Geological and Tectonic Setting of Andesitic Rock in Central Eastern Desert, Egypt

Objective. The current study aims to detect the geologic features, geochemical characteristics and tectonic setting of the investigated rock using field observations and geochemical analyses. Research methods. This work contains both field work (Collection samples and drawing of a new geological map) and laboratory work (preparation of thin sections for petrographic studies by polarizing microscope), X-ray Fluorescence analysis (XRF) in Institute of Biology, Southern Federal University and Mass-Spectrometer with Inductively Coupled Plasma (ICPMS) at the central Laboratory of Russian Geological Institute. Result. Investigated andesitic rock belongs to Dokhan volcanic that located in the Central Eastern Desert of Egypt a long Qena-Safaga Road. It is considered as one of the most important shear zones in Eastern Desert that includes distinctive rocks and economic mineral deposits. The investigated rock belongs to late to post tectonic magmatism of the East African Orogeny (EAO). Petrographically: Dokhan volcanic is represented by andesite according to petrographical studies. It consists of plagioclase, quartz, in addition to mafic minerals. Geochemically, the investigated andesite samples plotted in calk-alkaline nature. Conclusion. Tectonically, andesite samples fall in arc lava and continental fields. They are enriched in Ba, Sr, Rb, K, Nb and Ce with marked depletion in the most HFSEs like those of island arc calc-alkaline series.

Environmental and energy assessment of the use of Andesite in cement

The present study is a contribution to the research of new sources of supply of additions and raw materials in order to valorize local materials in the manufacture of cement. It consists in checking the environmental validity of the industrial use of andesite by evaluating the energy consumption of manufacturing andesitic cement. This evaluation was made on CEMI 52.5R type cement mortars whose basic constituent is clinker, with substitution rates of raw and calcined andesitic rock at 800 °C varying from 0-40%. and this through mechanical performance tests at several deadlines (2 days, 7 days, 28 days and 90 days). The results show that the analysis of the influence on the environment of this addition, in its raw state or calcined at 800 ° C, made it possible to say that globally the impact of andesite on the matrices seems positive to long term. The replacement of the cement by andesite systematically induces a reduction in the energy required to produce one ton of binder, due to the lower energy demand for grinding than that required for the thermal treatment of the clinker. Overall, the energy cost of andesite cement (in kWh per MPa compressive strength) is lower than that of ordinary cement for low rates of clinker replacement and obtaining cements with moderate strengths.

Modeling Folding Zone in Kedungsari Compassionate Area Kulon Progo Yogyakarta with Gravity Method

This study aims to determine the condition of subsurface by doing interpretation quantitatively. Quantitative interpretation is done by modeling to determine the shape and boundary of the anomaly. The gravity data reduction is done up to Complete Bouguer Anomaly (CBA) value is obtained. The complete Bouguer anomaly is brought to horizontal plane reduction and separation of local and regional anomalies using the upward continuation method. 2.5 modelling has been made from local anomaly data to illustrate the subsurface condition of the research area more clearly. The result shows R1 density value of 2.55 g / m3 which is a limestone and R2 2,8902 g/m3 which is andesitic rock. The position of the anticline axis is at coordinates 49 S 9128700 N 409844.9 E, while the syncline axis is at coordinates 9129037 N 408694,1 E.

Identifikasi Taksa Tanah di Situs Megalitik Gunung Padang Kabupaten Cianjur

Mount Padang was famous megalith sites placed in Cianjur District. Mani discipline of science studied Mount Padang sites in order to find out the truth of histories. Based on geological studies, Mount Padang sites constructed by andesitic rock, this argument need more fact for get the real data. This research aimed to analysis pedological proses in Mount Padang sites. The result of study was soil classification which description by soil profile. Based on result of reseach the soil in Mount Padang formed in Qv rock formation. The result of soil profile analized with 2 meters depth, there was 10 layer formed e.g Ap, AB, Bw1, Bw2, BC1, BC2, CB1, CB2, C1, and C1. The genesis of Mount Padang soil was in viril levels, due to molic epipedon and cambic that found as below horizon diagnostics. Based on soil taxonomy, this pedon were classified as Typic Dystrudepts.Key words: megalith sites, andesitics rock, soil profile, viril, cambic

Strength and permeability recovery of tuffisite-bearing andesite

Tuffisites, the products of subsurface fragmentation, transport and deposition, are common in explosive volcanic environments. Their study provides direct insight to the mechanical processes operating within volcanic conduits. Here we document the influence of the presence of coherent tuffisite veins on the physical properties of andesitic rocks. We find that (1) compressive strength is unaffected by the presence and/or orientation of tuffisites, (2) permeability doubles when tuffisites are oriented favorably (at 45° to the fluid flow direction), and (3) ultrasonic wave velocities show a continuous increase with depth, independent of vein presence and orientation. Although the influence of tuffisites on andesitic rock properties determined here is modest, we emphasize that the material tested represents the post-eruptive state of tuffisite. Thus, these results likely delineate the upper and lower boundaries of strength vs. permeability and porosity, respectively. Our evidence suggests that, via compaction and lithification, tuffisites may restore the strength of the volcanic host-rocks to that of their pre-tuffisite values.

The strength and permeability of tuffisite-bearing andesite in volcanic conduits

Tuffisites result from volcanically-induced subsurface fragmentation, transport and deposition, and are common in explosive volcanic environments. Their study provides direct insight to explosive volcanic processes operating within volcanic conduits. Here we report the influence of tuffisite veins on the fundamental physical properties of andesitic rocks. We find that: (1) strength is unaffected by the presence and/or orientation of tuffisites, (2) permeability doubles when tuffisites are oriented favorable (45 degrees to fluid flow), and (3) seismic wave velocities show a continuous increase with depth, independent of vein orientation. Although the influence of tuffisites on andesitic rock properties is modest, we emphasize that the material tested represents the post-eruptive state of tuffisite. Thus, these results delineate the upper boundary of strength and lower boundary of permeability and porosity. All evidence suggests that tuffisites become compacted and lithified on relatively short time scales, restoring the strength of the rock to their initial host rock values.

Riparian Vegetation of the Northern Range, Yellowstone National Park; Classification, Succession and Environmental Relationships

For many years interest in and research concerning wetlands has lagged behind the more extensive efforts put furth in upland and aquatic ecosystems. Recent years have seen wetlands featured in several symposia (Johnson and Jones 1977; Johnson and others 1985; Ratliff 1985; Brosz and Rodgers 1986). Within the Greater Yellowstone Ecosystem and contiguous areas several studies both intensive (Norton, et al 1981; Tuhy 1981; Mattson 1982; Mutz and Queiroz 1983)and extensive (Tuhy and Jensen 1982; Youngblood, et a1 1985; Pierce and Johnson 1986) have been completed. The climate of northern Yellowstone is a hybrid between continental and inland maritime. There is a gradient in precipitation and temperature between the lowest recording station Gardiner (1616 m) and the Northeast Entrance station (2244 m). Gardiner, by virtue of its low elevation, is the warmest and driest location with only 277 mm mean annual precipitation, of which most occurs in the late spring-early summer. The Northeast Entrance, the highest reporting station in this Northern portion of the park, is the wettest (670 mm) and coldest. However, precipitation at the Northeast Entrance is more evenly distributed throughout the year with distinct peaks in early summer and mid winter. Of potentially greater importance than climate to understanding wetland composition is water chemistry. Streams originating to the east of the study area in the Absaroka Range drain predominately extrusive igneous (andesitic) rock and glacial till. Streams originating to the south of the study area drain oligotrophic tephra and rhyolitic substrates. To the west and north a mix of sedimentary and glacial till substrates are represented. Groundwater from these distinct geologic substrates, in addition to water from unique thermal features producing a complexity of groundwater environments in this "northern range".

On the nature of withamite from Glen Coe, Scotland (With Plate IV.)

In 1824 Henry Witham discovered a beautiful red epidote mineral in the lavas of Glen Coe, Argllshire, which was described by Brewster under the name withamite. An analysis was made by Coverdale of obviously highly impure material, but later a more complete one was carried out by Heddle on carefully hand-picked mineral. Heddle admits, however, that his analysis shows ‘by no means a satisfactory agreement with the composition of epidote’, and from his figures it would seem very likely that his analysed material was also impure. In the Glen Coe Geological Survey Memoir no further data were recorded of this mineral, Heddle's analysis and description merely being quoted.The writer visited Glen Coe and collected material in a cutting on the new road, approximately 5½ miles west of King's House (Geological Survey, sheet 53), where it is fairly well exposed. It occurs in a fine-grained, rather altered andesitic rock, as narrow veinlets up to 120 mm. in length and 50 mm. in width ; also as infillings of vesicles. The veinlets may be straight or highly irregular; in the former case they possibly follow joint-planes, for the rock will often fracture along such a plane, producing one or two surfaces covered with the red epidote mineral. The vesicles vary greatly in size from approximately 0·3 to 70 mm., and in the larger ones calcite is a common associate.