Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1991. / Includes bibliographical references (p. 203-222). / by Kurt Lewis Feigl. / Ph.D.

Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2015. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 40-46). / The Maria Fold and Thrust Belt (MFTB) and Colorado River Extensional Corridor (CREC) were the sites of atypically extreme compression in Mesozoic time and extension in Cenozoic time, respectively. The orientations of these deformational structures are at odds with the Sevier and Laramide thrust belts and the Basin and Range Extensional Province surrounding these areas, a fact that remains largely unexplained. Data pertaining to metamorphic grade, deformational structures, and plutonism are compiled and reported in order to characterize compression and metamorphism. Field data on the 18.6 Ma Peach Spring Tuff are collected and presented and data on cooling ages are compiled in order to characterize extension. It is suggested that high metamorphic temperatures and ductile compressional structures are related to Late Cretaceous S-type plutonism; furthermore, it is suggested that later extension is related to earlier metamorphism and compression. It is demonstrated that the spread in attitudes of the Peach Spring Tuff correlates well with the degree of post- 18.6 Ma extension. Finally, a favored model is presented for the Mesozoic-Cenozoic evolution of the MFTB and CREC. / by James R. Pershken. / S.B.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, 1986. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND LINDGREN. / Vita. / Bibliography: leaves 136-143. / by Bruce Douglas Chapman. / Ph.D.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2010. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 73-76). / Discrepancies in interval velocities estimated from vertical well measurements made with different source central frequencies at Gypsy site could be primarily explained in terms of intrinsic attenuation. Four intervals were chosen for this study based on varying rock properties. The first interval is predominantly shale, second interval is mostly sandstone, and the third interval is made up of shale and sandstone. The fourth interval is the second and third intervals combined. The data used are acquired from three seismic sources; Full Wave Sonic (FWS), Bender log, and Vertical Seismic Profile (VSP) with estimated central frequencies 10kHz, 1kHz, and 100Hz, respectively. The modeling was done using the Discrete Wavenumber (DWN) method and the Logarithmic Dispersion Relation (LDR) to calculate a constant Quality Factor (Q) that best explains the observed velocity dispersion for each of the intervals of interest. The elastic scattering component of the dispersion is negligible. Intrinsic quality factors of 54,35,28, and 30 best explain the field data for first, second, third, and fourth intervals, respectively. The identification and subsequent modeling of velocity dispersion and its components provide key information for integrated reservoir characterization and better enable the prediction of the seismic response at different frequencies. / by Sami Ibrahim Alsaadan. / S.M.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1998. / Includes bibliographical references (leaves 196-210). / by Weiqun Shi. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1988. / Includes bibliographies. / by Michael Roy Nelson. / Ph.D.

Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2007. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 49-50). / Stabe isotope probe (SIP) incubation studies were performed using ¹³C-labeled carbon substrates on hyperthermophilic filamentous streamer communities inhabiting Octopus Spring in Yellowstone National Park. Biomass was removed from the outflow stream and incubated at near-in situ conditions with labeled bicarbonate, formate, or acetate. Lipids from the biomass were extracted and analyzed using gas chromatography-mass spectroscopy (GC-MS) and gas chromatography-isotope ratio monitoring-mass spectroscopy(GC-IRMS). We observed incorporation of ¹³C-labeled acetate into the total biomass, archaeal lipids, and a small number of bacterial lipids, but no incorporation of labeled formate or bicarbonate. During 67 hours of incubation, 0.060 [mu]g of labeled acetate was incorporated by the archaeal and bacterial community. The lack of acetate incorporation by most bacteria, or formate and bicarbonate incorporation by any community member may reflect rates of carbon turnover, the carbon acquisition pathway used, or inhibition under experimental conditions, / by Augusta K. Dibbell. / S.B.

Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2003. / Cataloged from PDF version of thesis. In title on title page, "[alpha] appears as lower case Greek letter. "May 21, 2003." / Includes bibliographical references (page 31). / We present results from observations of H107[alpha] recombination-line emission and the related 4800 MHz continuum emission of the HII region RCW 38 using the Australia Telescope Compact Array. We find the continuum emission to be concentrated in a ring-like structure with the 05 star, IRS2, approximately centered in the cavity within the ring. The temperature of the ionized gas ranges from 5200 to 7500 K and the emission is optically thin. The H107[alpha] line emission appears to be confined within the continuum ring. We also find the continuum ring to encircle the peak in the diffuse X-ray gas. The radio continuum emission matches closely to NIR observations with a bright western ridge containing the peak in the 10[mu]m emission known as IRS1 (Frogel et al. 1974) apparent in both observations. From calculations of continuum and line parameters, we estimate the spectral type of the ionizing source for the region to be an 05/06 star which is consistent with the spectral type of IRS2. / by Miquela Vigil. / S.B.

Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2009. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 25-30). / Sahara 99555 (SAH 99555) is the oldest dated angrite sample, a rare type of meteorite, and is only ~2 Myr younger than the age of the solar system (1, 2). SAH 99555 shows no post-cooling brecciation or weathering from the parent body, and does not display signs of significant terrestrial weathering. Therefore, paleomagnetic experiments were conducted for the first time on SAH 99555 to discover if it contains a primary paleomagnetism and then to determine a paleointensity estimate and its ferromagnetic mineralogy. Our studies show that the primary ferromagnetic mineral in SAH 99555 is magnetite and there are also some accessory ferromagnetic minerals including titanomagnetite and hematite. The natural remanent magnetization (NRM) of SAH 99555 appears to have a low-coercivity component probably from a collector's hand magnet or the Earth's field as well as a high-coercivity component, similar to D'Orbigny, another angrite. The paleointensity measurements of the high-coercivity component of SAH 99555,5 agree with the paleointensity estimates made for other angrites (D'Orbigny and A-881371) by Weiss et al. (2008) (4). Therefore, it appears that SAH 99555 does record a primary paleofield from when it was on the angrite parent body, which would be the oldest known paleomagnetic record yet identified in a planetary rock. Further studies are suggested to verify these conclusions, which make SAH 99555 one more key data point in the understanding of the early solar system. / by Sarah P. Slotznick. / S.B.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1991. / Includes bibliographical references. / by Randall Lee Mackie. / Ph.D.