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Full-Text Articles in Physical Sciences and Mathematics
Paleoenvironmental Constraints On Pleistocene Ice Sheets From Glacio-Volcanic Deposits In Northeast Iceland, Cameron Essex
Paleoenvironmental Constraints On Pleistocene Ice Sheets From Glacio-Volcanic Deposits In Northeast Iceland, Cameron Essex
Theses and Dissertations
There are indications that the melt-back of glaciers due to climate change can trigger new eruptions for volcanoes and magma reservoirs that rest under ice sheets. The ideal locality on Earth to study volcano-ice interactions is Iceland, an active volcanic island that has been totally covered in previous ice ages. Eruptions under glaciers produce distinctive landforms called tuyas, or table mountains, which can provide an estimate of ice thickness at the time of eruption. One research tool used to investigate ice thickness is volcanic glass, which is formed from rapid cooling of magma, and thus is abundant in the majority …
Surface Alteration In The Ölkelduháls, Nesjavellir, And Geysir Hydrothermal Systems, Iceland: Implications For Mars, Jordan Ludyan
Surface Alteration In The Ölkelduháls, Nesjavellir, And Geysir Hydrothermal Systems, Iceland: Implications For Mars, Jordan Ludyan
Theses and Dissertations
Silica- and sulfate-rich deposits observed by Mars Exploration Rover (MER) Spirit near Home Plate, Gusev crater, Mars, indicate alteration of Mars basalt by a diverse array of hydrothermal fluids and processes. Constraining the precise fluid conditions present at the time of deposition for these deposits on Mars relies on investigations of terrestrial hydrothermal systems that produce similar mineral assemblages. Alteration products and fluids collected from the Ölkelduháls, Nesjavellir, and Geysir hydrothermal areas in southern Iceland cover a wide range of end-member and intermediate fluid and alteration environments, and provide a means to compare the secondary minerals produced from different hydrothermal …
The Geochemistry And Mineralogy Of Surface Hydrothermal Alteration At Nesjavellir, Sw Iceland, Chase Glenister
The Geochemistry And Mineralogy Of Surface Hydrothermal Alteration At Nesjavellir, Sw Iceland, Chase Glenister
Theses and Dissertations
Abundant sulfates have been detected by the Mars Exploration Rover Spirit in the Columbia Hills of Mars, consistent with extensive alteration of basalt by hydrothermal processes. This study uses Iceland’s Nesjavellir geothermal system as an analogue for Columbia Hills hydrothermal alteration. This terrestrial site is home to a variety of acidic and near-neutral waters that are actively altering the Mars-like basalt of host volcano Mt. Hengill. Hydrothermal features heated by H2S gas and phase-segregated steam created oxidizing acid-sulfate conditions at the surface with pH values varying between 3.0 and 2.0 and near-boiling temperatures. Mobilization of cations (FeO, MgO, CaO, Na2O, …
Hydrothermal Acid-Sulfate Alteration At Krafla And Námafjall, Ne Iceland: Implications For Gusev Crater And Meridiani Planum, Mars, George L. Carson
Hydrothermal Acid-Sulfate Alteration At Krafla And Námafjall, Ne Iceland: Implications For Gusev Crater And Meridiani Planum, Mars, George L. Carson
Theses and Dissertations
Opaline silica, sulfate, and phyllosilicate-bearing deposits have been detected on Mars from both obiters and rovers, indicating extensive aqueous alteration of the basaltic surface, some of which likely occurred under hydrothermal conditions. Ongoing hydrothermal acid-sulfate alteration of Mars-like high-Fe (15.48-16.27 wt. % Fe2O3T) basalts and hyaloclastites in northeastern Iceland was studied to help interpret the products of alteration in analogous environments on ancient Mars. The Krafla and Námafjall areas feature intense surface alteration in gas- (fumarole) and fluid- (hot spring/mud pot) dominated settings. Influx of H2S gas (H2S + 2O2 = H2SO4) produced steam-derived acid-sulfate waters with pH values 1.96-2.50 …