Geology of the Sand Creek porphyry molybdenum prospect /

The Sand Creek Prospect is located within the eastern exposed margin of the Coast Plutonic Complex. The occurrence is a plug and dyke porphyry molybdenum deposit. The rock types, listed in decreasing age: 1) metamorphlc schists and gneisses; 2) diorite suite rocks - diorite, quartz diorite, tonalite; 3) rocks of andesitic composition; 4) granodiorites, coarse porphyritic granodiorite, quartzfeldspar porphyry, feldspar porphyry; and 5) lamprophyre. Hydrothermal alteration is known to have resulted from emplacement of the hornblende-feldspar porphyry through to the quartz-feldspar porphyry. Molybdenum mineralization is chiefly associated with the quartz-feldspar porphyry. Ore mineralogy is dominated by pyrite with subordinate molybdenite, chalcopyrite, covelline, sphalerite, galena, scheelite, cassiterite and wolframite. Molybdenite exhibits a textural gradation outward from the quartz-feldspar porphyry. That is, disseminated rosettes and rosettes in quartz veins to fine-grained molybdenite in quartz veins and potassic altered fractures to fine-grained molybdenite paint or 6mears in the peripheral zones. The quartz-feldspar porphyry dykes were emplaced in an inhomogeneous stress field. The trend of dykes, faults and shear zones is 0^1° to 063° and dips between 58° NW and 86* SE. Joint Pole distribution reflects this fault orientation. These late deformatior maxima are probably superimposed upon annuli representing diapiric emplacement of the plutons. A model of emplacement involving two magmatic pulses is given in the following sequence: Diorite pulse (i) dioritequartz diorite, (ii) tonalites; granodiorite pulse (iii) hornblende-fildspar microporphyry, hornblende/biotite porphyry, (iv) coarse grained granodiorite, (v) quartz-feldspar porphyry, (vi) feldspar porphyry, and (vii) lamprophyre. The combination of plutonic and coarse porphyritic textures, extensive propylitic overprinting of potassic alteration assemblages suggests that the. prospect represents the lower reaches of a porphyry system.

Geology of the Gander Group, Gander River Ultramafic Belt and Davidsville Group in the Jonathan's Pond - Weir's Pond Area, northeast Newfoundland /

The study area is situated in NE Newfoundland between Gander Lake and the north coast and on the boundary between the Gander and Botwood tectonostratigraphic zones (Williams et al., 1974). The area is underlain by three NE trending units; the Gander Group, the Gander River Ultramafic Belt (the GRUB) and the Davidsville Group. The easternmost Gander Group consists of a thick, psammitic unit composed predominantly of psammitic schist and a thinner, mixed unit of semipelitic and pelitic schist with minor psammite. The mixed unit may stratigraphically overlie the psammitic unit or be a lateral facies equivalent of the latter. No fossils have been recovered from the Gander Group. The GRUB is a terrain of mafic and ultramafic plutonic rocks with minor pillow lava and plagiogranite. It is interpreted to be a dismembered ophiolite in thrust contact with the Gander Group. The westernmost Davidsville Group consists of a basal conglomerate, believed deposited unconformably upon the GRUB from which it was derived, and an upper unit of greywacke and slate, mostly of turbidite origin, with minor limestone and calcareous sandstone. The limestone, which lies near the base of the unit, contains Upper Llanvirn to Lower Llandeilo fossils. The Gander and Davidsville Groups display distinctly different sedimentological , structural and metamorphic histories. The Gander Group consists of quartz-rich, relatively mature sediment. It has suffered three pre-Llanvirn deformations, of which the main deformation, Dp produced a major, NE-N-facing recumbent anticline in the southern part of the study area. Middle greenschist conditions existed from D^ to D- with growth of metamorphic minerals during each dynamic and static phase. In contrast, the mineralogically immature Davidsville Group sediment contains abundant mafic and ultramafic detritus which is absent from the Gander Group. The Davidsville Group displays the effects of a single penetrative deformation with localized D_ and D_ features, all of which can be shown to postdate D_ in the Gander Group. Rotation of the flat Gander S- into a subvertical orientation near the contact with the GRUB and the Davidsville Group is believed to be a Davidsville D^ feature. Regional metamorphism in the Davidsville Group is lower greenschist with a single growth phase, MS . These sedimentological, structural and metamorphic differences between the Gander and Davidsville Groups persist even where the GRUB is absent and the two units are in contact, indicating that the tectonic histories of the Gander and Davidsville Groups are distinctly different. Structural features in the GRUB, locally the result of multiple deformations, may be the result of Gander and/or Davidsville deformations. Metamorphism is in the greenschist facies. Geochemical analyses of the pillow lava suggest that these rocks were formed in a back-arc basin. Mafic intrusives in the Gander Group appear to be the result of magraatism separate from that producing the pillow lava. The Gander Group is interpreted to be a continental rise prism deposited on the eastern margin of the Late Precambrian-Lower Paleozoic lapetus Ocean. The GRUB, oceanic crust possibly formed in a marginal basin to the west, is believed to have been thrust eastward over the Gander Group, deforming the latter, during the pre-Llanvirnian, possibly Precambrian, Ganderian Orogeny. The Middle Ordovician and younger Davidsville Group was derived from, and deposited unconformably on, this deformed terrain. Deformation of the Davidsville Group occurred during the Middle Devonian Acadian Orogeny.

Geology of Hebes Chasma, Valles Marineris, Mars

Hebes Chasma is an 8 km deep, 126 by 314 km, isolated basin that is partially filled with interior layered deposits (ILD), massive deposits of water altered strata. By analyzing the ILD’s structure, stratigraphy and mineralogy, as well as the perimeter faults exposed in the plateau adjacent to the chasma, the evolution and depositional history of Hebes Chasma is interpreted. Three distinct ILD units were found and are informally referred to as the Lower, Upper and Late ILDs. These units have differing layer thicknesses, layer attitudes, mineralogies and erosional landforms. Based on observations of the plateau, wall morphology and slump blocks within the chasma’s interior, chasma evolution appears to be controlled by cross-faults that progressively detached sections of the wall. A scenario involving the loss of subsurface volume and ash fall events is proposed as the dominant setting throughout Hebes’ geologic history.

Geological collections : dynamical geology and petrography

UANL

Geology and Geochronology of Silica Sands of Coastal Plain of Thiruvananthapuram District, Kerala,India,With Special reference to Late Quaternary Environment

Department of Marine Geology & Geophysics, Cochin University of Science & Technology

The Engineering Geology of the Landslides on the North Coast of the Isle of Wight and their Stabilisation

Transfer thesis

Science 3 : biology and geology.

Ofrece los contenidos del currículo oficial de biología y geología de tercero de la ESO en inglés. Esta opción es para los centros que deseen incorporar el desarrollo del idioma inglés en la enseñanza de otras materias escolares. Facilita la integración de los conocimientos y fomenta el desarrollo del razonamiento. Permite cumplir los objetivos curriculares tanto en España como en el Reino Unido.

Science 3. Teacher's book : biology and geology.

Ofrece los contenidos del currículo oficial de biología y geología de tercero de la ESO en inglés. El propósito principal de este manual del profesor, es proporcionar apoyo en las aulas, desde un punto de vista científico y claro. El material que ha sido desarrollado desde una perspectiva científica, facilita la integración de los conocimientos y fomenta el desarrollo del razonamiento. Permite cumplir los objetivos curriculares tanto en España como en el Reino Unido.

Science 4 : biology and geology.

Ofrece los contenidos del currículo oficial de biología y geología del cuarto curso de la ESO en inglés. Esta opción es para los centros que deseen incorporar el desarrollo del idioma inglés en la enseñanza de otras materias escolares. Facilita la integración de los conocimientos y fomenta el desarrollo del razonamiento. Permite cumplir los objetivos curriculares tanto en España como en el Reino Unido.

Science 4. Teacher's book : biology and geology.

Ofrece los contenidos del currículo oficial de biología y geología del cuarto curso de la ESO en inglés. El propósito principal de este manual del profesor, es proporcionar apoyo en las aulas, desde un punto de vista científico y claro. El material que ha sido desarrollado desde una perspectiva científica, facilita la integración de los conocimientos y fomenta el desarrollo del razonamiento. Permite cumplir los objetivos curriculares tanto en España como en el Reino Unido.

OCR AS-A2 Geology

Texto de Geología para los cursos específicos del General Certificate of Education Advanced level (A,A2). Proporciona definiciones de términos clave importante de las especificaciónes. Incluye consejos sobre cómo mejorar los conocimientos para ayudar a los alumnos a prepararse para la evaluación práctica. La publicación está estructurada en cuatro unidades con preguntas de examen al final de cada una de ellas: Tectónica de la tierra; Rocas; Geología Ambiental; Evolución de la Vida, Tierra y Clima; y dos de habilidades prácticas para los niveles A y AS respectivamente. Tiene las soluciones a las cuestiones .

Physical geology : the science of Earth.

Es una herramienta de aprendizaje para entender los fundamentos científicos de la geología, así como las consecuencias de las acciones humanas sobre nuestro planeta. Ofrece a los estudiantes un marco para aprender y pensar de forma crítica y ayudarles a tomar decisiones sobre cuestiones tan importantes como: el calentamiento global, la superpoblación, el problema del agua dulce y otros.