Abstract The limestone caves of Stoney Middleton Dale are a Site of Special Scientific Interest (SSSI) for features of geological interest, but have been open access since at least the eighteenth century and have a documented history of geotourism. Using the examples of Carlswark Cavern and Merlin Cavern, this chapter sets out evidence that 300 years of open access has resulted in significant disturbance to the features of geological interest. In particular, the integrity of the overall site for scientific research was affected by historical removal of speleothem formations long before it became a SSSI, with damage still occurring today. As most cave SSSIs in Derbyshire have historically had similar open-access arrangements, the examples presented highlight that there is potential for the integrity of less well historically documented caves elsewhere to have been disturbed. This article highlights the importance of establishing a baseline of historical disturbance to recognize whether the integrity of cave SSSIs have been affected and help monitor if disturbance is still occurring. For cave SSSIs to be useful for geological research, it is suggested that there is a need for the historical legacy of open access to individual caves elsewhere to be better understood.

Abstract This paper outlines some significant visits made to north Norway by geologists and mountaineers from Britain and Ireland from the early to late nineteenth century. These visitors wrote up their travels and climbing experiences in a region in north Norway that was difficult to get to other than by sea: Øksfjordjøkelen and Lyngen. Early travellers revealed the sights of the fjord areas and thereby promoted the region for subsequent travellers. Leopold von Buch’s Travels though Norway and Lapland during the Years 1806, 1807, and 1808 probably prompted J. D. Forbes to visit and produce Norway and Its Glaciers and Archibald Geikie’s Geological Sketches at Home and Abroad as part of the contemporary discussions about the ‘glacial theory’. In the latter years of the nineteenth century the British climbers William Cecil Slingsby and George Hastings, with local climber Josef Caspari, explored the Lyngen Peninsula. Elizabeth Main (Mrs Aubrey Le Blond) also climbed in Lyngen. As well as providing written summaries of their exploits, the early explorers included photographs in their books. Some of these images are helpful in the reconstruction of the glacierized landscapes at the end of the Little Ice Age. It is suggested that present-day travellers might leave their observations available, in digital media, for future investigators.

The Black Sea basin presents an ideal laboratory for investigations of morphodynamic interplay between response (morphology) and force (processes) associated with shelf sedimentation. Recent studies along the perimeter of the basin have documented the existence of a complex, heterogeneous seafloor varyingly composed of sand, gravel, silt, and clay. Side-scan sonar data are utilized to establish the spatial patterns of bedform types in the area. In addition, a benthic tripod, configured with an acoustic Doppler current profiler, a rotary fanbeam sonar, and a conductivity-temperature sensor was deployed to record seabed dynamics in response to changing forcing conditions. Together, the tripod and side-scan survey data sets provide a complementary basis for deciphering the processes responsible for the observed seafloor morphology. The side-scan sonar data allows for the determination of spatial patterns of bedform length and orientation. In total, 2376 individual large sand wave bedforms were digitized in geographic information systems with mean and modal wavelengths of 72.8 and 15.7 m respectively. The correlation of near-inertial waves (velocity amplitude 12–20 cm/s and period 12–16 h) and bedform geometry suggest that the extensive sand-wave patches imaged across the shelf are affected by active modern processes and may themselves be modern features or perhaps relict features that remain active presently. Progressive vector diagrams of the nearbed mean current flow indicate a component of cross-shelf directed flow, suggesting an enhanced potential for artifact preservation via cross-shelf advection of anoxic bottom waters by the near-inertial flows measured in this study.

As of October 2005, the semipermanent Global Positioning System (GPS) network called MAGNET (Mobile Array of GPS for Nevada Transtension) included 60 stations and spanned 160 km (N-S) × 260 km (E-W) across the northern Walker Lane and central Nevada seismic belt. MAGNET was designed as a cheaper, higher-density alternative to permanent networks in order to deliver high-accuracy velocities more rapidly than campaigns. The mean nearest-neighbor spacing is 19 km (13–31 km range). At each site, the design facilitates equipment installation and pickup within minutes, with the antenna mounted precisely at the same location to mitigate eccentricity error and intersession multipath variation. Each site has been occupied ~50% of the time to sample seasonal signals. Using a custom regional filtering technique to process 1.5 yr of intermittent time series, the longest-running sites are assessed to have velocity accuracies of ~1 mm/yr. The mean weekly repeatability is 0.5 mm in longitude, 0.6 mm in latitude, and 2.1 mm in height. Within a few years, MAGNET will characterize strain partitioning in the northern Walker Lane to improve models of (1) geothermal activity, which is largely amagmatic in the Great Basin, (2) seismic hazard, (3) the ways in which northern Walker Lane accommodates strain between the Sierra Nevada block and the extending Basin and Range Province, and (4) Neogene development of the northern Walker Lane and its broader role in the ongoing evolution of the Pacific–North America plate-boundary system. MAGNET’s design is generally applicable to regions with an abundance of vehicle-accessible rock outcrops and could be replicated elsewhere.

We present a velocity and strain rate model for the northern Walker Lane derived from a compilation of geodetic velocities and corrected for transient effects owing to historic earthquakes on the Central Nevada seismic belt. We find that from 37°N to 40°N, the Walker Lane is characterized by an ~100-km-wide zone with near-constant strain rates associated with ~10 mm yr −1 total motion across the zone. The strain rates depict predominantly shear deformation, but south of 39°N, the extensional component of the strain rate tensor increases and thus reflects more of a transtensional domain there. We conclude that this transtension is a kinematic consequence of the motion of the Sierra Nevada–Great Valley block, which is not parallel to its eastern margin, i.e., the eastern Sierra front, south of 39°N. While the orientations of several normal and strike-slip faults in the Walker Lane region are consistent with the strain rate model results at several places, the mode and rate at which geologic structures accommodate the deformation are less clear. Left-lateral faulting and clockwise rotations there may contribute to the accommodation of the velocity gradient tensor field, and most normal faults are properly oriented to accommodate some component of the regional shear strain, but significant additional right-lateral strike-slip faulting is required to accommodate the majority of the 10 mm yr −1 relative motion. Overall, the along-strike variation in the active tectonics of Walker Lane suggests that (1) various mechanisms are at play to accommodate the shear, (2) parts of the surface tectonics may (still) be in an early stage of development, and (3) inherited structural grain can have a dominant control on the strain accommodation mechanism.

We combine horizontal Global Positioning System (GPS) velocities from a new compilation of published and new GPS velocities, results from an interferometric synthetic aperture radar (InSAR) study, and paleoseismic data to evaluate the postseismic response of historic earthquakes in the Central Nevada seismic belt. We assume that GPS velocity has contributions from time-invariant (i.e., steady permanent crustal deformation) and transient (i.e., time varying and associated with the seismic cycle) processes that are attributable to postseismic viscoelastic relaxation of the crust and upper mantle. In order to infer the viscosity structure of Basin and Range lower crust, η LC , and upper mantle, η UM , we apply three objective criteria to identify rheological models that fit both geodetic and geologic data. The model must (1) improve the apparent mismatch between geodetically and geologically inferred slip rates, (2) explain the InSAR-inferred vertical uplift rate, and (3) not imply time-invariant contractions anywhere in the extending province. It is not required for the postseismic deformation field to resemble the time-invariant velocity field in pattern, rate, or style. We find that the InSAR and horizontal GPS velocities form complementary constraints on the viscoelastic structure, excluding different parts of the model space. The best-fitting model has a lower crust that is stronger than the uppermost mantle, with η LC = 10 20.5 Pa·s and η UM = 10 19 Pa·s, a finding consistent with the majority of similar studies in the Basin and Range. The best-fitting viscosity model implies that the majority of Central Nevada seismic belt deformation is attributable to postseismic relaxation, and hence that western Basin and Range time-invariant deformation north of 39°N latitude is more tightly focused into the northern Walker Lane than would be inferred from uncorrected GPS velocities. However, significant deformation remains after correction for postseismic effects, consistent with Central Nevada seismic belt faults slipping at rates intermediate between the Walker Lane belt and the central Basin and Range.

Many important geotechnical issues (e.g., groundwater supply and contamination, subsurface waste disposal, hydrocarbon exploration and production) require a detailed understanding of porosity and permeability in subsurface clastic formations (= reservoir quality). Reservoir quality depends on the size, shape, and packing of sand grains as they are originally deposited, as well as diagenetic changes during burial. Obtaining enough samples to fully characterize the target formation is prohibitively expensive or physically impossible. Therefore, reservoir quality estimates must be extrapolated from analogues (± sparse samples) or derived from models. Forward-modeling approaches to predicting diagenetic effects on reservoir quality are well established, but they require information about the character of deposited sand, including mean grain size, sorting, matrix content, and composition of diagenetically relevant particles (i.e., all rock fragments, not just lithic fragments). In cases where deposited sand characteristics are not known, they must be estimated. To this end, we advocate an integrated genetic analysis, which simultaneously predicts multiple sand characteristics as a function of many environmental controls, including tectonic setting, provenance lithotype abundance, climate, regional topographic gradient, hinterland transport distance, basin transport distance, basin subsidence rate, and depositional environment. We have implemented this analytic procedure as a Bayesian belief network–based forward model that successfully predicts sand composition and texture in diverse settings, including provenance areas dominated by either volcanic, high-grade metamorphic, or sedimentary lithologic assemblages; climates ranging from tropical to desert; and a range of alluvial/fluvial drainage types represented by small steep drainages as well as continental-scale big rivers.

We investigate the fate of permafrost since the Last Glacial Maximum in the Laptev and East Siberian Seas, a submergent coastal environment. The shelf here is up to 700 km wide and less than 80 m deep, a large area highly sensitive to changes in environmental conditions. Climate and sea-level histories and the terrestrial and coastal geomorphology of the region are combined with direct observations from drilling campaigns to review existing notions on the distribution, thickness, physical state, and history of the development of terrestrial and offshore permafrost since the Last Glacial Maximum. Drilling transects running perpendicular to the coast in the nearshore zone show that the interface between unfrozen and frozen sediments varies in its angle of inclination as a result of a number of factors, primarily coastal retreat rate. A conceptual model of permafrost development prior to submergence suggests that thermokarst and nearshore processes are critical in altering the development of permafrost in the submarine environment.

We investigated the petrogenetic characteristics of the Paleogene Veneto volcanic province and compared them with other intraplate magmatic occurrences of the Adria–North Africa plate since Late Cretaceous time. Veneto volcanic province magmas were erupted through a transtensional rift system that resulted from intra-plate reactions to the Alpine collisional events. The lavas, mostly basic in composition, encompass a wide range of serial affinities from (mela)-nephelinites to quartz-normative tholeiites. Nephelinites and basanites often carry spinel-peridotite mantle xenoliths that have rheologic and thermobarometric characteristics that indicate an origin from the mechanical boundary layer at depths not exceeding 50–60 km. Incompatible element patterns of the most primitive Veneto magmas, together with their isotopic signature ( 87 Sr/ 86 Sr 0.70315–0.70386; 143 Nd/ 144 Nd 0.51279–0.51298; 206 Pb/ 204 Pb 18.8–19.8), share geochemical characteristics with other magmatic occurrences of Adria–North Africa domains, and they show a clear affinity with intraplate sodic lavas, particularly HIMU (high U/Pb = high µ) and, to a lesser extent, enriched-mantle–ocean-island basalt (EM2-OIB) magmas. An integrated petrogenetic model, generally applicable for Adria–North Africa domains, suggests that most of the magmas were generated within the spinel-peridotite lithospheric mantle, from progressively deeper sources (30–100 km) and with a concomitant decrease in the degrees of partial melting (25%–3%) from quartz-normative tholeiites to nephelinites. The modeled magma sources invariably require enrichments in incompatible elements and metasomatic phases comparable (or equivalent) to those observed in some mantle xenoliths associated with the Veneto volcanic province lavas. Two kinds of mantle sources were identified: lherzolites bearing amphibole ± phlogopite for tholeiites to basanites, and lherzolites bearing amphibole ± phlogopite plus carbonatitic components for nephelinites. The elemental and isotopic characteristics of these mantle sources correspond to variable mixing of HIMU and, to a lesser extent, EM2 metasomatic components with a pristine depleted-mantle (DM) lithosphere. The HIMU metasomatizing agents may possibly be related to the mantle plume that is thought to extend from the eastern Atlantic to Europe and the Mediterranean, including Adria–North Africa domains, since the Late Cretaceous. These components more effectively accumulated in the lower lithospheric portion, i.e., the thermal boundary layer, whereas older metasomatic EM2 components may have been better preserved in the upper, more rigid, mechanical boundary layer.

This paper integrates new field observations to summarize the evolution of the 37–39°S segment of the Andean margin during the Neogene period. The western Neuquén Andes represent a transitional segment between the high, broad Central Andes and the low, narrow Patagonian Andes. The Main Cordillera at this latitude was uplifted between 11 and 6 Ma. Since then, extension and transtension has dominated the area. South of 38°S, deformation concentrates along the Liquiñe-Ofqui fault zone, a crustal-scale dextral strike-slip system that accommodates part of the margin-parallel component of oblique subduction. The architecture of the volcanic arc is strongly controlled by this fault zone. We differentiate four main tectonic phases: (1) late Oligocene–middle Miocene extension and development of a segmented intra-arc continental rift basin and broad volcanic zone; (2) late Miocene shortening, resulting in uplift, exhumation, and inversion of the former basins and a volcanic gap in the Main Cordillera; (3) Pliocene–early Pleistocene extension of the orogenic structure, reestablishment of the volcanic arc, and transtension along the intra-arc zone; and (4) late Pleistocene–Holocene narrowing of the arc and localized extension-transtension along the axial intra-arc zone. In the Central Andes, shortening has been more or less continuous since the Miocene, whereas in the Neuquén Andes, shortening stopped at ca. 6 Ma, probably related to the increase of the slab angle triggering the extension of the former orogenic structure and the onset of arc-parallel strike-slip faulting. The episodic evolution and migration of volcanism are related to changes in dip of the subducting plate.

Nonpedogenic calcrete is difficult to distinguish from pedogenic calcrete in the fossil record; both alpha and beta textures have been observed from fossil and modern examples. However, a calcrete from the New Haven Arkose (Hartford Basin, Connecticut) is shown here to be of a nonpedogenic origin through sedimentologic and petrographic evidence. An accumulation of thin sheets of displacive calcite layers found in a decimeter-thick horizon of anastomosing veins within the upper portion of a red mudstone is correlated to calcite cement found in the overlying sandstone. Based on petrography, we recognize six generations of calcite in the mudstone-sandstone hosts. The first five generations are associated with rhizoliths that can be related to deep taproots and are interpreted to have formed by precipitation from shallow groundwater. There are no vadose-type cement morphologies; the calcite has luminescent zones, indicating that Mn was soluble and thus oxygen levels were low. These cements clearly formed several meters below what would have been the surface of the channel sand body. We suggest that calcite cement stratigraphy combined with redox models for the behavior of Mn (as well as Fe and U) may aid in the identification of nonpedogenic versus pedogenic carbonates in the geologic record. Additionally, the calcite from this carbonate layer has been dated using the U-Pb method. Our results provide insight into the environmental and diagenetic fluid conditions favorable for providing a spread in U/Pb ratios that are suitable for precise dating of calcites in otherwise undateable sections. Las calcretas no-pedogénicas son difíciles de diferenciar de las pedogénicas en el registro antiguo; los dos tipos de textura alfa y beta se reconocen en depósitos antiguos y recientes. Sin embargo, en el caso concreto de la calcreta de New Haven Arkose (Cuenca Hartford, Connecticut), los datos sedimentológicos y las evidencias petrográficas permiten demostrar su origen no-pedogénico. La presencia, dentro de lutitas rojas, de finas capas de calcita desplazativa dentro de un horizonte decimétrico de venas anastomosadas se puede correlacionar con la formación de cemento calcítico en las areniscas infrayacentes a dichas lutitas rojas. Petrográficametne se reconocen seis generaciones de calcita en las lutitas y areniscas que constituyen el sustrato. Las cinco primeras generaciones están asociadas con rizolitos de sistemas radiculares profundos y se pudieron formar por precipitación a partir de aguas freáticas someras. No hay cementos vadosos y la calcita tiene zonas luminiscentes indicando que el Mn era soluble y, por tanto, los niveles de oxígeno bajos. Estos cementos se formaron claramente varios metros por debajo de lo que fue la superficie del canal de arenas. Sugerimos que la estratigrafía de los cementos de calcita combinada con los modelos redox de comportamiento de Mn (también Fe y U) pueden ayudar en la identificación de los carbonatos pedogénicos y no-pedogénicos en el registro geológico. Además la calcita de esta capa carbonática se ha datado por el método de U-Pb. Nuestros resultados permiten una mejor caracterización de las condiciones ambientales y de los tipos de fluidos más favorables para ampliar el rango de valores U/Pb necesarios para datar calcitas en secciones que de otro modo no se podrían datar.