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Repository of stones used in Delhi and Agra UNESCO Sites
Published in Gurmeet Kaur, Sakoon Singh, Anuvinder Ahuja, Noor Dasmesh Singh, Natural Stone and World Heritage, 2020
Gurmeet Kaur, Sakoon Singh, Anuvinder Ahuja, Noor Dasmesh Singh
The Makrana marble quarries produce a flawless white variety along with other varieties, which have hues of grey, pink and brown or well defined bands of grey, greyish black and greenish grey colors imparting a patterned texture to the marble (Fig. 3.11a and b). The marble varies from fine to coarse-grained varieties. These exhibit granoblastic texture formed by interlocked recrystallized calcite grains, which imparts on the marble a high bearing strength. The Makrana white is pure calcitic marble with up to ~100% calcite crystals with no other major or minor mineral and thus can be termed as monomineralic (Fig. 3.11c and e). The banded brown, grey/green and pink varieties contain quartz, biotite, diopside, tremolite, actinolite, olivine and sometimes serpentine in traces. The rock shows mosaic texture in hand specimen and granoblastic texture in thin section (Garg et al., 2019; Fig. 3.11c–f). Makrana white marble with greenish grey bands display granulose texture comprising calcite, talc, wollastonite, forsteritic olivine and serpentine (Garg et al., 2019; Fig. 3.11d–f). The streaks, lenses and bands of grey and brown in white variety of Makrana marble can be attributed to the earlier-mentioned silicate mineral impurities.
Metamorphic rocks
Published in W.S. MacKenzie, A.E. Adams, K.H. Brodie, Rocks and Minerals in Thin Section, 2017
W.S. MacKenzie, A.E. Adams, K.H. Brodie
Figure 180 & 181 shows a granulite facies pyroxene granofels with a granoblastic texture of intergrown pyroxenes. An opaque mineral and minor colourless, lower relief plagioclase are also present.
Laboratorial Study of the Combined Effect of SO2 and High-Temperature Ageing on the Physical and Mechanical Properties of Encostinha Marble, a Portuguese Stone
Published in International Journal of Architectural Heritage, 2023
Edite Martinho, Amélia Dionisio, Ana Sofia Angélico
A Portuguese marble from the Estremoz Anticline (Borba, Portugal), located in the Encostinha extractive centre, thereafter referred to as “Encostinha Marble”, was selected for this study (Figure 1a). The Estremoz Anticline, located within the Ossa Morena Zone geological unity (Southern Branch of the European Variscides in Portugal), is a heterogeneous geological elliptic structure that extends for about 45 km × 8 km and striking NW-SE (Lopes and Martins 2014). The aesthetical and physico-mechanical properties of Estremoz marbles make them nationally and internationally recognized for their versatile uses, being applied in monumental Portuguese buildings since the Roman period, but also as cladding material and ornamental stone on contemporaneous building façades in Portugal and abroad. Estremoz Marble is usually calcitic, fine to medium grained, with a granoblastic texture, presenting colour variations from white, cream, pink, grey to black, and also streaks with hues in any combination of these colours. In the present study, a predominantly white-coloured marble (Figure 1b), with darker-coloured veins (grey to black) in some cases, was used (Figures 1c,d). According to Carvalho et al. (2013), Portuguese marble usually presents very low porosity (0.2%–0.5%), very low water absorption (0%–0.2%) and high bulk density (2710 kg/m3–2790 kg/m3).
Stratigraphic and igneous relationships west of Yass, eastern Lachlan Orogen, southeastern Australia: subsurface structure related to caldera collapse?
Published in Australian Journal of Earth Sciences, 2019
C. L. Fergusson, B. E. Chenhall, S. Guy, B. G. Jones, M. Solomons, G. P. Colquhoun
Most of the lower succession consists of interbedded greenish-grey/dark grey/black mudstone layers, 2–20 cm thick, and recessive limestone beds, ∼5–20 cm thick (Figure 8d). Many limestone beds are nodular and massive limestone also forms mappable lenses up to 250 m thick. In the absence of associated breccias and indicators of discordance, these are interpreted as probably allodapic limestone and shelf bioherms, respectively. Much of the limestone and mudstone is weakly to locally strongly contact metamorphosed; limestone has recrystallised to form fine- to medium-grained granoblastic marble. Cramsie et al. (1978) referred to the non-carbonate layers interbedded with the limestones as ‘tuffs’ but we have found no evidence that they are of volcanic origin. Limestones are locally fossiliferous containing crinoids, tabulate corals, pentamerid brachiopods, stromatoporoids and bryozoans (Pickett, 1982; Sherwin, 1968). The fossil faunas are poorly preserved in the unit and only a general Silurian age (probably Wenlock to Ludlow) has been determined (Colquhoun et al., 2012). Quartzose sandstone occurs on the western side of the quartz porphyry intrusion east of upper Limestone Creek (Smsm, Figure 4). Skarns occur locally near intrusions (Figure 4) and include zoned skarn with an outer layer of wollastonite and an inner layer of wollastonite and vesuvianite. Massive skarns contain grossular-rich garnet, epidote, wollastonite, and vesuvianite and minor altered plagioclase.
New age constraints for the Tommy Creek Domain of the Mount Isa Inlier, Australia
Published in Australian Journal of Earth Sciences, 2023
A. Brown, C. Spandler, T. G. Blenkinsop
The study area, covering approximately 13 km2 in the central portion of the TCD, comprises a complexly folded exposure of the Milo beds juxtaposed against the surrounding Corella Formation across a faulted and sheared contact (Figure 3). The Corella Formation is dominated by granoblastic calc-silicates with variable proportions of amphibole (actinolite, hornblende), diopside, albite, orthoclase, calcite and quartz, as well as calcareous metasiltstones and lenses of calcitic marble.