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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Petrology of basaltic sills from ocean drilling program sites 794 and 797 in the Yamato Basin of the Japan Sea

The basaltic sills from ocean drilling program sites 794 and 797 in the Yamato Basin of the Japan Sea are characterized petrographically on the basis of a detailed study of the composition of relict phenocryst and groundmass phases. The systematic variation in the rock compositions is discussed. Results of 1-atm melting experiments on a relatively primitive basalt from site 797 are reported. The sills are found to constitute two distinct groups of suites: primitive, olivine-bearing suites with low potassium and primitive olivine-bearing to evolved, olivine-free suites with relatively high potassium. A pseudoinvariant reaction relationship between olivine and augite and magnetite is inferred. Complex magmatic and tectonic evolutions in the region, perhaps reflecting a transitional stage between subduction zone activity and back arc spreading, are suggested.

Thy, P.↗
DOE OSTI2022

Atmospheric CO 2 estimates for the Miocene to Pleistocene based on foraminiferal $δ^{11}$B at Ocean Drilling Program Sites 806 and 807 in the Western Equatorial Pacific

Constraints on the evolution of atmospheric CO 2 levels throughout Earth's history are foundational to our understanding of past variations in climate. Despite considerable effort, records vary in their temporal and spatial coverage and estimates of past CO 2 levels do not always converge, and therefore new records and proxies are valuable. Here we reconstruct atmospheric CO 2 values across major climate transitions over the past 16 million years using the boron isotopic composition (δ 11 B) of planktic foraminifera from 89 samples obtained from two sites in the West Pacific Warm Pool, Ocean Drilling Program (ODP) Sites 806 and 807, measured using high-precision multi-collector inductively coupled plasma mass spectrometry. We compare our results to published data from ODP Site 872, also in the Western Equatorial Pacific, that goes back to 22 million years ago. These sites are in a region that today is near equilibrium with the atmosphere and are thought to have been in equilibrium with the atmosphere for the interval studied. We show that δ 11 B data from this region are consistent with other boron-based studies. The data show evidence for elevated pCO 2 during the Middle Miocene and Early to Middle Pliocene, and reductions in pCO 2 of ~200 ppm during the Middle Miocene Climate Transition, ~250 ppm during Pliocene Glacial Intensification and ~50 ppm during the Mid-Pleistocene Climate Transition. During the Mid-Pleistocene Transition there is a minimum pCO 2 at marine isotopic stage (MIS) 30. Our results are consistent with a coupling between pCO 2 , temperature and ice sheet expansion from the Miocene to the late Quaternary.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1988

Evidence of volcanic ash at a K-T boundary section: Ocean drilling program hole 690 C, Maud Rise, Weddell Sea off East Antarctica

Rare vitric volcanogenic ash but more abundant clay minerals considered volcanogenic in origin are associated with an expanded and essentially complete K-T boundary sequence from Ocean Drilling Project (ODP) Hole 690 C on Maud Rise in the Weddell Sea off East Antarctica. Results at this writing are preliminary and are still based to some extent on shipboard descriptions. Further shore-based studies are in progress. It would appear, however, that the presence of volcanic ash and altered ash in the Danian section beginning at the biostratigraphically and paleomagnetically determined K-T boundary on Maud Rise can be cited as evidence of significant volcanic activity within the South Atlantic-Indian Ocean sector of the Southern Ocean coincident with the time of biotic crises at the end of the Maestrichtian. This is a postulated time of tectonic and volcanic activity within this Southern Hemisphere region, including possible initiation of the Reunion hot spot and a peak in explosive volcanism on Walvis Ridge (1) among other events. A causal relationship with the biotic crisis is possible and volcanism should be given serious consideration as a testable working hypothesis to explain these extinctions.

Wise, S. W.↗
NASA NTRS1993

Abrupt climate change and transient climates during the Paleogene: a marine perspective

Detailed investigations of high latitude sequences recently collected by the Ocean Drilling Program (ODP) indicate that periods of rapid climate change often culminated in brief transient climates, with more extreme conditions than subsequent long term climates. Two examples of such events have been identified in the Paleogene; the first in latest Paleocene time in the middle of a warming trend that began several million years earlier: the second in earliest Oligocene time near the end of a Middle Eocene to Late Oligocene global cooling trend. Superimposed on the earlier event was a sudden and extreme warming of both high latitude sea surface and deep ocean waters. Imbedded in the latter transition was an abrupt decline in high latitude temperatures and the brief appearance of a full size continental ice-sheet on Antarctica. In both cases the climate extremes were not stable, lasting for less than a few hundred thousand years, indicating a temporary or transient climate state. Geochemical and sedimentological evidence suggest that both Paleogene climate events were accompanied by reorganizations in ocean circulation, and major perturbations in marine productivity and the global carbon cycle. The Paleocene-Eocene thermal maximum was marked by reduced oceanic turnover and decreases in global delta 13C and in marine productivity, while the Early Oligocene glacial maximum was accompanied by intensification of deep ocean circulation and elevated delta 13C and productivity. It has been suggested that sudden changes in climate and/or ocean circulation might occur as a result of gradual forcing as certain physical thresholds are exceeded. We investigate the possibility that sudden reorganizations in ocean and/or atmosphere circulation during these abrupt transitions generated short-term positive feedbacks that briefly sustained these transient climatic states.

NASA Program Exobiology↗
NASA NTRS2004

The Cretaceous/Paleogene Transition on the East Tasman Plateau, Southwestern Pacific

Ocean Drilling Program Leg 189 recovered a potentially complete shallow marine record of the Cretaceous-Paleogene boundary (KPB) at Site 1172 on the East Tasman Plateau. Here we present high-resolution (cm-scale) data from micropaleontology, geochemistry, sedimentology, and paleomagnetism that provide no evidence for a complete KPB, but instead suggest a boundary-spanning hiatus of at least 0.8 Ma. We interpret this hiatus to represent the sequence boundary between the uppermost Maastrichtian Tal.1 and lowermost Danian Ta1.2/ Da- 1 3rd-order sequence stratigraphic cycles. Microfloral assemblages indicate generally shallow paleodepths, restricted circulation, and eutrophic conditions through the section. Paleodepths progressively shallow through the late Maastrichtian, while more oceanic and warmer conditions dominate the early Danian. The Site 1172 KPB section is broadly comparable to other southern highlatitude sections in Antarctica and New Zealand, but appears to record a shallower and more restricted environment that permitted a eustatically-driven hiatus across the KPB mass extinction event.

Schellenberg, Stephen A.↗
DOE OSTI2021

The Indian Ocean, its supra-subduction history, and implications for ophiolites

We report Ophiolite complexes represent fragments of ocean crust and mantle formed at spreading centers and emplaced on land. The setting of their origin, whether at mid-ocean ridges, back-arc basins, or forearc basins has been debated. Geochemical classification of many ophiolite extrusive rocks reflect an approach interpreting their tectonic environment as the same as rocks with similar compositions formed in various modern oceanic settings. This approach has pointed to the formation of many ophiolitic extrusive rocks in a supra-subduction zone (SSZ) environment. Paradoxically, structural and stratigraphic evidence suggests that many apparent SSZ-produced ophiolite complexes are more consistent with mid-ocean ridge settings. Compositions of lavas in the southeastern Indian Ocean resemble those of modern SSZ environments and SSZ ophiolites, although Indian Ocean lavas clearly formed in a mid-ocean ridge setting. These facts suggest that an interpretation of the tectonic environment of ophiolite formation based solely on their geochemistry may be unwarranted. New seismic images revealing extensive Mesozoic subduction zones beneath the southern Indian Ocean provide one mechanism to explain this apparent paradox. Cenozoic mid-ocean-ridge–derived ocean floor throughout the southern Indian Ocean apparently formed above former sites of subduction. Compositional remnants of previously subducted mantle in the upper mantle were involved in generation of mid-ocean ridge lavas. The concept of historical contingency may help resolve the ambiguity on understanding the environment of origin of ophiolites. Many ophiolites with “SSZ” compositions may have formed in a mid-ocean ridge setting such as the southeastern Indian Ocean.

58 GEOSCIENCES↗
NASA NTRS1991

Fine structure of the late Eocene Ir anomaly in marine sediments

The Late Eocene Ir abundance profile in deep sea cores from Ocean Drilling Program Leg 113 Hole 689B on the Maude Rise off of Antarctica was studied with 410 samples continuously in 10 cm increments and measured with the Iridium Coincidence (ICS). The ICS was subsequently modified to measure 13 other elements simultaneously with the Ir. The abundance profiles of these elements were then determined in the Late Eocene Massignano section in central Italy with 250 samples (encompassing roughly 2 million years of accumulation) which were collected about every 5 cm in about 2 cm increments. These studies augmented a previous one (which included many elements) of deep sea cores from Deep Sea Drilling Project Site 592 on the Lord Howe Rise in the Tasman Sea between Australia and New Zealand. In the latter study, 50 samples (encompassing roughly 0.7 million years of accumulation) were collected continuously in 10 cm increments. The results from these studies are discussed.

Asaro, F.↗
NASA NTRS1993

Plio-Pleistocene time evolution of the 100-kyr cycle in marine paleoclimate records

A new time-series analysis technique (called envelope inversion), which is based on multiple taper spectral analysis, is used to address the question of an abrupt versus a gradual onset of the 100-kyr ice-age periodicity in the middle Pleistocene. Three long (greater than 2.6 m.y.) time series from Deep Sea Drilling Project site 607 (midlatitude Atlantic) and Ocean Drilling Program site 677 (equatorial Pacific) were analyzed using delta(O-18) records. Results do not yield compelling evidence for an abrupt change in the 100-kyr delta(O-18) signal. Rather, the results suggest that the 100-kyr delta(O-18) cycle is phase-locked with the 124-kyr eccentricity cycle some 300-400 kyr prior to its late Pleistocene growth in amplitude and phase lock with the 95-kyr eccentricity cycle.

Park, Jeffrey↗
NASA NTRS1994

The biostratigraphy and paleogeography of Maastrichtian inoceramids

The global distribution of Maastrichtian inoceramids is now known in enough detail that the patterns of disappearance can be used to place first-order constraints on paleoceanographic changes that may have occurred during that age. The Inoceramidae is an excellent group to focus on in a study of Maastrichtian events for the following reasons: (1) they were globally distributed in the early Maastrichtian; (2) they did not survive the age (i.e., they undergo change during the interval); and (3) they have left a rich microfossil and macrofossil record. Some inoceramids grew to be very large; however, even the largest often passively disaggregated and are preserved as hundreds of millions of characteristic, columnar, polygonal prisms of calcite approximately 100 microns across. This taphonomic process has greatly increased the inoceramid fossil record and provides a means of objectively estimating changes in their standing population. In addition, because these prisms commonly occur in Deep Sea Drilling Project (DSDP) and Ocean Drilling Program (ODP) cores, it is relatively easy to generate a truly global database. The existing macrofossil record of inoceramids has less temporal and spacial resolution but greater taxonomic resolution than the microfossil record. In concert the microfossil and macrofossil records of inoceramids demonstrate that important changes occurred during the Maastrichtian. These changes are distinct from the KT boundary catastrophe but are part of the larger KT transition.

Macleod, K. G.↗
NASA NTRS2003

Data Report: A Search for Deposits of the Late Pliocene Impact of the Eltanin Asteroid in Rise Sediments from the Antarctic Peninsula, Site 1096

Concentrations of Ir have been measured in 87 sediment samples from Ocean Drilling Program Site 1096 in search of evidence of fallout from the impact of the Eltanin asteroid, which occurred at 2.15 Ma, approx. 1300 km northwest of the site. An additional six samples were measured from a unique sand layer and adjacent sediments that are dated at approx. 1.6 Ma. These 93 sediment samples are all silts and muds that were deposited on a continental rise drift of the Antarctic Peninsula. No evidence of the Eltanin impact deposit was found in this study.

Kyte, Frank T.↗
NASA NTRS2001

Identification of Late Eocene Impact Deposits at ODP Site 1090

Anomalous concentrations of Ir have been found in upper Eocene sediments from Ocean Drilling Program (ODP) Hole 1090B. Clear and dark-colored spherules that are believed to be microtektites and clinopyroxene- bearing microkrystites, respectively, were found in the samples with highest Ir. The peak Ir concentration in Sample 177- 1090B-30X-5,105-106 cm (954 pg/g) and the net Ir fluence (14 ng/cm2) at this site are higher that at most other localities except for Caribbean site RC9-58. The Ir anomaly and impact debris are probably correlative with similar deposits found at ODP Site 689 on the Maude Rise and at other localities around the world.

Kyte, Frank T.↗
NASA NTRS2019

Outstanding Natural Occurrence of TiO2-II at the Chicxulub Crater - Anatomy of A Shock-Produced High-Pressure Polymorph

Scientific drilling of the end-Cretaceous, approximately 180 kilometers-diameter Chicxulub crater (Yucatan Peninsula, Mexico) during IODP–ICDP (Integrated Ocean Drilling Program - International Continental Scientific Drilling Program) Expedition 364 has provided new insights into the formation, shock metamorphism, structural evolution, and thermal history of peak rings in large complex impact craters. An outstanding feature in uplifted granitoid rocks of the Chicxulub peak ring is the preservation of TiO2-II, an orthorhombic high-pressure polymorph of TiO2 with an alpha-PbO2 structure, produced during the impact from rutile and/or anatase at shock pressures of approximately 12.5-17.5 gigapascals. Unlike other mostly micro- and cryptocrystalline occurrences of TiO2-II at terrestrial impact sites, ejecta deposits, and in rare ultra-high pressure metamorphic rocks, TiO2-II at Chicxulub occurs as abundant euhedral crystals greater than or equal to 70 microns in size within aggregates of altered magmatic titanite. This mode of occurrence provides an excellent opportunity to investigate the crystallography and transformation kinetics of the shock-produced high-pressure polymorph using scanning electron microscopic, micro-Raman, electron backscatter diffraction (EBSD), focused ion beam (FIB), as well as transmission-EBSD and transmission electron microscopic (TEM) techniques. Here we present refined microstructural and new crystallographic results for TiO2-II at the Chicxulub crater.

Schmieder, Martin↗
NASA NTRS1981

Sub-Ocean Drilling

The National Science Foundation (NSF) initialized a new phase of exploration last year, a 10 year effort jointly funded by NSF and several major oil companies, known as the Ocean Margin Drilling Program (OMDP). The OMDP requires a ship with capabilities beyond existing drill ships; it must drill in 13,000 feet of water to a depth 20,000 feet below the ocean floor. To meet requirements, NSF is considering the conversion of the government-owned mining ship Glomar Explorer to a deep ocean drilling and coring vessel. Feasibility study performed by Donhaiser Marine, Inc. analyzed the ship's characteristics for suitability and evaluated conversion requirement. DMI utilized COSMIC's Ship Motion and Sea Load Computer program to perform analysis which could not be accomplished by other means. If approved for conversion, Glomar Explorer is expected to begin operations as a drillship in 1984.

Source record↗
DOE OSTI2022

Nanoscale trace-element zoning in pyrite framboids and implications for paleoproxy applications

Pyrite framboids (spherical masses of nanoscale pyrite) are among the earliest textures of pyrite to form in sediments. It has been proposed that their trace-element (TE) contents can be used to track the TE composition of the water column in which they formed. However, it is not clear how these TEs are associated with the framboidal pyrite grains. For instance, it is important to know whether they are incorporated uniformly or are enriched in different regions of the framboid. Here, we used high-resolution scanning transmission electron microscopy to identify chemical zoning within pyrite framboids. We found that initial, nanoscale pyrite euhedral crystals, which make up the volumetric majority of the framboids, are covered/infilled by later pyrite that templates on the earlier pyrite. Further, this later pyrite is enriched in TEs, suggesting that many TEs are incorporated in pyrite relatively late (during early diagenesis; not in the water column). This observation suggests that although chemical analyses of pyrite framboids may provide ocean-water chemistry trends through time, the details are complex. Specifically, the TEs found in pyrite may be linked to adsorption onto organic matter, detrital material, and authigenic minerals such as Fe- and Mn-oxide phases followed by desorption in the sediments or release via dissolution and incorporation into pyrite as overgrowths on the initial nanoscale euhedral crystals that make up framboids. While the use of pyrite chemistry to understand past ocean conditions remains promising, and even diagenetic additions may not preclude the utility of pyrite for reconstructing ancient ocean conditions, care must be taken in interpretations because the end concentration may be influenced by diagenesis.

58 GEOSCIENCES↗
DOE OSTI2020

Physical Properties and Gas Hydrate at a Near-Seafloor Thrust Fault, Hikurangi Margin, New Zealand

The Papaku Fault Zone, drilled at International Ocean Discovery Program (IODP) Site U1518, is an active splay fault in the frontal accretionary wedge of the Hikurangi Margin. In logging-while-drilling data, the 33-m-thick fault zone exhibits mixed modes of deformation associated with a trend of downward decreasing density, P-wave velocity, and resistivity. Methane hydrate is observed from ~30 to 585 m below seafloor (mbsf), including within and surrounding the fault zone. Hydrate accumulations are vertically discontinuous and occur throughout the entire logged section at low to moderate saturation in silty and sandy centimeter-thick layers. In this paper, we argue that the hydrate distribution implies that the methane is not sourced from fluid flow along the fault but instead by local diffusion. This, combined with geophysical observations and geochemical measurements from Site U1518, suggests that the fault is not a focused migration pathway for deeply sourced fluids and that the near-seafloor Papaku Fault Zone has little to no active fluid flow.

58 GEOSCIENCES↗
NASA NTRS2019

Microstructural Characterization of TiO2-II in the Chicxulub Peak Ring

The peak ring of the approximately 180 kilometer-diameter Chicxulub impact crater on the Yucatan Peninsula, Mexico, was recently drilled during IODP-ICDP (International Ocean Discovery Program-International Continental Scientific Drilling Program) Expedition 364, producing core M0077A. The new core provides insights into the anatomy, composition, tectonic deformation, shock metamorphism, and post-impact overprint of crater-filling impactites and crystalline basement rocks. The basement rocks were shocked to approximately 12.5-17.5 gigapascals, uplifted, and hydrothermally altered. This study presents a combined Raman spectroscopic and electron backscatter diffraction (EBSD) study of TiO2-II, a high-pressure polymorph of TiO2 with an alpha-PbO2 structure (orthorhombic; space group Pbcn; density 4.34 grams per cubic centimeter, in shocked granitoid rock of the Chicxulub peak ring.

Schmieder, Martin↗
DOE OSTI2020

Slow slip source characterized by lithological and geometric heterogeneity

Slow slip events (SSEs) accommodate a significant proportion of tectonic plate motion at subduction zones, yet little is known about the faults that actually host them. The shallow depth (<2 km) of well-documented SSEs at the Hikurangi subduction zone offshore New Zealand offers a unique opportunity to link geophysical imaging of the subduction zone with direct access to incoming material that represents the megathrust fault rocks hosting slow slip. Two recent International Ocean Discovery Program Expeditions sampled this incoming material before it is entrained immediately down-dip along the shallow plate interface. Drilling results, tied to regional seismic reflection images, reveal heterogeneous lithologies with highly variable physical properties entering the SSE source region. These observations suggest that SSEs and associated slow earthquake phenomena are promoted by lithological, mechanical, and frictional heterogeneity within the fault zone, enhanced by geometric complexity associated with subduction of rough crust.

58 GEOSCIENCES↗
NASA NTRSDate not supplied

NASA Science Technology Development Programs for Ocean Worlds Exploration

The exploration of ocean worlds such as Europa and Enceladus supports NASA’s goal to search for life and potentially habitable regions elsewhere in the universe, and further promises to help us understand the origins, evolution, and limits of life on Earth. Over the past several years, NASA’s Planetary Science Division has funded several technology development programs to enable future surface and subsurface missions to ocean worlds. These programs include Instrument Concepts for Europa Exploration (ICEE), Concepts for Ocean Worlds Life Detection Technology (COLDTech), Scientific Exploration Subsurface Access Mechanism for Europa (SESAME), Applied Information Systems Research: Autonomous Robotics Research for Ocean Worlds (AISR:ARROW), and Astrodynamics in Support of Icy Worlds Missions. Tasks selected under these programs include the development of scientific instruments including seismometers, imagers, spectrometers, and organic analyzers, and platform technologies including drills, melt probes, through-ice communications, radiation-hard electronics, and autonomy for surface operations. This paper describes the objectives of each of these programs and provides a summary of the work that has been completed or is underway in each.

technology↗