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Dissertations / Theses on the topic 'Alkalic igneous rocks Geology'

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Published: 4 June 2021

Last updated: 10 February 2022

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1

Johnson, Geoffrey I. "The petrology, geochemistry and geochronology of the felsic alkaline suite of the eastern Yilgarn Block, Western Australia /." Title page, contents and abstract only, 1991. http://web4.library.adelaide.edu.au/theses/09PH/09phj67.pdf.

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Thesis (Ph. D.)--Dept. of Geology and Geophysics, University of Adelaide, 1992.
Typescript (Photocopy). Includes copies of 4 papers by the author as appendix 4 (v. 1). Errata slip inserted. Includes bibliographical references (leaves 170-192 (v. 1)).

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2

Bradshaw, Colin. "A petrographic, structural and geochemical study of the alkaline igneous rocks of the motzfeldt centre, south Greenland." Thesis, Durham University, 1988. http://etheses.dur.ac.uk/6446/.

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The Motzfeldt Centre (1310 +/- 31 MY) is one of four Gardar alkaline igneous Centres belonging to the Igaliko Nepheline syenite Complex, South Greenland. Motzfeldt is a multiphase, high-level intrusive ring-centre comprised principally of nepheline syenite and emplaced in the Proterozoic Julianehab granite and the overlying Gardar volcano-sedimentary succession. The Centre commenced with the intrusion of three poorly centralised satellitic intrusions of syenite, pulaskite and nepheline syenite, collectively known as the Geologfjeld Formation. These are partly truncated by concentric, multiple intrusions comprising the Motzfeldt Ring Series whose steep-sided contacts dip outwards and individual nepheline syenite units young inwards. On the basis of field relations, petrography and geochemistry the Ring Series is further subdivided into the Motzfeldt Sø and Flinks Dal Formations, and a number of minor intrusions collectively termed the Hypabyssal Series. The results of field surveys, carried out during two summer field seasons, are presented on a 1:50,000 geological map. The petrography and field relations are described for 16 distinct, plutonic and hypabyssal rock units which range in lithology from larvikite to lujavrite. These represent at least 10 separate intrusive episodes and show a remarkable array of rock textures, mineralogical and geochemical features.170 whole-rock (XRF), 33 Rare earth element (INAA) and over 300 mineral (EDS) geochemical analyses are presented. These show that the syenite/nepheline syenite lithologies in Motzfeldt can be subdivided chemically and mineralogically into the three groups: 'hypoalkaline', alkaline and peralkaline. The geochemical features of the various units are evaluated and elemental behaviour discussed. The data is additionally assessed, using non-parametric statistics, as a means of discriminating between the units. A number of units which have proved difficult to separate in the field are established to be geochemically distinct, whilst others are shown to be very closely associated. The peralkaline, pegmatite rich, silica saturated outer and upper margins of the Motzfeldt Sø Formation and its associated microsyenite sheet sequence, host extensive economic reserves of Nb, Ta, Zr, U, Th and LREE. The evolution of these mineralised zones is discussed and the importance of country rock (+ water) — magma interaction emphasised. Recent works have helped clarify the magmatic development of the Gardar Province. Here emphasis has been placed on the structural evolution of the Gardar with the aim of complementing these works. The Gardar represents a prolonged (c.200 MY), cyclic period of limited, passive intracontinental extension. Crustal thinning facilitated the rise, along deep fracture zones, of magmas generated by higher thermal gradients. In response to regional, sinistral shear stresses, ENE extensional fractures and associated dyking developed. In addition, crustal decoupling occurred along several parallel WNW-ESE sinistral strike-slip faults. Motzfeldt and other ring centres of the Gardar are preferentially located at the intersections of these zones of weakness.

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3

Liu, Junsuo. "Pétrogénèse des roches alcalines mafiques d'âge méso-cénozoique dans les provinces de Hunan et Guangxi, Chine septentrionale = petrogenesis of the mesosoic-cenozoic mafic alkaline subvolcanic rocks in Hunan-Guangxi provinces, southern China /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1992. http://theses.uqac.ca.

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4

Potgieter, J. E. "Anorogenic alkaline ring-type complexes of the Damaraland Province, Namibia, and their economic potential." Thesis, Rhodes University, 1987. http://hdl.handle.net/10962/d1001567.

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Anorogenic alkaline ring-type complexes form within continental plate settings. Alkaline magmatism is derived from the upper mantle, in which mantle metasomatism plays an important part, as well as from partial melting of the lower crust. Radial and concentric fractures develop during the ascent of alkaline magma. Extrusion of basic and felsic magma takes place along these fractures with felsic volcanics building-up central volcanoes. As a result of emptying of the magma chamber, the superstructure of the volcano collapses and a caldera is formed. During the caldera stage syenitic and granitic material are intruded into ring fractures. Alkaline ring-type complexes may be classified as (i) alkaline qranite and syenite-type and (ii) carbonatite and undersaturated-type. These ring-type complexes occur as distinct igneous provinces. Some major provinces occur in Brazil, Corsica, Namibia, Nigeria, Norway, Saudi-Arabia and Sudan. In Namibia the Damaraland igneous province is of Mesozoic aqe and it contains 15 alkaline ring-type complexes . These complexes are situated along north-eastern trends which correspond to transform directions of the South Atlantic. During the opening of the South Atlantic (Gondwana breakup) Pan-African age lineaments were reactivated which allowed emplacement of anorogenic alkaline magmatism. A zonation of alkaline granite and syenitetype in the west and carbonatite and undersaturated-type ring-complexes in the east correlates with down- and upwarp axes parallel to the line of Gondwana fragmentation. Alkali- and H⁺-metasomatism is related to the alkaline and syenite-type whereas alkali metasomatism (fenitization) is associated with carbonatite and undersaturated-type ring-complexes. Sn, W and Ta mineralization is associated with alkaline granites of some of the alkaline granite and syenite-type ring-complexes. Fe, F, PO₄ , Nb, Th, REE, Sr, Zn and Pb mineralization is associated with carbonatite complexes. Potential exists for: (i) porphyry Cu-Mo and epithermal-type (Au, Ag, Pt-metals, base metals) mineralization in the alkaline granite and syenite-type ring-complexes and (ii) disseminated Cu, Au, Aq and Pt-metals in carbonatite and undersaturated-type ring-complexes

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5

Esfarjani, H. R. "Engineering properties of basic igneous rocks." Thesis, University of Newcastle Upon Tyne, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374739.

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6

Smithies, Robert Hugh. "The geochemical evolution of three alkaline complexes in the Kuboos-Bremen igneous province, southern Namibia." Thesis, Rhodes University, 1992. http://hdl.handle.net/10962/d1005564.

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The Kuboos-Bremen Igneous Province comprises a linear zone of alkaline complexes that intrude Proterozoic and Pan-African rocks and trends in a northeast direction from the northwest of the Cape Province in South Africa into southern Namibia. Of the three most southerly complexes in Namibia. two comprise silicate rocks ranging from nepheline syenite to alkali-granite and are called the Grootpenseiland and Marinkas Kwela Complexes (GPC and MKC). The Marinkas Kwela Carbonatite Complex is the third and most northerly of the complexes. Isotopic age determinations on a number of rock types from both the silicate complexes yield ages around 520Ma and are consistent with published Pan-African ages for the Province. Each silicate complex shows a migrating locus of intrusion from Siundersaturated rocks in the southwest to Si-oversaturated rocks in the northeast. The complexes overlap in outcrop. The rocks are moderately to highly felsiC and none reflects primary magma compositions. The Si-undersaturated rocks from both complexes include side-wall cumulates formed from magmas that fractionated alkali-feldspar, clinopyroxene and amphibole. Foyaites also occur in the MKC and have a compositional range reflecting alkali-feldspar fractionation and, probably, some interaction with dolomite country rocks. Major and trace element data suggest that critically saturated alkali syenites occurring in both complexes evolved via protracted feldspar fractionation, and that critically saturated alkali-feldspar syenite occurring only in the GPC is a cumulate. The two rock types cannot be related genetically. Of the SI-oversaturated rocks in both complexes, those in the compositional range monzonite to granite were intruded before alkali-granites. Compositional diversity amongst the former reflects fractionation of feldspar and of mafic phases, but that process cannot genetically link the rocks to the alkali-granites. Isotopic compositions of Sr and Nd indicate that the silicate magmas were derived from an upper mantle source region characterised by low time-integrated Rb/Sr ratios and high time-Integrated Sm/Nd ratios, However, the evidence of Sr and 0 isotopic data is that the Si-oversaturated melts possibly interacted with a crustal component. presumably the Proterowlc rocks of the Namaqua Metamorphic Province. This interaction may explain the occurrence of apparently co-genetic rock series that evolved on opposite sides of the feldspar join in Petrogeny's Residua System. The Marinkas Kwela Carbonatite Complex was emplaced before the final intrusive phases of the MKC and exhibits unusually pronounced late-stage enrichment in manganese. The earliest intrusive rocks in the complex were nepheline syenites which were fenitised by later intrusions of sôvites. Although the commonly occurring magmatic sequence of sôvite-beforsite-ferrocarbonatite is observed at Marinkas Kwela, sôvites do not appear to have been parental to beforsites. Removal of apatite and early crystallisation of magnetite distinguish magnetite-rich beforsite from co-genetic apatite-rich beforsite. Two further magmatic sequences. the first from apatite-rich beforsite through ferrocarbonatite to Mn-rich ferrocarbonatite (high Fe/Mn) and the second from magnetite-rich beforsite to Mn-rich ferrocarbonatite (low Fe/Mn). reflect fractionation of dolomite and of dolomite+magnetite respectively.

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7

Lum, Clinton Chew Lun. "Aspects of the petrogenesis of alkali basalts from the Lunar Crater volcanic field, Nevada." Connect to resource, 1986. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1230660431.

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8

Pattie, Andrew J. D. "Hybridization of basic wall rocks in xenolithic igneous complexes." Thesis, Aston University, 1989. http://publications.aston.ac.uk/14371/.

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9

Chan, Heung-ngai. "Igneous and metamorphic rocks from SW Cyprus and NW Syria evidence for Cretaceous microplate collision and subsequent tectonic events in the Eastern Mediterranean /." Click to view the E-thesis via HKUTO, 2004. http://sunzi.lib.hku.hk/hkuto/record/B30711940.

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10

Riter, Joyce Christine Alexis. "Geochemical and tectonic evolution of the Colorado Plateau mantle lithosphere : evidence from Grand Canyon mantle xenoliths /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.

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11

Lang, James Robert. "Isotopic and geochemical characteristics of Laramide igneous rocks in Arizona." Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185600.

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Isotopic and trace element data on igneous rocks in nine multiphase magmatic complexes of Laramide age in Arizona place constraints on their petrogenesis and on the factors leading to the formation of porphyry copper deposits. The igneous rocks form a data array from ∊Nd(T) and Srₒ values of 0 and 0.704, to -14 and >0.710, respectively. Isotopic compositions indicate that early, intermediate volcanic rocks retained a mantle component whereas later intrusions were derived predominantly from Precambrian lower crust. The REE display temporally systematic behavior. Progressively younger igneous rocks in a district show a decreasing concentration of REE which is more pronounced for the HREE than for the LREE; they acquire greater upward concavity in their HREE profiles; and the Eu anomaly steadily becomes less negative. An increasing role for hornblende is indicated, either in the residuum of melting or as a fractionating phase. The evolving REE and isotopic behavior parallels the progression from barren, to subproductive, to productive intrusions. The geochemical behavior can be understood in the broader context of magmagenesis at the Laramide convergent margin. Early in the Laramide, the crust was cool and brittle, thereby allowing magmas formed in the mantle wedge as a consequence of volatile loss from the descending slab to ascend to high crustal levels. As the crust warmed the ascent of mantle-derived magmas was arrested in the lower crust where they induced anatexis in Precambrian crust. Three related models can account for the systematic REE behavior, crustal anatexis, and the timing of Laramide metallogenesis: (1) metasomatism of the lower crust, (2) progressively greater assimilation of hydrous crust by mantle-derived melts, and (3) migration of the anatectic zone into more hydrous rocks at higher crustal levels. Each process would allow melting to continue in confined columns of crust as well as provide increasingly volatile-rich magmas that were necessary for melts to evolve fluids capable of forming large porphyry copper deposits. The ultimate ability of a melt to form a porphyry copper deposit may, therefore, depend on characteristics obtained either in its crustal source region or during its passage through the crust.

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12

Wilt, Jan Carol. "Geochemical patterns of hydrothermal mineral deposits associated with calc-alkalic and alkali-calcic igneous rocks as evaluated with neural networks." Diss., The University of Arizona, 1993. http://hdl.handle.net/10150/186500.

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Six alkalinity and oxidation classes of fresh igneous rocks were correlated with trace elements in rock chip samples from temporally and spatially associated ore deposits. Learning vector quantization and back-propagation artificial neural networks correctly classified 100 percent of whole rock oxides and 99 percent of mineralized samples; discriminant analysis correctly classified 96 and 83 percent, respectively. The high degree of correlation between chemistries of igneous rocks and related mineralization implies genetic links between magmatic processes or sources and the ore deposits studied. The petrochemical classification was evaluated by assigning 43 deposits to classes defined on eight variation diagrams, training neural networks to classify analyses of 569 igneous and 887 mineralized samples, and testing the networks on their ability to classify new data. Whole rock analyses were obtained from mining districts in which trace element geochemistry was also available. Half the data was eliminated using five alteration filter graphs. The K₂O and Fe₂O₃/FeO versus SiO₂ diagrams and iron mineralogy best defined alkalinity and oxidation classes. Neural networks trained with 90, 80, 70, or 50 percent of the samples correctly classified 81 to 100 percent of randomly withheld data. SiO₂/K₂O ratios of alkali-calcic igneous rocks are 14-20 and of calc-alkalic 20-30. Fe₂O₃/FeO ratios are >0.8 with abundant magnetite and sphene for oxidized, 0.5-1.2 with magnetite, sphene, and rare ilmenite for weakly oxidized, and <0.6 with ilmenite only in reduced subclasses. Lead-zinc-silver deposits as at Tombstone and Tintic are related to oxidized alkali-calcic igneous rocks. Polymetallic lead-zinc-copper-tin-silver deposits, such as Santa Eulalia and Tempiute, Nevada, are associated with weakly oxidized alkali-calcic rocks. Tin-silver deposits of Llallagua and Potosi are correlated with reduced alkali-calcic intrusives. Porphyry copper deposits as at Ray and Sierrita are connected with oxidized calc-alkalic plutons. Gold-rich porphyry copper deposits, such as Copper Canyon and Morenci are linked to weakly oxidized calc-alkalic plutons. Disseminated gold deposits, such as Chimney Creek, Nevada, are temporally and chemically correlated with reduced calc-alkalic igneous rocks, although physical connections between plutons and Carlin-type deposits remain unconfirmed. Magma series classification and neural networks have profound applications and implications to exploration, alteration and zoning studies, and metallogenesis.

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13

Christodoulou, C. "Petrology of the plutonic rocks of the Macquarie Island Complex /." Title page, contents and abstract only, 1990. http://web4.library.adelaide.edu.au/theses/09PH/09phc556.pdf.

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14

La, Rocque Cynthia A. "Geochronology and petrology of north-central Gaspe igneous rocks, Quebec." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65499.

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15

Gallagher, Brookie. "A comparative study of the Badger Pass igneous intrusion and the foreland volcanic rocks of the McDowell Springs area, Beaverhead county, Montana implications for the local late cretaceous sequence of events /." unrestricted, 2008. http://etd.gsu.edu/theses/available/etd-04212008-172506/.

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Thesis (M.S.)--Georgia State University, 2008.
Title from file title page. Timothy E. LaTour, committee chair; Hassan A. Babaie, Eirik J. Krogstad, William J. Fritz, committee members. Electronic text (111 p. : ill. (some col.), maps (some col.)) : digital, PDF file. Description based on contents viewed Aug. 20, 2008. Includes bibliographical references (p. 100-104).

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16

Huang, Kuan. "Geological studies of igneous rocks and their relationships along the Kyrenia Range, Northern Cyprus." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/b40204030.

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17

Chan, Heung-ngai, and 陳向毅. "Igneous and metamorphic rocks from SW Cyprus and NW Syria: evidence for Cretaceous microplate collision andsubsequent tectonic events in the Eastern Mediterranean." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B30711940.

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18

Brewster, D. "Thermoremanence and other magnetic characteristics of synthetic analogues of the altered olivines of igneous rocks." Thesis, University of Newcastle Upon Tyne, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356138.

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19

Housden, J. "A magneto-mineralogical study of igneous rocks from the Rhum layered intrusion and the oceanic basements." Thesis, University of Newcastle Upon Tyne, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370858.

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20

Huang, Kuan, and 黃寬. "Geological studies of igneous rocks and their relationships along the Kyrenia Range, Northern Cyprus." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40204030.

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21

Curl, Edward Alexander 1972. "Parental magmas of the Bushveld Complex, South Africa." Monash University, Dept. of Earth Sciences, 2001. http://arrow.monash.edu.au/hdl/1959.1/9080.

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22

Perry, Anna F. Parker Donnie Franklin. "Petrology of Cascade Head Basalt, Oregon Coast Range, USA." Waco, Tex. : Baylor University, 2007. http://hdl.handle.net/2104/5079.

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23

Buick, Ian S. "The petrology and geochemistry of granitic rocks from the Entia domal structure, Harts Range, eastern Arunta Block, Central Australia /." Title page, contents and abstract only, 1985. http://web4.library.adelaide.edu.au/theses/09SM/09smb932.pdf.

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24

He, Yanhong. "Ages and geochemistry of the Xiong'er volcanic rocks along the southern margin of the North China Craton implications for the outgrowths of the paleo-mesoproterozoic supercontinent Columbia (Nuna) /." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B4163424X.

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25

Chhun, Eath. "Ordovician igneous rocks of the central Lachlan Fold Belt : geochemical signatures of ore-related magmas /." University of Sydney. Geosciences, 2004. http://hdl.handle.net/2123/610.

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The majority of economic gold deposits in NSW are associated with Ordovician-aged igneous rocks and are examples of the Cu-Au porphyry-skarn-epithermal association commonly developed in convergent margin to orogenic settings. They are among the oldest porphyry Cu-Au deposits in the Pacific Rim region. They are similar to younger deposits in terms of tectonic setting and structure, but the largest are chemically distinct, being associated with shoshonite magmas (Cadia, Ridgeway and Northparkes). The Lachlan Fold Belt (LFB) porphyries are subdivided into four sub-groups based mainly on their age relative to development of the Lachlan Transverse Zone (LTZ) structure. Two subgroups pre-date the LTZ, one group is syn�LTZ and one group post-dates the LTZ. No mineralisation has been found or reported among pre-I.TZ porphyries. but it is common in post- . l Z_ porphyries. Petrographic analysis and microprobe results establish a wide range of primary and secondary features within the Ordovician rocks examined in this study. Cale alkaline to shoshonitic affinities are supported by the variable abundance of primary K-feldspars. Primary mineral phases such as pyroxenes and igneous magnetite provide an indication of fractioning mineral assemblages responsible for igneous trends in magma chemistry. The hydrothermal mineral assemblages documented in these LFB study areas are characteristic of younger Cu-Au Porphyry style mineralisation. As expected, the most pervasive alteration is associated with highly mineralised shoshonitic Ordovician rocks at Ridgeway, and Cadia. the less strongly mineralised calc alkaline Ordovician rocks at Cargo. Copper Ilill and Fairholme. are correspondingly less strongly altered overall. although secondary mineral assemblages are locally abundant. Many varieties of oxides and carbonates are observed at the different study localities. Most of the studied samples conform to igneous chemical trends because they are weakly altered, although post magmatic processes, such as veining, are detectable in certain trends. The K2O enrichment of the studied samples is consistent with subductionmoditied mantle wedge sources. A few effects, such as the high Fe203 contents of some Ridgeway samples, probably reflect porphyry-style hydrothermal alteration processes. Host rocks at the Cadia and Ridgeway are entirely alkalic on the K2O versus SiO2 plot and shoshonitic on the Total Alkalies versus SiO2 plot. Igneous rocks at the other deposits display a range of compositions between low K tholeiites to shoshonites that in some cases reflects multiple igneous suites. The LREE and L1LE enrichments, and HFSE depletions (Nb, Ta and Ti) of the magmas associated with these deposits are characteristics of a subduction-related tectonic setting. They all fall in the volcanic-arc granite and syn-collisional granite field of the Nb-Y tectonic discrimination diagram. Several magma types are identified by differences in the HFSE and REE trends. Differences in the extent and style of magma fractionation are evident in the trace element data. The Ridgeway samples define a wider range of trace element concentrations than the Cadia samples that may indicate a greater extent of fractionation during emplacement of the Ridgeway magmas. Fairholme samples display a high Nh and /If trends that are distinct from the main fields on Zr variation diagrams. Compositional differences between larger Cu-Au deposits, Cadia-Ridgeway and smaller deposits, Copper Ifill, Cargo and Fairholme are evident in terms of Nb-Ta depletion and variation. The smaller deposits show constant Nb/Ta or negative Nb/Ta trends that extend to high Nb. The larger deposits display positive Nb/Ta trends that do not extend to high Nb. This distinction reflects a difference of preferential incorporation of Nb in a mineral phase (magnetite). Comparisons between Cadia-Ridgeway and other shoshonite (altered samples of Bajo de la Alumbrera, Argentina), calc alkaline magmas from New Zealand and rocks from other areas indicate that Nb/Ta is not directly correlated with the shoshonitic classification, K2O vs. SiO2, and that the Cadia-Ridgeway Nb and Ta variation is not the result of alteration. The fact that the weakly altered LFB Capertee shoshonites exhibit a narrow range of Nb and low Nb/Ta suggest the shoshonite trend for the LFB as a whole is a steep one on the Nb/Ta versus Nb plot. The results of this study could provide important information for exploration within the LFB. Only the Cadia and Ridgeway deposits display a wide range of Nb/Ta values and lack the near-horizontal trend seen for other localities associated with smaller deposits. The tectonic evolution of the LFB is a major factor contributing to occurrence of large porphyry Cu-Au deposits. The sequence of important events, however, commences with sub-crustal generation of oxidised magma and finishes with efficient Cu-Au accumulation by hydrothermal processes at favourable structural sites. The increase in Au-Cu deposit size from small (Copper Hill-Cargo) to world class (Cadia-Ridgeway) indicates the importance of magma composition during this process. The most obvious differences between the Cadia-Ridgeway and New Zealand rocks is that the latter are volcanic in origin and associated with an arc-back arc system. Therefore, they did not form in a tectonic regime suitable for the evolution of porphyries and the focussed movement of hydrothermal fluids during dilatant episodes. As a result, they are not linked to mineralisation despite having Nb-Ta and Nb/Ta variations that are typical of the high oxidation states in Au-prospective magmas of the LFB.

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26

McCormick, Andrew G. "Isotopic studies on the Eastern Mourne Centre and other tertiary acid igneous rocks of North East Ireland." Thesis, Queen's University Belfast, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335990.

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27

Kwong, J. K. P. "Effects of geological and environmental factors on the engineering properties of weathered igneous rocks in Hong Kong." Thesis, University of Leeds, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.354221.

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28

Ryskamp, Elizabeth Balls. "Petrogenesis of Eocene-Oligocene magmatism of the Sulphur Springs Range, central Nevada: The role of magma mixing." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1607.pdf.

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29

Basu, Arindam. "A study of the origin and evolution of jointing in igneous rocks of Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31227120.

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30

Rodriguez, Dionisio. "Geology and geochemistry of igneous rocks associated with mineral deposits in Northeastern Nicaragua, Central America." Licentiate thesis, Luleå tekniska universitet, 1994. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-25803.

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31

Ressel, Michael W. "Igneous geology of the Carlin Trend, Nevada the importance of Eocene magmatism in gold mineralization /." abstract and full text PDF (free order & download UNR users only), 2005. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3210296.

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32

Lewis, Kayla Christine. "An approach to modeling two-phase flow of seawater near an igneous dike." Thesis, Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/25709.

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33

MacLachlan, Kate. "The Wild Bight Group, Newfoundland Appalachians : a composite early to middle-Ordovician ensimatic arc and continental margin arc-arc rift basin /." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0011/NQ36208.pdf.

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34

Hulley, Vierah. "Reactions between country rock xenoliths and the magma of Uitkomst Complex, with implications for the origin of the sulphide mineralisation." Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-05282008-101011.

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35

Grosser, Benjamin. "Petrology and geochemistry of the Wildcat Gulch syenite, Gunnison County, Colorado /." Electronic version (PDF), 2005. http://dl.uncw.edu/etd/2005/grosserb/benjamingrosser.pdf.

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36

Leglue, Parker C. "Investigating the Origin of the Sierra Quemada Structure, Big Bend National Park, Texas through Geochemical Analyses of Related Igneous Rocks." Thesis, University of Louisiana at Lafayette, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=10814287.

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The origin of the Sierra Quemada structure, located near the center of Big Bend National Park in Texas, has long been debated. It was originally described as a large igneous pluton by Maxwell et al. (1967) and later as a caldera by publications from Barker et al. (1986), Henry et al. (1986), and Duex et al. (1994). However, more recent publications from the United States Geological Survey (USGS) from Scott et al. (2007) and Page et al. (2008) interpreted the Sierra Quemada structure as a failed caldera without associated collapse. The main objective of this thesis is to investigate relationships between units from outside of the Sierra Quemada structure and units from inside of it by determining the geochemical composition of each sample through X-ray Fluorescence (XRF) analyses. XRF analyses were performed on over thirty samples collected from both inside (I) and outside (O) of the Sierra Quemada, including members of the Chisos Formation such as the Ash Spring Basalt (Tasb), the Bee Mountain Basalt (Tbmb), the Mule Ear Spring Tuff (Tmet), and the Tule Mountain Trachyandesite (Ttmt) as well as ring fracture intrusions (RF), ash flow tuffs (AFT), lithic rich tuffs (LRT), and Chisos Undifferentiated (Tchu). The results of the analyses were plotted on Harker Variation Diagrams that compare SiO2 concentrations to other major elements and oxides that are common in igneous rocks, such as Al2O3, K2O, FeO, Fe2O3, MnO, CaO, TiO2, MgO, and Zr. Harker Variation Diagrams are used to investigate genetic relationships between samples. Some of the diagrams show strong correlations between samples that are suspected to be related, but others show somewhat weaker relationships. These variable results could be attributed to analytical uncertainties from the XRF which are common for elements with atomic numbers (Z) lower than 14 or to variations in lithologic compositions among samples.

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37

Rivard, Benoit. "Petrochemistry of a layered Archean magma chamber and its relation to models of basalt evolution." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66046.

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38

Miggins, Daniel Paul. "Temporal and geochemical insights related to volcanic and plutonic activity within Big Bend National Park, Texas." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2009. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.

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39

Abdollahi, Mohammad Javad. "Petrologic and geochemical study of crustal xenoliths from Calbuco Volcano, Chile (latitude 41°20ʹS)." FIU Digital Commons, 1990. http://digitalcommons.fiu.edu/etd/1080.

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Twenty Four samples of xenoliths and country rocks from the 1961 lava flow of Calbuco volcano have been studied. Fourteen samples have been analyzed for major elements and P, Ni, Ba, Cr, V, Zr, Sc, Y, and Sr. Five of these samples were further analyzed for Sm, Nd, Sr, and Pb isotope ratios. Seventeen samples were studied under the microscope and three samples were analyzed by microprobe for their pyroxene compositions. Based on petrographic studies xenoliths were divided into three groups. Fine grained xenoliths (groups I and II) probably formed from metamorphosed MORB-like basalts, whereas coarse grained xenoliths (group III) were apparently derived from cumulate minerals that crystallized from the Calbuco magma. The fine grained xenoliths were probably entrained in magma at intermediate levels of the crust, near the stability limit of amphibole to form pyroxene and plagioclase. In the coarse grained xenoliths amphibole that formed at depth dehydrated as the xenoliths were brought to the surface. The country rocks are apparently unrelated to the xenoliths.

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Mawby, Joanna. "Metamorphic and geochronologic constraints on Palaeozoic tectonism in the eastern Arunta Inlier." Title page, table of contents and abstract only, 2000. http://web4.library.adelaide.edu.au/theses/09PH/09phm462.pdf.

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Appendix 4 and 5 in pocket on back cover. Bibliography: p. 123-130. The isotopic data indicates the Harts Range Metamorphic Complex formed within a previously unrecognized intracratonic tectonic province in Central Australia

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41

Wodzicki, Wojtek Alexander. "The evolution of Laramide igneous rocks and porphyry copper mineralization in the Cananea district, Sonora, Mexico." Diss., The University of Arizona, 1995. http://hdl.handle.net/10150/187049.

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This study investigates the relationship between the evolution of the igneous and hydrothermal systems in the Cananea mining district located in northern Sonora, Mexico. The Cananea district was chosen for this study because post-mineral uplift and erosion has tilted the Cananea Range ∼15° to the east and exposed an oblique section through approximately 6 vertical kilometers of a mineralized volcano-plutonic system and because porphyry-related stockwork, breccia, and pegmatitic silicate-sulfide mineralization are all well developed and well exposed. Major, trace element, and isotopic data suggest that the Laramide (∼64-56 Ma) igneous rocks represent a cogenetic calc-alkaline magmatic series ranging in composition from gabbro to granite. Neodymium isotope (εNd = +0.7 to -5.7) and strontium isotope (⁸⁷Sr/⁸⁶Sr(initial) = 0.70570 to 0.71037) values show a smooth inverse correlation and combined with the major and trace element data suggest that the Laramide rocks evolved from a mantle-derived parent melt by coupled assimilation and fractional crystallization. Phase petrology, mineral compositions, whole rock geochemistry, and alteration mineralogy indicate water, metal, chlorine, and sulfur content of the magmas increased with increasing differentiation and reached a maximum in late stage differentiates. The mineralized quartz-feldspar porphyries represent the rapid upward emplacement of this enriched differentiate. Porphyry-related mineralization in the Cananea district includes pegmatitic silicate-sulfide mineralization represented by the La Colorada and Maria deposits. Detailed field and geochemical work on the Maria deposit suggests that the fluids, alteration assemblages and paragenetic relations in silicate-sulfide pegmatites are similar to those seen in stockwork- and breccia pipe-hosted porphyry Cu systems, but that silicate-sulfide mineralization represents transitional conditions in which magmatic fluids are concentrated in a small volume and undergo efficient cooling and decompression leading to formation of high-grade telescoped mineralization.

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42

Raymond, Anne Charlotte. "Carboniferous rocks of the eastern and central Midland Valley of Scotland : organic petrology, organic geochemistry and effects of igneous activity." Thesis, University of Newcastle Upon Tyne, 1991. http://hdl.handle.net/10443/315.

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An integrated organic petrological and geochemical approach has been adopted to evaluate the variation in the type of organic materials contributing to the Carboniferous succession in the eastern and central Midland Valley and to assess the extent to which both extrusive and intrusive igneous activity have modified the optical and geochemical properties of organic matter in this province. The type investigation reveals that the succession is extremely rich in organic matter, much of which originated from the vascular tissues of higher plants. The profound influence of terrestrial sedimentation throughout the Carboniferous is evident from the marked terrestrial overprinting of many known marine horizons. Much of the accumulated organic matter has been subjected to varying degrees of microbial reworking. In addition to the characterisation of organic matter in oil shales (lamosites and torbanitic shales), humic coals, sapropelic coals, marine bands and carbonaceous clasts incorporated in volcanic vent deposits, each of which bear different petrological and/or geochemical signatures, a detailed evaluation was undertaken of the Lower Carboniferous (Vis6an) sequence in east Fife, since the algal-rich shales in the Visean have long been considered as the most likely source rocks for the oil shows and modest petroleum accumulations which occur in the Midland Valley. Although many of the oils and bitumens studied have suffered varying degrees of biodegradation and/or water washing, these early suspicions have been confirmed by the close correspondence between the biomarker profiles of the oils/bitumens studied and those of the non-marine, lamositic shales of the Lothians Oil- Shale Group (Lothians oil shales). Notwithstanding the close spatial relationship which exists between oil shows and igneous materials in many areas of the Midland Valley, a hightemperature origin for all of these hydrocarbons need not be invoked because consideration of regional maturation levels indicates that the Lower Carboniferous succession attained maturities conducive to the generation of liquid (and gaseous) hydrocarbons through the "conventional" course of burial metamorphism by the end of the Carboniferous period. For the rank investigation, maturation profiles (based on vitrinite reflectance) for nearly forty boreholes and field sections in the Midland Valley were constructed and rank maps were prepared for different horizons throughout the Carboniferous. Lateral and vertical patterns of paleaoheatflow were monitored both before and after the intrusion of the Midland Valley Sill. The higher regional levels of organic maturation recorded in the west of the Midland Valley, at all levels in the Carboniferous, correspond to an increased thickness of the volcanic pile in the central and western parts of the province, suggesting that a greater regional heat sink existed in the west during the Carboniferous. The optical and textural properties of vitrinite have been used to constrain the timing of sill emplacement with respect to the imposition of regional levels of coalification, from which deductions have been made about the importance of igneous activity in modifying background maturation profiles, not only in the Midland Valley, but elsewhere in the world. The early Permian tholeiitic Midland Valley Sill, which underlies most of the eastern and central Midland Valley, has caused the development of extensive thermal aureoles, in marked contrast to the preceding Lower to mid-Carboniferous alkaline-dolerite intrusions which have failed to induce any widespread alteration of organic matter. This major difference in organicmatter response is explained in terms of differing rank levels of organic matter at the time of intrusion and to differences in the degree of sediment compaction and water saturation, factors which probably also strongly influenced the rank level of organic matter prior to invasion by magmas. Maturation of organic matter closely associated with extensive Surtseyan-type volcanicity in the eastern part of the Midland Valley displays no relationship to the regionally developed coalification in associated sediments. Maturation levels of clasts in pyroclastic vent deposits have generally not been raised much above the regional reflectance level, suggesting the incorporation of organic matter in ash streams in which water was an important coolant and protective agent. The effects that different heating rates have had on commonly used molecularmaturity indices, based on both saturated and aromatic hydrocarbons, in different types of organic matter were also investigated. Results show that molecular-maturity parameters may significantly underestimate the maturities of samples in which the organic matter has experienced high rates of heating, either through igneous activity or a high background geothermal gradient, and that distinct "reversals" occur in many ratios at elevated ranks. Type influences are inferred for Tmas and hopane/moretane ratios and for parameters based on distributions of methylphenanthrene isomers. Anomalous assessments of sample maturity may additionally derive from the lowering (suppression) of vitrinite reflectance which invariably occurs in samples containing abundant liptinitic materials, principally sporinite in the Carboniferous of the Midland Valley. The results presented in this thesis carry important implications for hydrocarbon exploration. Accurate appraisals will only be achieved through the complete integration of organic petrological, geochemical and geological data in sedimentary sequences containing abundant hydrogen-prone organic components and/or in basins in which there has been widespread igneous activity.

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43

Asmerom, Yemane. "Mesozoic igneous activity in the southern Cordillera of North America: Implications for tectonics and magma genesis." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184421.

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The first part of this dissertation deals with the timing of Mesozoic igneous activity in southern Cordillera of North America and its tectonic implications. A representative section in Santa Rita Mountains is dated using the zircon U-Th-Pb isotopic method. The oldest unit, the lower member of the Mt. Wrightson Formation, is concordantly dated at 210 ± 3 Ma. Initial basaltic andesite to andesite volcanism was followed by deposition of redbeds and associated volcanic rocks that are dated at 200 Ma. Felsic volcanism and eolian sand deposition may have spanned from 190 to 170 Ma. The Piper Gulch Granodiorite, representing the earliest Mesozoic intrusive equivalent, gives concordant dates of 188 ± 2 Ma. A second cycle of andesite and rhyolitic volcanism and sedimentation is dated at 151 ± 5 Ma using the whole-rock Rb-Sr isotopic method. The Hovatter Volcanics in the Little Harquahala Mountains, southwestern Arizona is dated at 165 Ma. Whole-rock Rb-Sr isotopic method on the same rocks gives a coherent reset isochron of 70 ± 3 Ma (Appendix III). A new stratigraphic correlation is proposed based on the dating data. Tectonic models proposed by previous workers to account for what seemed to be the lack of Triassic volcanic rocks are not necessary. This part of the Cordillera was an uplifted arc terrane during the Early Mesozoic (Appendix II) and may have provided volcanic detritus to the Late Triassic Chinle Formation in the Colorado Plateau. The second part of the dissertation deals with magma evolution and crust modification during arc magmatism. Rocks in southeastern Arizona have ƭ(N)(d) values of -3.4 to -6.4, while rocks to the west have ƭ(N)(d) values ranging from -8.5 to -9.2. An ƭ(N)(d) value of +2 for a Jurassic basalt indicates the presence of depleted mantle under the arc. Using lower crust and mantle end-members, 20 to 40% mantle input is estimated. This seems to argue for continuous growth model of the continental crust. Combined REE and isotopic data indicate that assimilation of lower crust by mantle melts followed by fractional crystallization took place. Detailed study indicates that the lower crust along sites of arc magmatism gets progressively hybridized by the mantle, becoming more mantle-like with time.

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44

Marchand, Kateri. "Étude d'éléments structuraux dans la demie nord du Canton de McKenzie, Chibougamau /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1990. http://theses.uqac.ca.

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45

Barker, Walter Blaine. "The Tertiary Igneous Terrain in the Vicinity of the King Tonopah Mine, Tonopah, Nevada: An Exploration Case Study." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/244077.

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Uneconomic epithermal precious metal mineralization and associated alteration occur in the Tonopah Property, and are similar in style, although much less intense, to the deposits of the Tonopah camp two miles south. Mineralization is localized within a set of northwest-trending faults within the Tonopah, Mizpah, and King Tonopah Member of the Fraction-Tuff formations, and is associated with widespread propylitic and sparse fracture-localized potassic and argillic alteration. A younger set of Mn-calcite veins, anomalous in manganese, mercury, arsenic, and antimony, occurs in northeast-trending faults cutting older formations as well as the younger Tonopah Summit Member of the Fraction Tuff. This mineralization is possibly associated with silicification, zeolitization, and clay-alteration of the Fraction Tuff. The Tonopah Summit Member of the Fraction Tuff is reinterpreted as younger than the King Tonopah Member. Mega-breccia and basin morphology in the northeast may indicate an eruptive vent in this area.

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46

Lawrence, Robert William. "The structure and metamorphism of the Irindina supracrustal assemblage on the western side of the Entia Dome, Harts Range, central Australia /." Title page, contents and summary only, 1987. http://web4.library.adelaide.edu.au/theses/09PH/09phl4225.pdf.

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Thesis (Ph. D.)--University of Adelaide, Dept. of Geology and Geophysics, 1987.
Typescript. Maps in back pocket of v. 1. Microfiches in back pocket of v. 2. Microfiches contain petrographic descriptions, total rock XRF analyses and microprobe analyses. Includes bibliographical references (leaves 160-183 (v. 2)).

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47

Vogel, Derek Christian. "The geology and geochemistry of the Agnew Intrusion : implications for the petrogenesis of early Huronian mafic igneous rocks in central Ontario, Canada /." Connect to thesis, 1996. http://eprints.unimelb.edu.au/archive/00000708.

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48

BOISSON, DOMINIQUE. "Etude geologique du massif du nord d'haiti (hispaniola - grandes antilles)." Paris 6, 1987. http://www.theses.fr/1987PA066771.

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Le massif du nord est un edifice cretace et tertiaire polyphase appartenant a la bordure nord de l'orogene caraibe. Son etude stratigraphique et petrographique permet d'y distinguer : une logique de depot post-danienne caracterisee par : une sedimentation neogene essentiellement detritique : deux cycles de plate-forme carbonatee (l'un a l'eocene et l'autre au miocene inferieur) separes par une discordance fini-eocene et une lacune locale de sedimentation oligocene. Tous ces terrains sont supportes par l'ensemble volcano-sedimentaire de l'arc cretace recoupe par plusieurs generations d'intrusifs; le chimisme de cet ensemble indique clairement son appartenance a une lignee calco-alcaline d'arc insulaire. Le substratum de cet ensemble affleure tres peu et est constitue de roches basiques et ultrabasiques d'age inconnu. L'inventaire des differentes structures qui affectent les terrains du massif du nord combine aux contraintes stratigraphiques conduit a y retenir six episodes de deformation

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49

Pilote, Pierre. "Stratigraphie et significations des minéralisations dans le secteur du mont Bourbeau, canton de McKenzie, Chibougamau /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1986. http://theses.uqac.ca.

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Mémoire (M.SC.A.)--Université du Québec à Chicoutimi, 1986.
"Mémoire présenté en vue de l'obtention de la maîtrise en sciences de la terre" Cartes contenues dans une pochette. CaQCU CaQCU Document électronique également accessible en format PDF. CaQCU

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50

Mwenze, Tshipeng. "The implications of Sr and Nd isotope data on the genesis of the Platreef and associated BMS and PGE mineralisation, Bushveld Igneous Complex, South Africa." University of the Western Cape, 2019. http://hdl.handle.net/11394/6922.

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Philosophiae Doctor - PhD
The Platreef is a platinum group elements (PGE) deposit located in the Northern limb of the Bushveld Igneous Complex (BIC). It is a series of mafic and ultramafic sills that are overlain by rocks from the Main Zone (MZ) of the BIC. In comparison to PGE deposits (i.e., Merensky Reef and the UG-2 chromitite) occurring in the Critical Zone (CZ) of the Eastern and Western Limbs of the BIC, which are less than 1 m in thickness, the Platreef is 10 to 400 m in thickness and is comprised of a variety of rocks. PGE mineralisation in the Platreef is not confined to a specific rock type, and its distribution and styles also vary with depth and along strike. Despite the numerous researches that have been conducted, the genesis of Platreef is still poorly understood. New major and trace elements in conjunction with Sr–Nd isotope data, generated from whole-rock analyses of different Platreef rocks, were collected from four drill cores along its strike. The data were examined to determine the source of the magmas and identify the processes involved in its genesis. The study also aimed at establishing whether a genetic link exists between the Platreef magmas and the magmas that formed the Lower Zone (LZ), CZ and MZ in the Rustenburg Layered Suite (RLS) of the BIC. The petrography revealed that the Platreef in the four drill cores consists of harzburgite, olivine pyroxenite, pyroxenite, feldspathic pyroxenite and norite. Based on the textural and modal mineralogy variations, feldspathic pyroxenite was subdivided into five types (I, II, III, IV and V). The variation in the average contents of MgO, LaN/YbN and ΣREE for the Platreef rocks are consistent with the modal mineralogy from the least to the most differentiated rocks. However, the Sr–Nd isotope data of the Platreef rocks have revealed two distinct groups of samples with decreasing ɛNd2060. Group 1 consists of pyroxenite and feldspathic pyroxenite II, III and V having ɛNd2060 values that range from –8.4 to –2.9, and 87Sr/86Sr2060 values from 0.707281 to 0.712106. The Platreef rocks of group 2 consist of olivine pyroxenite and feldspathic pyroxenite Type I with ɛNd2060 ranging from –12.6 to –10.8, and 87Sr/86Sr2060 ranging from 0.707545 to 0.710042. In comparison to the LZ, CZ and MZ rocks, which have ɛNd values ranging from –8.5 to –5.1, and 87Sr/86Sr ranging from 0.704400 to 0.709671, Platreef pyroxenite of group 1 have lower negative ɛNd2060 values (from –3.8 to –2.9) and higher 87Sr/86Sr2060 values from 0.709177 to 0.710492, whereas feldspathic pyroxenite of group 1 have overlapping ɛNd2060 values (from –8.4 to –4.9) but also higher 87Sr/86Sr2060 values (from 0.707281 to 0.712106). Instead, the Platreef olivine pyroxenite and feldspathic pyroxenite in group 2 highly negative ɛNd2060 values and overlapping 87Sr/86Sr2060 values. It is therefore suggested that the Platreef magmas derived from the partial melting of an heterogeneous mantle source comprising depleted mantle melts and both metasomatized slightly unradiogenic Nd enriched melts and highly unradiogenic Nd enriched melts from the subcontinental lithospheric mantle. These magmas ascended via the continental crust using different paths and interacted with rocks of different Sr–Nd isotopic compositions which resulted in the formation the hybrid magmas. The study speculates that sulphide saturation in the Platreef magmas was reached in the staging chambers at depth, and the varying styles of the PGE mineralisation in the Platreef rocks are the result of the varying degree of partial melting of the heterogeneous source for their magmas. In conlusion, this study suggests that the genesis of the Platreef is much more complex and should be considered very much independent from processes involved in the genesis of the RLS in the Eastern and Western Limbs of BIC in agreement with earlier studies.
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