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The aim of this study, which covers the Tigris River and its tributaries (Kizilsu River) established in Cizre and its surroundings, in the province of Sirnak in the Southeastern Anatolia Region, it is to examine the valley evolution process, geomorphologicalfeatures, response to tectonic. This works the evolution process of the Kizilsu River, which settled in the region by crossing Kasrik George the aim of to the factors affecting the morphological structure of the region. This area is important in terms of covering a part of Tigris River valley, one of Turkey’s most important rivers and tectonism-fluvial system relationship. In this research around Kasrik George; the formation process of the George (antesedant split valley), the step structure sandrock terrace formed by effect of tectonism on morphology are discussed and tectonism-fluvial system relationship is studied. The area where the Cizre district center was established and its immediate surroundings draw attention with the terraces of the Tigris River. In this study area, the Tigris River formed S1 (100-125 m), S2 (50-70 m), S3 (10-30 m) and S4 (3-5 m) terraces. The upper (S1) level of these landforms is covered with basalt sand formed a structural lava plateau. In addition, different drainage networks formed by the Tigris River and its tributaries are also seen in the study area.

The Udokan volcanic plateau differs from other volcanic regions of the Late Cenozoic volcanic province of East Asia in the high alkalinity of volcanic rocks, their potassium specialization, and rock composition, varying from melaleucytitis and melanephelinites to alkaline trachytes. The presence of alkaline-salic rocks in volcanic associations makes it unique to the province. The reasons that determined the unique magmatism of the Udokan plateau are considered. The data of geochemical and isotopic studies have shown that the moderately enriched magma of the mantle plume served as a melt source in the region. The initial melts were formed under conditions of garnet stability at low degrees of melting. This contributed to their enrichment in alkalis and other incompatible elements that is especially characteristic of ultramafic rocks. It is established that fractionation processes controlled the distribution of the trace elements in the rocks of volcanic associations. Deep differentiation of the magmas to alkaline trachytes occurred in the peripheral magma chambers. Here, magmas interacted with intracrustal waters, which led to a change in their oxygen isotopic composition. It is shown that contamination did not play a decisive role in the formation of lava plateau rocks.

The Tharsis region of Mars is a vast volcanic plateau which hosts the immense Tharsis Montes shield volcanoes. The Tharsis region is suggested by multiple lines of morphologic and modeling evidence to have been a site of coincident volcanic and glacial activity throughout the majority of the geologic history of Mars. The prolonged and overlapping histories of volcanism and glaciation within the Tharsis region raise the likelihood of widespread surficial glaciovolcanism, a possibility which is supported by the recognition of glaciovolcanic landforms in the region by past investigations. Given this likelihood, we perform an exploratory study to assess the potential role that surficial glaciovolcanism may have played in the geologic and hydrologic history of the Tharsis region. We first review the history and characteristics of volcanism and glaciation in the Tharsis region, as well as previously documented evidence for past glaciovolcanic activity, in order to outline relevant conditions and parameters. The outlined volcanic and glacial conditions are then used in conjunction with results and predictions from past modeling of surficial glaciovolcanic processes to assess the potential role of glaciovolcanism in the formation of the Tharsis region's major tectonic and hydrologic features. We conclude that surficial glaciovolcanism may plausibly have contributed to the formation of many of the tectonic and fluvial features in the Tharsis region, offering advantages over prior formation models, particularly for the large basin/chaos-sourced outflow channels concentrated in the area. The formation of a range of investigated features in the Tharsis region by surficial glaciovolcanism does not require ambient warm and wet climate conditions therefore suggesting potential consistency between the observed features and a predominantly cold and icy climate. Consequently, this analysis represents an incremental contribution to better understanding the climatic and hydrologic evolution of Mars. However, analyses performed in this work indicate that the glaciovolcanic origin models we considered are unable to viably account for the complete range of explored features, indicating that future work is required to better resolve the processes involved in their formation.

The paper reports the isotope-geochronological and petrological-geochemical studies of the Pliocene moderately-acid volcanism of the Akhalkalaki Plateau in the central part of the Lesser Caucasus (Javakheti highland, Georgia). K-Ar dating showed that young dacitic lavas and pyroclastic rocks were formed in the mid-Pliocene (3.28 ± 0.10 Ma) in relation with the explosive–effusive eruptions of small composite volcanic cones and formation of minor extrusive domes confined mainly to the eastern margin of the region. Isotope-geochronological data in the combination with results of structural drilling indicate that the considered short-term pulse of the volcanic activity occurred during a short gap between two phases of the Pliocene–Early Pleistocene mafic magmatism widespread within the Akhalkalaki plateau. The studied Pliocene dacites were erupted at the post-collisional stage of the evolution of the Lesser Caucasus, but bear petrological-geochemical affinity of adakitic series. They are characterized by the steady presence of amphibole phenocrysts, the elevated contents of Sr, Ba, LILE and the lowered contents of Y, Nb, Ta, and HREE, and have depleted Sr isotopic composition (87Sr/86Sr < 0.7045). Analysis of petrogenetic models earlier proposed to explain the generation of adakite-like magmas in the modern collision zones showed that the origin of the Pliocene dacitic lavas of the Akhlkalaki plateau is best described by the crystallization differentiation of water-saturated calc-alkaline basaltic melts with removal of common mafic rock-forming minerals (first of all, amphibole and pyroxene) and accessory phases (apatite, titanite, Ti-magnetite) as cumulus minerals. Crustal assimilation of evolved magmas only insignificantly contributed to the petrogenesis of the dacites.

On the Ground • When Yellowstone National Park (YNP) was established in 1872, American bison (Bison bison) were living in the park's forests and mountains. • A study conducted in the 1960s concluded that those were Mountain bison (Bison bison athabascae), a subspecies adapted to mountain habitat. It was assumed that those historical bison occupied their native habitat and had done so in prehistoric times. • When archaeological evidence of YNP bison was discovered in the mid-1990s it seemed reasonable to assume that those bones were derived from a herd of native prehistoric bison. • However, a review of archaeological, historical, genetic, and ecological evidence suggests a different history. Namely, herds of bison were absent before 1840. Sometime between 1840 and the mid-1850s, plains bison were driven into the mountain forest in and near YNP. In those forests, bison were relatively safe from horse-mounted, bow-and-arrow-armed Native American hunters. • Archaeological evidence suggests that YNP’s prehistoric bison were bulls that left herds on the low-elevation plains that surround the park; the bulls would have traveled up mountain drainages to the Yellowstone volcanic plateau. • Bison played no significant role in the ecological processes that shaped YNP’s prehistoric landscape. YNP’s modern bison herd is causing significant changes in range condition.

Highlights • The volcanic nature of the Mozambique Ridge is clearly established. • It is a Large Igneous Province. • It is formed by a mantle plume originating from the African LLSVP. Abstract The Mozambique Ridge (MOZR) is one of several bathymetric highs formed in the South African gateway shortly after the breakup of the supercontinent Gondwana. Two major models have been proposed for its formation - volcanic plateau and continental raft. In order to gain new insights into the genesis of the Mozambique Ridge, R/V SONNE cruise SO232 carried out bathymetric mapping, seismic reflection studies and comprehensive rock sampling of the igneous plateau basement. In this study, geochemical data are presented for 51 dredged samples, confirming the volcanic origin of at least the upper (exposed) part of the plateau. The samples have DUPAL-like geochemical compositions with high initial 87Sr/86Sr (0.7024–0.7050), low initial 143Nd/144Nd (0.5123–0.5128) and low initial 176Hf/177Hf (0.2827–0.2831), and elevated initial 207Pb/204Pb and 208Pb/204Pb at a given 206Pb/204Pb (Δ7/4 = 2–16; Δ8/4 = 13–167). The geochemistry, however, is not consistent with exclusive derivation from an Indian MORB-type mantle source and requires a large contribution from at least two components. Ratios of fluid-immobile incompatible elements suggest the addition of an OIB-type mantle to the ambient upper mantle. The MOZR shares similar isotopic compositions similar to mixtures of sub-continental lithospheric mantle end members but also to long-lived, mantle-plume-related volcanic structures such as the Walvis Ridge, Discovery Seamounts and Shona hotspot track in the South Atlantic Ocean, which have been proposed to ascend from the African Large Low Shear Velocity Province (LLSVP), a possible source for DUPAL-type mantle located at the core-mantle boundary. Interestingly, the MOZR also overlaps compositionally with the nearby Karoo-Vestfjella Continental Flood Basalt province after filtering for the effect of interaction with the continental lithosphere. This geochemical similarity suggests that both volcanic provinces may be derived from a common deep source. Since a continuous hotspot track connecting the Karoo with the MOZR has not been found, there is some question about derivation of both provinces from the same plume. In conclusion, two possible models arise: (1) formation by a second mantle upwelling (blob or mantle plume), possibly reflecting a pulsating plume, or (2) melting of subcontinental lithospheric material transferred by channelized flow to the mid-ocean ridge shortly after continental break-up. Based on geological, geophysical and geochemical observations from this study and recent published literature, the mantle-plume model is favored.

Quantifying water contents of the lithospheric mantle is key for our understanding of global geodynamics, mantle composition and related physical properties. Most of the mantle lithologies contain little water, but some heterogeneities like pyroxenites, likely contain more water, and by their mineralogical assemblage melt at lower temperatures. The quantification of their water content brings new information about water distribution in the mantle. This study focuses on two continental lithospheric domains: the Massif Central (France) and the Adamawa Volcanic Plateau (Cameroon). Garnet pyroxenites in Adamawa Volcanic Plateau are more hydrated ([H2O]Cpx = 386-685 ppm; [H2O]Opx = 124-155 ppm; [H2O]Garnet < 0.5 ppm) than those of French Massif Central ([H2O]Cpx = 112-465 ppm; [H2O]Opx = 61-104 ppm; [H2O]Garnet < 0.5 ppm). These water concentrations are representative of lithospheric water (no water loss during xenolith ascent), however water content of French Massif Central pyroxenites have been modified by metasomatism. Pyroxenites have been dehydrated by a hot carbonatitic fluid, whereas rocks of Adamawa Volcanic Plateau were likely not affected by metasomatic events. In both regions, the metasomatic episodes modified the LREE contents (e.g., Ce). Consequently H2O/Ce ratio, which could be a good source tracer, might not be the most appropriate tool to identify pyroxenites implication in magmas genesis.

Georgia is in the middle of the area (70, 000 km2) almost 25 in the Europe. The formation of the country's territory counts for one billion years. All forms of relief are presented in Georgia, which is known worldwide. There are hundreds of natural monuments on the territory of Georgia that make a special impression on the visitors. It is also important that such monuments of nature are concentrated on a small area that increases their tourism and recreational purpose. With the diversity of nature, Georgia can be presented in the world geographical parks (geoparks) networks, and will further increase its tourist attraction. Georgia has not been presented in the world geographical parks (geoparks) networks, what is an interesting as Caucasus Office of Nature Protection World Fund, as state and local tourist organizations. The relevant nomination can be submitted by Elizbarashvili (2018): 1. Javakheti—volcanoes and Vardzia canyon is located in southern Georgia (Akhalkalaki administrative district). It is made of lavish streams flowing from the slopes of the Mordian direction. There are several volcanic cones on this ridge that create effective peaks. The western boundary of the Plateau passes through the Vardzia canyon (the administrative district of Aspinza), with an average depth of 500 m, and a length of 7 km. It is in the middle of the medieval city of Vardzia (13-storey cave building) and monastery complex, which is nominated for a UNESCO cultural heritage monument. Some volcanic lakes are presented under geopark, which present Ramsar Convention site and are in composition of protected territories of Javakheti. 2. Imereti—The dinosaur footprint and the Imereti Cave Complex (including the Kutaisi city and Tskaltubo administrative districts) in central Georgia—There are over 200 unique footprints of dinosaurs, which are found in 1933 on the mercury limestone. The footprint is located at 500 m above the sea level, with subtropical humid conditions and the western exposition winds (slopes from the Black Sea). Nearby, there are several karst caves, geological, paleontological, zoological, and botanical monuments. The Tskaltubo Cave is one of the most remarkable places in Europe. 3. Khevi—Glacier (Kazbegi), Gudauri volcanic plateau and Dariali Gorge—The glacier is located on the central Caucasus in northern Georgia (Stepantsminda administrative district). Its height is 5033 m. The local population call it “Khevi bride". The glacier is a “dormant” volcano that lasted 6,000 years ago. Here the lavish deer runs in three—south, east, and north-east. One of the mythological and one historical (Gergeti Trinity) monument is the monument on the edge of the glacier. Mythology is connected to Amiran (the analog of Prometheus) attached to the Caucasus. According to the tradition, God Amiran right here climbed the cliff, and “on top of the snow-ice gear and the glacier of the glacier". At the foot of the glacier, Dariali canyonic gorge is represented in the rocks formed in the form of volcanoes developed over 300–400 million years ago, central Caucasus. Its length is 11 km, and the relative height is more than a thousand meters. There is also a volcanic plate of Gudauri, whose vertical slopes are formed by lava cooling (suspension).

International audience; This paper presents a multi-proxy geoarchaeological analysis of the complex pedo-sedimentary archives of a small pond situated within the protohistoric site of Corent, in central France. A robust chrono-stratigraphic framework was developed integrating all chronological data from previous studies. Micromorphological, geochemical and sedimentological analyses were performed on a radiocarbon-dated core. Results are discussed alongside palynological data from previous work on the same core, in order to reconstruct human-environmental interactions on the Corent volcanic plateau since the Neolithic. After intense soil erosion recorded during the Early and Middle Neolithic, the Late Neolithic is characterized by vegetation recovery and soil stability in the basin contemporaneous with site abandonment, perhaps due to pronounced soil degradation in the plateau. During the Early Bronze Age, agropastoral land use contributed to major environmental changes in the pond’s basin, including soil profile sealing and gleyfication. Environmental impact patterns detected in the pedo-sedimentary record indicate settlement intensification during the Middle Bronze Age. After the substantial impacts of an intense anthropogenic disturbance in the Early Iron Age, the Lac du Puy becomes a vertic depression recurrently flooded while a late Iron Age Gallic oppidum develops on the plateau, and is finally backfilled at the end of the Iron Age. The detailed multi-proxy picture from this intra-urban wetland helps nuance our understanding of the environmental impacts of prehistoric societies in Western Europe. Indeed, our results highlight the importance of keeping a long term perspective when dealing with past human-environment interactions.

Large-scale pyroclastic density currents (PDCs) produce inhomogeneity of distributions, thicknesses, stratigraphic structures, and temperatures, thereby causing poor understanding of PDC emplacement processes. Millennium Eruption (ME) of Tianchi volcano in 946 A.D. produced masses of PDCs, covering an area of more than 1570 km2 around the caldera in the Chinese territory. To understand PDC emplacement processes, we examine the proximal to distal variations in the PDC facies during the ME by analyzing the topography, stratigraphy, granulometry, and petrography. The topography of Tianchi volcano has different slopes, including the cone (> 6°), lava shield (2–5°) and lava plateau (< 1°), which affected the PDC emplacement during the ME. The shape of the PDC deposits radiates outward from the caldera, and the periphery has two pyroclastic aprons. The proximal strata (< 10 km) are less than 4 m thick and consist of eutaxitic and lava-like structures in the gullies of the cone. The medial strata (10–20 km) are 10–60 m thick, with columnar joints, pumice-rich layers, and lithic-rich layers in the valleys of the shield. The distal strata (> 20 km) are less than 10 m thick, with coarse-tail layers, ground surge layers, climbing layers, and carbonized woods in the plateau. From the proximal to the distal strata, the emplacement temperature of the PDCs decreased from 740 to 280°C. The medial layers indicate a gravitational differentiation effect and weakened transportation, which led to the formation of thick beds. The distal PDCs demonstrate fluidization characteristics and a density lower than that of the proximal and medial strata, which exhibit clear stratification. Grain size data (< 64 mm) show that the median diameters decreases with increasing distance from the caldera. Rhyolitic and trachytic pumice were found and are assumed to be associated with the composition of the magma chamber. Magmatic mixing structures were confirmed through microscope observations. The volume of the PDCs in the Chinese territory is approximately 7 km3. Our results assist in unraveling some PDCs emplacement processes, marked by a high level of topography confinement, about 50 km runout distance, 280–750°C emplacement temperatures, and more than 7 km3 volume, which provide insights of the PDCs destruction during the ME.

Lechmine n’Ait El Haj (LNH) is a monogenetic plioquaternary maar, lying in the volcanic province of the MiddleAtlas. It is a 110-m-deep crater located in the Liassic limestones. The tephra deposits surrounding the crater are mainly made up of depositional units (surges and projectas) interpreted as deposits of phreatomagmatic origin. They are topped by a small unit of massive breccia tuff reflecting magmatic deposits. The maar is a result of the interaction between the ascending magma and karstic water, in an intraplate volcanism context. Water, causing this eruption, is drained by an open system of fractures in the limestone. The explosion started by phreatomagmatic dynamism, producing a big stack of pyroclastic deposits and pyroclastic falls. During the eruption, the crater grows progressively from the eruptive center to the Northwest. The upper part of the phreatomagmatic deposits is characterized by a typical mud crack structure. A transition to a strombolian dynamism occurred throughout the end of volcanic activity. Meanwhile, a lava flow, coming from the volcanic plateau, discharged in the crater’s center. With the eruption resumption, the lava is strongly fragmented; therefore, a small cone is created especially in the northern flank of the maar. Towards the end of the volcanic activity, a supply of karstic water causes another transition of the eruptive style from strombolian to phreatomagmatic dynamism. A significant karst collapse in the southern flank of the LNH maar has occurred, leading to its current morphology.

The Erzurum-Kars Volcanic Plateau (EKVP) was formed by volcanic eruptions during the Messinian-Zanclean (~5.5 Ma) period, related to a continental collision event between Eurasia and Arabia, initiated ~15 Ma ago. The EKVP unconformably overlies a series of older sedimentary formations spanning in age from Cretaceous to Miocene. It starts with a ~400 m thick pyroclastic-rich layer at its bottom, named the Akkoz basal tuff, consisting of rhyolitic and dacitic ignimbrites, pyroclastic fall and surge deposits, which are intercalated with andesitic and dacitic lavas. Upper layers of the plateau are dominated by andesitic and basaltic andesitic lavas (~100 m).In the northwest of the study area, an eroded stratovolcano, named Hamamlı volcano, which is possibly coeval with the plateau volcanism is present. It covers ~280 km2 area and consists of a thick sequence of rhyolitic lavas, tuffs, ignimbrites, perlites and obsidians. The best preserved volcanic edifice in the study area is the Greater Aladağ Stratovolcano with a footprint of ~230 km2. It is composed of intermediate lavas with andesitic, dacitic, trachy-andesitic compositions, erupted ~3.55 Ma in Piacenzian. A small volcanic cone, named in this study as the Lesser Aladağ volcano, sits on the northern flank of the Greater Aladağ. Lesser Aladağ has an elliptical shape and is composed of basaltic-andesitic and basaltic trachy-andesitic lavas. Three semi-circular shaped rhyolitic domes called the Odalar rhyolite sit on the southern and eastern slopes of the Greater Aladağ. In the N and NE, the Aladağ volcanic sequence is unconformably overlain by a younger (~2.7 Ma) sequence of olivine basalts and basaltic andesites, which is known as the Kars volcanic plateau.All volcanic products in the study area are calc-alkaline in character with a clear subduction signature. Results from our petrological modelling studies indicate that the magmas that fed the Aladağ volcanic system were evolved in a chamber, which was periodically replenished by fresh and primitive basaltic magma. Our assimilation model results based on the equations of DePaolo (1981) and Aitcheson and Forrest (1994) show that fractional crystallization was more important than crustal assimilation process in evolved lavas of the Aladağ system. Interestingly, EC-AFC model results indicate that some of the youngest basalts from the Kars volcanic plateau contain higher degrees of crustal assimilation relative to more evolved lavas.Crystal chemistry of amphiboles by EMP from the amphibole-bearing lavas of the Akkoz basal tuff layer indicates that they had experienced crystallization pressures between 5.63 and 6.45 kbar and temperatures between 949 and 1026 °C during their magma chamber evolution. On the other hand, pyroxene thermo-barometry of the Aladağ units has given crystallization pressures between 0.8 and 4.8 kbar, and temperatures from 1025 to 1078 °C, implying polybaric fractionation. Calculated crystallization pressures and temperatures from the younger lavas of the Kars volcanic plateau are ~8.8 kbar and ~1179 °C respectively. Our partial melting models indicate that the primitive basaltic magmas might have been derived from a metasomatised spinel peridotite source with varying melting degrees from 0.7% to 2%.

Curie point depths in southwestern Yemen were determined from radially averaged power spectra of the reduced to the pole aeromagnetic data by the modified centroid method. The results show that shallow CPD zones occurred in the western and southeastern parts of the area associated mainly with Tertiary and Quaternary volcanic regions, respectively. The distribution of hot springs and hot groundwater wells through the area is correlated well with the mapped shallow zones and thermal gradient regions around them. On the other hand, the deepest CPD zone is attributed to a hot mantle upwelling underplating the crust beneath the volcanic plateau and crystalline basement margins in the middle part of the area. This spot forming the most probable source of magma for the Quaternary volcanic activity in the area. The observed geothermal activity at Al Lisi–Isbil, Damt, and Al Qafr fields is ascribed to the heat derived from shallow magmatic bodies, with temperature less than Curie temperature of magnetite, and also to the heat transferred from the underlain hot mantle spot through a net of deep faults affected this region.

New data on the geology, age, and composition of the Late Cenozoic volcanic rocks of the Vitim Depression, a satellite of the Vitim Lava Plateau (VLP), have been obtained. Two-stage volcanic activity has been revealed. In the Middle Miocene (14–13 Ma), a basalt and trachybasalt (hawaiite) lava covers were formed. In the Pleistocene (1.6–0.7 Ma), basanite erupted from scoria cones. Both stages of volcanism were coeval to similar pulses of volcanism within the VLP. However, unlike the latter, there were no Pliocene and Late Miocene eruptions within the Vitim Depression. Additionally, the Vitim Depression basalts have depleted geochemical characteristics comparative to those of the VLP. These features of the Vitim Depression volcanics imply their autonomous formation, whereas the synchroneity of the initial and final stages of volcanism in the depression and in the VLP reflects the existence of a common regulating mechanism of igneous activity.

The Neogene Kağızman–Tuzluca Basin is located in the NE Anatolia and extends eastward into Armenia Oktemberian Basin. The Halıkışlak (Late Oligocene), Turabi and Tuzluca formations (Lower–Middle Miocene) are time equivalents of the organic-rich Oligo-Miocene Maikop Series in the Caspian region. However, depositional conditions within the KBT are appreciably different and source rocks are not as richer as it. The Halıkışlak Formation has little source rock potentials, with very low values of TOC (0.04–0.25%), HI (14–90 mg HC/TOC) and genetic potential-GP (i.e. Rock–Eval S 1 + S 2 = 0.05 to 0.22 mg HC/g rock). Although a peat facies sample has a relatively high TOC (6.78%), T max of 428 °C, HI values are very low (45 mg HC/TOC). TOC and GP values for the Tuzluca Formation are between 0.06 and 0.39 wt%, and 0.16–1.51 mg HC/g rock, respectively. Some levels of the Turabi Formation have TOC contents up to 6.14 wt%; however, mainly T max values are low 435 °C, and HI range from 25 to 54 mg HC/TOC. The extract of one low-maturity Turabi sample possesses biomarker distributions of an immature rock. Low relative abundance of tricyclic terpane and dominant C29 ααα (20R) are in accordance with the immature source rock. Some samples collected from the outcrops nearby Pliocene/Pleistocene lava series show localized maturation stage. We suggest that the Oligocene to Middle Miocene units could be more studied beneath the volcanic plateau.

Peculiarities of the forest vegetation dynamics and the main factors and mechanisms of environmental filtering were studied on loose deposits of the Tolbachinskii Dol Volcanic Plateau (Kamchatka) by means of plant life-form analysis. It was found that, in the earlier stages of plant succession, polycarpic herbs, acrocarpous mosses, and fruticulose lichens dominated. Forest communities of 35 years old differed from the old-growth ones by the proportions of plant life-forms and the total coverage. Environmental filtering is manifested by the most successful development of plants having special morphological adaptations of belowground systems to loose unstable substrata.

The Paleocene volcanic rocks in the Nuussuaq Basin on Disko and Nuussuaq comprise the Vaigat Formation (c. 62–61 Ma) and the Maligât Formation (c. 60 Ma). The Vaigat Formation in this area is 0–1600 m thick and is dominated by olivine-rich picrites. The formation was deposited during three volcanic episodes and is divided into 10 formally defined members and about 20 informal units. The first episode gave rise to the Anaanaa Member. The second episode gave rise to the Naujánguit Member, which is intercalated with the minor, crustally contaminated Nuusap Qaqqarsua, Nuuk Killeq, Asuk, Tunoqqu and Kûgánguaq members and the uncontaminated Qordlortorssuaq Member. The third episode gave rise to the Ordlingassoq Member and the minor alkaline Manîtdlat Member. Contemporaneous sediments deposited during the first two episodes are the marine Eqalulik Formation, and during the third episode the nonmarine Atanikerluk Formation. During the second episode, the polarity of the geomagnetic field changed from normal (Chron C27n) via a transition zone to reversed (C26r). The deposits of the first volcanic episode are situated on western Nuussuaq. During the second and third episodes, the volcanism gradually spread eastwards and southwards so that the Vaigat Formation now forms a domed structure, thickest in the north, thinning out on northern Disko and reaching eastwards to the high gneiss country on central Nuussuaq. The earliest eruptions took place on the sea floor and quickly built up a subaerial lava plateau. All three episodes gave rise to complicated facies changes between subaqueous and subaerial eruption products caused by the eastmoving volcanism, subsidence, volcanic aggradation and blockage of the sea connection against the elevated eastern gneiss country. Eruption sites are widespread for all three volcanic episodes. Within certain time periods, a number of contemporaneous high-level magma reservoirs developed within sediments of the Nuussuaq Group, and the crustally contaminated members formed in these reservoirs by reaction between Mg-rich magmas and sediments. The uncontaminated rocks in the Vaigat Formation are picrites with 12–31 wt% MgO and subordinate basalts with 7–12 wt% MgO. The crustally contaminated rocks range from silicic picrites with 12–16 wt% MgO (Nuusap Qaqqarsua Member) to native-iron-bearing magnesian andesites with 6–10 wt% MgO and up to 62 wt% SiO2 (Asuk Member). The Asuk Member includes unique, strongly reduced rock types with native iron, graphite and sulfide. The contaminated units have individually distinct compositions, indicating individually different contamination events. The alkaline Manîtdlat Member contains an enriched lithospheric component. Present-day seeps of migrated oil are widespread in the oldest part of the volcanic succession on western Nuussuaq. Some of the contaminated magmas in the Asuk and Kûgánguaq members have fractionated sulfides with Cu and Ni and have been explored for nickel and platinum-group elements.

Volcanism associated with the Kerguelen Large Igneous Province is found scattered in southwestern Australia (the ca 136 to ca 130 Ma Bunbury Basalts, and ca 124 Ma Wallaby Plateau), India (ca 118 Ma Rajmahal Traps and Cona Basalts), and Tibet (the ca 132 Ma Comei Basalts), but apart from the ∼70 000 km2 Wallaby Plateau, these examples are spatially and volumetrically minor. Here, we report dredge, geochronological and geochemical results from the ∼90 000 km2 Naturaliste Plateau, located ∼170 to ∼500 km southwest of Australia. Dredged lavas and intrusive rocks range from mafic to felsic compositions, and prior geophysical analyses indicate these units comprise much of the plateau substrate. 40Ar/39Ar plagioclase ages from mafic units and U–Pb zircon ages from silicic rocks indicate magmatic emplacement from 130.6 ± 1.2 to 129.4 ± 1.3 Ma for mafic rocks and 131.8 ± 3.9 to 128.2 ± 2.3 Ma for silicic rocks (2σ). These Cretaceous Naturaliste magmas incorporated a significant component of continental crust, with relatively high 87Sr/86Sr (up to 0.78), high 207Pb/204 Pb ratios (15.5–15.6), low 143Nd/144Nd (0.511–0.512) and primitive-mantle normalised Th/Nb of 11.3 and La/Nb of 3.97. These geochemical results are consistent with the plateau being underlain by continental basement, as indicated by prior interpretations of seismic and gravity data, corroborated by dredging of Mesoproterozoic granites and gneisses on the southern plateau flank. The Cretaceous Naturaliste Plateau igneous rocks have signatures indicative of extraction from a depleted mantle, with trace-element and isotopic values that overlap with Kerguelen Plateau lavas reflect crustal contamination. Our chemical and geochronological results therefore show the Naturaliste Plateau contains evidence of an extensive igneous event representing some of the earliest voluminous Kerguelen hotspot magmas. Prior work reports that contemporaneous correlative volcanic sequences underlie the nearby Mentelle Basin, and the Enderby Basin and Princess Elizabeth Trough in the Antarctic. When combined, the igneous rocks in the Naturaliste, Mentelle, Wallaby, Enderby, Princess Elizabeth, Bunbury and Comei-Cona areas form a 136–124 Ma Large Igneous Province covering >244 000 km2.

The Junggar Basin is a large superimposed basin with multistage evolution. The Carboniferous volcanic rock in the middle-lower part of the basin has been an important target of oil and gas exploration. Therefore, it is crucial to establish a set of efficient methods and techniques to find out the distribution of the Carboniferous volcanic rock and the tectonic factors related to the reservoir forming of the volcanic rock. Our research reveals that the density and magnetism of the Carboniferous volcanic rock are obviously higher than those of the Mesozoic and Cenozoic sedimentary rocks. With a series of frequency domain filters and boundary enhancement techniques, we determine the residual gravitational and magnetic anomalies caused by the Carboniferous volcanic rock. Combined with borehole and seismic data from the studied areas, the horizontal and vertical distributions of the Carboniferous volcanic rock are defined, and the lithologies of different types of volcanic rocks are predicted. Furthermore, the gravitational and magnetic anomalies are used to estimate the basement faults and topography. The regional deep faults and their secondary faults of the basement are outlined, and the model of basement relief is constructed. Finally, the effects of the fracture structure and the basement topography in the process of volcanic activity and hydrocarbon accumulation are fully discussed. These results provide fundamental information for optimal selection of the favorable area of volcanic reservoir.

Although the last rhyolite eruption occurred around 70 ka ago, the silicic Yellowstone volcanic field is still considered active due to high hydrothermal and seismic activity and possible recent magma intrusions. Geodetic measurements document complex deformation patterns in crustal strain and seismic activity likewise reveal spatial and temporal variations in the stress field. We use earthquake data recorded between 1988 and 2010 to investigate these variations and their possible causes in more detail. Earthquake relocations and a set of 369 well-constrained, double-couple, focal mechanism solutions were computed. Events were grouped according to location and time to investigate trends in faulting. The majority of the events have normal-faulting solutions, subordinate strike-slip kinematics, and very rarely, reverse motions. The dominant direction of extension throughout the 0.64 Ma Yellowstone caldera is nearly ENE, consistent with the perpendicular direction of alignments of volcanic vents within the caldera, but our study also reveals spatial and temporal variations. Stress-field solutions for different areas and time periods were calculated from earthquake focal mechanism inversion. A well-resolved rotation of σ 3 was found, from NNE-SSW near the Hebgen Lake fault zone, to ENE-WSW near Norris Junction. In particular, the σ 3 direction changed throughout the years around Norris Geyser Basin, from being ENE-WSW, as calculated in the study by Waite and Smith (2004) , to NNE-SSW, while the other σ 3 directions are mostly unchanged over time. The presence of “chocolate tablet” structures, with two sets of nearly perpendicular normal faults, was identified in many stages of the deformation history both in the Norris Geyser Basin area and inside the caldera.

The article discusses data on paleosol, mineralogy, and paleobotany obtained as a result of studying material collected from the Maastricht-Early Paleocene sediments of the Tanyurer Formation of South Chukotka. The burial of organic matter in the sedimentary rock of the Tanyurer Formation is associated with deflationary processes during the period of activation of volcanic activity. On the drained volcanic plateau of soil formation, a sod humus-accumulative process prevailed under the steppe vegetation. Humic substance dispersed in sedimentary rock was represented by a group of humins resistant to microbial decomposition. As a result of exposure to high pressures and temperatures, the colloidal form of humus was transformed into kerogen. Organic compounds (cellulose, lignin) in the plant tissue of buried tree trunks were replaced by silicon compounds. Weathering processes have affected the thin surface layer of dense sedimentary rock. Under the influence of the temperature and humidity gradient, loosening of loose rock and disintegration of clots of colloidal forms of humus occurred.

Author(s): Behar, Nicole; Shaar, Ron; Tauxe, Lisa; Asefaw, Hanna; Ebert, Yael; Heimann, Ariel; Koppers, Anthony AP; Ron, Hagai

Direct observations of vertical movements of the earth's surface are now possible with space-based GPS networks, and have applications to resources, hazards and tectonics. Here we present data on vertical movements of the Earth's surface in New Zealand, computed from the processing of GPS data collected between 2000 and 2015 by 189 permanent GPS stations. We map the geographical variation in vertical rates and show how these variations are explicable within a tectonic framework of subduction, volcanic activity and slow slip earthquakes. Subsidence of >3 mm/yr is observed along southeastern North Island and is interpreted to be due to the locked segment of the Hikurangi subduction zone. Uplift of 1–3 mm/yr further north along the margin of the eastern North Island is interpreted as being due to the plate interface being unlocked and underplating of sediment on the subduction thrust. The Volcanic Plateau of the central North Island is being uplifted at about 1 mm/yr, which can be explained by basaltic melts being injected in the active mantle-wedge at a rate of ∼6 mm/yr. Within the Central Volcanic Region there is a 250 km2 area that subsided between 2005 and 2012 at a rate of up to 14 mm/yr. Time series from the stations located within and near the zone of subsidence show a strong link between subsidence, adjacent uplift and local earthquake swarms.

The continental collision between Arabia and Eurasia created large strike-slip faults in Turkey as well as mountains in the Caucasus and the volcanic plateau between them. In this study, we use regional waveforms of a new seismic array deployed between 2008 and 2012 to constrain the focal mechanisms and depths of small to moderate sized earthquakes occurring in the western part of the Central Caucasus and northeast Turkey. The distribution of aftershocks and the twelve focal mechanisms involved in the sequence of the 2009 earthquake in Racha are clearly a reactivation of a deeper segment of the 1991 M7 Racha rupture zone. The deeper segment is not well connected to the shallower decollement separating the basement and sedimentary basin. The earthquakes we determined in northeastern Turkey and southern Georgia are related to the strike-slip fault system. We further combined all of the reliably determined focal mechanisms over the last 30 years to investigate the current stress status of the crust in three areas: Racha in the western Greater Caucasus, Javakheti near the Lesser Caucasus and in Northeast Turkey. Our results show that the directions of maximum compressional stress consistently fall within − 2 to 14°N throughout the entire study region. This appears to be controlled by the continental collision. Nonetheless, the minimum compression switches from vertical (in the Greater Caucasus) to the east-west direction (in northeastern Turkey), due to the westward extrusion of the Anatolia block, which is driven partly by the Hellenic subduction. The transition of the stress field is close to the Javakheti volcanic plateau in the Lesser Caucasus, where the relative magnitude between the principal stresses appears to be strongly variable.

The Pernambuco marginal basin is located on the eastern continental margin of northeastern Brazil, covers an area of 20,800 km 2 , and represents one of the most prominent frontiers for deep water oil and gas exploration off the Brazilian coast. The onshore region of this basin was highly affected by extrusive and intrusive magmatism during the Upper Albian, and the relation of that event with the volcanic structures observed in the offshore sector has not been thoroughly characterized to date. This study aims to characterize the major extrusive and intrusive volcanic structures of the offshore portion of this basin, which is dominated by the Pernambuco Plateau, and its stratigraphic relations. A set of 143 2D multichannel seismic sections that cover the Pernambuco Plateau region are used to interpret the major tectono-stratigraphic sequences and describe the distribution of volcanoes, sills, vent complexes and related volcaniclastic sequences. The interpretations are supported by aeromagnetic and gravimetric geophysical surveys. Volcanoes are classified into two groups that differ in terms of their morphology: shield-like structures and cone-shaped volcanic structures. Sill intrusions are mainly identified beneath the volcanic structures and are characterized by high-amplitude reflectors with short extensions and abrupt terminations. Volcaniclastic sequences are found adjacent to the volcanoes and are characterized by high-amplitude, disrupted reflections with local chaotic configurations. Vent complexes are classified on the basis of their morphologies as either eye-shaped or crater-shaped. The volcanic features identified within the available seismic dataset are concentrated in two main areas: in the centre of the plateau and near its northeastern border. These two regions are host basement outer highs and are surrounded by hyper-extended continental crust, which forms the plateau itself. The extrusive and intrusive features described in the offshore region were formed during the post rift Cretaceous and Cenozoic intervals and point to the continuation of magmatic events after the rifting process. The findings presented in this report provide a better understanding of the magmatism on the northeastern passive margin of Brazil and can also be useful for future modelling of the Pernambuco Basin petroleum system.

The transition from the Formative to the Late period (c. 1000 BP) on the volcanic plateau of Antofagasta de la Sierra in northern Argentina saw various changes in landscape use and settlement pattern. New power structures and social identities appear in the archaeological record in the wake of an increasing emphasis on cultivation and herding, coincident with a regional shift to greater aridity. The novel analysis reported here reveals that these changes also had an impact on pottery technology, notably vessel thickness, and considers the role of technological innovation as both cause and consequence of the changing world experienced by the inhabitants of Antofagasta de la Sierra.

The Middle Siberian volcanic plateau is characterized with respect to its paleoecological environments. In this area, volcanism commenced in the Severodvinian (Vishkilian) Age. The lower (tuffaceous) part of the plateau section (Lebedev deposits) was formed in the Vyatkian Age. Its middle (tufflava) part (Khungtukun deposits) is correlative with the Goudikeng Formation (interval of 65–111 m) in the Dalongkou type section of China and corresponds to the Quadrocladus pachyphyllus ... Echinolimnadia mattoxi Zone. The top of this sedimentary unit (111 m up from the base of the Goudikeng Formation) should be correlated with the base of the Otoceras Ecozone. The upper (lava) part of the plateau (Putorana deposits) corresponds to the interval of 111–210 m, belongs to the Elatocladus linearis ... Cornia vosini Ecozone, and is older than the Hindeodus parvus Zone, which is now considered as the basal unit of the Triassic marine sequences. The volcanic plateau section shows now evidence of any biotic crisis.

Primary plant successions on volcanic deposits of the Tolbachinskii DoI Plateau (Central Kamchatka) were studied. The main factors determining the succession rate were revealed. The peculiarities of plant successions on lava flows and ash-scoria deposits differed significantly. Some common mechanisms for all volcanic regions of the world were revealed. The leading factors of plant succession on lava flows were the type of lava surface, the texture of lava, and the fine tephra accumulation rate. The main factors determining plant succession on ash-scoria deposits were wind and water erosion and the distance to the seed sources. The time of formation of a secondary permanent larch (Larix cajanderi Mayr.) forest should take about 1500-2000 years on lava flows and up to 1000 years (but not less than 300-500 years) on ash-scoria plains.

Based on 112.5 km2 of 3-D seismic data and data of 8 prospecting wells drilled volcanic rocks in the 3rd member of the Paleogene Shahejie Formation in Hongxing area of the Eastern Sag of the Liaohe Depression, Bohai Bay Basin, three levels of volcanic interfaces (stage→edifice→lithofacies) of the intermediate-mafic volcanic formation are identified to reveal favorable prospecting facies through comprehensive studies on geology, well logging and seismic data in single well and multiple wells following the seismic volcano stratigraphy principle. According to stage interfaces, three volcanic stages were identified in the 3rd member of Shahejie Formation. One or more volcanic edifice-seismic facies were identified in each volcanic stage and volcanic facies-seismic facies were identified in each volcanic edifice-seismic facies. Based on single well points, we described volcanic edifices on well-tie seismic sections; identified volcanic bodies by extracting coherent seismic attribute (superimposed volcanic edifices) taking the volcanic stages as the units; then identified volcanic edifices and volcanic lithofacies by extracting waveform classification properties. Volcanic facies mapping were completed by constituting the relationship between the volcanic facies and the seismic facies in drilling wells, seismic cross sections and mappings. There are two types of plane volcanic facies sequences in the intermediate-mafic volcanic facies of this study area: volcanic conduit facies→extrusive facies (→explosive facies)→effusive facies→volcanic sedimentary facies, volcanic conduit facies (→explosive facies)→effusive facies→volcanic sedimentary facies. Among them, the near crater assemblage (volcanic conduit, extrusive and explosive facies) has better hydrocarbon shows and is the most favorable target of hydrocarbon exploration. Key words: intermediate-mafic volcanic rock, volcanic facies, seismic facies, volcanic stratigraphy, volcanic stage, Liaohe Depression

We present the results of a detailed photogeological study of a region surrounding Acidalia Mensa (43–50°N, 15–35°W) based on analysis of a mosaic of the CTX images (nominal resolution ~5 m/px). The main result of the study is the unfolding of the geologic history of the study region and determination of absolute model ages of its major episodes. The documented history begins with the formation of a volcanic plateau of Acidalia Mensa ~4 Ga ago. The surface of the Acidalia plateau was strongly modified since its formation. The crater size-frequency distribution (CSFD) on the plateau indicates that the resurfacing was likely consisted of multiple episodes. The latest such episode recognizable by the crater statistics occurred ~3.65 Ga ago. The vast majority of the surface around Acidalia Mensa is covered by materials of the background plains that correspond to the interior unit of the Vastitas Borealis Formation (VBF). The CSFD on the background plains corresponds to an absolute model age (AMA) of ~3.58 Ga, which is completely within the range of AMAs determined for the VBF along its boundary with the southern uplands. Small-scale features such as bright cones/mounds, polygonal troughs, and flow-like mantling materials postdate the emplacement of the background plains and manifest the post-formational evolution of the VBF. The majority of crater ejecta in the study area have higher albedo in the CTX and HiRISE images, but appear as dark spots in the THEMIS-IR nighttime images. These wavelength-dependent properties of the ejecta indicate the presence of light-toned and fine-grained material beneath the surface of the background plains. This material was the source of numerous bright cones/mounds. We interpret the formation of this reservoir as the result of sorting of large amounts of water/mud deposited in the study area and, by implication, within the northern lowlands. The final episodes of the ancient geologic history of the study area were related to the emplacement of materials of the thick flows at topographically high levels within the Acidalia plateau ~3.47 Ga ago. The morphology of the flows is inconsistent with lava and we interpret the occurrences of the thick flows as the result of displacement of water-saturated regolith in the form of either soli- or gelifluction flows, or ice-cored rock glaciers.

Many of the volcanic plateau margins of the eastern, formerly glaciated, foreland of the Patagonian Andes are undermined by giant landslides (≥108 m3). One cluster of such landslides extends along the margin of the Meseta del Lago Buenos Aires (MLBA) plateau that is formed mainly by Neogene-Quaternary basalts. The dry climate is at odds with numerous >2-km long earthflows nested within older and larger compound landslides. We present a hydrological analysis, a detailed geomorphic map, interpretations of exposed landslide interiors, and radiocarbon dating of the El Mirador landslide, which is one of the largest and morphologically most representative landslide. We find that the presence of lakes on top of the plateau, representing low infiltration rates, correlates negatively with the abundance of earthflows on landslide debris along the plateau margins. Field outcrops show that the pattern of landslides and earthflows is likely controlled by groundwater seepage at the contact between the basalts and underlying soft Miocene molasse. Numerous peat bogs store water and sediment and are more abundant in earthflow-affected areas than in their contributing catchment areas. Radiocarbon dates indicate that these earthflows displaced metre-thick layers of peat in the late Holocene (

International audience; The relationships between volcanic activity and tectonics at the southernmost termination of the Main Ethiopian Rift (MER), East Africa, still represent a debated problem in the MER evolution. New constraints on the timing, evolution and characteristics of the poorly documented volcanic activity of the Dilo and Mega volcanic fields (VF), near the Kenya-Ethiopia border are here presented and discussed. The new data delineate the occurrence of two distinct groups of volcanic rocks: 1) Pliocene subalkaline basalts, observed only in the Dilo VF, forming a lava basement faulted during a significant rifting phase; 2) Quaternary alkaline basalts, occurring in the two volcanic fields as pyroclastic products and lava flows issued from monogenetic edifices and covering the rift-related faults. 40Ar/39Ar dating constrains the emplacement time of the large basal lava plateau to ~3.7 Ma, whereas the youngest volcanic activity characterising the two areas dates back to 134 ka (Dilo VF) to as recent as the Holocene (Mega VF). Volcanic activity developed along tectonic lineaments independent from those of the rift. No direct relations are observed between the Pliocene, roughly N-S-trending major boundary faults of the Ririba rift and the NE-SW-oriented structural trend characteristic of the Quaternary volcanic activity. We speculate that this change in structural trend may be the expression of (1) inherited crustal structures affecting the distribution of the recent volcanic vents, and (2) a local stress field controlled by differences in crustal thickness, following a major episode of reorganization of extensional structures in the region due to rift propagation and abandonment

The Manihiki Plateau is a Large Igneous Province (LIP) in the central Pacific. It was emplaced as part of the "Super-LIP" Ontong Java Nui and experienced fragmentation into three sub-plateaus, possibly during the break-up of Ontong Java Nui. The Manihiki Plateau is presumably the centerpiece of this "Super-LIP" and its investigation can therefore decipher the break-up mechanisms as well as the evolution of the plateau after its initial emplacement. By analyzing two seismic refraction/wide-angle reflection profiles crossing the two largest sub-plateaus of the Manihiki Plateau, the High Plateau and the Western Plateaus, we give new insights into their crustal structure and magmatic evolution. The High Plateau shows a crustal structure of 20 km thickness and a seismic P wave velocity distribution, which is comparable to other LIPs. The High Plateau experienced a strong secondary volcanism, which can be seen in relicts of seamount chain volcanism. The Western Plateaus on the other hand show no extensive secondary volcanism and are mainly structured by fault systems and sedimentary basins. A constant decrease in Moho depth (9–17 km) is a further indicator of crustal stretching on the Western Plateaus. Those findings lead to the conclusion, that the two sub-plateaus of the Manihiki Plateau experienced a different magmatic and tectonic history. Whereas the High Plateau experienced a secondary volcanism, the Western Plateaus underwent crustal stretching during and after the break-up of Ontong Java Nui. This indicates, that the sub-plateaus of the Manihiki Plateau play an individual part in the break-up history of Ontong Java Nui.

The Giant’s Causeway and Causeway Coast lies at the foot of high cliffs along the North Sea in the coast of Northern Ireland. It is composed of some 40,000 massive columns of basalt sticking out of the sea. The Giant’s Causeway itself is a sea-level promontory outcrop and pavement running out to sea. Exposure of the columns in a pavement of such perfect horizontal sections is considered unique and is also scenically remarkable. The Causeway Coast is an unparalleled displays of geological formations, remnants of volcanic activity some 50–60 million years ago, forming the largest remaining lava plateau in Europe. Geological studies of this lava flow over the last 300 years have greatly contributed to the analysis of Tertiary volcanic events in the North Atlantic.

This paper takes its inspiration from Karl W. Butzer's course on the Human Use of Landforms at the University of Chicago. It builds upon that concept through an exploration of regional settlement patterns and landforms in the Deccan volcanic province of west-central India. The first section develops a conceptual framework for analyzing human adjustment to landforms on regional, settlement, and site scales. The second section employs that framework to analyze four major landform-settlement configurations in the Deccan from antiquity to the end of the eighteenth century. The Satavahana kingdom (ca. 100 BCE to 200 CE) had a strong southeast to northwest alignment along the Godavari River. Their capital city of Paithan was located at a navigable sacred ford across the river (tirtha), which was linked with upstream confluences (sangams), tanks (kunds), mountain passes (ghats), and port cities on the Arabian Sea. Subsequent Hindu dynasties (ca. 850–1300 CE) shifted from fluvial landforms to a north-south alignment along steep mesa escarpments and buttes in the central Deccan that provided defensive fortress and cave temple sites. Sultanate and Mughal forces expanded the urban footprint on nearby plateau lands at sites protected by surrounding mesas (ca. 1330–1700 CE). These cities were supported by local watershed runoff and long distance water channels. The final precolonial phase of Deccan settlement entailed a shift from the semiarid central plateaus to humid headwaters of the Western Ghats, whose buttes and scarps provided sites for scores of forts controlled by the founder of the Maratha empire Chhatrapati Shivaji in the seventeenth century. Maratha success led to development downstream at the capital city of Pune (1627–1803 CE), located at a river confluence flanked by mesas, which combined the strategies of previous periods. Over two millennia these four distinct, yet intersecting, patterns of human-landform relations have shaped an evolving geocultural region on the Deccan plateau that deserves comparison with other flood basalt regions. Keywords: Butzer; Historical geomorphology; Flood basalt; Rock cut caves; Deccan; Maharashtra

In this chapter, the geomorphological characterization of volcanic highland of southern Georgia is presented. The orographic units are considered in detail, such as the Erusheti Highland, Mtkvari River upper gorge, Javakheti Upland with its subregions (the Akhalkalaki Plateau, the northern hilly low mountainous subregion, and the southwestern hilly subregion), Nialiskuri, Samsari and Javakheti ranges, Tsalka depression and the volcanic plateaus of Bedena, Kvemo Kartli, Chochiani, Gomareti, and Dmanisi. The text also provides geological structure, tectonic conditions, and current exogenic processes in the study region. Each subchapter is accompanied by appropriate images and maps.

The bacterial biocontrol agent Serratia entomophila and the insecticide diazinon were applied as separate granular formulations with ryegrass seed and compared with a seedonly control treatment on three pastures of different ages and composition on the North Island volcanic plateau In the first 2 years diazinon and S entomophila significantly reduced healthy grass grub populations compared with the control However by the third year populations in the diazinon treatments had recovered and were significantly higher than in S entomophila or control plots Grass grub populations were reduced by disease outbreaks after S entomophila was applied which infected >40 of grass grub larvae in the treated plots in year two Bacterial extraction from soil a year after application confirmed establishment and persistence of S entomophila in treated plots Visual positive pasture growth responses were noted in both the S entomophila and diazinontreated plots