Tuff Rock | Properties, Formation, Uses » Geology Science
2023年8月15日 · Tuff rock, also simply known as “tuff,” is a type of sedimentary rock that forms from the consolidation of volcanic ash and other volcanic debris. It is a unique rock type that results from explosive volcanic eruptions, during which a mixture of hot ash, rock fragments, and gases is expelled into the atmosphere.
Generation of late Mesozoic felsic volcanic rocks in the Hailar …
2019年11月1日 · The felsic volcanic rocks are mainly rhyolites, dacites, and rhyolitic tuffs (Fig. S1). The rhyolites are either massive or display flow structures, and they are porphyritic with phenocrysts of...
Rhyolite - Wikipedia
Rhyolitic ash-flow tuffs are among the most voluminous of continental igneous rock formations. Rhyolitic tuff has been used extensively for construction. Obsidian , which is rhyolitic volcanic glass , has been used for tools from prehistoric times to the present day because it can be shaped to an extremely sharp edge.
Zircon U-Pb geochronology of crystal tuff on Lingshan Island and …
2018年8月24日 · Sedimentary sequences interbedded with tuff layers unconformably overlay metamorphic rocks in the Sulu Orogen. This research presents a more reliable geochronological dataset of a tuff layer on...
Petrogenesis and tectonic significance of the late Triassic mafic …
2016年2月15日 · We present zircon U–Pb ages and geochemical data on the late Triassic mafic dikes (diabase) and felsic volcanic rocks (rhyolite and rhyolitic tuffs) in the East Kunlun Orogenic Belt (EKOB). These rocks give a small age window of 228–218 Ma.
Europium and barium enrichments in compositionally zoned felsic …
2020年6月15日 · In this paper, we compare the geochemical signatures of a wide spectrum of felsic tuffs of subalkaline, alkaline and peralkaline affinity to show that enrichments in Ba and Eu (and, less consistently, Sr), in felsic volcanic rocks, especially the presence of positive Eu anomalies in glasses, provide clear support for cumulate formation and ...
Felsic maar-diatreme volcanoes: a review | Bulletin of Volcanology
2017年2月8日 · Felsic maar-diatreme volcanoes host major ore deposits but have been largely ignored in the volcanology literature, especially for the diatreme portion of the system. Here, we use two Mexican tuff rings as analogs for the maar ejecta ring, new observations from one diatreme, and the economic geology literature on four other mineralized felsic ...
Lithogeochemical and Nd isotopic constraints on felsic …
2021年2月1日 · In summary, the Aillik Group felsic volcanic rocks comprise felsic tuff and rhyolite. The felsic tuff is commonly compositionally banded and includes crystal, crystal-lithic and lithic tuff (Fig. 4 b). Rhyolite occurs throughout the region as porphyritic to massive units, commonly spatially associated with felsic tuff (Fig. 4 c).
Parameters Controlling the Eruption Frequency of Long‐Lived Felsic ...
2022年2月23日 · The volcanic centers, that contributed limited volumetric products, are described as subaerial dacitic-rhyolitic volcanoes (Halepa and Plakes) and rhyolitic tuff cones (Trachilas and Fyriplaka complexes in the northern and southern parts of Milos) are concentrated along a horst and graben structure found on Milos island (e.g., Papanikolaou et ...
Subaqueous felsic volcanic sequence and its contribution to the …
2023年6月8日 · The rhyolitic welded tuff provides evidence of the evolution of a subaqueous felsic eruption where the water-rock reaction played a fundamental role in alkalizing the lake by providing the lake with sodium ions in Mahu Sag.