A Report Of The Bezymianny Volcano During The Kamchatka Peninsula Of Russia

According to Thompson and Turk (2011), there are two types of igneous rocks—extrusive and intrusive—and the primary difference between the two types of igneous rocks is that the rocks are formed in two separate locations: within the Earth’s crust and on the Earth’s surface (35). Extrusive igneous rocks form when “magma rises all the way through the crust to erupt onto Earth’s surface” (35). Since the crystals do not have much time to grow, extrusive sedimentary rocks, also commonly known as volcanic rocks, have “fine-grained textures, with crystals too small to be seen with the naked eye” (Thompson & Turk, 2011, 36). For example, basalt is a common very fine-grained volcanic rock. On the other hand, intrusive igneous rocks form when

Sims et al. (1989) synthesized U-Pb zircon ages for the Pembine-Wausau terrane. Sims concluded that the volcanic rocks were generated from around 1889 to 1860 Ma as island arcs and closed back-arc basins above the south-dipping subduction zone (Niagara fault zone). Granitoid rocks in the terrane, emplaced from around 1870 to 1760 Ma, are mainly granodiorite and tonalite but include gabbro, diorite, and granite. These developed as island arcs above the Eau Pleine shear zone. The Niagara fault zone contains a relict ophiolite, suggesting that the rocks in the Pembine-Wausau terrane probably accumulated on

The youngest of these rocks are dated at about 220,000 years ago. Rhyodacties and quartz latites in the modern caldera area extruded from about 320,000 years ago to 260,000 years ago, and then silica-rich rhyolites at Glass Mountain northeast of the caldera erupted from about 210,000 years ago to 80,000 years ago. The scattered distribution of the initial mafic eruptions indicates that they were erupted from the mantle, while the slightly younger domes and flows were from a deep-crustal source. The youngest rhyolite eruptions erupted at the northeast rim of the caldera at Glass Mountain and were the first activity of the silicic Long Valley magma chamber (Bailey, et. al., 1989).

Next, we can see that the rock displays a subtle porphyritic texture with plagioclase comprising the phenocrysts. The overall texture of the surrounding groundmass is granoblastic equigranular. Under thin section we also see a weakly defined foliation evidenced in the preferential alignment of actinolite grains and to a lesser extent chlorite grains. Undulose extinction is also observed in quartz indicating the rock was subject to deformation. The normalized quartz, alkali-feldspar, and plagioclase (QAP) values of this rock indicate that it is classified as a grano-diorite according to the IUGS QAPF classification system which is consistent with the hand sample interpretation.

About 7,700 years ago, Mount Mazama erupted on itself after building upon itself and reaching an impressive height of 12,000 feet. The aftermath of the collapse left a crater more than 2000 feet deep and 6 miles wide (Reichmann)! The rocks and minerals from the Mount Mazama

Lane County Historical Society 28, no.1 (Spring 1983): 16-28. “Igneous Rocks.” Living With Volcanic Past. http://vulcan.wr.usgs.gov/LivingWith/ VolcanicPast/Notes/igneous_rocks.html (accessed May 23, 2012). International Correspondence Schools.

Metasomatism is when an aqueous solution chemically alters a rock that in encounters. Apatite is a useful tool for identifying these metasomatic changes in rocks. This widespread mineral, being a reservoir, can give information on timing, duration, and composition of this solution. The two main factors involved in tracking metasomatic processes in apatite are apatite’s anion column and the presence or absence of rare earth elements.

Kundo, 1982). The basalts have become under saturated that is moving toward a nepheline compositions. The andesites become less abundant that moving toward silica-rich, high alumina, and K20, Pyroxenes, and hornblende. Cat Hills is going through crystal fractionation and also crustal contamination that explains the observed trends (Albert M. Kundo, 1982). The basalt compositions are that are being controlled by the intersection of the Jemez lineament with the Rio Grande Rift and cause magma to be a trap in the mantle diapir below the rift. Cat hills have an existence of a high alumina alkali basalt that is over 40 km south of the transverse zone. This indicates that deep trapping of the magma has occurred away from the zone (Albert M. Kundo, 1982). The shallow origins indicated in the south of low-alkali olivine tholeiite and high-k andesites at Albuquerque and Los Lunas. The low-alkali olivine in Albuquerque volcanoes that is abnormal. The geothermal gradient is most of the basaltic magma, which is generated deeper below the zone that has high-alumina alkali basalts are formed (Albert M. Kundo,

A swarm of aplite barriers, identified with the quartz diorite, is meddlesome into the contact zone. The Vermont quartz diorite is barged in by the Feliz granodiorite, a monstrous molten shake, which goes in organization from quartz diorite toquartz monzonlte. The sporadic, granulated and slickensides con-respect with the Vermont quartz diorite plutonic body and with the changeable shake complex is deciphered as importance interruption by an about strong gem charged magma. A blame piece of foliated quartz diorite Lar pluton is uncovered in the northeastern part of the range. The foliation, which is essentially because of adjusted, circle formed totals of biotite, is presumably aprimary magmatic stream structure. Various sporadic embankments of malchite and of basalt are nosy into the Lar quartz

by phreatomagmatic eruptions at the central summit (Pullinger, 1998). This suggests that there is high hydrothermal activity

Qfd1 (labeled as Qbws1 on the chart) was found at River Mile 189.5 preserved between a Black Ledge lava dam remnant and a basalt flow. The base of the deposit was 110m above the current river level while the top of the deposit was 170 m above the current river level. The clasts were 92% basalt and had identical Rare-earth element (REE) patterns, which indicated that they came from the same lava dam source. The clasts ranged in size from hyaloclastite ash and lapilli to a 6 m diameter limestone boulder. Based on age and pattern of REE, Qfd1 deposits seemed to have correlated with the dam produced by the Upper Prospect lava flows (Fenton et al. (2004)). While the Toroweap Dam correlated in age to Qfd1, its REE pattern did not align in a parallel

Most known mineral occurrences in the RRB are in the RLWZ, as it is the best exposed and most explored part of the block. Modest gold and silver production occurred here in the past (25,000 oz Au; 3,000 oz Ag) and magmatic sulfide deposits have been outlined in the Grassy Portage intrusion (two separate mineralized zones: 300,000 t @ 1.89% Cu and 300,000 t @ 0.8% Cu; Poulsen 2000). The RLWZ also hosts VMS-style prospects in a bi-modal volcanic pile that is underlain by a composite trondhjemite-tonalite-gabbro-anorthosite intrusion. Zn is predominant in this volcanic complex, with lesser Cu, indicating shallow water and (or) low temperature mineralization process affected the rocks. Au has been documented in the volcanic pile, but may represent orogenic style mineralization. These metal assemblages and the geometry of the volcanic pile are similar to Sturgeon lake VMS camp (e.g. Hudak 2003), indicating it has potential for hosting economic Zn-Cu deposits. However, the atypical lithologic make-up of the composite subvolcanic intrusion (i.e. anorthosite-dominated) does not match well-endowed VMS camps (Galley 2003) and the proximal high-grade metamorphism (amphibolite facies) and strong deformation (shearing) may have compromised the preservation of hypogene mineralized zones. If mineralized zones are preserved, they could be Au-rich, as the structural setting (bounded by crustal-scale faults) and inferred paleotectonic setting (rifted arc or

The meteor is thought to have flash melted the crust which proceeded to differentiate into a granophyre and a leuconorite to norite composition. The granophyre makes up 60% of the complex and the leuconorite and norite make up the remaining 40% (Figure 1b)(Barnes et. al., 2005). About 50% of the ore is found in the sublayer norite and the breccia that is associated with the norite. This ore is mainly disseminated sulphides. The massive sulphides are located in the center

Galeras has been an active volcano for at least a million years, with andesite as the dominant product.[4] Two major caldera-forming eruptions have occurred, the first about 560,000 years ago in an eruption which expelled about 15 cubic kilometres (3.6 cu mi) of material. The second some time between 40,000 and 150,000 years ago, in a smaller but still sizable eruption of 2 cubic kilometres (0.48 cu mi) of material. Subsequently, part of the caldera wall has collapsed, possibly due to instabilities caused by hydrothermal activity, and later eruptions have built up a smaller cone inside the now horseshoe-shaped caldera.

     Igneous rocks are classified first by texture. This is broken down mainly into grain size. First there are intrusive, or plutonic igneous rocks. These types of rocks cool within the crust and forms large, visible crystals. The opposite would be extrusive, or volcanic rocks. These cool at the surface rapidly, forming small grains. A combination