History Of Volcanic Activity Research Articles

Volcanism in The Pre-Semilir Formation at Giriloyo Region; Allegedly as Source of Kebo-Butak Formation in the Western Southern Mountains

Kebo-Butak Formation was known to be the oldest volcanic rocks limited in regional terms in the lower Baturagung Hills, Gedangsari area, Gunungkidul Regency. The main constituents of the Kebo-Butak Formation consist of intersection of volcanic-clastic rocks and calcareous sediments, locally also found basalt lava with pillow structures; which distinguished it from other volcanic rock formations in the Southern Mountains. This study aims to determine the relationship of volcanic rocks exposed in Giriloyo with the Kebo-Butak Formation in the Baturagung Hills; the chronostratigraphy and the history of volcanic activities that produced the volcanic rocks of Giriloyo. This research was approached by volcanic geological mapping using surface mapping suported by gravity anayses. From the bottom to the top of the frontier areas result volcaniclastic rocks consisting of black tuffs with several fragments of volcanic bombs with basalt composition intersecting with thin basaltic lava inserted by calcareous claystone having an age of N5-7 (Early Miocene); pyroxene-rich basalt volcanic sequence consists of thick layers of tuff with creamy-brown color intersecting with lava and breccia inserted by calcareous sandstone aged N7-8; dikes, lava and agglomerates with basaltic composition and lava and agglomerates with andesitic composition. Stratigraphically, the volcanic rocks exposed at Giriloyo correlated with the volcanic rocks exposed at Karangtalun (Wukirsari) were under the Semilir Formation, bordered with normal fault N210oE/77o, the hanging wall composed by light grey tuff of Semilir Formation. Gravity analyses found high anomalies below the Semilir Formation exposed at Karangtalun-Munthuk (east of study area) continued to below the Giriloyo area. The high anomalies were identified as the igneous/ignimbrite volcanic sequence. Descriptively and stratigraphically, the Giriloyo volcanic sequence are a part of Kebo-Butak Formation. The petrogenesis of the volcanic rocks will be discussed in further research to interpret magmatological properties, the evolving paleo-volcano, and the absolute age of the rocks.

The Gardner volcanic complex on the Moon: Geological characteristics and its volcanic history

Lunar volcanic complexes are prominent features with a high concentration of various volcanic characteristics. They are ideal objects to study the lunar nearside volcanic activity and its thermal evolution. The Gardner volcanic complex is located in the nearside of the Moon, between Mare Serenitatis and Mare Tranquillitatis. It has a series of volcanic features, such as domes and rilles, which make it an ideal object to study the lunar volcanic history. In this study, we make use of recent high-resolution lunar images (Terrain Camera, TC) and multispectral data (Clementine UVVIS) to study the topography, geomorphologic features, iron and titanium contents, and the geochronology of the Gardner volcanic complex. We identified and analyzed different geomorphologic features, such as impact craters, domes, massifs, scarps, and a suspected fault. Spectral analyses indicated that the Gardner region is covered by low-Ti basalt. Absolute model ages of the different units in the Gardner region were obtained using crater size-frequency distribution (CSFD) measurement. The results show that Gardner may have experienced three periods of volcanic activities, which were aged between Nectarian and Imbrium. The volcanic eruption may decrease with time. The relatively high crustal density and the positive Bouguer gravity anomaly of Gardner show that the Gardner volcanic complex is composed of dense volcanic materials on the surface and in the subsurface. An irregular steep-sided depression is located in the central area of the Gardner plateau, which is different from the depression caused by impacting. We suggest that this depression could be a caldera and is once a possible vent responsible for the emplacement of surrounding lava flows. The long history of volcanic activities in this region makes it an ideal area to study the lunar nearside volcanism and thermal evolution, and we suggest it as a candidate landing site for China’s future lunar exploration missions.

Age Determination of Martian Low Shield Volcanoes by Crater Size-Frequency Measurements

Summary: Based on high-resolution images of thecurrent NASA-spacecraft Mars ReconnaissanceOrbiter , the technique to determine absolute agesof planetary surfaces by impact crater counts isdemonstrated. The results will be useful to inter-pret geologic processes on the planet’s surface,such as the history of volcanic activity. This paperdescribes the statistical technique for a low shieldvolcanoin theTharsisregionanditsadjacentplainswith the discussion of the results and problems.Planetary remote sensing data are processed andprepared for the later use in GIS environments andstatistical analysis. The crater counts were done in-dependently with two different cameras, whichprovided comparable results. The derived absoluteages are in good agreement with the results of ear-lier works. Zusammenfassung: Altersbestimmung von niedri-genSchildvulkanenaufdemMarsanhand von Kra-tergrosen-Haufigkeitsverteilungen . Auf Grundla-ge der aktuellen, hochauflosenden Bilddaten derNASA-Raumsonde Mars Reconnaissance Orbiter

Episodic Volcanism in the Buck Creek Complex (Central British Columbia, Canada): A History of Magmatism and Mantle Evolution from the Jurassic to the Early Tertiary

The Buck Creek volcanic complex of the Intermontane Superterrane of the Canadian Cordillera records a long history of volcanic activity from the Cretaceous through to the Eocene, when magmatic activity peaked, to the Miocene. Its basement includes primitive continental arc volcanic rocks of the Jurassic Hazelton Group (∼200 Ma; mainly basalt and andesites) emplaced prior to the accretion of Stikinia during the Mesozoic. In contrast, in the post-accretionary volcanic complex, the major pulse of volcanism started with the extrusion of continental margin calc-alkaline rocks (basaltic andesites to rhyolites) of the Cretaceous Tip Top Hill Formation (∼85 Ma). Their Nd-Sr isotopic compositions resemble those of the pre-accretionary Hazelton Group. However, this post-accretionary Cretaceous arc was more evolved and its crust was significantly thicker than the Hazelton. Mafic rocks of both the Hazelton and Tip Top Hill suites were generated from a spinel-bearing mantle source. The Eocene volcanics (∼50 Ma) evolved from typical high-K calc-alkaline mafic/intermediate rocks to flows that resemble intraplate tholeiitic basalts. Collectively, the Eocene rocks had a common (and comparatively deep) source, likely garnet-bearing subcontinental lithosphere. These compositional variations are probably related, in part, to an increase in the degree of partial melting. They record a gradual change from a compressional to an extensional tectonic environment, and overall represent an arc setting that matured and thickened over ca. 35 m.y., culminating in Eocene extension coincident with the cessation of compression in the foreland fold-and-thrust belt. Overlying intraplate alkali basaltic rocks of Miocene age appear to represent the final stage of this transition, as subduction-modified lithospheric mantle was replaced by a new asthenospheric mantle source. The association of Cretaceous, Eocene, and Miocene volcanic rocks in the Buck Creek complex is widespread in the region, suggesting that this model of tectono-magmatic evolution can be applied elsewhere in central British Columbia.

Volcanic disasters and cultural discontinuities in Holocene time, in West New Britain, Papua New Guinea

Abstract An evaluation of the relationship between culture change and the history of volcanic activity from the Witori and Dakataua volcanoes in West New Britain province, Papua New Guinea, demonstrates the importance of studies focusing on long time spans to an understanding of cultural adaptation to volcanic disasters. Using a chronostratigraphy based on several techniques for matching tephras, the cultural responses to five volcanic events are compared and contrasted between the Willaumez Peninsula and Yombon, areas whose environment and proximity to the volcanoes vary significantly. Archaeological analyses of material show that human groups did not immediately adjust to the effects of the most severe volcanic events but abandoned both regions. In contrast, adaptation on a long-term basis may be indicated by the occurrence of a punctuated trend in lithic technology inferred to reflect a decrease in mobility and an increase in the intensification of subsistence practices. This pattern, combined with limited radiocarbon dating, suggests that the length of abandonment decreased after each eruption, probably because of changes in social organization and subsistence practices. The paper demonstrates the value of collaboration between archaeology and geology in the study of long-term human responses to natural hazards.

Tephra-Loam Stratigraphy and history of volcanic activity at Bandai Volcano, Fukushima Prefecture, Tohoku-Honshu, Japan

Tephra-Loam Stratigraphy and history of volcanic activity at Bandai Volcano, Fukushima Prefecture, Tohoku-Honshu, Japan

Neocene stress field of the Japanese arcs and its relation to igneous activity

The Neogene stress field in the southern part of Northeast Japan and the eastern part of Southwest Japan was restored with special reference to its time scale, based mainly on K-Ar ages and strike directions of dike swarms. The present study indicates the changes of stress field at about 22 Ma B.P., 15 Ma B.P., 12 Ma B.P. and 8 Ma B.P. in the southern part of Northeast Japan and at about 15 Ma B.P. in the eastern part of Southwest Japan. The stress changes are also thought to have occurred at about 12 Ma B.P., 9 Ma B.P. and 1 Ma B.P. in the eastern part of Southwest Japan. These results imply that some common causes generated the stress changes in both Northeast and Southwest Japan at about 15 Ma B.P., 12 Ma B.P. and 8–9 Ma B.P. Major igneous activity in the Japanese arcs seems likely to have taken place almost at same times as the stress changes. The history of volcanic activity in the northwest Pacific region during the Miocene also shows the temporal correlation with the change of the stress regime. The tectonic evolution in subduction zones, therefore, appears to be characterized by the synchronism of stress changes and intensive igneous activity.

Effect of Oligocene volcanism on sedimentation in the Trans-Pecos volcanic field of Texas

The nature and history of volcanic activity in the Trans-Pecos volcanic field of Texas controlled depositional timing, environmental distribution, and lithologic character of associated sediments. Tuffaceous and epiclastic sedimentary rocks of the Tascotal and Fresno Formations and the Perdiz Conglomerate are part of the intermediate-source facies of the field. Rhyolitic and trachytic activity in major calderas produced abundant pyroclastic debris that has been reworked into sandy alluvial fans adjacent to the caldera complexes, whereas post-volcanic alluvial-fan sediments are tuffaceous or epiclastic conglomerates. The intermediate-source facies consists of four components: active apron, inactive (or epiclastic) apron, eolian sand sheet, and valley facies. The arrangement and timing of development of these facies depend upon the eruptive history of the volcanic centers. The Tascotal, Fresno, and Perdiz contain five depositional units. (1) The Chinati apron unit recorded rhyolitic and trachytic activity in the Chinati Caldera during the 105–106 yr after its collapse. (2) The southern apron unit formed around the San Carlos–Sierra Rica eruptive center in Mexico before eruption of the San Carlos Ignimbrite. (3) The conglomerate and limestone unit formed as epiclastic fans around the Solitario uplift and as braided-stream and lake deposits between aprons and the Solitario. (4) The eolian unit of the Tascotal formed as drainage off the Chinati eruptive center adjusted from carrying fine pyroclasts to coarser epiclasts. (5) The Perdiz Conglomerate and equivalent epiclast-rich, conglomeratic parts of the Tascotal and Fresno are a bajada-like accumulation of fluvial epiclastic conglomerate from non-volcanic sources and the Chinati eruptive center after its activity ceased. Framework mineral composition is a function of grain size; very fine and fine tuffaceous sandstones consist mostly of reworked glass shards, and rocks that have textures coarser than medium sand are mostly epiclastic VRF's. Active apron rocks formed by deposition from sheet-floods and poorly defined channels in a bajada-like accumulation that resembles sandy distal alluvial-fan deposits because the volcanos provided so much sand-sized debris, but little clay.

36.History of volcanic activity and stress field of NE Honshu Arc. : the Fall Meeting of the Society

36.History of volcanic activity and stress field of NE Honshu Arc. : the Fall Meeting of the Society

"The Hawaii Earthquake of November 29, 1975: Low dip angle faulting due to forceful injection of magma""

The mechanism of the Hawaii earthquake of November 29, 1975 (Ms = 7.1), which took place on the south flank of Kilauea Volcano, is discussed on the basis of a comprehensive set of body wave and surface wave data, the aftershock distribution, and tsunami and crustal deformation data. The aftershock distribution defines a gently dipping plane at about 10‐km depth beneath the south flank of Kilauea. This suggests that the shallowly dipping P wave nodal plane fits the fault of the Hawaii earthquake better than the nodal plane that has a nearly vertical dip angle. The fault length is fixed well by the aftershock distribution, which is also consistent with the tsunami and crustal deformation data. The fault width which is obtained from tsunami and crustal deformation data is, however, significantly greater than that obtained from the aftershock distribution. This discrepancy implies that about half of the main shock fault plane was not associated with aftershock activity. The source parameters are strike N70°E; dip angle 20°SSE; fault length 40 km; seismic moment 1.8×1027 dyne‐cm; fault width 20–30 km; fault movement is pure normal dip slip of 3.7–5.5 m, and stress drop is 43–93 bars. Results of geodetic surveys throughout the twentieth century and a history of volcanic activity on Kilauea imply that a north‐south compression due to magma injected into rift zones may have steadily increased on the south flank of Kilauea since the 1868 earthquake, an event comparable to the 1975 shock. This compressional stress was possibly released by the 1975 Hawaii earthquake. The long‐term eruptive activity of Kilauea may be affected by large earthquakes like the 1868 and 1975 events and may also have a similar 100‐yr recurrence interval.

恐山火山の岩石学的研究

Osore-yama is a composite volcano formed in the latest Pleistocene age and resting on Neogene and Pleistocene sediments. It is 878.6m in height and situated at the northern end of Honshu Island. The history of volcanic activity is devided into the following three stages: 1) Kamabuse-yama stratovolcano stage consisting of lava flows and scoria flows of basaltic andesite (A) and lava flows of pyroxene dacite (B); 2) main body stage of pumice flows, intermediated pyroclastic flows (Aramaki, 1957) and lava flows of pyroxene andesite and dacite (C); and 3) post “caldera” stage of pumice flows, lava flows and lava domes of hornblende andesite and dacite (D). Basaltic andesite (A) and pyroxene dacite (B) belong to the pigeonitic rock series, while pyroxene andesite and dacite (C) and hornblende andesite and dacite (D) belong to the hyperthenic rock series (Kuno, 1950). This paper is based mainly on the bulk chemical composition and trace element contents of twenty-nine representative rock samples from the volcano; and partly on groundmass materials and phenocrystic minerals of some of the samples. The chemical data suggest that both andesite-dacite suites are produced by fractional crystallization of early precipitated olivine, orthopyroxene, augite, magnetite and plagioclase from basaltic andesite magma which is represented by the most mafic rocks in this volcano. It is concluded that this type of basaltic andesite magma is itself a parental magma, because it is impossible to derive such magma of extremely low K2O content from any other kind of basaltic magma. The variation of Ni, Co and Cr can be explained by the modified Rayleigh fractionation model. The difference in Ni and Cr contents between the pigeonitic rock series and the hyperthenic rock series of this volcano is considered to be due to the differences in the degree of fractionation of mafic minerals under varying condition. The origen of the basaltic andesite magma which is characterized by low Ni and Cr contents is probably neither derived by fractionation from olivine tholeiitic magma nor by partial melting of peridotite. It is probably more a product of partial melting of other rocks composed of minerals having low Ni and Cr contents.

Remnants of upper Paleozoic volcanoes in Kalmakemel syncline, central Kazakhstan

The upper Paleozoic (predominantly Carboniferous) history of volcanic activity in the geosyncline is compiled from the lithology and sequence of the intrusives, the ancient topography (typically volcanic forms), and the attitude of the extrusive rock. The geosyncline was essentially a graben; therefore, extrusion occurred through a fissure channel complex along the southwestern and southern margins of the geosyncline. The lithologic sequence in the Upper Carboniferous was andesite-dacite-liparite. All three types are represented by tuffs, breccias, and lavas.

A summary of volcanic and seismic activity in Katmai National Monument, Alaska

A compilation of observations of volcanic eruptions since 1870 and ash stratigraphy shows that Katmai National Monument on the Alaska Peninsula has had a long history of volcanic activity. Six of the recently active vents lie in a gently curved arc, but two lie to the north of this arc and show no obvious structural relationship to it. Recent volcanic events have consisted of fumarolic activity, steaming from main vents, ash eruptions, extrusion of viscous lava flows, and pyroclastic eruptions. The observed activity shows no obvious correlation with a compilation of seismic events recorded teleseismically since 1912 and relocated by the authors using a digital computer. The eruption attributed to Mt. Katmai in 1912 has left many unanswered questions including the thickness of the ash flow tuff in the Valley of Ten Thousand Smokes. Seismic refraction results show that this tuff has a compressional velocity of about 0.6 km/sec and that considerable morainal debris may underlie it at the northern end of the Valley.

Tephrochronology of New Volcanic Ash

When a volcano eruptes, its pyroclastics are deposited over the surface of the earth, so the depositional features of the pyroclastics tell us the history of volcanic activities. Therefore, if we wish to investigate the tephrochronology of pyroclastics which spread over the surface of the earth, the following works should be done.1) At first, we must classify the sorts of the pyroclastics which spread over the surface of the earth and study the characteristics of each pyroclastic. Then we must research their areal distribution and the sources of their eruptions.2) Next, we must determine the time of eruption of those pyroclastics, and in this case the following principles should be adopted as fundamental ideas.a) When natural trees grow on pyroclastic forming the surface soil, we can estimate the age of the pyroclastic by means of calculation of their annual ring.b) When pyroclastic falls on peat lands, peat begins to develop on the pyroclastic. As the annual rate of increase of the peat layer thickness is considered to be constant, so by determining the depth of the peat layer growing on the pyroclastic, we can estimate the time when the pyroclastic was deposited.c) When we find carbonized trees in a layer of pyroclastic, we can estimate the age of the pyroclastic by means of determining the 14C of those carbonized trees.d) When we find a prehistoric site in a layer of pyroclastic, we can estimate the age of the pyroclastic by determining the age of the prehistoric site by archaeologists.e) When we find obsidian stone implements made by aborigines in a layer of pyroclastic, we can estimate the age of the pyroclastic by determining the thickness of the hydrated surface layer which has been formed outside the obsidian.f) Moreover, if we can correlate the age which has been estimated by means of the above mentioned methods to ancient records of the volcanic activity, we may possibly estimte still more accurately the age of the pyroclastic.

Human Remains in O-sima Volcano, Izu, and the History of Volcanic Activity

Human Remains in O-sima Volcano, Izu, and the History of Volcanic Activity