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Petroleum Geological Survey
Published in Muhammad Abdul Quddus, Petroleum Science and Technology, 2021
Under-ground water may be stationery or running depending on the environmental condition. The water running through subsurface rock formations dissolves some of the constituents of the rock. With time and distance traveled, the dissolved minerals are built up to saturation point in the water. At the saturation stage, less soluble minerals, limestone and dolomite, precipitate out and are re-deposited and accumulate in a new environment to produced calcite and dolomite rocks. The chemical rock is also formed from naturally occurring minerals or by chemical precipitation. Precipitated calcium carbonate is formed by the interaction of carbonic acid with calcium ions present in the soluble saturated solution. Dolomite is the double carbonate of calcium and magnesium. At shallow depth, calcite is metamorphosed into oolite sedimentary rock. Oolite is a spheroidal grain of lime. Gypsum (CaSO4) is a mineral of salt rock; it is precipitated and deposited from water containing sulfate ions.
Recognising the different types of building stone
Published in John A. Hudson†, John W. Cosgrove, Understanding Building Stones and Stone Buildings, 2019
John A. Hudson†, John W. Cosgrove
The fourth example limestone is Ancaster stone, an oolitic Jurassic limestone from Lincoln-shire, this being our most northern illustrative limestone example. The term ‘oolitic’ means containing ooliths—which are small, spherical, calcium carbonate particles of the order of 0.25–2 mm diameter. The term derives from the Greek for ‘egg’ and the oolites form by the precipitation of calcium carbonate around a small fragment of a shell or sand grain. Water currents can form cross-bedding in these oolites in exactly the same way as they do in sandstones (see Section 3.5.3) and it is the cross-bedding that gives the Ancaster stone its characteristic texture, e.g., Figures 3.41 and 3.42. Like many of the building stones in Britain, this limestone has been used for centuries by the Romans and Saxons through to the present day. The stone can be found in all the principal churches in Norwich, and has been used for the church and castle at Newark, and in buildings in Cambridge.
Minerals, rocks and sediments
Published in Richard J. Chorley, Stanley A. Schumm, David E. Sugden, Geomorphology, 2019
Richard J. Chorley, Stanley A. Schumm, David E. Sugden
Boundstones are autochthonous (i.e. formed in place) coral-reef (i.e. bioherm) or platform biochemical deposits exhibiting growth bedding and other growth structures. The calcareous clastics are allochthonous (i.e. formed elsewhere and mechanically broken up and transported). Coarse clastics are either breccias, especially that formed by wave attack on the coral-reef front, or conglomerates, formed as the result of marine and fluvial transportation of coarse limestone material. Carbonate sandstones include wide admixtures of carbonate sand and muds, which were originally deposited on reef flats to the seaward of reef faces and in back-reef zones. A particularly pure and well-sorted carbonate sand is composed of oolites, which are spherical marine carbonate deposits around nuclei developed especially in offshore areas of strong bottom currents. Carbonate mudstones, characteristic of lagoons, tidal flats and deep-sea environments, are mainly developed from the abrasion of carbonate sand particles or pieces of coral or from the silt and clay-sized particles produced by calcareous planktons and algae (e.g. chalk).
Effective poroelastic properties of N-layered composite sphere assemblage: An application to oolitic limestone
Published in European Journal of Environmental and Civil Engineering, 2023
H.T. Trieu, N.B. Nguyen, M.N. Vu, T.T.N. Nguyen, N.H. Tran, D.T. Pham, T. Nguyen-Sy
As stated by Lion, Ledésert, et al. (2004), the external envelopes of oolite are much more porous than the oolite itself and the cement matrix. This observation is similar to several oolitic rocks studied in the literature (e.g. Fabre & Gustkiewicz, 1997; Ghabezloo et al., 2009; Gourri, 1991; Hart & Wang, 1995). In micromechanical point of view, we consider the highly porous boundary of the ooid as the interphase between ooid and the cement matrix. An ooid is coated by two layers interphase and the matrix, i.e. 3-layered concentric spherical composite material. Therefore, four-phase composite sphere model is used for the studied limestone. Moreover, each phase (i.e. oolite, interphase and cement matrix) is made from solid (calcite) and pores. Two-step homogenisation approach (micro-meso and meso-macro) is proposed to estimate the poroelastic properties of the Bourgogne oolitic limestone. In the following, pore and calcite (micrite, sparite) are referred as the microscale; while ooid, interphase and cement matrix are considered as the mesoscale; and finally a REV of the limestone is envisaged as the macroscale. Figure 4 shows the principle scheme of the proposed two-step micromechanical model. The first step (step I) consists in the upscaling from the microscopic to mesoscopic scales, which is performed by using the differential self-consistent scheme (Norris, 1985; Zimmerman, 1996). The second step (step II) derives the macroscopic poroelastic properties of the oolitic limestone from properties of mesoscopic components (oolite, interphase and cement matrix) in the framework of the four-phase CSA model.
Geoheritage at the small scale: tidal-zone bubble-sand structures as diagnostic paleo-environmental indicators, and their geoheritage significance
Published in Australian Journal of Earth Sciences, 2019
Globally, bubble-sand structures have been recorded as keystone vugs (in the ‘bubble-sand structure’ sense of the term as determined from description and illustrations in the literature and excluding general birdseyes’, shrinkage cracks’ and microbial and algal fenestral structures) in rocks of Cenozoic, Mesozoic, Devonian, Silurian and Cambro-Ordovician age, but they are rare. Given the confusion in terms and misapplication of terms as discussed above, mere mention of keystone vugs in the literature was not sufficient for us to accept that bubble-sand structures had been recorded—we opted to accept the occurrence of ‘keystone vugs’ as ‘bubble-sand structures’ in ancient sequences if they were illustrated or were accompanied by stratigraphic/sedimentary descriptions indicating beach deposits, or perhaps tidally exposed shoal situations. In this context, keystone vugs have been recorded and illustrated from Cretaceous beach calcarenite in Texas (Inden & Moore, 1983), the interpreted swash zone of an oolite beach in Cretaceous sequences capping a guyot (Strasser, Arnaud, Baudin, & Röhl, 1995), in Jurassic oolitic beach calcarenites in Scotland (Hesselbo & Coe, 2000), in Silurian beach oolite in Poland (Kozowski, 2003), perhaps in Cambro-Ordovician higher energy ooid, intraclast, skeletal grainstones of peritidal facies in Kansas, USA (Franseen, Byrnes, Cansler, Steinhauff, & Carr, 2004), and in the Neoproterozoic of the Comba Basin, Republic of Congo (Préat, Delpomdor, Ackouala Mfere, & Callec, 2018). The oldest recorded occurrence was in the Neoproterozoic of the Comba Basin. In Australia, bubble-sand structures have been found locally in Mesozoic tidal-flat facies of the Broome Sandstone of the Canning Basin (Semeniuk, 2008).
Depositional environments and microfacies of the upper Turonian–Maastrichtian Kawagarh Formation, Kalachitta Range, Lesser Himalayas, Pakistan
Published in Australian Journal of Earth Sciences, 2021
S. U. Rehman, N. Ahsan, M. M. Shah, M. J. Munawar, M. A. F. Miraj, F. Rehman, Khalid Mahmood
Inner ramp is the shallowest part of ramp lying above the Fair Weather Wave Base (FWWB) and is characterised by high-energy and agitated conditions owing to surface water action caused by the wind and tide activity (Tucker & Wright, 1990). Benthonic foraminifera, suspension feeders and/or oolite-bearing packstone/grainstone and wackestone are the main carbonate rock types of this environment (Boggs, 2014; Flügel, 2004).