scholarly journals Exploring the Restless Floor of Yellowstone Lake

Eos ◽  
2017 ◽  
Author(s):  
Robert Sohn ◽  
Robert Harris ◽  
Chris Linder ◽  
Karen Luttrell ◽  
David Lovalvo ◽  
...  

Yellowstone Lake, far from any ocean, hosts underwater hot springs similar to those on mid-ocean ridges. A research team is investigating the processes that drive the lake’s hydrothermal systems.

2021 ◽  
Author(s):  
Cécile Massiot ◽  
Craig Miller ◽  
Matthew Stott ◽  
Pilar Villamor ◽  
Hiroshi Asanuma ◽  
...  

<p>Calderas are major volcanic features with large volcanic and seismic hazards. They also host diverse microbiota, provide heat, energy, mineral and economic benefits. Despite their scientific and socio-economic importance, we still do not completely understand calderas and the interactions between volcanism, tectonism, fluid circulation and the deep biosphere because in-situ and subsurface observations are sparse.</p><p>The Okataina Volcanic Centre (OVC) in Aotearoa New Zealand, is one of two active giant calderas of the Taupō Volcanic Zone within the rapidly extending continental intra-arc Taupō Rift. This superb natural laboratory has: 1) numerous past eruptions of varied size and style, 2) documented co-eruptive earthquakes, 3) vigorous hydrothermal manifestations, 4) diverse microbial communities in hot springs but unknown in the subsurface.</p><p>We propose to establish a scientific drilling programme at the OVC to address:</p><ul><li>What are the conditions leading to volcanic eruptions; and volcano-tectonic feedbacks in intra-rift calderas?</li> <li>What controls fluid circulations in active calderas/rift regions?</li> <li>Does subsurface microbial community composition vary with tectonic and/or volcanic activity?</li> </ul><p>High temperatures complicate drillhole design, restrict data collection and prevent exploration of the biosphere. By targeting the cooler parts of the caldera, this project will use conventional engineering to maximise sampling (drill cores and fluids), downhole logging and establish long-term observatories.</p><p>Two preliminary drill targets are suggested: (1) in the centre of the caldera; (2) through the caldera margin. Drill data will provide a comprehensive record of past activity, establishing eruption frequency-magnitude relationships and precursors. Combined with well-known fault rupture history, the relative timing of tectonic and magmatic activity will be untangled. Drill data will unravel the relationships between the groundwater and hydrothermal systems, magma, faults and stress, informing thermo-hydro-mechanical regional caldera models with findings applicable worldwide. Drill cores and a dedicated fluid sampler triggered by nearby earthquakes will reveal the composition, function and potential change of microbial activity in response to rock and fluid variations.</p><p>The programme is informed by indigenous Māori, regulatory authorities and emergency managers to ensure scientific, cultural, regulatory and resilience outcomes. The programme will underpin 1) community resilience to volcanic and seismic hazards; 2) sustainable management of groundwater and geothermal resources, and 3) understanding of subsurface microbial diversity, function and geobiological interactions. At these early stages of planning, we invite the scientific community to contribute to the concept of this project in the exceptional OVC settings and strengthen linkages with other ongoing research and scientific drilling programmes.</p>


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Laura Sánchez-García ◽  
Daniel Carrizo ◽  
Antonio Molina ◽  
Victoria Muñoz-Iglesias ◽  
María Ángeles Lezcano ◽  
...  

AbstractDetecting signs of potential extant/extinct life on Mars is challenging because the presence of organics on that planet is expected to be very low and most likely linked to radiation-protected refugia and/or preservative strategies (e.g., organo-mineral complexes). With scarcity of organics, accounting for biomineralization and potential relationships between biomarkers, mineralogy, and geochemistry is key in the search for extraterrestrial life. Here we explored microbial fingerprints and their associated mineralogy in Icelandic hydrothermal systems analog to Mars (i.e., high sulfur content, or amorphous silica), to identify potentially habitable locations on that planet. The mineralogical assemblage of four hydrothermal substrates (hot springs biofilms, mud pots, and steaming and inactive fumaroles) was analyzed concerning the distribution of biomarkers. Molecular and isotopic composition of lipids revealed quantitative and compositional differences apparently impacted by surface geothermal alteration and environmental factors. pH and water showed an influence (i.e., greatest biomass in circumneutral settings with highest supply and turnover of water), whereas temperature conditioned the mineralogy that supported specific microbial metabolisms related with sulfur. Raman spectra suggested the possible coexistence of abiotic and biomediated sources of minerals (i.e., sulfur or hematite). These findings may help to interpret future Raman or GC–MS signals in forthcoming Martian missions.


2015 ◽  
Vol 112 (25) ◽  
pp. 7668-7672 ◽  
Author(s):  
Jill M. McDermott ◽  
Jeffrey S. Seewald ◽  
Christopher R. German ◽  
Sean P. Sylva

Arguments for an abiotic origin of low-molecular weight organic compounds in deep-sea hot springs are compelling owing to implications for the sustenance of deep biosphere microbial communities and their potential role in the origin of life. Theory predicts that warm H2-rich fluids, like those emanating from serpentinizing hydrothermal systems, create a favorable thermodynamic drive for the abiotic generation of organic compounds from inorganic precursors. Here, we constrain two distinct reaction pathways for abiotic organic synthesis in the natural environment at the Von Damm hydrothermal field and delineate spatially where inorganic carbon is converted into bioavailable reduced carbon. We reveal that carbon transformation reactions in a single system can progress over hours, days, and up to thousands of years. Previous studies have suggested that CH4 and higher hydrocarbons in ultramafic hydrothermal systems were dependent on H2 generation during active serpentinization. Rather, our results indicate that CH4 found in vent fluids is formed in H2-rich fluid inclusions, and higher n-alkanes may likely be derived from the same source. This finding implies that, in contrast with current paradigms, these compounds may form independently of actively circulating serpentinizing fluids in ultramafic-influenced systems. Conversely, widespread production of formate by ΣCO2 reduction at Von Damm occurs rapidly during shallow subsurface mixing of the same fluids, which may support anaerobic methanogenesis. Our finding of abiogenic formate in deep-sea hot springs has significant implications for microbial life strategies in the present-day deep biosphere as well as early life on Earth and beyond.


Geofluids ◽  
2022 ◽  
Vol 2022 ◽  
pp. 1-25
Author(s):  
Xiwei Qin ◽  
Haizhou Ma ◽  
Xiying Zhang ◽  
Xiasong Hu ◽  
Guorong Li ◽  
...  

The Nangqen and Qamdo (NQ-QD) basins in China have very rich geothermal and brine resources. The origin and spatiotemporal evolutionary processes of its hot and saline springs however remain unclear. Geochemical and isotopic (18O, 2H, 3H) studies have therefore been conducted on the water from the geothermal and saline springs in the NQ-QD Basin. All saline springs in the study area are of the Na-Cl geochemical type while geothermal waters show different geochemical types. The oxygen and hydrogen isotopic compositions of the springs in the NQ-QD Basin are primarily controlled by meteoric water or ice-snow melt water and are influenced by rock-water interactions. It is found that the saline springs in the study area are derived from the dissolution of halite and sulfate that occur in the tertiary Gongjue red bed, while the hot springs in the QD Basin are greatly influenced by the dissolution of carbonatites and sulfates from the Bolila (T3b) and Huakaizuo (J2h) formations. Results from silica geothermometry and a silicon-enthalpy hybrid model indicate that the apparent reservoir temperatures and reservoir temperatures for the hot springs in the QD Basin range from 57–130°C to75–214°C, respectively. Deuterium analysis indicates that most of the hot springs are recently recharged rain water. Furthermore, the saline springs have a weaker groundwater regeneration capacity than the hot springs. Tritium data shows that the ranges of calculated residence times for springs in this study are 25 to 55 years, and that there is a likelihood that hot springs in the QD Basin originated from two different hydrothermal systems. The geochemical characteristics of the NQ-QD springs are similar to those of the Lanping-Simao Basin, indicating similar solute sources. Thus, the use of water isotope analyses coupled with hydrogeochemistry proves to be an effective tool to determine the origin and spatiotemporal evolution of the NQ-QD spring waters.


2021 ◽  
Author(s):  
◽  
Thomas O. H. Orr

<p>Basement rocks in the southern Tararua Range are part of the Torlesse Supergroup, possibly Late Triassic to Late Jurassic in age, and form two distinct associations. The sedimentarv association consists mainly of quartzo-feldspathic sandstone and argillite with minor olistostrome, calcareous siltstone and microsparite. The sandstone and argillite were deposited as turbidites in a mid- to outer- submarine fan environment. The sediment was derived from a heavily dissected active continental margin that was shedding sediment of mainly plutonic and metamorphic origin. The volcanic association consists mainly of metabasite and coloured argillite with minor chert and limestone. Geochemical data indicate that the metabasites were erupted in an oceanic intraplate environment. The nature of amygdules in amygdaloidal metabasites suggests eruption in less than 800m of water. Coloured argillites have two distinct origins, namely sediments formed by the degredation of basalt; and also pelagic material modified by metal-rich effluent either from hydrothermal systems associated with mid-ocean ridges or intraplate volcanism. The rocks of the volcanic association indicate formation in an environment similar to present day mid-ocean islands. Nowhere were rocks of the two associations observed to be conformable. Coupled with this, the nature of the two associations suggests that they were formed in separate environments. The following structural history is proposed: 1) Early veining; 2) Isoclinal folding and development of a NNE striking cleavage; 3) Faulting both at low and high angles to bedding, extreme amounts of which have resulted in mélange; 4) NE-SW trending close to open folds; 5) E-W trending open to gentle folds; 6) Recent faulting, predominantly NE trending strike-slip faults. The nature of the two associations and the deformational style and history supports an accretionary prism model for the development of the Torlesse Supergroup. Rocks of the southern Tararua Range show many similarities with, and probably represent a northward continuation of, the Esk Head Mélange of the South Island.</p>


2022 ◽  
Vol 131 (1) ◽  
Author(s):  
Nibendu Mondal ◽  
Aditya Peketi ◽  
Tarunendu Mapder ◽  
Chayan Roy ◽  
Aninda Mazumdar ◽  
...  

2021 ◽  
Author(s):  
Håvard Stubseid ◽  
Anders Bjerga ◽  
Haflidi Haflidason ◽  
Rolf Birger Pedersen

&lt;p&gt;Volcanic eruptions are far less common along slow-spreading ridges compared to fast-spreading ridges. Consequently, knowledge of the volcanic rejuvenation along close to 1/3 of the global mid-ocean ridges is poorly constrained. To determine the temporal evolution of the rift valley of one of the slowest spreading-ridges in the world, the Mohns Ridge in the Norwegian-Greenland Sea, we have interpreted more than 3000 km of sub-bottom profiles. Sedimentation rates derived from several core locations along the ridge are used to calculate the age of the underlying volcanic crust. Here we present a framework for understanding the geological evolution of rift valleys of slow-spreading ridges using an integrated approach combining geological and geophysical data. The high-resolution dataset acquired using autonomous underwater vehicles, cover more than 50% of the 575 km long Mohns Ridge. The results unravel large variation in sediment thickness inside the central rift area, from exposed basalts to several meters of sediments, within only a few hundreds of meters. Studied sub-bottom profiles reveal active volcanism in the deepest parts of the ridge, areas thought to be inactive, surrounded by significantly older crust covered in meters of sediments. We find that all axial volcanic ridge systems (AVRs) in our area completely renewed their surface within the last 30-50 ka. Detailed volcanological investigation of the central parts of an AVR reveal at least 72 individual eruptions during the last 20 ka ranging in size from 1.2x10&lt;sup&gt;3 &lt;/sup&gt;m&lt;sup&gt;2&lt;/sup&gt; - 2.6 x10&lt;sup&gt;5&lt;/sup&gt; m&lt;sup&gt;2&lt;/sup&gt;. These estimates have been verified with visual observations and sampling using an ROV. Our estimates indicate that more than 230 eruptions are required to renew the surface of an average AVR. Based on the acquired age assessments a volcanic eruption is anticipated to occur approximately every 200 years. Volcanic renewal is a first order control on the lifetime of magmatically driven hydrothermal systems.&lt;/p&gt;


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