Nora Noffke is an American geologist who is a professor in the Department of Ocean and Earth Sciences, Old Dominion University in Norfolk, Virginia, USA. Noffke's research focuses on the sedimentology of biofilm forming sedimentary structures in modern aquatic environments, where clastic deposits dominate. Such structures occur in the fossil record as well. Her studies are interdisciplinary combining sedimentology with microbiology, geochemistry, and mineralogy. [1]
Noffke's interest in fossils originated from her early years when she would spend time hiking with her parents on the Schwaebische Alb, a mountain chain in Germany. The area was rich in fossils, paving the way for her lifelong career in the field of paleontology and geology. [2]
Noffke received a Bachelor of Science and a Master of Sciences (Diploma) in geology-paleontology from the University of Tübingen, Germany. Her diploma thesis advisor was Dolf Seilacher. Together they carried out research on trace fossils including Daedalus halli from the Lower Arenigian, Montagne Noire, France. [3] Noffke did her Ph.D. in Geomicrobiology at the University of Oldenburg, Germany where she worked alongside Gisela Gerdes, a microbiologist who conducted research in the field of modern microbial mats in siliciclastic deposits. [3] In 2000, Noffke migrated to the US, where she was a postdoctoral researcher at the Department of Organismic Biology and Evolution, at Harvard University, as a guest of Andy Knoll. Shortly thereafter, she became professor for sedimentology at the Department of Ocean and Earth Sciences at Old Dominion University, Norfolk, Virginia. [4]
Noffke is known for her work on microbial mats causing microbially induced sedimentary structures (MISS) in sandy deposits. Her work employs the actuopaleontological approach in the examination of the Earth's past. [1] [5] MISS allow insight into past prokaryote and single-celled benthos, and the paleoenvironment and paleoclimate. Noffke discovered 17 different types of MISS that result from microbial growth and EPS-production, trapping, biostabilization, baffling, and binding. The Dresser Formation, Pilbara, Western Australia, includes some of the oldest MISS. [6] The fossil microbial mats covered clastic tidal flats, channels and pools. [7] MISS at Dinosaur Ridge, added knowledge on paleoenvironmental conditions under which the Upper Crustaceous "J" Sandstone formed, and broadened insight of track sites development. [8]
In collaboration with Gerdes, Thomas Klenke, and Wolfgang E. Krumbein, Noffke suggested a new, fifth group to Pettijohn and Potter's classification of primary sedimentary structures. They called the group bedding modified by microbial mats and biofilms, and divided it into two classes: one for those on bedding planes, and the second for those within beds. [9] The first class includes microbial wrinkle structures, mat/sand chips, erosional remnants and pockets, palimpsest/multidirectional ripple marks, shrinkage cracks and mat curls. [9] The second class, within beds, includes biolaminites, gas domes, sponge pore fabrics and fenestrae structures, as well as "microbially induced sedimentary textures (MIST) such as oriented grains, sinoidal laminae, and mat-layer-bound grain sizes. [9]
Noffke's work on microbially induced sedimentary structures (MISS) in sandy deposits is summarized in a textbook. [5] The book describes MISS as biosignatures valuable for the exploration extraterrestrial life. [10]
Noffke is Acting Chair of the Subcommission on Precambrian Stratigraphy of the International Stratigraphic Commission, [11] and is the editor for the volume Prokaryota of the Treatise of Invertebrate Paleontology. [12] Noffke has organized the SEPM Field Conference on Siliciclastic Microbial Mats 2010, and together with John Stolz has established the Gordon Research Conference: Geobiology. [5] She was one of the early chairs of the Division for Geobiology and Geomicrobiology of the Geological Society of America (GSA). [13]
In honor of Noffke's service to the science community, a 550 million year old fossil group from the Ediacaran Grant Bluff Formation, Australia, was named after her: Noffkarkys storaaslii [14] ('net of Noffke')
Noffke was named a fellow of the American Association for the advancement of Science (AAAS). This award is the equivalent of an Oscar for an actor. The AAAS cited her for her work.
"seminal contributions to the field of geobiology, particularly for elucidation of the previously unrecognized 3.5 billion year fossil record of microbially induced sedimentary structures". [15]
Recently, she was elected president of the geological society of Washington, D.C.
Publications
Stromatolites or stromatoliths are layered sedimentary formations (microbialite) that are created mainly by photosynthetic microorganisms such as cyanobacteria, sulfate-reducing bacteria, and Pseudomonadota. These microorganisms produce adhesive compounds that cement sand and other rocky materials to form mineral "microbial mats". In turn, these mats build up layer by layer, growing gradually over time. This process generates the characteristic lamination of stromatolites, a feature that is hard to interpret, in terms of its temporal and environmental significance. Different styles of stromatolite lamination have been described, which can be studied through microscopic and mathematical methods. A stromatolite may grow to a meter or more. Fossilized stromatolites provide important records of some of the most ancient life. As of the Holocene, living forms are rare.
Sedimentology encompasses the study of modern sediments such as sand, silt, and clay, and the processes that result in their formation, transport, deposition and diagenesis. Sedimentologists apply their understanding of modern processes to interpret geologic history through observations of sedimentary rocks and sedimentary structures.
Geomicrobiology is the scientific field at the intersection of geology and microbiology and is a major subfield of geobiology. It concerns the role of microbes on geological and geochemical processes and effects of minerals and metals to microbial growth, activity and survival. Such interactions occur in the geosphere, the atmosphere and the hydrosphere. Geomicrobiology studies microorganisms that are driving the Earth's biogeochemical cycles, mediating mineral precipitation and dissolution, and sorbing and concentrating metals. The applications include for example bioremediation, mining, climate change mitigation and public drinking water supplies.
A concretion is a hard, compact mass formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular shapes also occur. The word 'concretion' is derived from the Latin concretio "(act of) compacting, condensing, congealing, uniting", itself from con meaning "together" and crescere meaning "to grow".
The Paleoarchean, also spelled Palaeoarchaean, is a geologic era within the Archean Eon. The name derives from Greek "Palaios" ancient. It spans the period of time 3,600 to 3,200 million years ago. The era is defined chronometrically and is not referenced to a specific level of a rock section on Earth. The earliest confirmed evidence of life comes from this era, and Vaalbara, one of Earth's earliest supercontinents, may have formed during this era.
Geobiology is a field of scientific research that explores the interactions between the physical Earth and the biosphere. It is a relatively young field, and its borders are fluid. There is considerable overlap with the fields of ecology, evolutionary biology, microbiology, paleontology, and particularly soil science and biogeochemistry. Geobiology applies the principles and methods of biology, geology, and soil science to the study of the ancient history of the co-evolution of life and Earth as well as the role of life in the modern world. Geobiologic studies tend to be focused on microorganisms, and on the role that life plays in altering the chemical and physical environment of the pedosphere, which exists at the intersection of the lithosphere, atmosphere, hydrosphere and/or cryosphere. It differs from biogeochemistry in that the focus is on processes and organisms over space and time rather than on global chemical cycles.
Gerard Viner Middleton FRSC, often known as Gerry Middleton, was a Canadian geologist and university teacher.
A microbial mat is a multi-layered sheet of microorganisms, mainly bacteria and archaea, or bacteria alone. Microbial mats grow at interfaces between different types of material, mostly on submerged or moist surfaces, but a few survive in deserts. A few are found as endosymbionts of animals.
Microbially induced sedimentary structures (MISS) are primary sedimentary structures formed by the interaction of microbes with sediment and physical agents of erosion, deposition, and transportation. The structures commonly form when microbial mats are preserved in the sedimentary geological record. There are 17 main types of macroscopic and microscopic MISS. Of those, wrinkle structures and microbial mat chips are the most abundant in the fossil record. Other MISS include sinoidal structures, polygonal oscillation cracks, multidirected ripple marks, erosional remnants and pockets, or gas domes.
John P. Grotzinger is the Fletcher Jones Professor of Geology at California Institute of Technology and chair of the Division of Geological and Planetary Sciences. His works primarily focus on chemical and physical interactions between life and the environment. In addition to biogeological studies done on Earth, Grotzinger is also active in research into the geology of Mars and has made contributions to NASA's Mars Exploration Program.
Arumberia is an enigmatic fossil from the Ediacaran period originally described from the Arumbera Sandstone, Northern Territory, Australia but also found in the Urals, East Siberia, England and Wales, Northern France, the Avalon Peninsula and India. Several morphologically distinct species are recognized.
Stanley Awramik is an American biogeologist and paleontologist. He is best known for his work related to the Precambrian. In 2013, he was inducted as a fellow of the Geological Society of America.
The Shady Dolomite is a geologic formation composed of marine sedimentary rocks of early Cambrian age. It outcrops along the eastern margin of the Blue Ridge province in the southeastern United States and can be found in outcrops in the states of Alabama, Georgia, Tennessee, North Carolina, and Virginia. It can also be found in the subsurface of Kentucky, Ohio, and West Virginia. The Shady is predominantly composed of dolomite and limestone with lesser amounts of mudrock. It contains fossils of trilobites, archaeocyathids, algae, brachiopods, and echinoderms, along with the enigmatic fossil Salterella. The Shady Dolomite was first described by Arthur Keith in 1903 and was named for exposures in the Shady Valley of Johnson County in the state of Tennessee. Near Austinville, Virginia, the Shady hosts ore deposits that have been mined extensively for lead and zinc ore.
The earliest known life forms on Earth may be as old as 4.1 billion years old according to biologically fractionated graphite inside a single zircon grain in the Jack Hills range of Australia. The earliest evidence of life found in a stratigraphic unit, not just a single mineral grain, is the 3.7 Ga metasedimentary rocks containing graphite from the Isua Supracrustal Belt in Greenland. The earliest direct known life on land may be stromatolites which have been found in 3.480-billion-year-old geyserite uncovered in the Dresser Formation of the Pilbara Craton of Western Australia. Various microfossils of microorganisms have been found in 3.4 Ga rocks, including 3.465-billion-year-old Apex chert rocks from the same Australian craton region, and in 3.42 Ga hydrothermal vent precipitates from Barberton, South Africa. Much later in the geologic record, likely starting in 1.73 Ga, preserved molecular compounds of biologic origin are indicative of aerobic life. Therefore, the earliest time for the origin of life on Earth is at least 3.5 billion years ago, possibly as early as 4.1 billion years ago — not long after the oceans formed 4.5 billion years ago and after the formation of the Earth 4.54 billion years ago.
Dawn Yvonne Sumner is an American geologist, planetary scientist, and astrobiologist. She is a professor at the University of California, Davis. Sumner's research includes evaluating microbial communities in Antarctic lakes, exploration of Mars via the Curiosity rover, and characterization of microbial communities in the lab and from ancient geologic samples. She is an investigator on the NASA Mars Science Laboratory (MSL) and was Chair of the UC Davis Department of Earth & Planetary Sciences from 2014 to 2016. She is Fellow of the Geological Society of America.
Microbialite is a benthic sedimentary deposit made of carbonate mud that is formed with the mediation of microbes. The constituent carbonate mud is a type of automicrite ; therefore, it precipitates in situ instead of being transported and deposited. Being formed in situ, a microbialite can be seen as a type of boundstone where reef builders are microbes, and precipitation of carbonate is biotically induced instead of forming tests, shells or skeletons.
Automicrite is autochthonous micrite, that is, a carbonate mud precipitated in situ and made up of fine-grained calcite or aragonite micron-sized crystals. It precipitates on the sea floor or within the sediment as an authigenic mud thanks to physicochemical, microbial, photosynthetic and biochemical processes. It has peculiar fabrics and uniform mineralogical and chemical composition.
Tanja Bosak is a Croatian-American experimental geobiologist who is currently an associate professor in the Earth, Atmosphere, and Planetary Science department at the Massachusetts Institute of Technology. Her awards include the Subaru Outstanding Woman in Science Award from the Geological Society of America (2007), the James B. Macelwane Medal from the American Geophysical Union (2011), and was elected an AGU fellow (2011). Bosak is recognized for her work understanding stromatolite genesis, in addition to her work in broader geobiology and geochemistry.
The Dresser Formation is a Paleoarchean geologic formation that outcrops as a generally circular ring of hills the North Pole Dome area of the East Pilbara Terrane of the Pilbara Craton of Western Australia. This formation is one of many formations that comprise the Warrawoona Group, which is the lowermost of four groups that comprise the Pilbara Supergroup. The Dresser Formation is part of the Panorama greenstone belt that surrounds and outcrops around the intrusive North Pole Monzogranite. Dresser Formation consists of metamorphosed, blue, black, and white bedded chert; pillow basalt; carbonate rocks; minor felsic volcaniclastic sandstone and conglomerate; hydrothermal barite; evaporites; and stromatolites. The lowermost of three stratigraphic units that comprise the Dresser Formation contains some of the Earth's earliest commonly accepted evidence of life such as morphologically diverse stromatolites, microbially induced sedimentary structures, putative organic microfossils, and biologically fractionated carbon and sulfur isotopic data.
Judith Ann McKenzie was an American biogeochemist known for her research on past climate change, chemical cycles in sediments, and geobiology.
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