A review of all available surface and subsurface data on Triassic and Lower Jurassic rocks in northeastern Arizona has revealed the following information. The Moenkopi Formation, the Chinle Formation, and the Glen Canyon Group of Triassic and Early Jurassic age are present throughout most of the study area. These units form a sequence of continental and transitional marine origin that shows notable vertical and lateral facies changes. The Moenkopi Formation thickening west and northwestward with a maximum thickness of 134 meters. The unit comprises sandstone and shale, and shows more shaley facies westward. The Chinle Formation shows minimum thickness to the north and thickens toward east and south with a maximum thickness toward west. This unit dominantly consists of sandy shale, but contains more sandstone westward and north westward. The unit contains some limestone in north and northern region. The Chinle Formation is overlain by the Glen Canyon Group, which in ascending order comprises the Wingate Sandstone, the Moenave Formation, the Kayenta Formation, and the Navajo Sandstone. The Wingate Sandstone shows its maximum thickness in the central and southcentral region of the study area and thins west and eastward. This unit mainly comprises sandstone, particularly in its upper part. The Moenave Formation displays its zero thickness, in the eastern region and shows its maximum thickness, 198 meters, in the west-central part. The unit mainly consist of sandstone. The Kayenta Formation attains its greatest thickness, 204 meters, in the southwestern part of the region and thins east and northward. This formation contains high percentages of sandstone. Within the area of this study, the Navajo Sandstone is the thickest formation in the Glen Canyon Group. This unit almost entirely consist of sandstone pinches out toward the south and east, and displays its maximum thickness, 300 meters, northward.

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<p>Melanin is a ubiquitous biological pigment found in bacteria, fungi, plants, and animals. It has a diverse range of ecological and biochemical functions including display, evasion, photoprotection, detoxification, and metal scavenging. Two forms of melanin produced from different molecular precursors are present in nature - eumelanin (dark brown-black in color) and pheomelanin (orange-red in color). Both eumelanin and pheomelanin are complex highly cross-linked biopolymers that are found intertwined with proteins, lipids, and metal ions in nature. </p><p> </p><p>Recent reports have used morphological evidence to suggest the presence of melanin in the fossil record. These studies have been met with criticism due to their lack of chemical evidence to support melanin identification. This dissertation describes chemical approaches to unambiguously verify the presence of melanin in the fossil record and characterize the ancient pigment. It also explores the limitations for the survival of melanin in the fossil record and the possibility that melanin acts as a protective matrix to preserve other biomolecules that are embedded in the pigment. </p><p>Melanin has unique chemical signatures that are commonly used to characterize and compare the pigment of modern organisms. We applied these chemical approaches to the study of fossil pigmentation. Analysis of the black pigmentation of two > 160 million year old (Mya) Jurassic cephalopod ink sacs provided the first conclusive evidence for eumelanin in the fossil record. The preserved fossil eumelanin was then compared to modern cephalopod eumelanin from Sepia officinalis. Using these chemical approaches we found that fossil eumelanin was chemically and morphologically identical to S. officinalis eumelanin. </p><p> Although there is mounting chemical evidence for the presence and preservation of melanin in the fossil record, there is very little data constraining its long-term survival. We applied the analytical approaches designed to study fossil melanins and techniques used to study fossil sediments to compare the fossil inks from three deposits of similar age and lithology, but different maturation histories. Specifically, two ~ 180 Mya fossil ink sacs from a site that has entered the oil window in Holzmaden, Germany were compared to the previously analyzed fossil inks from two less mature sites in southern England. The chemistry of eumelanin was shown to alter at the onset of the oil window regardless of the age of the specimen. The decrease in surviving melanin was accompanied by an increase in the relative abundance of organic macromolecular material (kerogen), but no consistent change in melanin morphology. </p><p> Finally, the role of melanin as a matrix that enhances the preservation of other biomolecules in the fossil record was considered. Proteins, commonly associated with melanin in modern organisms, were discovered in the aforementioned fossil ink sacs during full-scale chemical analysis. The amino acid profile of the protein in each fossil specimen was determined with an amino acid analyzer and compared to the amino acid profile the protein in modern S. officinalis. Statistical analysis of the amino acid distributions indicated that there is no significant difference between the amino acid profile of modern and fossil melanins. In order to verify the ancient origin of the amino acids in the fossil ink sacs, the ratio of D/L amino acid isomers was determined. While the proteins of living organisms consist of only L-amino acids, post-mortem the amino acids slowly convert from L to D form until they reach equilibrium (D/L = 1). This process is called racemization. The amino acids in the fossil ink sacs were racemized, which suggests their ancient origin. This marks the oldest determination of protein in a fossil system and provides evidence that the longevity of proteins may be enhanced when associated with melanin.</p> / Dissertation

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The Jurassic Quiet Zone (JQZ) is a region of low amplitude, difficult-to-correlate magnetic anomalies located over Jurassic oceanic crust. We collected 1200 km of new deep-tow magnetic anomaly profiles over the Pacific JQZ that complement 2 deep-tow profiles reported in Sager et al. (1998). Our primary goals were to extend the correlation of deep-tow magnetic anomalies farther back in time, to evaluate the correlatability and repeatability of anomalies, and to refine the Jurassic geomagnetic polarity reversal time scale (GPTS). Correlations of anomalies were excellent over M34 and over supposedly older seafloor to the south of ODP Site 801. In contrast, the correlation in the region between M34 and Site 801 was difficult. Using anomaly correlation models, we made magnetic polarity block models to establish a revised Jurassic GPTS extending until 169.4 Ma. Age calibration was accomplished with radiometric dates from two ODP holes. Systematic changes in anomaly amplitudes occur along the survey lines with the amplitudes decreasing backward in time and then increasing again in the oldest part of survey area. The zone of the most difficult to correlate anomalies corresponds to a period of ~4 m.y. that appears to have an abrupt end. This low amplitude zone suggests unusual magnetic behavior during the Jurassic. It has been said that many of the larger anomalies are likely caused by changes in polarity, whereas smaller anomalies may be intensity fluctuations. Although it is impossible to identify which anomalies are caused by reversals and which are not, magnetization structures observed in ODP Hole 801C suggest that many of the smallest anomalies, particularly around Hole 801C indicate polarity reversals. We concluded that (1) the new data demonstrates repeatability and correlatability of the JQZ magnetic anomalies implying that they are seafloor spreading lineations and (2) good correlations made new GPTS models extending back to 169.4 Ma; and (3) the origin of the JQZ may be a combination of rapid polarity reversals in the Jurassic low magnetic dipole field and closely spaced, tilted magnetization structure in the oceanic crust.

The Jurassic Quiet Zone (JQZ) is a region of low amplitude, difficult-to-correlate magnetic anomalies located over Jurassic oceanic crust. We collected 1200 km of new deep-tow magnetic anomaly profiles over the Pacific JQZ that complement 2 deep-tow profiles reported in Sager et al. (1998). Our primary goals were to extend the correlation of deep-tow magnetic anomalies farther back in time, to evaluate the correlatability and repeatability of anomalies, and to refine the Jurassic geomagnetic polarity reversal time scale (GPTS). Correlations of anomalies were excellent over M34 and over supposedly older seafloor to the south of ODP Site 801. In contrast, the correlation in the region between M34 and Site 801 was difficult. Using anomaly correlation models, we made magnetic polarity block models to establish a revised Jurassic GPTS extending until 169.4 Ma. Age calibration was accomplished with radiometric dates from two ODP holes. Systematic changes in anomaly amplitudes occur along the survey lines with the amplitudes decreasing backward in time and then increasing again in the oldest part of survey area. The zone of the most difficult to correlate anomalies corresponds to a period of ~4 m.y. that appears to have an abrupt end. This low amplitude zone suggests unusual magnetic behavior during the Jurassic. It has been said that many of the larger anomalies are likely caused by changes in polarity, whereas smaller anomalies may be intensity fluctuations. Although it is impossible to identify which anomalies are caused by reversals and which are not, magnetization structures observed in ODP Hole 801C suggest that many of the smallest anomalies, particularly around Hole 801C indicate polarity reversals. We concluded that (1) the new data demonstrates repeatability and correlatability of the JQZ magnetic anomalies implying that they are seafloor spreading lineations and (2) good correlations made new GPTS models extending back to 169.4 Ma; and (3) the origin of the JQZ may be a combination of rapid polarity reversals in the Jurassic low magnetic dipole field and closely spaced, tilted magnetization structure in the oceanic crust.

The stratigraphic organization of clastic successions deposited during the early synrift phase is controlled by the rates of tectonic subsidence and the growth of the master faults, which, coupled with eustatic sea-level changes, control the generation of accommodation. The highly heterolithic, Lower Jurassic Upper Åre and Tilje succession (100 to 300 m thick), which occurs in the Halten Terrace of offshore Norway, represents an excellent example of ancient synrift deposits that accumulated within a NNE-SSW-oriented structurally controlled embayment where sedimentation was dominated by tidal currents, with secondary influence by river and wave processes. Overall, the Tilje was deposited in a deltaic setting near the lowstand shoreline, forming a shallowing-upward succession, which is organized in two, thick, tabular second-order sequences. These sequences are separated by two main sequence boundaries (SB2 and SB3) associated with two main rift-related tectonic pulses. The first pulse formed SB2 and is believed to have exerted a major regional control on the geomorphology of the basin, causing a change from an open, wave-dominated setting (upper Åre Fm.) to a funnel-shaped, tide-dominated setting in the Tilje Fm. SB2 shows shallow incision into the underlying Åre Fm., and the overlying sediment accumulated predominantly in a distributary-mouth-bar environment. Sequence 3 rests erosively on Sequence 2, and is characterized by proximal tidal-fluvial distributary-channel fills and mouth-bar deposits showing at least 2 main oblique to axial fluvial input points, one from the N-NW and a second one from the NE, with overall increase in wave influence and deepening toward the S. Local rapid subsidence of elongated narrow hangingwalls associated with the active master faults exerted a subtle control on the succession thickness, as well as a local control on the location of the tidal-fluvial distributary channels by “tectonic axial funnelling” during the onset of the second-order base-level rises. The internal architecture and facies distribution are less complex than other thick tide-dominated successions worldwide, because the rate of creation of accommodation was sufficient to avoid channel amalgamation throughout most of the succession. / Thesis (Ph.D, Geological Sciences & Geological Engineering) -- Queen's University, 2012-05-09 23:39:27.538

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The cinema, as originally an analogue apparatus of representation, has a particularly complex and contradictory relationship to the incursion of new digital practices and potentialities. This thesis examines this relationship through a study of the impact of computer-generated images (CGI) on the Hollywood mode of production, and on its visual and narrative filmic codes. Computer animation is unquestionably a technology of digital simulation, and its initial presence is necessarily based on an aesthetics of simulation, visually separating, and diegetically demarcating, the digital image as virtual and artfficial. Consequently, most previous accounts of CGI have focused predominantly on films depicting cyberspace and VR, such as Tron and The Lawnmower Man, within the parameters of debates on special effects, the generic conventions of science fiction, and postmodern concerns with virtuality and simulation. In the early 1 990s, however, technological innovations facilitated the transition to an aesthetics of photorealism, emphasising the seamless compositing and integration of CGI characters, objects and environments with live-action. The thesis argues that the this shill is fundamental in establishing the commercial and aesthetic credibility of CGI as a production tool, and it is closely examined through a case study of Jurassic Park. The processes by which the first organic, photorealistic CG characters were created are analysed, with particular reference to the role of procedural and hand methods of computer animation in constructing a new virtual aesthetics. The integration of CGI as a production tool is also related to the diegetic presence of information technologies as narrative devices, and the extra-textual commercial and professional discourses through which CGI is explicated and celebrated. The thesis argues that the cinema is able to exploit the potential of digital methods, whilst simultaneously displaying a fundamental anxiety over the status of its own representational codes. Finally, strategies of visibility and virtuality in computer animation are further examined in the context of the emerging digital mode of production in Hollywood, and of the high concept film's role in multimedia marketing and distribution strategies