ASTM test and other methods carried out on dimension rocks from Tierra del Fuego.

ACEVEDO, R. Y GONZ¨¢LEZ GUILLOT, M.

Santiago de Chile

Congreso; GeoSur 2007; 2007

Pontificia Universidad Cat¨®lica de Chile

Dimension stones, which includes monumental stones, are natural rocks quarried for the purpose of obtaining blocks or slabs that meet specifications as to size and shape for residential construction, paving and memorials.   This is the first essay in laboratory over this type of rocks in Tierra del Fuego. This land had a potential not evaluated until now on respect of the possible use of native dimension stones. Local hard rocks as dimension stone never were used in the argentine side of the island until now. Metamorphic rocks (slates) only have been applied for facing, facades and flooring in buildings. Last years only two little quarries of igneous rocks have been opened. One of them in the Jeu-Jepen mountain, worked for build the breakwaves of R¨ªo Grande harbour and the national railroad; and the other in the Ushuaia peninsula, started initially to remove a hill for locate the airport and recently used for facings. In the present work, the chosen fuegian samples were put under standard ASTM test methods for determining compress strength and modulus of rupture, practice in accord to IRAM specification for determining apparent density, water absorption and open porosity and Dorry hardness test for measuring the resistance to abrasion. In Isla Grande of Tierra del Fuego the major types of dimension rock are scarce and random granitic bodies. According with our analysis any of them have relatively high compressional and tensional resistance: the dioritic plutonite of Jeo Jupen mountain (¦Òc131MPa and ¦Òf26MPa),  the discovered here plutonite of the Kranck mountain in the Beauvoir chain (¦Òc212MPa) and also the Jeu-Jepen lamprophyres (¦Òc147MPa and ¦Òf23MPa) and Beauvoir-Yahgan hornfels (¦Òc177MPa and ¦Òf44MPa). Nevertheless astonishingly low results gave granodioritic erratic boulders of Sina¨ª Point (¦Òc77MPa and ¦Òf8MPa) due to glacial meteorization and Estancia T¨²nel hornblendite (¦Òc71MPa) due to rock microfissuring. (¦Òc85MPa and ¦Òf10MPa).   The extended effusive rocks, riolites-riodacites of Serie Porfir¨ªtica (¦Òc121MPa), and andesite-basalts, diabases and spilites of the Alvear Cordillera (¦Òc112MPa and ¦Òf25MPa), show intermediate register contents. Sandstones outcrop extensibily but its are not significative as dimension rocks (¦Òc28MPa) and the only one with high water absorption (%9.50). Marbles and travertines are too little or absent but there is a beauty variety of limestones with Turritellas, in small amounts, considered to be special minor type. The resistance to abrasion in flagstones (slates of the Yahgan Formation) is 0,66  (excellent performance for roads) but in diabase is 2,01 because the petrological characteristic which most readily affect the Dorry essay is the presence of veins and pockets of calcite.