On 30 December 1986, a local fisherman incidentally discovered the remains of a seventeenth-century merchantman off the coast of Rincon, a small municipality on Puerto Rico's west coast. Some days later, he and some acquaintances extracted objects from the site and stored them in a nearby restaurant. The assemblage of artifacts recovered included, among other items, pins, scissors, ordnance, pewter ware, woodworking tools, a myriad of concretions and a nautical astrolabe. It is from the last that the wreck site took its name. The operation continued for months until local authorities, alerted by a member of the salvage group, issued a cease and desist order. At that point, the whole affair entered a legal process that on the summer of 2005 had not reached its conclusion. The purpose of this thesis is twofold. First, the author presents the story of the shipwreck from the moment it was found until the court ruled regarding ownership of the artifacts. Since this was the first time ownership of a shipwreck was debated in Puerto Rican courts in recent history, this gives the reader an idea of how legal precedence was established concerning the island's submerged cultural resources. Second, based on what was popularly perceived to be the site's most remarkable find, a study was developed on the sea or mariner's astrolabe, a navigation instrument that played a fundamental role in the process of European maritime expansion during the late fifteenth, sixteenth and seventeenth centuries. The reader of this text will learn that, during the fifteenth century, Portuguese navigators saw the need to gradually depart from the traditional Mediterranean navigation technique known as "dead reckoning." As their explorations along the West African coast forced them to sail far into the Atlantic Ocean for prolonged periods, a new method was developed that consisted of measuring the angle of certain heavenly bodies above the horizon in order to determine the latitude of the observer with reasonable precision. For this purpose, instruments that traditionally belonged to the field of astronomy were adapted to be used by seamen. Among them was the astrolabe, which became the most popular by the turn of the sixteenth century. After discussing the instrument's origin and development, the author analyzes how a renewed interest on the nautical astrolabe, which emerged in Portugal in the early twentieth century, introduced the instrument to the field of modern scholarly research. This work also presents a catalogue of sixteen sea astrolabes, some of which have never been published. The catalogue shows statistics and other relevant information, while placing the artifacts in the context of the previously existing data.

Thesis (D. Min.)--Northern Baptist Theological Seminary, Lombard, Ill., 2001. / Abstract. Includes bibliographical references (leaves 117-120).

The modern insular shelf and slope of western Puerto Rico is characterized by reef carbonate and siliciclastic sedimentary environments controlled by the complex interplay of tectonic arching and faulting, vigorous erosion of the elevated island of Puerto Rico, fluvial incision and sedimentation pulses, reef growth, and rapid late Quaternary eustatic sea-level changes. For this study, I interpret 725 km of high-resolution, single-channel seismic lines that were collected over the western insular shelf and slope by the RV Isla Magueyes in 2000 to better understand tectonic, erosional, and eustatic controls on late Quaternary history. The seafloor geology of the western shelf and slope area of Puerto Rico has been well studied and mapped mainly from grab and short cores collected by geoscientists at the U.S. Geological Survey and at the University of Puerto Rico at Mayagü̈ez. Because of low tectonic uplift rates from the western coast of Puerto Rico, the onland late Quaternary sedimentary history is not recorded in Quaternary coastal outcrops. The results of my seismic interpretation and correlation with multi-channel seismic data collected in 1972, reveal four main units defined by characteristic stratal reflection terminations and seismic facies. These units include: Unit 1 (basement) - a gently folded and faulted basal section correlated to the Oligocene-early Pleistocene carbonate shelf of Puerto Rico; deeper penetration, industry multi-channel seismic lines show that these rocks are deformed in a broad east-west-trending arch; Unit 2 (lowstand systems tract, LST) - chaotic channel fill deposits filling deep (~ 30 meter) incisions formed during the Last Glacial Maximum about 20 ka; Unit 3 (transgressive system tract, TST) - poorly stratified deposits truncating the top of Unit 2 and deposited during early Holocene transgression of the shelf margin; Unit 4 (highstand system tract, HST) - late Holocene, highly stratified deposits related to aggradation as the Holocene transgression began to slow. The base of unit 4 is a downlap surface interpreted as a maximum flooding surface likely formed about 8 ka. East-northeast-striking faults are observed that offset the late Quaternary units in three separate zones off the west coast of Puerto Rico. Because of a lack of wells and long cores from the shelf and slope area, age estimates for the four units are based on correlations with sea-level curves derived from dated coral samples in the Caribbean and western Atlantic region. All four units are deformed by faulting that should be considered active and possibly hazardous for the rapidly developing west coast of Puerto Rico. In one area, a large, late Holocene-slump (~ 0.016 km³) is mapped using seismic, sidescan sonar and bathymetric data. Onland continuations of these faults are likely, but have not been identified due to cultural overprint of natural scarps on late Quaternary floodplains. / text

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Thesis (Ed. D.)--Teachers College, Columbia University, 1986. / Typescript; issued also on microfilm. Sponsor: Joan Gussow. Dissertation Committee: Isobel Contento. Bibliography: leaves 138-143.

Thesis (Ed.D.)--Teachers College, Columbia University. / Typescript; issued also on microfilm. Includes tables. Sponsor: Walter E. Sindlinger. Dissertation Committee: Ralph R. Fields. Includes bibliographical references.

Thesis--Heidelberg. / Includes bibliographical references (p. 512-520).

Thesis (M.A.)--University of Wisconsin--Madison, 1983. / Typescript. Includes bibliographical references (leaves 193-201).