5.8 Volcanic Landforms and Hazards

Huff, Warren D.; Owen, Lewis A.

doi:10.1016/b978-0-12-374739-6.00089-0

Cited by 4 publications

(2 citation statements)

References 71 publications

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“…Similarly, Schindler and Kasting ( 6 ) estimated the CH 4 flux from submarine volcanism to be ∼10 −2 Tmol/y. Although mud volcanoes, geological structures that transport clay rocks and sediment from Earth’s interior to the surface, can emit large amounts of methane and CO 2 ( 59 ), the methane is largely thermogenic, ultimately deriving from organic matter produced by life ( 60 ). In principle, a terrestrial planet could abiotically emit methane through mud volcanoes given an abiotic source for the organic matter, such as hydrocarbon deposition from an organic haze.…”

Section: Resultsmentioning

confidence: 99%

The case and context for atmospheric methane as an exoplanet biosignature

Thompson

Krissansen‐Totton

Wogan

et al. 2022

Proc. Natl. Acad. Sci. U.S.A.

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Significance Astronomers will soon begin searching for biosignatures, atmospheric gases or surface features produced by life, on potentially habitable planets. Since methane is the only biosignature that the James Webb Space Telescope could readily detect in terrestrial atmospheres, it is imperative to understand methane biosignatures to contextualize these upcoming observations. We explore the necessary planetary context for methane to be a persuasive biosignature and assess whether, and in what planetary environments, abiotic sources of methane could result in false-positive scenarios. With these results, we provide a tentative framework for assessing methane biosignatures. If life is abundant in the universe, then with the correct planetary context, atmospheric methane may be the first detectable indication of life beyond Earth.

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Section: Resultsmentioning

confidence: 99%

The case and context for atmospheric methane as an exoplanet biosignature

Thompson

Krissansen‐Totton

Wogan

et al. 2022

Proc. Natl. Acad. Sci. U.S.A.

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“…This caldera interpretation is supported by the wide distribution of pyroclastic breccia deposits and other explosive eruption products at the outer parts of the volcanic edifice. After the collapse of an older volcanic edifice that formed a caldera, later effusive eruptions produced lava flows that covered much of the caldera floor [6]. Four (4) lithological units have been mapped in this studied area (Figure 2), and from the oldest to the youngest ages they consist of: 1. intercalation of pyroclastic breccia with lapilli tuff, 2. tuffaceous marl with calcareous sandstone inlay, 3. basaltic lava, and 4. alluvium deposit.…”

Section: Results 41 Local Geologymentioning

confidence: 97%

Geology of the Kebasen Paleovolcano in Banyumas Regency, Central Java Province, Indonesia

Taruna,

Setijadji,

Akmaluddin

2024

IOP Conf. Ser.: Earth Environ. Sci.

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The new interpretation on geology of Kebasen district in Central Java, Indonesia which is located in the middle parts of Sunda Arc indicates the existence of a paleovolcano. This conclusion is achieved through 1:25,000 geological mapping with a focus on volcanic facies, characterization of lithology types, mineralogy, and fossil analysis, to clarify its volcanic history and paleo-environment. Laboratory analysis works on representative rock samples are done using petrography and fossil identification on calcareous sedimentary members. Our research results conclude that Kebasen paleovolcano was a composite volcano with a diameter of about 8 km, elongated in NW-SE orientation, with Kebasen city located at the SW rim of the old volcanic edifice. The volcanic history and resulting volcanic rocks consisted of two contrasting volcanic stages. The first one was explosive caldera-forming eruptions that produced thick and partly welded pyroclastic rocks, dominated by pyroclastic breccia at the lower parts and finer tuff members at the upper parts. After caldera-forming eruptions, volcanic activity was followed by effusive eruptions of basaltic to andesitic lavas that covered the caldera floor. The lavas have abundant pillow structures indicating a submarine environment, intermediate to basaltic composition, and porphyritic texture, with plagioclase and pyroxene as the most abundant phenocryst minerals. Available rock geochemistry data demonstrate that lavas have mafic to intermediate compositions, with magma affinity at the transition of calc-alkaline to tholeiitic series. Results of geomorphological and lithology association analysis conclude that the research area was part of the central to distal facies of a paleovolcano complex, with the paleo depositional environment in the open marine environment. The results of fossil analysis on calcareous sedimentary rocks between volcanic layers indicate that the age of volcanism was Early Pliocene (N18) with the paleobathymetry transitioning from upper-middle bathyal to outer–middle neritic, which were parts of the continental margin. It is concluded that Kebasen paleovolcano is a newly identified submarine caldera-type Pliocene volcano within the middle parts of the Sunda Arc in Central Java, Indonesia.

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