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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Estudio de la genesis del crates iturralde provincia Abel Iturralde, departamento de La Paz - Bolivia

Jarandilla Altuzarra, Ivan January 2009 (has links)
En el caso particular del trabajo de investigación, se tiene el cráter “ITURRALDE” que resalta el tipo de estructura geológica como ser una depresión que presumiblemente fuese de un cráter de impacto. En Bolivia no se tiene registros acerca de la investigación sistemática desarrollada en estructuras de impacto. El presente documento se describir las características geológicas, geomorfológicas, petrográficas geofísicas (método gravimétrico) del cráter “ITURRALDE”, y se analizan las características sedimentologicas del cráter “ITURRALDE”. El cráter “ITURRALDE”, se encuentra en la amazonia boliviana ubicada en el departamento de La Paz, Provincia Abel Iturralde, Municipio Ixiamas a 400 km al Nor - Este de la ciudad de La Paz. Hidrográficamente se halla próximo al arroyo Huipa, afluente del río Manupare y el rió Madidi que es afluente del rió Beni, la población más cercana es Ojaki, ubicada al Sud - Este del cráter “ITURRALDE”. superficie rasgos geológicos de impacto a simple vista donde no se ve las destrucciones de las capas geológicas y grandes volúmenes de roca inmensamente deformadas y fracturadas, ya que esta cubierta por una capa de material sedimentario y suelo. La geología regional del área de estudio se encuentra constituida por el Cuaternario Holoceno (Qh), generalmente presenta depósitos aluviales, fluvio-lacustre y coluviales. Geológicamente el cráter “ITURRALDE”, esta comprendida por el contacto discordante del sistema Terciario y Cuaternario, donde se halla la Fm. Candelaria (Qca) y los depósitos lagunares. Por la forma circular del cráter y las geoformas que presenta es característico de un cráter complejo de impacto. Se interpretaron e identificaron cinco geoformas del cráter “ITURRALDE” como ser: escarpes, conos de deyección, conos de escombro, área ondulada y áreas de inundación. El cráter “ITURRALDE”, presenta un diseño de drenaje centripetal, típico de un cráter de impacto. Las muestras petrográficas estudiadas no exponen señales de metamorfismo de impacto. Las esférulas encontradas fuera del cráter son típicas características de cráteres de impacto. La anomalía de gravedad en el cráter muestra que hay una estructura significante enterrada bajo el sedimento.
2

Lost in low lunar orbit crater pattern detection and identification

Hanak, Francis Chad 03 September 2009 (has links)
Recent emphasis by NASA on returning astronauts to the Moon has placed attention on the subject of lunar surface feature tracking. Although many algorithms have been proposed for lunar landmark tracking navigation, much less attention has been paid to the issue of navigational state initialization from lunar craters in a lost in low lunar orbit (LLO) scenario. A new crater detection and identification algorithm is developed in this dissertation that allows for navigation state initialization from as few as one image of the lunar surface with no a priori state knowledge. Craters are detected by a filter that is an extension of the Circular Hough Transform, after which verification is performed by a number of checks on the illuminated portion of the candidate crater interior. Detected craters are identified by matching them to entries in the USGS crater catalog via non-dimensional crater triangle parameters. False identifications are rejected based on a probability check. The algorithm was tested on Apollo 16 LLO images, and shown to perform well. / text
3

Geochemical analysis of the Monturaqui Impact Crater, Chile.

Kloberdanz, Christine Marie 01 December 2010 (has links)
No description available.
4

An investigation of the Whitecourt meteorite impact crater (Alberta, Canada)

Kofman, Randolf Unknown Date
No description available.
5

A petrological, mineralogical and geochemical ore characterisation of the crater facies kimberlite bodies of the Fore a la Corne Province, Saskatchewan, Canada

Brown, Julian William January 1999 (has links)
No description available.
6

An investigation of the Whitecourt meteorite impact crater (Alberta, Canada)

Kofman, Randolf 06 1900 (has links)
The <1,130 year old Whitecourt Meteorite Impact Crater, located several kilometres south of Whitecourt, Alberta (Canada), is a well-preserved bowl-shaped structure having a depth and diameter of ~6 m and 36 m. There are less than a dozen known terrestrial sites of similar size and age. Unlike most of these sites, the Whitecourt Crater contains nearly all the features associated with small impact craters including meteorites, an ejecta blanket, an observable transient crater boundary, a raised rim, and a number of associated shock indicators. The results of this study indicate that the crater formed from the impact of a type IIIAB iron meteorite travelling east-northeast at <10 km/s, striking the surface at an angle between 40 and 55 to horizontal. At present, it appears that the main mass survived atmospheric transit relatively intact to fragment and partially melt during impact, ejecting meteoritic shrapnel, most of which landed downrange.
7

A gravity investigation of Meteor Crater, Arizona

Harding, Norman. January 1954 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1954. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
8

The geochemistry of basalts and mantle inclusions from the Lunar Crater volcanic field, Nevada : petrogenetic and geodynamic implications /

Kargel, J. S. January 1987 (has links)
Thesis (M.S.)--Ohio State University, 1987. / Includes bibliographical references (leaves 370-393). Available online via OhioLINK's ETD Center.
9

Reconstructing the past climate at Gale crater, Mars, from hydrological modeling of late-stage lakes

Horvath, David G., Andrews-Hanna, Jeffrey C. 28 August 2017 (has links)
The sedimentary deposits in Gale crater may preserve one of the best records of the early Martian climate during the Late Noachian and Early Hesperian. Surface and orbital observations support the presence of two periods of lake stability in Gale craterprior to the formation of the sedimentary mound during the Late Noachian and after the formation and erosion of the mound to its present state in the Early Hesperian. Here we use hydrological models and late-stage lake levels at Gale, to reconstruct the climate of Mars after mound formation and erosion to its present state. Using Earth analog climates, we show that the late-stage lakes require wetter interludes characterized by semiarid climates after the transition to arid conditions in the Hesperian. These climates are much wetter than is thought to characterize much of the Hesperian and are more similar to estimates of the Late Noachian climate.
10

Geologic and environmental modelling of impact ejecta processes

Croskell, Michael Sinclair January 2002 (has links)
No description available.

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