STUDY OF GEOLOGICAL CONDITION OF MELUKOTE REGION FOR FINDING THE SUITABILITY OF MINERALS AND ROCKS FOR CONSTRUCTION AND FINDING ECONOMICAL MINERALS

A study was carried out to understand the geological condition in and around MELUKOTE region. THE MELUKOTE located in Mandya district, Karnataka. During the geological survey we have found different minerals and rocks such as Gneiss, foliated and non-foliated rocks, foliated schist, sedimentary rock (Breccia), metamorphic rocks, mica sheets, mica schist, pink granite gneiss rock, Biotite, muscovite, sillimanite. The samples collected were analyzed for various physical properties that is form, colour, streak, lustre, cleavage, fracture, hardness, specific gravity, chemical composition. Among all these minerals quartzite and mica minerals are abundant and can be extracted economically. The rocks undergone physical, chemical, biological, weathering. Chemical weathering processes are among the most fundamental natural processes operating at and near the surfaces of earth [1]. These rocks are not suitable for construction. By the study of pediments near the new tank project, shows that Kaveri river is dried.

Prologue

On August 28, 1963, while much of America nervously watched the March on Washington, nearly one thousand demonstrators gathered in the all-black neighborhood of East Austin, Texas, to march toward the state capitol in 102-degree heat. Their two-mile route wound its way down crumbling streets, passed run-down houses and segregated schools, and finally crossed over into the white section of town, with its gleaming, pink granite capitol and lily-white Governor’s Mansion. Veteran activists of all colors from across the state flanked several hundred local black teen agers, while groups of white college students and Mexican American activists joined the procession. Picket signs calling for “Freedom Now” competed with a dizzying array of homemade placards. One linked Texas governor John Connally to the infamous segregationist George Wallace of Alabama. Others carried slogans that connected civil rights to labor: “No more 50¢ per hour,” read one, and “Segregation is a new form of slavery.” Still another praised the president while adding some Spanish flair: “Kennedy ...

Nb-Ta oxide minerals from miarolitic pegmatites of the Baveno pink granite, NW Italy

Chemical composition and cell parameters were ascertained on new data from Ti-Nb-Ta complex oxides from the miarolitic pegmatites of the Baveno pink granite (Southern Alps, NW Italy). The crystals are tiny, single or aggregated in small sprays, prismatic or tabular, from yellow-orange to brownish in colour. Typical associated minerals include fluorite, zinnwaldite, gadolinite-group minerals and Sc-minerals. Cavity paragenesis is typical of NYF pegmatites, and shows two stages of crystallization developing in magmatic-pneumatolitic and hydrothermal conditions. X-ray data show that some oxides belong to the aeschynite mineral group; others are polycrase and fersmite. Aeschynite and polycrase are chemically heterogeneous and structurally disordered because of their metamict state. This disorder does not always seem to be related to radionuclide contents. Two main trends are indicated, considering the behaviour of Y. The high Y contents fit with very low Ca and LREE contents in the A site; the HREE contents follow the Y trend. In the B site, Ti is the dominant cation, followed by some Nb and very little Ta. Small quantities of Y fit with increasing Ca, U, Th and REE contents. In the B site, Nb cations often exceed those of Ti. The Th contents are often greater than those of U. Besides the already known aeschynite-(Y) and vigezzite, new varieties, ‘titano-vigezzite’ and ‘niobo-aeschynite-(Y)’, are identified here in the Baveno miarolitic cavities. Samples 14 (analysis a) and 2502 (analysis b) have Ca as the main occupant of the A site, followed by Y, Th and REE; in the B site, Ti prevails over Nb. These compositions cannot be considered as pure vigezzite, but as a new variety called ‘titano-vigezzite’. In the same way, analysis a of sample 3 may be considered a new variety of aeschynite-(Y), with Nb prevailing over Ti in the B site, and here called ‘niobo-aeschynite-(Y)’. Neither variety has ever been mentioned in the literature. Epitaxial growth of aeschynite on polycrase (sample 3194) allows some inferences on the crystallization sequence.

U–Pb geochronology of the Opatica tonalite-gneiss belt and its relationship to the Abitibi greenstone belt, Superior Province, Quebec

U–Pb ages for zircon, monazite, and titanite from samples collected from two transects across the Opatica tonalite-gneiss belt in the Superior Province of Quebec indicate that the belt contains rocks that are significantly older than those in the adjacent low-grade northern Abitibi belt. Tonalite and tonalite gneiss, which make up most of the belt, formed over an interval of 100 Ma, from pre-2800 to 2702 Ma. Five samples have ages of ca. 2807 ± 13, 2773 ± 23, [Formula: see text], [Formula: see text], and 2702 ± 3 Ma. Zircon growth at 2718–2721 Ma in the two oldest samples may record an early period of high-grade metamorphism in the belt. Hornblende diorite, monzodiorite, and tonalite plutons were intruded at 2693–2696 Ma, particularly along the southern boundary with the Abitibi belt. These include the Canet pluton at [Formula: see text][Formula: see text] Ma, the Lac Ouescapis pluton at 2693 ± 2 Ma, and the Barlow pluton at 2696 ± 3 Ma. Pink granite plutons and dykes are the youngest intrusive rocks in the belt; three samples have yielded zircon ages of 2690 ± 2 and 2686 ± 4 Ma and a monazite age of 2678 ± 2 Ma. The timing of D1 deformation is bracketed by the age of the youngest gneiss sample containing the D1 structures, at 2702 ± 3 Ma, and the 2690 ± 2 Ma age of a granite dyke that cuts D1 structures. The south-vergent D2 event is recorded in the 2693–2696 Ma plutons and must have occurred synchronously with or after this plutonism. D3 dextral strike-slip movement on the Nottoway River shear zone occurred after 2686 ± 4 Ma, and may be associated with post-regional metamorphic titanite growth at 2672 and 2657 Ma. Titanite ages cluster at 2678–2681 Ma along the Matagami transect and at 2665 Ma north of Chibougamau, and record the time of cooling of the belt below the titanite closure temperature.

The origin of the Kennethmont granite-diorite series, Insch, Aberdeenshire

SummaryThe Insch granite-diorite complex of Aberdeenshire consists of acid and intermediate igneous rocks that are quite distinct from, and younger than, the differentiates of the Insch basic mass.The main components of the complex include two types of uniform granite (one pink, one grey), and a variety of inhomogeneous dioritic rocks (diorite xenoliths in grey granite matrix, granodiorite with residual mafic inclusions, and more uniform diorite). Full chemical analyses for major and trace elements are presented for sixteen rocks representative of all types, together with initial 87Sr/86Sr ratios and rare-earth-element distribution patterns for a selection of samples. The pink granite is not chemically related to the remaining members of the complex. Comparison with chemical data for a range of basic igneous rocks of the Insch and Boganclogh basic masses discredits the hypothesis that the diorite rocks were produced by assimilation of any of these in the grey granite magma. A primary diorite magma is recognized as essential to the petrogenesis of the complex.