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Geological Origin as the Basis for the Systematics of Deposits
Published in Artur Dyczko, Andrzej M. Jagodziński, Gabriela Woźniak, Green Scenarios: Mining Industry Responses to Environmental Challenges of the Anthropocene Epoch, 2022
Extrusive igneous deposits are associated with undersea magma eruptions or lava flows onto the Earth’s surface. The first results are pyrite deposits in which iron sulphides are the dominant component, as well as chalcopyrite, bornite, sphalerite, galena and others. They form elongated forms with lengths of thousands of meters. This class includes specific mineral formations: pyrite, copper-pyrite and polymetallic-pyrite (Gruszczyk 1984). Other classes of deposits assigned to this category include: exhalation-sedimentary (in which the mineral substance that builds the rocks was brought into the basin by submarine exhalations, but they have a form and structure typical of sedimentary rocks), effusive rocks (related to openings formed in the initial and final stages of geosynclinal development, diversified in terms of minerals and chemicals, including basalts, andesites, dacites), pyroclastic (made of pyroclastic deposits, i.e. blocks and volcanic bombs, lapilles, sands, and volcanic ashes), associated with gas exhalations (e.g. some native sulphur deposits) and associated with hot springs (Hg, Sb, Mn, W, Au and Ag ore deposits).
Minerals and rocks
Published in A.C. McLean, C. D. Gribble, Geology for Civil Engineers, 2017
Extrusive igneous rocks have formed (as lavas) by rapid cooling of magma at the surface, and are fine grained. Conversely, most, but not all, fine-grained igneous rocks are extrusive. Hypabyssal igneous rocksform minor intrusions (dykes and sills, see Section 2.2.3) which have solidified below the surface, and have cooled more slowly than extrusive rocks because of the thermal insulation of the surrounding country rocks. They are typically, but not invariably, medium grained. Plutonic igneous rocks have formed by the slow cooling of great volumes of magma, typically at depths of a few kilometres, within the Earth. It is erosion throughout geological time that has removed the overlying rocks and revealed these plutonic intrusions at the surface. The heat from their enormous bulk can dissipate only very slowly and they are normally coarse grained.
Aggregates for Asphalt and Concrete Mixes
Published in Rajib B. Mallick, Tahar El-Korchi, Pavement Engineering, 2017
Rajib B. Mallick, Tahar El-Korchi
Geologically, parent rocks can be divided into three types: igneous, sedimentary, and metamorphic. Extrusive igneous rocks are formed from magma—a viscous liquid composed of silicates, which is erupted onto the earth’s surface as ash, lava flows, or solid chunks. These rocks are classified according to their texture and mineralogy and are generally finer grained than the intrusive igneous rocks (which are not visible on the earth’s surface, but remain below it). Extrusive rocks include andesite, basalt, and rhyolite. In the case of intrusive igneous rocks, magma is forced into other rocks as crosscutting or parallel (to layers of other rocks) and may consist of large areas consisting of thousands of square miles. Such large masses tend to contain a greater amount of silica (50%–60%), compared to smaller dark-colored intrusions, which are sometimes referred to as trap rock. Intrusive rocks include granite, diorite, gabbro, and peridotite. Generally, good-quality aggregates can be produced from different types of igneous rocks, which may contain a wide variety of minerals.
Reconciling the onshore/offshore stratigraphy of the Canning Basin and implications for petroleum prospectivity
Published in Australian Journal of Earth Sciences, 2023
C. T. G. Yule, J. Daniell, D. S. Edwards, N. Rollet, E. M. Roberts
A suite of mafic igneous rocks consisting of several units, comprise the North West Shelf MMP. These igneous rocks have age ranges from 336 ± 2 Ma to 163 ± 13 Ma derived from a variety of geochronological techniques (Yule & Spandler, 2022). The aggregation of mafic igneous units were mapped across the onshore Canning, offshore Canning, Browse, Roebuck and Northern Carnarvon basins (Figure 7). The time range of the North West Shelf MMP is 172–5865 ms (TWT) where it is shallowest on the southern Browse Basin and northeast Northern Carnarvon Basin and deepest towards the Argo Abyssal Plain. The maximum thickness of the mafic lava delta system in the Roebuck Basin is ∼3700 ms (TWT) (Figure 5c). This thickness is consistent with other studies including MacNeill et al. (2018) and Rollet, Shi, et al. (2019). The thickest section that has been drilled is ∼500 m in Hannover South 1 and Anhalt 1 in the Roebuck Basin where they have been broadly described as ‘weathered volcanics’ in the well completion reports. Samples of mafic igneous units across the study area confirm that these rocks are either intrusive dolerites or extrusive basalts and mostly consist of plagioclase, pyroxene and magnetite (Yule & Spandler, 2022). Generally, the North West Shelf MMP is flat onshore and near the coastline, and the dip steepens downdip. However, it is anomalously deeper in the Fitzroy Trough (which hosts a ∼3.5 second [TWT] thick and ∼40 km wide intrusion; Figure 5a, c), shallower on the Bedout High, and absent on the Broome Platform. Mafic igneous units are easily identifiable from seismic reflectors that are generally much stronger than the surrounding sedimentary rocks and feature strong signal attenuation below (Figure 3; Yule et al., 2022).
Defluoridation of drinking water by magnesium and aluminum electrocoagulation in continuous flow-rate: a response surface design
Published in Environmental Technology, 2022
Ana Gabriela Sierra-Sánchez, Verónica Martínez-Miranda, Elia Alejandra Teutli-Sequeira, Ivonne Linares-Hernández, Guadalupe Vázquez-Mejía, Monserrat Castañeda-Juárez
Temascalcingo is located at the northeastern tip of Mexico state (Figure 2(a)). At 19° 48′ 10″ north latitude and 99° 53′ 49″ west longitude of the Greenwich Meridian. Surface water is from the runoff of the volcanic system [27]. The predominant geology is extrusive igneous rock, mainly andesite (32.38%), whose mineral composition generally comprises plagioclase and several other ferromagnesic minerals, such as pyroxene, biotite and hornblende (rich in Si, Ca, Mg, Fe, Al and F).