascade Cove, which crosses the outer coast near West Cape. The last Cove Fault is a minor structure which cannot be traced beyond last Cove rather than a major fault of regional extent as has been previously suggested. [ABSTRACT FROM AUTHOR]

We develop procedures for evaluating the efficacy of the M8 algorithm and producing probability forecasts in both time and space. Our modelling method uses the Critical Series developed by Harte et al. in 2003 as a predictor variable in a logistic regression. The M8 algorithm calculates seven time series, and the Critical Series embodies the nonlinear rules for combining the behaviour of these seven time series. The M8 algorithm is typically evaluated in (spatial) circles of quite large radius. Our implementation of this has many large overlapping circles covering New Zealand. This raises both practical and statistical problems. From a practical perspective, we really want probability forecasts within relatively small non-overlapping synoptic cells. Further, statistical evaluation of the overlapping circles approach is complicated by the lack of independence. In this paper, we develop both the overlapping circle and synoptic forecasting methods and statistical tests for their evaluation. We then compare results of the two approaches. Although the results indicate a significant relationship between the M8 Critical Series and numbers of large earthquake events, the forecasting success may be largely due to their dependence on slow variations in deep activity, which might be better examined directly as a possible source of predictive information. [ABSTRACT FROM AUTHOR]

This paper presents a systematic review and correlation of river terraces identified in 44 river catchments in the North Island, New Zealand, to assess river behaviour over the last c. 30 000 yr. This provides a comprehensive foundation from which to assess controls on river dynamics over this critical period of landscape development from the last glacial through to the present interglacial. From this review, an integrated framework for elucidating fluvial responses to environmental change is proposed. Sensitivity of river systems to climate change is variable over this time-scale. Substantial sediment inputs to valley floors during the last glacial reduced sensitivity to subtle climatic shifts. Sensitivity increased during the Holocene, with terraces forming in response to episodes of storminess. Tectonics and volcanic activity may both override climatic forcing to cause either cutting or filling of the valley floor. [ABSTRACT FROM AUTHOR]