A global database of Mars-relevant hydrovolcanic environments on Earth with potential biosignature preservation

In the southwest USA, the Colorado Plateau is encircled by Late Cenozoic volcanic fields, most of which have eruptive histories that are marginally constrained. Establishing the spatiotemporal evolution of these volcanic fields is key for quantifying volcanic hazards and understanding magma genesis. The Black Rock Desert (BRD) volcanic field covers ∼700 km 2 of west‐central Utah. We present 46 new 40 Ar/ 39 Ar ages from the BRD ranging from 3.7 Ma to 8 ka, which includes 40 Ar/ 39 Ar plateau ages from olivine separates. These new ages are combined with 13 recently published 40 Ar/ 39 Ar ages from the Mineral Mountains to evaluate the spatiotemporal evolution of all five BRD subfields. The oldest lavas and domes are located to the southwest, whereas the youngest lavas, which are only a few hundred years old, are located ∼30 km to the NNE. However, BRD vent migration patterns over the last 2.5 Ma are non‐uniform. They are also not consistent with North American Plate motion over a partial melt zone nor have they migrated toward the center of the Colorado Plateau. BRD eruptions are almost always coincident with mapped Quaternary faults. A shear‐velocity (Vs) model beneath the BRD indicates that the lithosphere has been thinned and that asthenospheric melt has coalesced at the lithosphere‐asthenosphere boundary, which is supported by the trace element compositions of BRD lavas that signify that they have incorporated continental lithospheric mantle. Our data and observations suggest that the asthenosphere‐lithosphere‐volcanic system in the BRD is inherently complex.

The Pleistocene-Holocene Serdán-Oriental basin (SOB), located in the eastern sector of the Trans-Mexican Volcanic Belt, hosts a large active monogenetic volcanic field characterized by a multifaceted volcanism including isolated and clustered maars, tuff rings, cinder and lava cones, lava flows, and domes. Recent studies have highlighted its magmatic bimodal nature, characterized by scattered basaltic-to-andesitic eruptive centers and the emplacement of voluminous rhyolitic domes, as well as the presence of mafic melts erupted directly from upper lithospheric mantle sources. In this view, the SOB, with its erupted magmas, represents a unique natural laboratory to investigate the geometry and evolution of a large transcrustal magmatic network beneath active monogenetic volcanic fields. With this aim, we carried out a chemical characterization of the erupted macrocryst-cargo, we applied a suite of inverse thermobarometry models, and integrated the results with a synthesis of published geochemical data and geophysical literature. Our findings indicate the existence of a transcrustal (0–0.9 GPa), vertically distributed, hot (1100–1200 °C) magma plumbing system beneath the volcanic field controlling the ascent, differentiation (through Pl-Cpx fractionation) and eruption of basalt-to-andesite melts, with the presence of two major mafic magma stagnation levels, the first one located in the lower crust above the crust-mantle transition (~ 30–35 km) and the second one approximatively at depth of the middle crust (~15 km). Also, the mantle crystal-cargo at the Tecuitlapa maar represents further evidence of a possible pyroxenite mantle source at the local crust-mantle transition zone (0.9–1.2 GPa, 1200 °C). In contrast, the limited mineral-melt equilibrium pairs in rhyolites do not allow a reconstruction of the related feeding system. Moreover, the highly variable bulk compositions of rhyolites, together with their existing Sr-Nd-Pb isotope data, suggest a significant role for the local upper crust in the genesis of the SOB high-silica felsic melts. We conclude that the SOB monogenetic volcanic field evolved through two main stages of volcanic activity: a Pleistocene stage (490–25 ka) and a Holocene stage (11 ka – active), respectively. The proposed magmatic scenario is not intended to be conclusive but wants to stimulate further research on both the evolution of the SOB volcanic field and on a broader scale on the petrological and volcanological processes controlling the evolution of large active monogenetic volcanic fields. • SOB is fed by a vertically distributed hot transcrustal magma system. • Basaltic and rhyolitic melts feeding the SOB volcanic field are genetically linked. • Magmas evolved through crustal assimilation and fractional crystallization. • Thermobarometry indicates pre-eruptive conditions were 1000–1200 °C at 0–1.2 GPa.

The role of external environmental factors in changing eruption styles of monogenetic volcanoes in a Mio/Pleistocene continental volcanic field in western Hungary

<p>The Arxan-Chaihe Volcanic Field (ACVF) is a young intracontinental monogenetic volcanic field erupted since the Pliocene and located in the northeast of China. ACVF preserves at least 47 vents in a 2000 km<sup>2</sup> area. The small-volume volcanic edifices and their eruptive products resemble typical landforms such as tuff rings, scoria cones, fissure-controlled vents, and complex, but small volcanic cones. The youngest known eruption site at Yanshan, located in the centre of the volcanic field along an elevated normal-fault bounded, SW-NE-aligned zone, dated by C<sup>14</sup> method and yielded closely spaced but various ages of – 2040 +/−75; 1960+/−70; 1990+/−100; 1900+/−70, BP. The age variation is in good concert with the presence of nested vent complex as the reconstructed source of this eruption, forming amalgamated scoria and spatter cones with three distinct vents. The volcanic landforms are well-preserved due to the abundance of accumulated agglutinated and clastogenic lavas in their crater rims. It is apparent, that the Yanshan-event produced an extensive and multi-tephra pyroclastic succession, that formed an ash plain just east of the cone complex. The extend of the ash blanket revealed to be far more than previously thought as recent SENTINEL imagery marks ash coverages - even in patchy mode - well over 20-km from the vent. Large rafted, welded cone blocks, mostly in the SW opening of the main cone where a major lava flow broke out, create strong surface ruggedness and young volcanic surface features in the vicinity of the vents. The lava flows (mostly rubble, slabby pahoehoe) apparently filled a north-westward steeply inclined rift shoulder and reached the Halaha River valley within 8 km, in about 230 m elevation drop. When the lava flows reached the Halaha River valley floor, in the combination of sudden slope angle changes of the terrain and the wet valley floor produced a spectacular lava tumuli field. Present day lacustrine systems are inferred to be formed after the major lava flows from the Yanshan vent diverted the fluvial channels about 2000 years ago. Analysing of SENTINEL satellite imagery, it is evident, that the Halaha River lava field is far more complex, and not exclusively derived from the Yanshan vents. A large crater (~1.1-km across), Dahei Gou just about 5-km to the SW from Yanshan shows young lava lake within its crater and slightly older lava outflow toward the Halaha Valley on SENTINEL imagery. Lava flows are seemingly diverted and partially “invaded” the Dahei Gou lava flow system in the axis of the Halaha Valley, marking a relative chronology of volcanic events inferred to be driven by a SW to NE directed fissure opening that likely took place over weeks or even years based on the lava flow surface patterns. In addition, a 6.5-km long fissure connects the Dahei Gou and Yanshan vents. This volcan-morphological study reveals an important volcanic hazard this region and making the youngest volcanic event a key eruption scenario future volcanic hazard planning of the region needs to observe.</p>

Evolution of a large Quaternary monogenetic field; the multifaceted volcanism of the Serdán-oriental basin, México

Microprobe analyses of glass and radiocarbon dating of samples associated with three basaltic volcanic ashes in the deposits of Lake Bonneville make the ashes useful stratigraphic markers for correlation within the Bonneville basin. Two of the ashes were derived from tuff cones (Pavant Butte and Tabernacle Hill) that erupted into Lake Bonneville in what is now the Black Rock Desert of south-central Utah. Near Kanosh, Utah, the Pavant Butte ash is interbedded with barrier-beach lagoon marl that is slightly less than 16,000 yr old. Five radiocarbon dates on carbonate materials stratigraphically associated with the ash elsewhere in the Sevier Desert average 15,300 yr B.P. Lake Bonneville was in its transgressive phase, about 15 m below the Bonneville Shoreline, when the Pavant Butte eruption began. At the Tabernacle Hill tuff cone, a basalt flow that has pillows, wave-rounded cobbles, and tufa on its outer margins was erupted into Lake Bonneville shortly after the tuff cone at or near the Provo Shoreline. The Tabernacle Hill tuff cone and basalt flow are older than a radio-carbon date of about 14,300 yr B.P. on tufa collected from the outer margin of the basalt flow, but younger than the Bonneville Flood at about 14,500 yr B.P. The third ash, informally termed the Thiokol ash, has been found interbedded with Lake Bonneville deposits in two exposures in northern Utah and in sediment cores from the Great Salt Lake. It is about 25,000 yr old, and may have been erupted from a volcanic field on the northwest shore of Great Salt Lake or from the Snake River Plain. Microprobe analyses of glass from samples of the Black Rock Desert ashes show them to have similar chemical compositions, but glass from Tabernacle Hill can be distinguished from Pavant Butte glass by its higher concentrations of CaO and P 2 O 5 . Systematic differences in chemical composition between samples of Pavant Butte glass can be explained by comagmatic processes. Thiokol glass has less SiO 2 , AI 2 O 3 , MgO, and Na 2 O but greater total iron and P 2 O 5 than do the Black Rock Desert glasses.

The complexities of assessing volcanic hazards along the Cameroon Volcanic Line using spatial distribution of monogenetic volcanoes

La Garrotxa monogenetic volcanic field (GVF) is located in northeastern Iberia and forms part of the Catalan Volcanic Zone (CVZ), which is a province of the Quaternary alkaline volcanism of the European rift system. The GVF corresponds to an area of about 100 km2 located between the cities of Olot and Girona. This basaltic volcanic field comprises more than 50 monogenetic cones including cinder and scoria cones, lava flows, tuff rings, and maars, ranging in age from 0.6 Ma to early Holocene. Strombolian and phreatomagmatic episodes have combined in the construction of most of these cones, which exhibit a wide range of deposits and eruptive sequences. By combining field work, the stratigraphic logging of both water wells and geotechnical drill holes, and the application of shallow geophysical methods, we have been able to establish for the first time a volcano-stratigraphy of the area that identifies the products of each single eruption, their relative stratigraphy, and their areal extent. This volcano-stratigraphy constitutes an essential tool for understanding the evolution of this volcanic field and for volcanic hazard assessment.

Reconstructing eruption processes of a Miocene monogenetic volcanic field from vent remnants: Waipiata Volcanic Field, South Island, New Zealand

40Ar/ 39Ar geochronology of Neogene phreatomagmatic volcanism in the western Pannonian Basin, Hungary

New eruptions in monogenetic volcanic fields conceptually occur independently of previous ones. In some instances, however, younger volcanic structures and vents may overlap with older edifices. The genetic links between such co-located eruptions remain unclear. We mapped and analysed the stratigraphic relationships between eruptive units on the 400 × 900-m island of Chagwido off the western coast of Jeju Island, a Pleistocene to Holocene intraplate volcanic field. Chagwido consists of an eastern, older tuff ring with a nested scoria cone and a western tuff, scoria and lava flow sequence. The two stratigraphic packages are separated by a prominent paleosol. The East-Chagwido tuff and scoria deposits were eroded and a period of intense weathering and soil development occurred, before a subsequent West-Chagwido tuff ring and scoria cone and lava complex was erupted. The two eruptions were fed by three chemically distinct magmas. The older eastern eruption consists of magma with composition transitional between high-Al alkalic basalt and low-Al alkalic basalt and has stratigraphic characteristics, composition and syn-eruptive trends akin to the neighbouring Dangsanbong tuff cone. This magma type is typical for the transitional stage from high-Al alkalic (pre 500 ka) to low-Al alkalic (post 250 ka) identified for the greater Jeju volcanic system. The East-Chagwido volcanic complex thus formed as the westernmost in a chain of three volcanoes along a fissure system, with a small volcanic remnant island Wado 1 km to the east and the large Dangsanbong tuff cone another 1 km eastward. A new Ar/Ar age of 446 ± 22 ka for Dangsanbong likely characterizes the age of the whole chain. The second, West-Chagwido eruption started with low-Al alkalic basalt forming a phreatomagmatic phase and ended with subalkalic basalt forming a scoria cone and lava flows. The occurrence of subalkalic lavas is known across Jeju to have started only at ~250 ka, and thus, the well-developed paleosol represents at least 200 kyr between the two co-located eruptions. The distinctive magma compositions show that each eruption tapped an independent region within the same underlying mantle source. These observations show that contrary to most assumptions of monogenetic volcanism, an already “tapped” source region may become fertile again through mantle convection/migration and eruptions can thus be expected from old vent sites in long-lived volcanic fields.

ABSTRACTThe monogenetic Quaternary La Garrotxa Volcanic Field forms part of the Catalan Volcanic Zone (north‐east Iberian Peninsula), one of the alkaline volcanic provinces of the European rift system. It harbours more than 50 basaltic monogenetic cones that range in age from the Middle Pleistocene to the Early Holocene and include cinder and scoria cones, lava flows, tuff rings and maars. This study is the result of extensive fieldwork, including the study of ephemeral outcrops and the stratigraphic logging of new water wells and geotechnical drill holes, also taking into account existing information gathered by recent geophysical studies that have applied shallow geophysical methods to establish the substrate geology of this volcanic field. We have obtained a comprehensive volcanic stratigraphy of the area that identifies the products of each single eruption, their relative stratigraphy and their surface area. This volcanic stratigraphy constitutes an essential tool for understanding the evolution of this volcanic field and for establishing a correct volcanic hazard assessment for the area, but it also provides a precise reference for the Quaternary tephrochronology of the lake sediments in neighbouring areas.

LiDAR-based quantification of lava flow susceptibility in the City of Auckland (New Zealand)

Auckland Volcanic Field (AVF) is a basaltic intraplate volcanic field in North Island, New Zealand, upon which >1.6 million people live. Seismic velocity tomography and geochemistry suggest a primary mantle source region at a depth of 70–90 km. Geochemical analysis indicates a range of magma compositions, and that melts ascend with little crustal interaction. Eruptions generally began with a phreatomagmatic phase forming maar and tuff rings with tephra fall, base surges, and ballistic projectiles as the main hazards. Subsequent magmatic phases formed scoria cones, and sometimes produced lava flows. Ages of 47 of the 53 volcanic centres reveal that the AVF first erupted ∼193 ka, and last erupted ∼500 yrs. BP. These geochronological constraints indicate repose periods ≤0.1–13 kyr, which have decreased since ∼60 ka. From known geological and exposure information, and using an interdisciplinary approach, eight future eruption scenarios have been developed for planning processes. Outstanding questions for the AVF concern the cause of mantle melting, the structure of the underlying lithosphere, magma ascent rates, controls on repose periods and eruptive volumes. Answering these questions may improve our understanding of warning periods, monitoring strategies, spatiotemporal risk profiles, and socio-economic impacts of volcanism on New Zealand’s largest city.

Volcanic Geotopes and Their Geosites Preserved in an Arid Climate Related to Landscape and Climate Changes Since the Neogene in Northern Saudi Arabia: Harrat Hutaymah (Hai’il Region)