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1

Vaughan, Pamela Georgina. "Cretaceous Nerineacean gastropods." Thesis, Open University, 1988. http://oro.open.ac.uk/54369/.

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The Nerineacea form a distinctive and significant component of shallow marine Mesozoic Tethyan macrofaunas. They occur in shelf sediments deposited in tropical regions during the Jurassic and Cretaceous. The group first appears in the early Jurassic and high diversity levels had developed by late Jurassic and early Cretaceous times. A major extinction episode occurred during the latter part of the Cenomanian and the Turonian, with the Nerineacea becoming finally extinct in the Maastrichtian. The heterostrophic nature of the ncrineacean protoconch (described here from Nerineidae and Nerinellidae species) indicates opisthobranch affinities. The Nerineacea is placed in the Entomotacniata, an independent order within the Opisthobranchia. The Entomotaeniata is considered to show greatest affinities with some members of the Acteonacea. The Pyramidcllacea are not included in the Entomotaeniata. The order contains the Ceritellidae, Nerineidae, Nerinellidae and ltieriidae. Early phylogenetic separation of the first three families is indicated. Within each family a limited number of "stable" internal fold patterns developed independently which reflected anatomical features of the abapical portion of the nerineid animal. The Nerineacea typically inhabited warm, clear, carbonate-dominated shallow marine environments on and around off-shore "highs", however, some genera lived in prelittoral or lagoonal situations. Only Ptygmatis shows any evidence of tolerance of abnormal salinities. Carbon and oxygen isotope analyses demonstrate that Nerinella and Simploptyxis specimens from Austrian Gosau deposits lived in water of normal marine salinity. Most Cretaceous nerineid genera were probably mobile epifaunal herbivores, although Nerinellidae species may have been infaunal. Cretaceous Nerineacea are taxonomically reviewed; the diagnoses of the subfamily Umboneinae; Diozoptyxis, Adiozoptyxis; Julesia and Phaneroptyxis are revised. Stratigraphic and palaeogeographic ranges indicate that certain species could potentially be used for correlation. Quantitative measurements of various parameters are included in specific descriptions; the value of these in specific resolution is tested in appropriate cases. An analysis of morphological range in one species (Diozoptyxis cochleaeformis) demonstrates wide continuous variation in overall shell shape and whorl concavity. However, external ornament and internal fold pattern do not show significant intraspecific variation; these features therefore provide reliable characters for species definition.
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2

Crampton, James Scutts. "Palaeobiology of cretaceous inoceramid bivalves." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308302.

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3

Misaki, Akihiro. "Stratigraphy of mid-Cretaceous to upper Cretaceous system in the Aridagawa area, Wakayama, southwest Japan : implication of Cretaceous megafossil assemblages in the Aridagawa area." 京都大学 (Kyoto University), 2007. http://hdl.handle.net/2433/136783.

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4

Ehrendorfer, Thomas Wolfgang. "Late cretaceous (Maestrichtian) calcareous nannoplankton biogeography with emphasis on events immediately preceding the cretaceous/paleocene boundary." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/52958.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1993.
Vita.
Includes bibliographical references (leaves 205-218).
by Thomas Wolfgang Ehrendorfer.
Ph.D.
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5

Morrison, Joan Olivia. "Cretaceous marine invertebrates: A geochemical perspective." Thesis, University of Ottawa (Canada), 1991. http://hdl.handle.net/10393/7784.

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A diagenetic evaluation was performed on marine fossil shell material from Cretaceous sediments of North America, the Arctic, the Antarctic and several localities in Europe. Trace element chemistry, XRD, SEM and stable isotope geochemistry were consistent in their results. Preservation of the original shell material of the low-Mg calcite organisms, brachiopods and belemnites, and the numerous aragonitic organisms was slightly variable with the majority of samples well preserved. Those samples that were altered underwent diagenetic stabilization in both reducing and oxic environments. Using the chemical data from only well preserved fossil shell material, basin paleo-reconstructions showed that from Aptian to Maastrichtian time, the Cretaceous seas were generally aerobic with some dysaerobia evident at the sediment/water interface and in the shallow sediment column. Paleosalinities fluctuated from brackish to normal marine, especially in the Western Interior Seaway of North America and the Paris Basin. The Lower Saxony basin, the Arctic and Antarctic were mainly normal marine with brackish conditions developing on occasion. Paleotemperatures determined from $\partial\sp $O data of preserved aragonite and low-Mg calcite shell material, also showed some variance. The Arctic and Antarctic were coolest, with Campanian/Maastrichtian temperatures about 12 or 13$\sp\circ$C, whereas the Lower Saxony basin and the Western Interior Seaway were slightly warmer, ranging from 11 to 20$\sp\circ$C. The Barremian/Aptian appeared to be the warmest time and a cooling trend was fairly consistent from then on.
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6

Söderblom, Fredrik. "Disparity of Early Cretaceous Lamniformes sharks." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-256605.

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The geological range of lamniform sharks stretches from present day species such as Carcharodon carcharias (great white shark) back to the at the moment oldest undoubted fossil finds during the Early Cretaceous. In this paper a geometric morphometric analysis was performed on images of Early Cretaceous lamniform teeth collected from published literature in order to examine the change in disparity (range of morphological variation within a group) throughout the time period. Due to limited availability of published material and time constraints only the Barremian and Albian ages were investigated. The Barremian exhibited tall and narrow tooth morphologies while the Albian showed a wide range of morphological variation including more robust, wide and sometimes triangular shapes but also displayed further specialization of the tall and narrow forms. This change is likely indicative of a dietary and ecological expansion from only eating for example small fish and soft-bodied creatures to a wide range of prey for the group, including larger and more robust animals such as marine turtles and large bony fish. This in combination with the decline of some marine predators as well as the diversification of possible prey is interpreted as that an adaptive radiation of the Lamniformes could have taken place during the latter half of the Early Cretaceous.
Morfologisk disparitet är ett mått på hur stor utsträckningen av morfologisk variation är. Detta mått räknas ut genom att jämföra landmärken utplacerade på bilder av föremål som ska undersökas. I detta projekt undersöktes den morfologiska dispariteten hos tänder från håbrandsartade hajar (Lamniformes) under tidig krita. Att just deras tänder undersöktes beror på att den större delen av hajars skelett är gjort av brosk vilket lätt bryts ned efter djuret avlidit. Deras tänder är dock gjorda av ben vilket har lättare att bli bevarat som fossil. Utöver detta så kan formen på tänder beskriva djurs födoval och levnadssätt. Gruppens tänder undersöktes därför även för att belysa eventuella förändringar i diet och ekologi under tidig krita. Resultatet av denna analys visar på en expansion av tandform under denna period från långa och smala tänder under Barremium till en större variation under Albium där även mer triangelformade och robusta tänder dyker upp. Detta har tolkats som en adaptiv artbildningsperiod för gruppen då både nya byten (t.ex. teleostfiskar och havs-sköldpaddor) diversifierade och uppkom samtidigt som vissa marina predatorer (ichthyosaurer och plesiosaurer) minskade i antal under denna tidsperiod. Detta ändrade troligen de selektiva trycken på håbrandsartade hajars tandmorfologi samt lämnade ekologiska nischer öppna som dessa kunde anpassa sig till vilket i sin tur ledde till expansioner i morfologisk disparitet, diet och ekologi.
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7

Street, Christianne. "Palaeobiogeography of Early Cretaceous calcareous nannoplankton." Thesis, University College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322002.

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8

Hayes, Peta Angela. "Cretaceous angiosperm leaf floras from Antarctica." Thesis, University of Leeds, 1999. http://etheses.whiterose.ac.uk/21096/.

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Late Cretaceous angiosperm leaf floras from the Antarctic Peninsula have been studied and described for the first time. The Hidden Lake Formation (Coniacian) and Santa Marta Formation (Santonian-early Campanian) floras were preserved within shallow marine strata exposed on James Ross Island. This area was located at approximately 65°S during the Late Cretaceous. These fossils represent the remains of vegetation growing in the southern high latitudes on an emergent volcanic arc. The plants probably grew on the delta top and along the edge of streams. The leaf fossils are preserved as isolated and fragmentary impressions and although cuticular anatomy is not present, the angiosperm leaves show the well-preserved fine detail of leaf architecture. These leaves have been drawn and described using Hickey's (1979) terminology. Attempts were made to group the leaves into morphotypes to allow reconstruction of floral composition and palaeoclimates. Several methods of grouping leaves were used, including visual grouping, Single character classification, and multivariate approaches. Multivariate statistical analysis allowed many characters to be considered simultaneously and even allowed fragmentary specimens, which were harder to deal with visually, to be evaluated. Clustering analysis was performed and dendrograms were produced for the Hidden Lake Formation and Santa Marta Formation floras, which were used in conjunction with visual assessments to group leaves with distinct morphologies into morphotypes. A total of 41 morphotypes were identified, 30 in the Hidden Lake Formation flora and 31 in the Santa Marta Formation flora, with 20 in common. Detailed descriptions of each morphotype and representative illustrations are presented. Comparisons have been drawn with fossil and living angiosperm leaves. Architectural characteristics suggest that some of the leaves may have affinities with the Cunoniaceae, Lauraceae, Sterculiaceae, Nothofagaceae, Myrtaceae and Elaeocarpaceae. If botanical affinities can be confirmed, many of these occurrences would extend the ranges of angiosperm taxa on the Antarctic Peninsula. Palaeoclimatic interpretation of the leaf floras included comparisons with possible nearest living relatives, analysis of leaf margins, shapes and sizes, and the application of simple linear regression and multiple linear regression models. The climate is considered to have been warm and moist. Mean annual temperature estimates of 12-21°C were provided for the Hidden Lake Formation flora and 14-23°C for the Santa Marta Formation flora. Evaluation of published data suggests that these Coniacian-early Campanian leaf floras may reflect the warmest time during the Cretaceous in Antarctica.
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9

Penny, J. H. J. "Early Cretaceous angiosperm pollen from Egypt." Thesis, University of Cambridge, 1986. https://www.repository.cam.ac.uk/handle/1810/273106.

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10

Witts, James David. "Marine biodiversity during the latest Cretaceous in Antarctica and the nature of the Cretaceous-Paleogene mass extinction." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/13742/.

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The Cretaceous–Paleogene (K–Pg) mass extinction event occurred 66 million years ago, the most recent of the ‘Big Five’ extinction crises of the last 540 million years. This event had a profound effect on both life and the broader Earth system, with the extinction of up to 75% of life. Despite years of detailed research, debate continues as to the nature and timing of the extinction. Ideas for an abrupt crisis, triggered by bolide impact at Chicxulub in the Gulf of Mexico, contrast with those suggesting a more gradual extinction, involving volcanism from the Deccan Traps Large Igneous Province in India and/or climatic changes. Evidence from the high latitudes has been used to suggest that the fossil record from Antarctica is incompatible with models for a single, sudden event, and that extinction intensity declined at high latitudes. This thesis presents a detailed study of extensive fossil and sediment collections from the highest southern latitude onshore outcrop containing the K–Pg transition; the highly expanded and fossiliferous López de Bertodano Formation of Seymour Island, James Ross Basin, located at 65°S today, and during the Cretaceous. New biostratigraphic and diversity data for the molluscan (bivalves, gastropods, cephalopods) faunas of the López de Bertodano Formation, and geochemical datasets (seawater sulphur and pyrite sulphur isotopes) are compared to published records, and evidence for palaeoenvironmental change. They suggest a single, rapid extinction event coincident with the K–Pg boundary, with no precursor decline. The magnitude of the extinction in Antarctica is also consistent with lower latitudes, suggestive of a global, catastrophic trigger for the K–Pg extinction, such as bolide impact. Sulphur isotope data suggest the K–Pg sulphur cycle was able to respond to rapid environmental changes before, and after the K–Pg mass extinction. A decoupling of the carbon and sulphur cycle occurred during the latest Cretaceous, but productivity collapse after the K–Pg extinction also affected the sulphur cycle. The recovery to pre-extinction values was achieved on the same timescale as carbon cycle and initial ecological recovery, suggesting close geosphere-biosphere links at this time.
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11

Kiel, Steffen. "Taxonomy and biogeography of late Cretaceous gastropoda." [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=964103850.

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12

Jeffery, Charlotte Hannah. "Echinoid evolution across the Cretaceous-Tertiary boundary." Thesis, Imperial College London, 1997. http://hdl.handle.net/10044/1/8292.

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13

Bata, Timothy Peter. "Geochemical consequences of Cretaceous sea level rise." Thesis, University of Aberdeen, 2016. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=230129.

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During the Cretaceous, the CO2 content of the global atmosphere increased in response to the volcanism associated with the disintegration of the former continents. This led to a considerable rise in global temperatures, leading to a significant rise in the global sea level and the landward movement of coastlines. Cretaceous marine strata transgressed directly on the underlying basement or much older sedimentary strata. Extreme environmental conditions in the Cretaceous involved a possibly more acidic and chemically destructive atmosphere than at present, which favoured widespread deep weathering at that time. The extensive Cretaceous palaeo-seaways played a vital role in transporting and depositing the huge volume of sediments generated during the weathering events, which included economically important placer deposits (e.g., gold, diamond and platinum). A direct consequence of the extreme Cretaceous global warmth was the widespread development of Cretaceous silcretes. Much of the world's heavy oil occurs in Cretaceous reservoir sands. The geological processes responsible for the widespread occurrence of the Cretaceous oil sands can also be traced back to the unique Cretaceous greenhouse climatic condition. The warm climatic conditions imply a higher heat flow regime in the subsurface, which contributed to the thermal maturation of the organic rich sediments that are closely associated with the Cretaceous transgressive sands. The oils were generated as conventional light oil, which later degraded into heavy oils, rather than thermally cracked oils from over-matured source rocks. Oils migrated into shallow warm reservoir sands that were favourable for microbial activities. All the studied Cretaceous oil sands show evidence of hopane degradation without the formation of 25-norhopanes despite diasterane degradation in some of the samples. This strongly implies that biodegradation in these studied Cretaceous oil sands occurred at shallow depths. Pyrite precipitated from an open system by means of microbial sulfate reduction as part of the biodegradation process.
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14

Adams, D. P. M. "Cretaceous and Eocene geology of South Westland." Thesis, University of Canterbury. Geology, 1987. http://hdl.handle.net/10092/7117.

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The Cretaceous and Eocene sequence of South Westland crops out within a 6km wide coastal area from Ship Creek to the Mahitahi River. The oldest unit, the Otumotu Formation (Motuan-Arowhanan), lies with angular unconformity on the Paleozoic Greenland Group. It is divided into two members, an older Tauweritiki Member (new) overlain by the Topsy Member. Both are entirely clastic but the lower unit is significantly coarser ranging from boulder conglomerate to mudstone, while granule conglomerate, sandstone analysis of sedimentary features to pebble breccia and the upper member comprises and mudstone. Detailed suggests that the lower member represents alluvial fan and plain sedimentation in a tectonically active setting changing to a more stable semi-arid fluvial and lacustrine depositional regime in the younger deposits. The Butler Formation (new) (Piripauan), which lies unconformably on the Otumotu Formation, consists of conglomerate, sandstone and mudstone, with high and medium volatile bituminous coal seams. The sediments represent an environment of rivers and coal forming swamps and lakes which produced thick (up to 3m) coal seams. The Tauperikaka Formation (new), previously the Tauperikaka Coal Measures, (Haumurian) overlies the Butler Formation, with a disconformity marked by a low relief scour surface, and is divided into the Moeraki (lower), Paringa (middle) and Rasselas (upper) Members. The Moeraki Member consists of pebble conglomerate, cross-bedded and horizontally bedded pebbly and granular sandstone and carbonaceous massive silty mudstone. The sequence is thought to represent a coastal fluvial environment. The Paringa Member includes large scale planar tabular cross-bedding with mud drapes (“tidal bundles”), bi-directional flaser bedded, trough and planar cross-bedded sandstone, siltstone and mudstone. The depositional environment is interpreted as a tide dominated coastline. The Rasselas Member, which consists of interbedded burrowed and structureless glauconitic sandstone in which both the density and diversity of burrows and the sediment grain size decrease upwards, was probably deposited in a large open marine bay. The sediments of the Otumotu, Butler and Tauperikaka Formations are derived from a Greenland Group and Tuhua Group source which probably lay to the west of the basin. The change in depositional environment within the Tauperikaka Formation, from a marginal marine to an off shore marine environment is responsible constituents in the sediment composition, and the rock fragment component has been greatly depleted. The eruption of the Arnott Basalt towards the end of the Haumurian is possibly related to extension which led to thinning of the crust. The Eocene Law Coal Measures (new) (Kaiatan) are composed of clast supported very well rounded cobble to pebble conglomerate, well sorted medium sandstones, carbonaceous siltstone and mudstone and thick (up to 4m) high volatile bituminous coal seams. The sequence is interpreted as marginal marine, with coal forming reed swamps developing between fluvial clastic fans. A marine transgression from the east resulted in the end of coal measure sedimentation. The Tititira Formation (Miocene) lies unconformably on the Law Coal Measures. Differences in coal type and coal geochemistry distinguish the coal in the Butler Formation from coal in the Law Coal Measures. The pH of the Law Coal Measure swamps was elevated by a marine influence which has produced a distinctive coal type characterised by a low Tissue Preservation Index. The coal also contains very little inertinite compared with coal from the Butler Formation. The Coal in the Law Coal Measures can be distinguished using the relatively high Na₂O content which is totally organically associated and is present in a constant amount within different seams. The Butler Formation coal contains a high proportion of clay compared to the coal in the Law Coal Measures and has negligible Na₂O. A thrust system involving both Paleozoic basement and cretaceous and Tertiary cover rocks has developed in post, Miocene time and accounts for a substantial amount of shorting (in the range of 40km and possibly more). The Mistake fault, a splay off the Alpine Fault, is the sole thrust of the Mistake Thrust Sheet which is part of a duplex thrust system which has subsequently been buckled into an antiformal stack. The anti formal stack includes at least two other thrust sheets, one below and one above the Mistake Thrust Sheet. The thrust complex appears to extend south to Milford Sound and up to 100km north of the area mapped and it is likely similar thrust systems are developed along the entire length of the Alpine Fault.
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15

Gaylor, Jonathan. "40Ar/39Ar Dating of the Late Cretaceous." Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-01017165.

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As part of the wider European GTS Next project, I propose new constraints on the ages of the Late Cretaceous, derived from a multitude of geochronological techniques, and successful stratigraphic interpretations from Canada and Japan. In the Western Canada Sedimentary Basin, we propose a new constraint on the age of the K/Pg boundary in the Red Deer River section (Alberta, Canada). We were able to cyclostratigraphically tune sediments in a non-marine, fluvial environment utilising high-resolution proxy records suggesting a 11-12 precession related cyclicity. Assuming the 40Ar/39Ar method is inter-calibrated with the cyclostratigraphy, the apparent age for C29r suggests that the K/Pg boundary falls between eccentricity maxima and minima, yielding an age of the C29r between 65.89 ± 0.08 and 66.30 ± 0.08 Ma. Assuming that the bundle containing the coal horizon represents a precession cycle, the K/Pg boundary is within the analytical uncertainty of the youngest zircon population achieving a revised age for the K/Pg boundary as 65.75 ± 0.06 Ma. The Campanian - Maastrichtian boundary is preserved in the sedimentary succession of the Horseshoe Canyon Formation and has been placed ~8 m below Coal nr. 10. Cyclostratigraphic studies show that the formation of these depositional sequences (alternations) of all scales are influenced directly by sea-level changes due to precession but more dominated by eccentricity cycles proved in the cyclostratigraphic framework and is mainly controlled by sand horizons, which have been related by autocyclicity in a dynamic sedimentary setting. Our work shows that the Campanian - Maastrichtian boundary in the Western Canada Sedimentary Basin coincides with ~2.5 eccentricity cycles above the youngest zircon age population at the bottom of the section and ~4.9 Myr before the Cretaceous - Palaeogene boundary (K/Pg), and thus corresponds to an absolute age of 70.65 ± 0.09 Ma producing an ~1.4 Myr younger age than recent published ages. Finally, using advances with terrestrial carbon isotope and planktonic foraminifera records within central Hokkaido, Northwest Pacific, sections from the Cretaceous Yezo group were correlated to that of European and North American counterparts. Datable ash layers throughout the Kotanbetsu and Shumarinai section were analysed using both 40Ar/39Ar and U-Pb methods. We successfully dated two ash tuff layers falling either side of the Turonian - Coniacian boundary, yielding an age range for the boundary between 89.31 ± 0.11 Ma and 89.57 ± 0.11 Ma or a boundary age of 89.44 ± 0.24 Ma. Combining these U-Pb ages with recent published ages we are able to reduce the age limit once more and propose an age for the Turonian - Coniacian boundary as 89.62 ± 0.04 Ma.
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16

Woodfine, Richard Gareth. "Chemostratigraphy of Jurassic-cretaceous Italian carbonate platforms." Thesis, University of Oxford, 2002. http://ora.ox.ac.uk/objects/uuid:03c84d34-a27d-46fd-89b0-d69a1501d888.

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Samples of shallow-water carbonates were collected from Jurassic and Cretaceous Italian carbonate platforms and subjected to petrographic, diagenetic and chemostratigraphic analyses (87Sr/86Sr, δ13Ccarb, δ13Corg, δ18O). In general, the new chemostratigraphic data generated reflect trends established by previous work, some of which has been carried out on biostratigraphically calibrated reference sections. Consequently, chemostratigraphic correlations (87Sr/86Sr, δ13Ccarb) of isotope profiles taken from platform carbonates with well-dated reference sections have allowed the application of high-resolution dating frameworks to the biostratigraphically poorly constrained carbonate platforms. The increased resolution in dating of the Italian carbonate platforms has, furthermore allowed a detailed investigation into the facies response of these carbonate platforms to major geological events. In particular, platform responses to oceanic anoxic events and other periods of major perturbation in the global carbon cycle are analysed (early Toarcian, Aalenian-Bajocian, Oxfordian-Tithonian, Valanginian-Hauterivian, Aptian-Albian, Cenomanian-Turonian, Coniacian-Santonian). Lower Jurassic levels of the Trento Platform record platform devastation in the early Toarcian synchronous with a major negative δ13Ccarb excursion, followed by platform recovery synchronous with a pronounced δ13Ccarb positive excursion and return to background values. The Campania-Lucania Platform shows negligible response to the oceanographic events of the early Toarcian even though the characteristic carbon-isotope profile is readily identifiable. The Trento Platform drowned at approximately the Aalenian-Bajocian Stage boundary, synchronously with a reproducible negative followed by positive δ13Ccarb excursion, whereas the Campania-Lucania Platform underwent a facies transition from oolite to cyclically bedded micrite. The Friuli Platform showed negligible depositional response to the carbon-cycle perturbations of the Kimmeridgian-Tithonian, Valanginian-Hauterivian, Aptian-Albian and Cenomanian- Santonian (as registered in the δ13Ccarb record). The Campania-Lucania Platform registered flooding and increased levels of organic-matter preservation coincident with pronounced positive δ13Ccarb excursions at Cenomanian-Turonian and Coniacian-Santonian levels. Observations on the responses of carbonate platforms to oceanographic conditions during periods of global carbon burial lead to the conclusion that temperature excess is a hitherto neglected control on global carbonate accumulation rates.
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Wilson, Paul Alastair. "The evolution of Cretaceous Pacific Ocean guyots." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363102.

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Cicchino, Alex. "Compaction of Cretaceous mudrocks offshore mid-Norway." Thesis, Durham University, 2014. http://etheses.dur.ac.uk/10639/.

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The Cretaceous mudrocks at Haltenbanken are buried 2-4 km below seafloor. Density porosity ranges over a factor of two at the same depths in different wells, with higher porosities in the west. Although the Cretaceous mudrocks are overpressured, pore pressure is laterally invariant across Haltenbanken; hence porosity differences cannot be due to differences in effective stress. Differences remain after plotting porosity against temperature. Porosity differences are somewhat reduced by adjusting depths for recent exhumation and burial. I suggest the following sequence of events: the Cretaceous mudrocks were normally compacted and hydrostatically pressured in the early Pliocene, because Tertiary sedimentation rates were low; Pliocene exhumation and deposition of Naust Formation glacial sediments occurred rapidly, without porosity loss because low-permeability overburden inhibited pore water expulsion; enhanced temperatures accelerated clay diagenesis, and lithification occurred with a laterally invariant pore-pressure profile because horizontal permeability is much higher than vertical permeability. If this interpretation is correct, the Cretaceous mudrocks at Haltenbanken exhibit chemical undercompaction, where pore water expulsion was inhibited during clay diagenesis and lithification. This finding illustrates the risk in predicting pore pressure in exploration wells using data from offset wells, and suggests a method for estimating Pliocene exhumation history on the Norwegian margin.
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Craig, Robert S. "Western Australian Late Cretaceous and Cenozoic brachiopoda." Thesis, Curtin University, 1999. http://hdl.handle.net/20.500.11937/2320.

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The research reported in this thesis focuses on Late Cretaceous and Cenozoic fossil brachiopods of Western Australia. Although the work is primarily taxonomic, it also includes biodiversity, distribution and some aspects of ecology of the brachiopods described.The most recent information on the anatomy, physiology and ecology of brachiopods is summarised at the beginning of the thesis.Identification of brachiopods is determined primarily on internal morphological features as brachiopods tend to be homomorphic, many species looking externally the same. The morphological features used in the identification of the brachiopods described within the thesis are defined.The fossil material studied has come from four sedimentary basins in Western Australia. The Carnarvon Basin contains Late Cretaceous and Cenozoic fossil material. The Perth Basin also has Late Cretaceous and late Cenozoic brachiopods The Bremer and Eucla Basin have Cenozoic deposits. The stratigraphy of the deposits containing the brachiopods is described.Until this study commenced, eight species had been described from Western Australia. This thesis describes fifty eight species including thirty new species, one new family and two new genera.In preparing descriptions of the new species it become evident that many of the species from the Southern Hemisphere were quite different to those found in the Northern Hemisphere. Their closest affiliation was with genera and species described from the Antarctic Peninsula. Four genera and one species from the Late Cretaceous deposits of Western Australia are common to the Late Cretaceous deposits of the Antarctic Peninsula. In the examination of the Tertiary material from the Carnarvon Basin, it also became clear that there was a strong correlation with Tertiary material from the Antarctic Peninsula. At least four genera are common to both deposits. Six brachiopod genera from the Middle Miocene deposits of the South Shetland Islands Antarctica are common to New Zealand. Nine genera, identified from the La Meseta Formation, Seymour Island, Antarctic Peninsula, are also common to New Zealand. These genera are also found in Australia. This evidence has led to the proposal that in the Late Cretaceous there was a common shelf environment from the Antarctic Peninsula to the north-west coast of Western Australia. In this area, which formed the high latitude southern circum-Indo-Atlantic faunal province, brachiopods evolved different genera and species than those in the northern hemisphere. Many then dispersed into northern areas of the Indian, Atlantic and finally Pacific Oceans.When the material from the Middle to Late Eocene of the Bremer and Eucla Basin was examined, five genera were found to be common to the Early Tertiary of the Carnarvon Basin. When comparing the species from the south-western basins and those from the south- east it was evident that similar species occur in the Middle to Late Eocene of the Bremer, Eucla, St Vincent and Murray Basins. There are some fifteen species in common. Many of these species then occur in the Late Oligocene south-eastern basins near Victoria and Tasmania as the gap between the Australia mainland and Tasmania began to open. One species that occurs in the Late Eocene of Western Australia is also described from the Late Oligocene of New Zealand.In considering the distribution of the Cenozoic brachiopods, genera first appear in the north-west of Western Australia and they then appear in chronological order in the south-western basins and south-eastern basins of South Australia, then the south-eastern basins of Victoria and Tasmania and then New Zealand. By the Late Eocene, there was a shallow marine connection between the Bight and the Tasman Sea. By the Late Oligocene this had widened and Australia was finally totally separated from Antarctica.The Proto-Leeuwin Current was responsible for the distribution of the brachiopods from the north-west of Western Australia to the southern coast. Possible mechanisms for the distribution of genera to New Zealand include rafting and an extended larval stage.It has been suggested that brachiopods in Australia are distributed according to the substrate on which they settle rather than any other factor. Using the information on the distribution of brachiopods in Western Australia throughout the Cenozoic this hypothesis is examined. It is suggested that avoidance of light in the photic zone and food availability with competition with bivalves are more important factors than substrate conditions.
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20

Craig, Robert S. "Western Australian Late Cretaceous and Cenozoic brachiopoda." Curtin University of Technology, School of Applied Geology, 1999. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=12043.

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Abstract:
The research reported in this thesis focuses on Late Cretaceous and Cenozoic fossil brachiopods of Western Australia. Although the work is primarily taxonomic, it also includes biodiversity, distribution and some aspects of ecology of the brachiopods described.The most recent information on the anatomy, physiology and ecology of brachiopods is summarised at the beginning of the thesis.Identification of brachiopods is determined primarily on internal morphological features as brachiopods tend to be homomorphic, many species looking externally the same. The morphological features used in the identification of the brachiopods described within the thesis are defined.The fossil material studied has come from four sedimentary basins in Western Australia. The Carnarvon Basin contains Late Cretaceous and Cenozoic fossil material. The Perth Basin also has Late Cretaceous and late Cenozoic brachiopods The Bremer and Eucla Basin have Cenozoic deposits. The stratigraphy of the deposits containing the brachiopods is described.Until this study commenced, eight species had been described from Western Australia. This thesis describes fifty eight species including thirty new species, one new family and two new genera.In preparing descriptions of the new species it become evident that many of the species from the Southern Hemisphere were quite different to those found in the Northern Hemisphere. Their closest affiliation was with genera and species described from the Antarctic Peninsula. Four genera and one species from the Late Cretaceous deposits of Western Australia are common to the Late Cretaceous deposits of the Antarctic Peninsula. In the examination of the Tertiary material from the Carnarvon Basin, it also became clear that there was a strong correlation with Tertiary material from the Antarctic Peninsula. At least four genera are common to both deposits. Six brachiopod ++
genera from the Middle Miocene deposits of the South Shetland Islands Antarctica are common to New Zealand. Nine genera, identified from the La Meseta Formation, Seymour Island, Antarctic Peninsula, are also common to New Zealand. These genera are also found in Australia. This evidence has led to the proposal that in the Late Cretaceous there was a common shelf environment from the Antarctic Peninsula to the north-west coast of Western Australia. In this area, which formed the high latitude southern circum-Indo-Atlantic faunal province, brachiopods evolved different genera and species than those in the northern hemisphere. Many then dispersed into northern areas of the Indian, Atlantic and finally Pacific Oceans.When the material from the Middle to Late Eocene of the Bremer and Eucla Basin was examined, five genera were found to be common to the Early Tertiary of the Carnarvon Basin. When comparing the species from the south-western basins and those from the south- east it was evident that similar species occur in the Middle to Late Eocene of the Bremer, Eucla, St Vincent and Murray Basins. There are some fifteen species in common. Many of these species then occur in the Late Oligocene south-eastern basins near Victoria and Tasmania as the gap between the Australia mainland and Tasmania began to open. One species that occurs in the Late Eocene of Western Australia is also described from the Late Oligocene of New Zealand.In considering the distribution of the Cenozoic brachiopods, genera first appear in the north-west of Western Australia and they then appear in chronological order in the south-western basins and south-eastern basins of South Australia, then the south-eastern basins of Victoria and Tasmania and then New Zealand. By the Late Eocene, there was a shallow marine connection between the Bight and the Tasman Sea. By the Late Oligocene this had widened and ++
Australia was finally totally separated from Antarctica.The Proto-Leeuwin Current was responsible for the distribution of the brachiopods from the north-west of Western Australia to the southern coast. Possible mechanisms for the distribution of genera to New Zealand include rafting and an extended larval stage.It has been suggested that brachiopods in Australia are distributed according to the substrate on which they settle rather than any other factor. Using the information on the distribution of brachiopods in Western Australia throughout the Cenozoic this hypothesis is examined. It is suggested that avoidance of light in the photic zone and food availability with competition with bivalves are more important factors than substrate conditions.
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21

Smith, Elizabeth T. Biological Earth &amp Environmental Sciences Faculty of Science UNSW. "Terrestrial and freshwater turtles of early cretaceous Australia." Awarded By:University of New South Wales. Biological, Earth & Environmental Sciences, 2009. http://handle.unsw.edu.au/1959.4/43808.

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An unusual turtle fauna from Lightning Ridge, New South Wales (Albian) reveals that Australian turtles had a more extensive Mesozoic history than previously indicated. Reevaluation of several primitive groups provides novel information on turtle evolution in the southern hemisphere. Seven turtle taxa are identified at Lightning Ridge. Two are Testudines indet. and two indeterminate chelid groups are evinced by isolated elements. Three new taxa are assigned to the new family Spoochelyidae in the superfamily Meiolanoidea. Spoochelys ormondea n. fam., gen. et sp., Sunflashemys bartondracketti n. gen. et sp. and Opalania baagiwayamba n. gen. et sp. are predominantly land-living turtles with high-domed shells and short manus and pes. The sister-group relationship with the Meiolaniidae, supported by a suite of cranial and postcranial synapomorphies, increases the stratigraphic range of the horned turtles by around ~ 50 my. Primitive structures in Spoochelys (postparietal, supratemporal and interpterygoid vacuity), occur with derived features that are variably developed across Triassic and Jurassic turtles. Phylogenetic analysis precariously resolves the meiolanoids as sister group to a clade containing Palaeochersis and Proterochersis. Limited pleurodiran attributes suggest that meiolanoids may be pleurodiromorphs, closer to primitive pleurodires than to cryptodires. As basal ‘side-necked’ turtles, the Lightning Ridge meiolanoids permit first insights into cranial and postcranial progressions in pleurodiran stem taxa. Evidence of diverse meiolanoids in Early Cretaceous Australia and ancient radiations of meiolanoid-like turtles in southern Pangea, suggest that the horned turtles are a Triassic group and that the dichotomy between Pleurodira and Cryptodira occurred well before the Late Triassic. Early Cretaceous chelids at Lightning Ridge occur at higher palaeolatitude than in South America. The temporal range of Australian chelids is extended by ~ 50 my, demonstrating that chelids had a Jurassic history in Australia, with broad diversifications across the polar supercontinent. The palaeoecological setting of Lightning Ridge is comprehensively described for the first time. Diverse invertebrates and vertebrates include terrestrial, freshwater aquatic and rare marine forms that are anomalous at this near-polar palaeolatitude (~65-70oS). The anachronistic occurrence in Early Cretaceous Australia of distinctive radiations of ‘Triassic-type’ turtles, and other relic groups, implies prolonged intervals of biogeographic isolation in the eastern provinces of Pangea.
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22

Chambers, Paul Martin. "Late Cretaceous and early Palaeocene marine diatom floras." Thesis, University College London (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265772.

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23

Jones, Charles Edward. "Strontium isotopes in Jurassic and Early Cretaceous seawater." Thesis, University of Oxford, 1992. http://ora.ox.ac.uk/objects/uuid:fe3733bd-8e31-4bba-a78b-6d8275a0075f.

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The collection and analysis of a large number of belemnites and oysters with excellent biostratigraphic and diagenetic control has resulted in a highly detailed determination of the seawater Sr-isotope curve through the Jurassic and Early Cretaceous. The new data confirm the broad trends established by previous work, but the much sharper resolution of the new data allows the application of Sr-isotope stratigraphy with an optimal stratigraphic resolution of ± 1 to 4 ammonite subzones (± 0.5 to 2 Ma). The data show a general decline from the Hettangian (Early Jurassic) to a minimum in the Callovian and Oxfordian (Middle/Late Jurassic). This is followed by an increase through the Kimmeridgian (Late Jurassic) to a plateau reached in the Barremian (Early Cretaceous). In addition, there are major negative excursions in the Pliensbachian/Toarcian (Early Jurassic) and Aptian/Albian (Early Cretaceous). Stable isotope data collected from belemnites and oysters have resulted in the most extensive Jurassic δ13C and δ18O database to date. While both the carbon and oxygen data appear to give reasonable marine signals, the scatter in the data suggests that future research must document possible biological fractionation effects and develop better indicators for the diagenetic alteration of 613C and 6i 8O. The final chapter documents an unexpected correlation between sudden shifts in the Sr-isotope curve, the occurrence of positive 513C excursions, and the eruption of flood basalts. In the Jurassic and Cretaceous there is a correlation in time between sudden downward shifts in the Sr-isotope curve (Pliensbachian, Aptian, Cenomanian/Turonian), the occurance of positive 613C excursions, and the eruption of flood basalts. Each of these major downward shifts in the Sr-isotope curve is followed by a sudden upward shift, which although associated with a positive 613C excursion is not associated with an episode of flood basalt volcanism. In the Cenozoic the Sr-isotope curve no longer displays downward shifts, but the correlation continues between the occurrence of flood basalts and positive 513C excursions. Several lines of evidence suggest that the eruption of flood basalts is associated with pulses of hydrothermal activity, and that this hydrothermal activity brings about the conditions necessary for the genesis of carbon-burial events.
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24

Hart, Stephen Francis. "Palaeoceanography and sedimentology of a mid-Cretaceous Greensand." Thesis, University of Oxford, 1991. http://ora.ox.ac.uk/objects/uuid:ac7da904-aad1-4525-8d11-9c520fc131d3.

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The Upper Albian (mid-Cretaceous) sediments of the Anglo-Paris Basin display a range of condensation phenomena, including glauconitic and phosphoritic sands, glauconitic intraformational pebble beds, and mineralised nodular hardgrounds. These are interpreted as the result of sedimentation rate fluctuations controlled by small-scale relative sea-level changes of at least regional nature. The regional signal was modified by local tectonics, including occasional synsedimentary faulting and the development of thinned successions and complex condensation horizons over broad submarine highs. Candidate sequence boundaries, marine flooding surfaces and systems tracts are proposed. Episodic, high-energy storm events record a spectrum of storm intensities and periodicities in the Upper Greensand Formation. Storm processes interacted with early submarine lithification to produce a suite of pebble-shell beds, simple and amalgamated coquinas, and storm-scoured hardgrounds. Analysis of shell bed fabrics and taphonomy indicates the important role of high-energy storms in generating a distinct event stratigraphy. Stable isotope analysis has detected a positive secular change in carbon-isotopic ratios within carbonates of dispar zone age, resolved as two smaller positive shifts across nodular hardgrounds. This correlates with the development of organic-rich sediments in a range of settings world-wide. Analytical problems, including silica diagenesis, have been addressed by a series of parallel control studies. Geochemical and petrographic analysis has confirmed the widespread development of glauconitic minerals throughout the Upper Greensand, and has been used to investigate grain evolution in a range of lithologies. A review of the global development of the Cretaceous glauconitic facies has been used to compile depositional models for a range of settings. Volumetric calculations of Cretaceous glauconite production rates have shown secular changes, with peak Aptian to Santonian values linked to transgressions across the broad shelf seas which developed globally during this time of rising sea-levels and sea-level highstand.
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25

Holbourn, Ann Elizabeth Lucette. "Lower cretaceous benthic formanifera of the Indian Ocean." Thesis, University College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336285.

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26

Littler, K. "Climate and carbon-cycling in the Early Cretaceous." Thesis, University College London (University of London), 2011. http://discovery.ucl.ac.uk/1335899/.

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The Cretaceous (~145–65 Ma) is widely regarded as a greenhouse period with warm, equable climates and elevated atmospheric CO2 relative to the modern. However, the earliest Cretaceous (Berriasian–Barremian; 145–125 Ma) is commonly characterised as a relatively colder “coolhouse” interval, typified by lower global temperatures than the mid-Cretaceous. Unfortunately, the lack of absolute sea surface temperature (SST) estimates prior to the Barremian has hampered efforts to definitively reconstruct Early Cretacous climate. Here, the TEX86 palaeotemperature proxy, for which a detailed review is provided, has been used to generate a 13 myr record of SST estimates for the Early Cretaceous, based on sediments from assorted deep-sea drilling sites. A consistent offset in the TEX86 ratio between transported mudstones and pelagic carbonates in the low-latitude marine sediments (DSDP Sites 603 and 534) has been identified, which may be linked to post-burial diagenesis or a difference in organic matter type between lithologies. Mindful of these apparent lithological effects on TEX86, only the pelagic sediments were used to subsequently reconstruct Early Cretaceous SSTs. These TEX86 records demonstrate both elevated SSTs (>27 ºC) at low and mid-latitudes relative to the modern, and the apparent stability of these high temperatures over long timescales. This lack of SST variation in the low-latitudes during the Valanginian positive carbon-isotope event (CIE; ~135–138 Ma), casts doubt on the warming-weathering feedback model put forward to explain this major perturbation. Additionally, new paired bulk organic (δ13Corg) and bulk carbonate (δ13Ccarb) carbon-isotope records from North Atlantic DSDP sites, have been used to reconstruct relative changes in pCO2 across the CIE. These observed fluctuations in Δ13C imply changes in carbon-cycling and a possible drawdown in CO2, due to excess organic matter burial associated with the CIE.
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27

Howe, Jodie. "Mid Cretaceous fossil forests of Alexander Island, Antarctica." Thesis, University of Leeds, 2003. http://etheses.whiterose.ac.uk/295/.

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Spectacular fossil trees and shrubs are preserved within fossil soils in their original growth positions in mid Cretaceous rocks on Alexander Island, Antarctic Peninsula. These fossils indicate that diverse forest communities grew upon the floodplain areas of Alexander Island during the Albian at a palaeolatitude of 69-75 ° S. The fossil forests are preserved within the fluvial sediments of the Triton Point Formation of the Fossil Bluff Group, which represents the infill of a fore-arc basin. The fluvial environment matured from a braided river system, with frequent floods and unstable channel banks, to a more mature meandering river system with more stable floodplain areas. Low energy floods preserved plants that grew on the river channel banks in fine muds and silts. Catastrophic floods occurred rarely, possibly as a result of volcanic activity upon the magmatic arc 200 km away. These high-energy floods covered floodplain areas in coarse sands, entombing trees. Well-drained mollisols formed on emergent surfaces becoming rich and fertile and supporting diverse forest communities. The flora within the forests occurred as well structured communities that occupied different parts of the river floodplain. Open-woodland forests dominated by araucarian conifers, ferns and shrubs, occupied stable areas of the floodplain characterised by low-energy floods. Disturbance vegetation dominated by Taeniopteris, liverworts, angiosperms and ferns, occupied river channel banks where frequent floods provided fresh surfaces for these early colonising plants to flourish. Patch forest communities dominated by podocarp conifers, ginkgo trees, cycadophytes and ferns, grew on stable areas of the floodplain distal to the river channel. These mature climax forests were rarely disturbed by catastrophic floods. Evidence from the palaeosols, sediments and fossil wood of Alexander Island suggest that the climate was warm, temperate, and semi-arid with seasonal precipitation and intermittent wet phases. In structure and composition the Alexander Island forest are very similar to the warm temperate rainforests of New Zealand which experience mean summer temperatures of 16-22 °C and mean winter temperatures of 3-8 ° C. This study and other palaeobotanical data suggests that the Alexander Island forests are likely to have grown under similar temperatures.
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28

McCord, Robert Dudridge 1955. "Late Cretaceous microherpetofaunas of the Kaiparowits Plateau, Utah." Diss., The University of Arizona, 1997. http://hdl.handle.net/10150/282518.

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The microherpetofaunas recovered from the Kaiparowits Plateau, Utah, are described. Small reptiles and amphibians from 16 families and at least 22 genera were obtained from the Cenomanian Dakota, Turonian to Santonian Straight Cliffs, the early Campanian Wahweap, and the Campanian (Judithian) Kaiparowits Formations. A new genus and species of polyglyphanodontine, Manangyasaurus saueri, is described. The function of the unusual teeth of polyglyphanodontines is uncertain, but may have been related to frugivory. The polyglyphanodontines, in the restricted sense, appear to be confined to the western localities of the "southern communities" in the Judithian and Lancian. The early occurrence (Turonian) of Paraglyphanodon in the Straight Cliffs Formation suggests that the polyglyphanodontines may have been widespread during earlier Ages, permitting their dispersal to or from Asia. The genus Albanerpeton is best considered a member of the Order Caudata and its provisional assignment to the Family Prosirenidae is reasonable. The Polyglyphanodontidae, as presently defined, consists of a holophyletic group consisting of Polyglyphanodon, Paraglyphanodon, Manangyasaurus, and Cherminsaurus, and a poorly defined group consisting of the Asian "Macrocephalosauridae" Peneteius may also be a polyglyphanodontine, as the subfamily is presently defined.
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29

Beaumont, Hazel. "Cretaceous sedimentology of the Barmer Basin, Rajasthan, India." Thesis, Keele University, 2017. http://eprints.keele.ac.uk/3530/.

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The Barmer Basin, western India, is a well-known and prospected petroleum system. However, the Lower Cretaceous Ghaggar-Hakra Formation has not been recognised as basin fill and not documented prior to this study. The formation outcrops in rotational fault blocks at the Sarnoo Hills and surrounding areas, on the eastern Barmer Basin margin. The thesis here describes and analyses the nature and evolution of the formation at both outcrop and within the subsurface, producing facies and depositional models. At outcrop, the deposits of the Ghaggar-Hakra Formation contain three dominant fluvial sandstone successions, known as the Darjaniyon-ki Dhani, Sarnoo and Nosar sandstones. The Darjaniyon-ki Dhani Sandstone is a gravel bedload dominated, low sinuosity fluvial system, the Sarnoo Sandstone represents a mixed-load, high sinuosity fluvial system and the Nosar Sandstone is highly erosive well-developed, bedload dominated, low sinuosity fluvial system. The intervening mudrocks represent floodplain deposits. The growth and development of the fluvial system between the Darjaniyon-ki Dhani and Sarnoo sandstones indicates that the climate and tectonics were stable at the time of deposition. However, the Nosar Sandstone represents rejuvenation of the fluvial system as it is suggested that this change in deposition style is due to the activation of the fault network forming the Barmer Basin and West Indian Rift System. The facies models derived from this work are applied to the subsurface to provide interpretations of the Cretaceous succession. This provides significant insights into the sedimentology, geometries of the sediment packages with the net to gross and the petrography, all indicating the reservoir quality of the Ghaggar-Hakra subsurface material.
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30

Shafik, Samir. "Late Cretaceous, early Tertiary calcareous nannofossils from Australia." Title page, contents and summary only, 1989. http://hdl.handle.net/2440/19212.

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31

Swinburne, Nicola Helga Margaret. "The extinction of the rudist bivalves." Thesis, Open University, 1990. http://oro.open.ac.uk/54415/.

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The rudist bivalves were one of the many and varied groups of organisms to be extinguished at the end of the Cretaceous Period. They were a group of bivalves which evolved during Late Jurassic times to dominate the carbonate shelves on the margins of the Tethys Ocean during the Cretaceous Period. Through Late Cretaceous times their diversity climbed to a peak and then entered a period of rapid decline, resulting eventually in the complete extinction of the group. Theories as to the cause of that extinction should clearly be based upon a knowledge of the detailed pattern of the decline. Most important is the question of the timing of the extinction: How long did it take from the peak of diversity to the elimination of the entire group? Is there one main extinction event - or are there several - or is the pattern a gradual decline? In answering these questions this work adopts a new approach to dating end Cretaceous strata by using strontium isotope stratigraphy. The method works by measuring the 87 Sr/86Sr of palaeo-seawater preserved in marine carbonate, such as the thick low-Mg calcite layer of rudist shells. The 87Sr/86Sr of seawater was changing fairly rapidly through time in the latest Cretaceous. The pattern of change has been established in detail using samples from Boreal sequences of which the ages are known with respect to the belemnite stratigraphy. Using this as a standard graph, Tethyan rudist samples have been dated by a comparison of the Sr isotope ratio. The use of Sr isotope stratigraphy has enabled a time axis to be established, against which the ranges of rudist bivalves and of their facies have been ploued. From these data it can be clearly seen that the ranges of many of the established biostratigraphic markers are in error and that the stage boundaries, as defined by the belemnite and planktonic foraminiferal stratigraphies, are offseL When the pattern of rudist diversity is plotted against this time scale it can be seen that, at a specific level, the rudists were at their most diverse at the Campanian/Maastrichtian boundary. Their decline lasted until I almost the end of the Maastrichtian after which the only survivors are Tertiary forms. The decline is related to the disappearance of rudist facies with the end Cretaceous regression, though that graph is slightly displaced from that of rudist diversity. This shows that the rudist extinction is not merely due to non-exposure of terminal Maastrichtian strata.
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32

Shellhouse, Kody. "The Cretaceous-Paleogene Boundary Deposit in LaSalle Parish, Louisiana." Thesis, University of Louisiana at Lafayette, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10287319.

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The Cretaceous-Paleogene Boundary Deposit is an impact-induced sedimentary deposit across the Gulf of Mexico basin, deposited due to the catastrophic effects of the Chicxulub Impact. The purpose of this project was to determine what the lithology and sedimentology evidence found in the Justiss Louisiana Central IPNH No. 2 well core from LaSalle Parish, Louisiana, tells us about the depositional history of the end-Cretaceous deposit and how the formation of this deposit was influenced by the effects of the Chicxulub Impact over 1000 km to the south. Project objectives were to characterize the end-Cretaceous sediments found in LaSalle Parish, Louisiana, to determine their depositional history as it relates to the Chicxulub Impact in Yucatan, Mexico, and to relate these onshore sediments to the basin-wide Cretaceous-Paleogene Boundary Deposit. A full description of the core was made and 35 thin sections from throughout the core were created and analyzed. Sedimentology evidence suggests that the end-Cretaceous chalk was deposited by seismically-induced mass wasting and later tsunami activity as a direct result of the Chicxulub Impact, and that the previously-proposed thickness of the Cretaceous-Paleogene Boundary Deposit may be overestimated.

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33

Leier, Andrew. "The Cretaceous Evolution of the Lhasa Terrane, Southern Tibet." Diss., Tucson, Ariz. : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1340%5F1%5Fm.pdf&type=application/pdf.

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34

Oakley, Daniel. "Cretaceous Angiosperm Woods; Insights into Svstematics, Ecology and Biogeography." Thesis, University of Bristol, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.520229.

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35

Iorio, Marina. "High resolution palaeomagnetic analyses of Cretaceous shallow water carbonates." Thesis, University of Plymouth, 1995. http://hdl.handle.net/10026.1/1931.

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A sequence of 88 m of continuous borehole cores of Lower Cretaceous shallow water carbonates from Southern Italy was obtained and studied lithologically and palaeomagnetically. It was found that the rocks are organized in cyclic lithofacies representing depositional environments from subtidal to supratidal and their magnetic remanences are all measurable and stable even if very weak. Cyclicities in the Milankovitch band were found using F.F.T analyses in both the sedimentological and palaeomagnetic records, and these matched the astronomical periodicities predicted for the Early Cretaceous. From this link it is possible to date the absolute time represented by the sediments, and the absolute time of acquisition of the palaeomagnetic signal. The palaeomagnetic signal is independent of sedimentological characteristics and lithofacies organization. The mean palaeolatitude and the tectonic results are consistent with other Lower Cretaceous structures in the Southern Apennines. The palaeomagnetic data, although still being studied, also shows shorter wavelengths signals than the Milankovitch cycles, some of which are likely to be comparable with secular variations of the geomagnetic field in the Early Cretaceous. Polarity changes are present, which correlate to the Geomagnetic Polarity Scale. Longer Normal polarities were found at about 1,000,000 years and in them the secular variations were found longer than usual. A repeatable magnetic behaviour characterises the polarity changes each about 230,000 years. It is hypothesized that climatic variations and the sea level oscillations affect the thickness, type and cyclicities of sediments and geomagnetic variations control the palaeomagnetic data. This study confirms that ultra-high resolution magnetostratigraphy can be undertaken on shallow water carbonates.
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36

Mc, Cann Oonagh. "Weathering history of a late Cretaceous palaeosol, Northeast Ireland." Thesis, Queen's University Belfast, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314014.

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37

Gardner, Adele F. "An organic geochemical study of the Cretaceous/Tertiary boundary." Thesis, Open University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321559.

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38

Blonder, Benjamin, Dana L. Royer, Kirk R. Johnson, Ian Miller, and Brian J. Enquist. "Plant Ecological Strategies Shift Across the Cretaceous–Paleogene Boundary." Public Library of Science, 2014. http://hdl.handle.net/10150/621250.

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UA Open Access Publishing Fund
The Chicxulub bolide impact caused the end-Cretaceous mass extinction of plants, but the associated selectivity and ecological effects are poorly known. Using a unique set of North Dakota leaf fossil assemblages spanning 2.2 Myr across the event, we show among angiosperms a reduction of ecological strategies and selection for fast-growth strategies consistent with a hypothesized recovery from an impact winter. Leaf mass per area (carbon investment) decreased in both mean and variance, while vein density (carbon assimilation rate) increased in mean, consistent with a shift towards ‘‘fast’’ growth strategies. Plant extinction from the bolide impact resulted in a shift in functional trait space that likely had broad consequences for ecosystem functioning.
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39

Cook, Elizabeth. "Sedimentology and taphonomy of Wealden (Lower Cretaceous) bone accumulations." Thesis, University of Bristol, 1995. http://hdl.handle.net/1983/0cc7847c-1cd7-476f-a498-94fc76ad7847.

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40

Uwins, Philippa Joanne Rashleigh. "Early to mid Cretaceous palynology of Cyrenaica, northeast Libya." Thesis, University of Aberdeen, 1987. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU010065.

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155 Early Cretaceous core and cuttings samples from 15 northeast Libyan wells have been dated, mainly on the basis of dinoflagellate cyst assemblages although stratigraphically important spore and pollen taxa have also been used when dinocysts are rare, absent or not age diagnostic. Spores and pollens have also helped with palaeoenvironmental reconstructions. Six distinct associations that are both stratigraphically and palaeoenvironmentally controlled are identified; these range from Hauterivian to early Cenomanian age. ? late Hauterivian to ? middle Barremian assemblages (IA) are dominated by dinoflagellate cysts thought to indicate lower than normal marine salinities, namely Cyclonephelium hystrix, Muderongia simplex microperforata, and Systematophora spp. Barremian assemblages (IB) are characterised by the presence of Aptea anaphrissa, and those from the early to late middle Aptian (II) by several other species of Aptea, especially A. securigera and the pollen Afropollis operculatus. An inner to middle shelf, pre-Vraconian Albian association (IIIA) comprises numerous morphologically varied dinoflagellate cysts including several species of each of the genera Coronifera, Oligosphaeridium, Spiniferites and Subtilisphaera notably S.terrula, and S.deformans/S.perlucida, whereas near-shore deposits of approximately the same age (IIIB) contain fewer cysts, more miospores and some megaspores. Both reflect a regression of the sea in the region prior to a major Late Cretaceous transgression, the early stages of which are indicated by two Vraconian-early Cenomanian associations (IVA and IVB). These consist of numerous chorate and proximochorate dinoflagellate cysts including Cyclonephelium, Dinopterygium, Florentinia, Oligosphaeridium, Spiniferites, Palaeohystrichophora infusorioides and Subtilisphaera cheit. Generic and species diversity is however higher in IVA, implying deposition in more open marine conditions than assemblages identified as IVB, which contain larger numbers of miospores. The complexities of intergeneric and intra- and interspecific morphological variation are described and illustrated for several taxonomic groups, including Aptea, Coronifera, Cyclonephelium, Dinopterygium, Florentinia, Kiokansium, Occisucysta, Oligosphaeridium, Palaeohystrichophora, Protoellipsodinium, Subtilisphaera and Xiphophoridium. Several possible synonymies at both generic and specific levels are suggested, and 10 informal species and three varieties of Florentinia berran are described.
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Slipper, Ian Jeffrey. "Turonian (Late Cretaceous) Ostracoda from Dover, south-east England." Thesis, University of Greenwich, 1997. http://gala.gre.ac.uk/6302/.

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Ostracod assemblages from samples collected through the Turonian Stage of the Late Cretaceous from Dover, Kent, south-east England, consist of one hundred and three species group taxa. These are described and illustrated. This represents a significant increase in the knowledge of the Turonian fauna, since previous estimates of the number of species present during the Turonian are less than thirty. This improvement has been brought about by the selection of an appropriate processing method. Freeze-thaw processing is recommended for chalks and hardgrounds which comprise much of the Turonian Stage. The white spirit, solvent method is shown to be preferable for marls. Nineteen species and six subspecies are here described as new: Polycope lunaplena sp. nov, Cytherella truncatoides sp. nov., Cytherella vulna sp. nov., Cytherella weaveri sp. nov., Cytherelloidea granulosa parca ssp. nov., Cardobairdia longitecta sp. nov., Bairdoppilata turonica sp. nov., Pontocyprella robusta cometa ssp. nov., Pterygocythereis (Diogmopteron) carolinae sp. nov., Bythoceratina (Bythoceratina) saxa sp. nov., Bythoceratina (Bythoceratina) staringi conmacula ssp. nov., Monoceratina minangulata sp. nov., Patellacythere weaveris sp. nov., Schulerides langdonensis sp. nov., Karsteneis nodifera tabasca ssp. nov., Karsteneis oculocosta sp. nov., Karsteneis petasus petasus sp. et ssp. nov., Karsteneis petasus antecursor sp. et ssp. nov., Karsteneis praekarsteni sp. nov., Idiocythere carburnensis sp. nov., Isocythereis postelongata sp. nov., Mauritsina? paradordoniensis sp. nov., Rehacythereis stellatus sp. nov., Rehacythereis venticursus venticursus sp. et ssp. nov., Rehacythereis venticursus patbrowni sp. et ssp. nov., and one new name, Bythoceratina (Bythocertatina) antetumida nom. nov. is introduced for a secondary junior homonym. By comparison with faunas from Devon and the Czech Republic, the biostratigraphical analysis is shown to only have only local significance due to diachronism of Ostracoda. This diachronism is used to explore migration pathways which suggest that the origin of the Turonian ostracod fauna may have had more than one source. A model relating ostracod diversity inversely to sea-level is given for the Cenomanian to Santonian stages of the Late Cretaceous which suggests that the sea-level at Dover during the Turonian was greater than previously thought, given its marginal setting.
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42

Hildebrand, Alan Russell. "Geochemistry and stratigraphy of the Cretaceous/Tertiary boundary impact ejecta." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/186109.

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An array of stratigraphic, chemical, isotopic, and mineralogical evidence indicates that an impact terminated the Cretaceous Period. The 180-km-diameter Chicxulub crater, which now lies buried on the Yucatan peninsula of Mexico, was probably formed by the impact. The impactor was probably a long-period comet. Shock devolatization of the thick carbonate/evaporite sequence impacted at Chicxulub probably led to a severe and long-lasting greenhouse warming and a prompt pulse of sulfuric acid rain. The fallout of crater ejecta formed two layers: a lower layer which varies in thickness following a power-law relation based on distance from the Chicxulub crater and an upper, globally-distributed, uniformly ∼3-mm-thick layer. The upper layer probably represents the fallout of condensates and entrained solid and liquid particles which were distributed globally by the impact fireball. The lower layer consists of brecciated rock and impact melt near the crater and largely altered tektites far from the crater. The clasts of this layer were probably ballistically transported. The Raton, New Mexico K/T boundary section preserves the fireball and ejecta layers in a coal-free nonmarine environment. Siderophile, chalcophile, and lithophile trace element anomalies occur similar to those found at marine K/T boundary localities. Soot occurs peaking in the 3-mm-thick fireball layer and the immediately overlying 3 mm of sediment, implying prompt burning of the Cretaceous forests. The Brazos River, Texas continental-shelf K/T sections preserve coarse boundary sediments which were probably produced by impact waves. Siderophile and chalcophile trace-element anomalies occur suggesting that the fireball layer and possibly part of the ejecta layer are interbedded with the coarse boundary sediments. The Beloc, Haiti deep-sea K/T sections preserve a thick ejecta sequence including altered and unaltered tektites and shocked minerals capped by the fireball layer. The thick K/T ejecta preserved at this and other nearby K/T localities require a source crater of Chicxulub's size and location. The composition of the tektites and shocked grains require an impact into recently extracted continental crust with a carbonate/evaporite component as found at the Chicxulub crater.
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Ayorinde, Adebayo O. "MINERALOGY AND GEOCHEMISTRY OF THE BAUXITE DEPOSITS (CRETACEOUS), WILKINSON COUNTY, GEORGIA." Digital Archive @ GSU, 2011. http://digitalarchive.gsu.edu/geosciences_theses/30.

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Cretaceous bauxite deposits from Hall and Veneer mines, Wilkinson County, Georgia are composed of kaolinite, gibbsite, goethite, anatase, nordstrandite and bohemite. Quartz and micas are absent in the samples. The presence of boehmite and goethite are evidence of intense weathering forming the bauxite deposits. The extremely high values of the Chemical Index of Alteration (CIA) which is over 99, and the low values of the alkali metals and alkali earth metals, support an intense weathering origin for the bauxite deposit. There is evidence of deposition in the mines based on the presence of pisoids in the bauxite samples and the composition of the parent materials, which vary markedly by the non-uniform TiO2/Al2O3 values which represent the accumulation of transported materials from contrasting source areas. Kaolin minerals were first produced by the hydrolytic weathering of aluminous sediments and then gibbsite was formed as early kaolin was desilicated.
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44

Pahnke, P. D. "Characterization of Cretaceous Chalk Microporosity Related to Depositional Texture: Based Upon Study of the Upper Cretaceous Niobrara Formation, Denver-Julesburg Basin, Colorado and Wyoming." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/5538.

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Prompted by increased interest in understanding microporosity, recent efforts at describing and classifying pore types in mudstones have focused primarily on siliceous, gas producing unconventional reservoirs with little attention being paid to carbonate, mixed oil-and-gas producers. The Niobrara Formation in the Denver-Julesburg Basin is a self-sourced resource play producing oil and natural gas from low permeability chalks. Key reservoir lithologies consist of chalk, chalky marl and marl. These lithologies contain flattened chalk fecal pellets which play a significant role in providing porosity. Integration of depositional fabric with pore-type distribution emphasizes the unique textural and depositional nature of chalk and provides a starting point for evaluation of diagenetic porosity modification. Chalk depositional textures comprise two main subdivisions. The first, called rainstone, includes chalks that form largely from settling of planktonic skeletal remains and fecal pellets as marine snow. New terms related to pelagic chalk textures are pelagic mudstone, pelagic wackestone, and pelagic packstone. The second, called allochthonous chalk, consists of chalks formed from syndepositional tectonic disruption of the seafloor, resulting in mass-movement and redeposition of chalk as turbidites and slide sheets. New terms related to allochthonous chalk textures are allomudstone, allofloatstone, and allorudstone. A chalk porosity classification consisting of four major pore types is presented that can be used to quantify Niobrara chalk pores and relate them to depositional texture, porosity networks, diagenetic history, and pore distributions. Interparticle porosity occurs largely between coccoliths and coccolith fragments, and decreases with burial ranging from 27-38% to 5-17%. Intraparticle porosity occurs within chalk pellets, coccospheres, coccolith plates and foraminifera tests, and also decreases with burial. Organic matter pores are intraparticle pores located within organic matter and are related to hydrocarbon generation. Channel pores, where present, can have significant influence on hydrocarbon storage and permeability networks. In the Niobrara, burial diagenesis in the form of mechanical compaction, chemical compaction, and syntaxial cement overgrowths, modifies pore shape and abundance. Porosity distribution is controlled by the abundance of chalk pellets and the mineralogy of the matrix. Permeability is a function of matrix lithology (micrite-rich vs. silt- and clay-rich). Understanding chalk depositional and diagenetic processes, and how they relate to porosity formation and pore evolution provide a foundation for more accurately predicting the occurrence and distribution of hydrocarbon source and reservoir rocks within the Niobrara.
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45

Vaziri, Mohammad Reza. "Patterns of microfaunal occurrence across the Cenomanian-Turonian boundary in England." Thesis, University of Liverpool, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363944.

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46

SHIN, JI-YEON. "TAXONOMIC DIVERSITY, FAUNAL ANALYSIS AND PALEOECOLOGY OF A MICROVERTEBRATE SITE IN THE LATE CRETACEOUS MEETEETSE FORMATION, NORTHERN WYOMING." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1118419811.

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47

Matthews, Kara. "Cretaceous Palaeogeography of Eastern Australia: Connecting the Deep Earth to Surface Processes." Thesis, School of Geosciences, 2009. http://hdl.handle.net/2123/5774.

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We have used the geodynamic modelling software CitcomS 3.0 to model the surface evolution of Australia since 140 Ma and constrain the location of the Cretaceous aged subduction zone that paralleled its eastern margin. Australia’s palaeogeography was profoundly affected by mantle convection processes during the Cretaceous. Eastward passage of the Australian plate over subducted slab material induced negative dynamic topography in eastern Australia, causing widespread time-dependent subsidence and formation of a vast epeiric sea during a eustatic sea-level low. Although there exists a considerable amount of geological evidence for active convergence between Australia and the palaeo-Pacific at this time, the exact location of the subduction zone has remained elusive. To constrain the location of subduction we tested two end-member models, one with the subduction zone directly adjacent to the continent, and an alternative model with subduction translated 23° east. Our forward geodynamic models incorporate a rheological model for the mantle and crust, plate motions since 140 Ma and evolving plate boundaries, implemented in the GPlates software. While mantle rheology affects the magnitude of surface vertical motions, the timing of uplift and subsidence depends critically on plate kinematic reconstructions and plate boundary geometries. Tectonic subsidence analysis using the backstrippping method was performed on 42 wells from the Eromanga and Surat basins in eastern Australia. This revealed Cretaceous tectonic subsidence trends with which to compare our modelled dynamic topography. Simulations with subduction proximal to the active continental margin resulted in accelerated basin subsidence delayed by 20 Myr compared with these tectonic subsidence data. However this timing offset was reconciled when subduction was shifted eastward. Comparisons between whole mantle seismic tomography images and equivalent model temperature cross-sections further validate our proposed eastward shift in subduction. Finally an absence of subduction zone volcanism along Australia’s east coast in the Early Cretaceous supports our conclusion that a back-arc basin existed east of Australia during the Cretaceous. Our models further allowed us to test alternative Tertiary plate boundary geometries east of Australia, in particular whether or not the proposed short-lived mid-Tertiary eastward dipping "New Caledonia subduction zone" may have been responsible for a prominent fast shear wave anomaly at ~1100 km depth beneath the Tasman Sea. Our models suggest that post 45 Ma westward dipping subduction along the Tonga-Kermadec Trench may have produced the slab material mapped by mantle tomography models in the lower mantle underneath the Tasman Sea. An additional eastward dipping subduction zone does not appear to be required by the tomographic images, as proposed previously.
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48

Ivy, Robert. "Regional Subsurface Investigation of the Uppermost Cretaceous of Northern Louisiana." Thesis, University of Louisiana at Lafayette, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10272215.

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Seismic features on a seismic horizon at or near the Cretaceous-Paleogene boundary in northern Louisiana seen by Egedahl (2012), and then studied in greater depth by Strong (2013), resemble large subaqueous dunes or “mega-ripples.” Both Egedahl (2012) and Strong (2013) hypothesize that these features represent subaqueous dunes emplaced by tsunami waves caused by the Chicxulub Impact, the large bolide impact on the Yucatán Peninsula, that is widely agreed to be one of the contributing factors to the demise of the dinosaurs. Three hundred and eighteen well logs in northern Louisiana were analyzed to determine whether possible subaqueous dunes are evidenced at the Cretaceous-Paleogene boundary in this data set. These same well logs were used to develop a contour map of the top of Cretaceous and to determine the topography of the top of the Cretaceous in northern Louisiana at the time of the Chicxulub Impact. Further, the log facies of these logs were interpreted to deduce paleo-shoreline for this topography at the time of the Cretaceous-Paleogene boundary.

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49

Smith, Robin James. "Biology and ontogeny of Cretaceous and Recent Cyprididae Ostracoda (Crustacea)." Thesis, University of Leicester, 1998. http://hdl.handle.net/2381/30470.

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Study of the biology and ontogeny of Cretaceous and Recent ostracods shows that the family Cyprididae exhibits conservative evolution over the last 100 million years. The Cretaceous cypridid ostracod Pattersoncypris micropapillosa Bate, 1972, with preserved appendages, is described and details of the limbs of its adults and juveniles are compared with Recent Cyprididae. A detailed study of the ontogeny of the Recent Cyprididae ostracod Eucypris virens Jurine, 1820) reveals that, with the exception of the last podomere on the antennules, the chaetotaxy (distribution pattern of setae) shows continual development on all podomeres of the limbs. Cyprididae ostracods have a pediform limb in the posterior part of the body, presumably to help them to attach to substrates; this is reflected by the pediform nature of one limb in all ontogenetic stages. This study has also shown that the fifth limb is more probably of thoracic origin and, hence, ostracods have only one pair of maxillae. The upper lip and hypostomes of 23 species of Cypridoidea (Podocopina) ostracods were studied and significant variation noted in morphology between species, genera and subfamilies. Several features of the upper lip and hypostome are described for the first time. The morphology of the upper lip can be used to identify species, but it cannot be used to diagnose genera or subfamilies. Spherical objects recovered from acetic acid preparation residues of vertebrate fossils from the Lower Cretaceous Santana Formation of north-east Brazil are postulated to be the eggs of the ostracod Pattersoncypris micropapillosa Bate, 1972. These spheres are phosphatized, range in diameter from 85 to 110 m, and are comparable in many respects to the eggs of several Recent ostracod species.
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Ross, Marcus R. "Richness trends of mosasaurs (diapsida, squamata) during the late Cretaceous /." View online ; access limited to URI, 2006. http://0-digitalcommons.uri.edu.helin.uri.edu/dissertations/dlnow/3248241.

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