Rock outcrops provide distinct physical resources for biological species that depend on them for persistence in terrestrial environments. This paper synthesises existing and new information to characterise and quantify geological features of tor outcrops in Otago Schist that host indigenous rock-dwelling lizards. The highest grade of metamorphism and structural reconstitution of schist, Textural Zone (TZ) 4, dominates regional lizard distribution, with some spillover into less well-foliated TZ 3 schist. Quartz lineations, abundant cross-cutting quartz veins, and joints are favourable for making ridges of protruding tors in TZ 4 landscape. The principal lizard habitat is in narrow (<6 cm), recessed (up to 30 cm), wedge-shaped pelitic schist cavities eroded beneath relatively erosion-resistant psammitic schist layers. Both schist lithologies provide basking surfaces for lizards but surface temperatures were highest on pelitic schist during experimental sun heating. The lithological controls on tor outcrop morphology provide explanatory and predictive data for habitat carrying capacity of lizards across Otago, although differences may exist between Caples and Torlesse Terrane schists in refuge density. This information can be integrated into conservation initiatives to preserve and enhance lizard populations.

In March, 2019, a trackway of seven footprints was found at a riverbank outcrop of Maniototo Conglomerate Formation in the Kyeburn River, Central Otago, South Island, New Zealand. In this study, we describe this first known occurrence of moa (Dinornithiformes) footprints to be found and recovered in Te Waipounamu/South Island. Footprints of the trackway were ∼46 mm deep, 272–300 mm wide and 260–294 mm in length. An associated separate footprint was 448 mm wide and 285 mm long. Cosmogenic nuclide dating of adjacent overlying beds from the same formation establishes a mean minimum age of burial age for the tracks of 3.57 Ma (+1.62/−1.18 Ma) with a mode of 2.9 Ma, which we interpret to be Late Pliocene, with a conservative age range of Pliocene to Early Pleistocene. The trackway maker is identified as a moa from the Emeidae family, probably from the genus Pachyornis, with a mean mass of 84.61 kg that was travelling at a speed of 2.61 kmh−1. The single adjacent footprint was made by an individual from the family Dinornithidae, most likely from the genus Dinornis with an estimated mass of 158 kg. These moa footprints represent the second earliest fossil record of moa.

The Patearoa saline site in Maniototo basin has developed on variably clay-altered Otago Schist. Decomposition and sedimentary redistribution of schist outcrop components has led to formation of bare soil-free substrates (upper metre scale) with contrasting permeability to rain and shallow groundwater percolation. Relatively impermeable clay-rich substrates, with a surface crust (cm scale) of detrital clay and muscovite, are saline with electrical conductivity (EC) of 1-35 mS/cm and locally hyperalkaline (pH > 10), with evaporative mineral accumulations. These saline substrates are downslope of more permeable substrates consisting of coarse schist debris and fractured outcrops, which have lower salinity (EC < 1 mS/cm) and lower pH (<7). A salt line can be mapped at metre scale between these substrate types on hillsides. The geochemical contrasts across the salt line have strong effects on plant communities that are colonising bare ground. Initial colonisation of bare saline substrates by some plants changes the geochemical signatures of the surficial few centimetres to form proto-soil with lower EC and pH. Proto-soil development facilitates further colonisation by pasture grasses, but the underlying substrates remain saline and highly alkaline. Salt lines similar to the one at Patearoa are mappable elsewhere in the Otago area and constitute fundamental geoecological boundaries.

Detached buoyant kelp can disperse thousands of kilometres at sea and can colonize newly available shores in the wake of disturbances that wipe out competitors. Localized earthquake uplift can cause extirpation of intertidal kelp populations followed by recolonization. Sources of recolonizing kelp can be detectable in genomic structure of contemporary populations. Our field observations combined with LiDAR mapping identified a previously unrecognized zone of uplifted rocky coastline in a region that is slowly subsiding. Intertidal kelp (Durvillaea antarctica) on the uplifted section of coast is genetically distinctive from nearby populations, with genomic signatures most similar to that of kelp 300 km to the south. Genetic divergence between these locations suggests reproductive isolation for thousands of years. Combined geological and genetic data suggest that this uplift event occurred during one of four major earthquakes between 6000 and 2000 years ago, with one of the younger events most likely. Extirpation of the pre-existing kelp required sudden uplift of approximately 2 metres, precluding several small incremental uplift events. Our results show the power of integrating biological (genomic) analyses with geological data to understand ancient geological processes and their ecological impacts.

Monogenetic volcanism in the Maniototo Basin in the Dunedin Volcanic Group was unusual because the eroded lavas, plugs and dikes comprise spatially and temporally restricted silica-saturated and silica-undersaturated magmas. Ar-40/Ar-39 dating coupled with existing data and field relationships indicate that volcanism was focused at similar to 11 Ma. Major and trace element data show the volcanic rocks to have mafic compositions and little evidence for fractionation and/or crustal contamination, but to have been variably altered. The volcanic rocks comprise an alkaline group and an alkaline to subalkaline transitional group, with one intermediate unit. With the exception of one flow, the transitional group has more radiogenic Sr-87/Sr-86 and less radiogenic Nd-143/Nd-144, Pb-206/Pb-204 and Pb-208/Pb-204 than the alkaline group, as well as smaller Ti and K primitive mantle-normalised anomalies. Overall, the different magma compositions cannot be related to varying degrees of melting of equivalent mantle sources. Trace element ratios indicate that residual Ti and K-bearing mantle phases (amphibole, phlogopite) probably played a major role in the source of alkaline group but a smaller role in the transitional group. Therefore, the varying compositions of the Maniototo volcanic rocks relates to melting of a heterogeneous lithospheric mantle, or/and varying degrees of interaction with mantle hydrous metasomes as the magmas ascended.

Soil-free saline substrates near Alexandra have developed from evaporated marine aerosols dominated by NaCl. The salts accumulate on impermeable substrates where there is minimal chemical interaction between water and rock. Most of the known saline sites occur on outcrops of clay-altered schist exposed immediately below the regional Miocene unconformity, and on clay-rich sediments eroded from altered schist. The unconformity zones that host these saline sites occur linearly along structurally controlled depressions. These unconformity zones have been major targets for placer gold mining, and most of the saline sites occur in abandoned mines where impermeable rocks were exposed by historic excavations. Native salt-tolerant plants (halophytes) have colonised parts of the saline substrates, especially on actively-forming clay pans derived from nearby steep mine cuts. Saline sites are ephemeral, as salt is readily removed in water, sediments can bury the surfaces, and incursion of adventive plant species encourages further sedimentation. Erosional disturbance can overcome these effects temporarily, and surface erosion to bare ground along the strike of the structurally controlled schist unconformity zones may also create new saline sites.

Osmium isotopes, whole rock and mineral geochemical data from peridotite xenoliths from two Miocene McMurdo Volcanic Group cinder cones in the Transantarctic Mountains (TAM) in Southern Victoria Land, Antarctica, reveal that the underlying mantle preserves evidence for major mid-Proterozoic lithosphere formation despite the crust being dominated by late Neoproterozoic-Ordovician (~0.65–0.47 Ga) rocks. The Hooper Crags xenolith suite is dominated by harzburgites with highly refractory olivine Mg# (up to 92.3) and depleted bulk rock major and platinum group element + Re abundances, with 187Os/188Os ratios indicating depletion in the mid-Proterozoic. Pipecleaner Glacier xenoliths, 18 km distant, are lherzolites with olivine Mg# (<91) and fertile major and platinum group element abundances, with Os isotope abundances defining an aluminochron that also indicates mid-Proterozoic depletion. Although exposed crust along this portion of Antarctica reveals only minor evidence for Proterozoic magmatism, the major episode of lithosphere formation indicated by the Os isotope data is supported by published bulk rock Sm-Nd isotope and zircon εHf mantle model ages of Neoproterozoic to Ordovician plutonic rocks. The heterogeneous circum-cratonic mid-Proterozoic mantle under Southern Victoria Land has therefore persisted on a Ga timescale, including through the formation and destruction of Rodinia and Gondwana supercontinents as well as extensive crustal melting and emplacement of the Ferrar large igneous province. This longevity may be due to the thick (>250 km) East Antarctic Craton lithosphere shielding the immediately adjacent circum-cratonic mantle from being affected by convective asthenosphere-driven erosion. This contrasts with mantle lithosphere accreted distally to the East Antarctic Craton (represented by the now-detached Zealandia continent), which did not attain extreme thickness and has therefore been more susceptible to tectonic reworking and lateral translation.

Late Holocene earthquake activity on the reverse Akatore Fault of southeastern South Island has caused uplift along >20 km of nearby coastline, with the last major earthquake event c. 800 years ago. Fault-related uplift has exposed a prominent rocky and sandy terrace along the coastline. We used a combination of approaches including land-based observations, LIDAR remote sensing, and radiocarbon dating of shell deposits, to reveal the extent and nature of past uplift in the region. Cumulative uplift of this terrace varies laterally from <1 m at the northern and southern ends to possibly exceed 5 m in the central portion. The coastal terrace lies below a steep fossil sea cliff. Caves at the base of this cliff contain shells with radiocarbon ages <500 years old, implying persistence of large wave incursion right across the terrace after uplift. A major uplift event of similar to 2 m along the whole 20 km of shoreline caused extirpation of some intertidal kelps that now have genetically distinct lineages in the uplift zone.

Localised deposits of Late Pleistocene and Holocene bird bones occur in wetlands throughout New Zealand. These are characterised by dense accumulations of mostly disarticulated bones, with assemblages dominated by large, flightless bird taxa; in particular the extinct ratite moa (Aves: Dinornithiformes). A wide range of deposition mechanisms were historically proposed for these sites, including large floods and stampedes during wildfires. We outline a simple method for analysing the orientation and spatial distribution of bones within these deposits using GIS software, and apply this method to the interpretation of three such deposits from South Island, New Zealand. The results are consistent with non-catastrophic, periodic miring of individual moa. Long bones within these sites were preferentially orientated and subhorizontally inclined, indicating post-deposition disarticulation and movement of the bones within the sediment by sediment liquefaction and raking from the legs of mired birds, with a possible influence from water flow. Small, light skeletal elements were significantly under represented in the deposits. This may be due to post-mortem scavenging or weathering of vertebra and crania, 'pumping' to the surface of light, buoyant elements during liquefaction events, or crushing of these elements by subsequently mired birds