Sarah K. Carmichael Ph.D.

Geochemistry, Petrology, and Biomineralogy -- My interests involve reactive fluid flow and mineralization in all levels of the earth's crust, in both ancient and modern environments - through regional and contact metamorphism, metasomatism at mid-ocean ridges, and through microbially mediated reactions at the earth's surface.

There are 15 included publications by Sarah K. Carmichael Ph.D.:

TitleDateViewsBrief Description
Climate instability and tipping points in the Late Devonian: Detection of the Hangenberg Event in an open oceanic island arc in the Central Asian Orogenic Belt 2015 6002 Sedimentary petrology and trace element geochemistry indicate that the Late Devonian to Early Carboniferous Heishantou Formation near Boulongour Reservoir (NW Xinjiang, China) was deposited on a steep slope, mid-latitude accreting island arc complex ...
Constraining reactions between MOR vent fluids and new oceanic crust: the hydrothermal upflow zone beneath M vent, 9°50'N EPR 2008 956 Conference Abstract
The Devonian-Carboniferous Boundary In Vietnam: Sustained Ocean Anoxia With A Volcanic Trigger For The Hangenberg Crisis? 2019 1664 The Devonian-Carboniferous transition (359 Ma) was a time of extreme climate and faunal change and is associated with the end-Devonian biodiversity crisis. The transition is characterized by transgressive/regressive cycles, which culminated in the on...
Formation of Replacement Dolomite in the Latemar Carbonate Buildup, Dolomites, Northern Italy: Part 1. Field Relations, Mineralogy, and Geochemistry 2008 3478 Replacement dolomite in the Latemar carbonate buildup, northern Italy, formed when limestone was infiltrated by and reacted with Mg-rich fluid. It occurs in discrete bodies in sharp contact with unreacted limestone. The dolomite developed in a nearly...
Formation of Replacement Dolomite in the Latemar Carbonate Buildup, Dolomites, Northern Italy: Part 2. Origin of the Dolomitizing Fluid and the Amount and Duration of Fluid Flow 2008 2778 Replacement dolomite in the Latemar carbonate buildup developed when limestone was infiltrated by reactive fluid. Minor-element, trace-element, and oxygen and carbon isotope compositions of dolomite and precursor limestone constrain the origin of the...
Mn(II)-oxidizing Bacteria are Abundant and Environmentally Relevant Members of Ferromanganese Deposits in Caves of the Upper Tennessee River Basin 2013 4954 The upper Tennessee River Basin contains the highest density of our nation's caves; yet, little is known regarding speleogenesis or Fe and Mn biomineralization in these predominantly epigenic systems. Mn:Fe ratios of Mn and Fe oxide-rich biofilms, co...
Mn(II)-Oxidizing Bacteria Are Abundant And Environmentally Relevant Members Of Ferromanganese Deposits In Caves Of The Upper Tennessee River Basin 2013 1589 The upper Tennessee River Basin contains the highest density of our nation’s caves; yet, little is known regarding speleogenesis or Fe and Mn biomineralization in these predominantly epigenic systems. Mn:Fe ratios of Mn and Fe oxide-rich bio?lms, coa...
New Insight Into The Origin Of Manganese Oxide Ore Deposits In The Appalachian Valley And Ridge Of Northeastern Tennessee And Northern Virginia, USA 2017 4394 Manganese oxide deposits have long been observed in association with carbonates within the Appalachian Mountains, but their origin has remained enigmatic for well over a century. Ore deposits of Mn oxides from several productive sites located in east...
A new model for the Kellwasser Anoxia Events (Late Devonian): Shallow water anoxia in an open oceanic setting in the Central Asian Orogenic Belt 2014 5578 The Frasnian–Famennian mass extinction event devastated tropical marine ecosystems and ranks in the top six in taxonomic and ecological severity. The close stratigraphic association between the extinction and the Kellwasser Anoxia Events support a li...
Nutrient Input Influences Fungal Community Composition And Size And Can Stimulate Mn(II) Oxidation In Caves 2015 763 Little is known about the fungal role in biogeochemical cycling in oligotrophic ecosystems. This study compared fungal communities and assessed the role of exogenous carbon on microbial community structure and function in two southern Appalachian cav...
The origin of replacement dolomite, Dolomites, northern Italy: Part 1 2005 1326 Conference Abstract
The origin of replacement dolomite, Dolomites, northern Italy: Part 2 2005 761 Conference Abstract
Paleogeography And Paleoenvironments Of The Late Devonian Kellwasser Event: A Review Of Its Sedimentological And Geochemical Expression 2019 5042 The Late Devonian (383-359 Ma) was a time of prolonged climate instability with catastrophic perturbation of global marine ecosystems at the Frasnian-Famennian (F-F) and the Devonian-Carboniferous (D-C) boundaries. The causes and mechanisms of anoxia...
Radioisotopic age, formation, and preservation of Late Pleistocene human footprints at Engare Sero, Tanzania 2016 677049 We report on the radioisotopic age, formation, and preservation of a late Pleistocene human footprint site in northern Tanzania on the southern shore of Lake Natron near the village of Engare Sero. Over 400 human footprints, as well as tracks of zebr...
Sustained Anthropogenic Impact in Carter Saltpeter Cave, Carter County, Tennessee and the Potential Effects On Manganese Cycling 2013 3007 Anthropogenic impact is a pervasive problem in heavily trafficked cave systems and fecal contamination is equally problematic in many cave and karst waters worldwide. Carter Saltpeter Cave in Carter County, Tennessee exhibits Mn(III/IV) oxide coating...