Geology of Flin Flon Area

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

Complete this week’s lab by filling in your responses to the questions from Geoscience Laboratory. Select answers are provided for you in red font to assist you with your lab work. Although you are only required to respond to the questions in this worksheet, you are encouraged to answer others from the text on your own.

This study classifies the two granites under one unit named the Kilbride Granite, however, the research, which uses both radiometric dating and composition analysis, identifies them as two compositionally separate units with different ages. On the other hand, it is not wrong to say that the granites were related as they are the two latest forming members of the Eastern Red Hills complex. (Bell and Harris, 1986)

First, we must examine the sedimentary formations; when they were formed, how they were formed, and what materials they consist of. About ninety-three to one hundred million years ago, the Western Interior Seaway rolled through the North American continent, eventually reaching the geographical area of today’s Mesa Verde National Park (National Park Service 2005). This sea deposited a thick, hard sandstone base that is called Dakota Sandstone, although this layer is not exposed in the park

Lutgens, F. K. & Tarbuck, E. J. (2011). Foundations of earth science (6th ed.). Upper Saddle River, NJ: Prentice

The Koffler Scientific Reserve at Joker’s Hill is located at the western end of Oak Ridges Moraine (ORM), hence they share common geological features. Therefore, just as in the rest of the ORM, the parent material or bedrock of Joker’s Hill is Ordovician shale and limestone (Johnson et al., 1992). 570 million years ago, what is now southern Ontario was under warm shallow seas (Rock Ontario, 1994, p.49). Between 401-417 million years ago, the sea started to recede and left sand, clay and silt deposits in the region. With time, the materials left behind were compressed into sedimentary rocks. After the retreat of the sea, coral reefs eventually became the coral rocks and the marine species eventually became carbonated rocks--both types of which contain calcium. After long term erosion, the calcium and carbonate rocks became the main composition of the limestone (Goreau, 2006). During the Pleistocene, about 2 million years ago, the Wisconsin glacier advanced across southern Ontario, depositing glacial sediments directly

The VH is located in northern MN, USA, approximately 60 miles north of Duluth and 3 miles southeast of Virginia. It is named for the abrupt bend in the Proterozoic Biwabik iron formation and subsequent horn-shape of exposed Archean bedrock. Rocks in the VH are part of the southern exposed margin of the Neoarchean Wawa

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 objective of this paper is to inform, and educate one in the origin of pseudotachylite and its parent rock for which it intruded. Pseudotachylite derives from early 1900 's when it was describe as glassy metamorphosed rock that was “almost a tachtylite” (Superfaults and Pseudotachylite). When a group of children slide down a snowy hillside on a wintry day, a process known as frictional melting is happening underneath them. At first, they cannot gain enough speed to fulfill their excitement because of the loosely packed snow. Eventually, their track that they have used over and over again becomes packed down and looks somewhat more glossy than the snow. Their tracks are frictional melting. As the weight of their sled is pushed downward by gravity to the snow-packed embankment, the cold dry snow is heated up by the energy of the two masses rubbing together and the snow melted quickly and was released to the atmosphere after the sled passed over. In geology, the sled and snow are replaced with plate boundaries that cover the earth (Mcgoughlin, 1992).

Intrusive rocks in the OB vary from mm-scale dikes and veins to meter-scale sills and dikes. They vary compositionally through ultramafic, pyroxenite, mafic, granodiorite, and granitic (Frey and Venzke 1991). Ultramafic rocks are altered and difficult to constrain as intrusive or extrusive. Sparse pyroxenite dikes and veins are coarse grained and sometimes biotite rich suggesting lamprophyre affinity. Gabbroic intrusives are the most common in the OB and occur as swarms of small dikes with chill margins (Frey and Venzke 1991). They are a cut locally by felsic intrusive rocks. Granodiorite dikes are siliceous and porphyritic. They locally occur as a series of small dikes but are more common as thick sills. These intrusive rocks may contain up to 60% xenolithic amphibole, biotite, magnetite, tourmaline, and pyrrhotite. Granodiorite dikes intrude mafic rocks, and are in turn cut by granitic dikes. Granitic intrusive rocks occur as small dikes composed of potassium feldspar and quartz. These small dikes cross-cut the intermediate and

The initial rocks are very ultramafic and as time goes on they became more felsic. The magma during the formation of the ultramafic to mafic rocks the magma becomes more felsic until these rocks stop forming. This is because compatible elements were crystallizing into minerals. These minerals then made up rocks after each step finished. Slowly the minerals and rocks formed became more felsic and the melt became less felsic. It will continue to get less felsic until all the magma has crystallized. For example, we went from Dunite (step1) all the way to Granodiorite(step ten). Dunite was very ultramafic while Granodiorite was more felsic since it had more silica in it. The last melt could have formed a Quartzolite or a Quartz-rich Granitoid depending on how much silica, alkaline feldspars, and plagioclase was left. Silica was the most abundant element in the melt so therefore the percentage of it in the melt remained high even after a decent amount of it had been removed. For example, at the end of step six there was still 125 silica atoms left in the melt. The steps that created ultramafic rocks were steps one through six since they had olivine, plagioclase, and pyroxenes in them. The mafic rocks were created in steps seven and eight since they had no olivine or felsic minerals in them, but still had pyroxene and plagioclase in them. The steps nine and ten created felsic rocks since they had felsic minerals (quartz and Alkali feldspars) as well as the mafic minerals in

The metamorphic rock I chose to research is Gneiss which is foliated.The protolith for this rock is schist and granite. It can be identified by its streaks, bands, and lenses. This rock is known for its strength, and hardness,it is also rough to the touch, the color varies, from dark and light bands. Gneiss rocks is a very diverse group that includes igneous rocks and metamorphosed sedimentary rocks.This rock is formed by regional metamorphism takes place when the materials and substances are deep under the ground. It is a high-grade metamorphic rock which means it recrystallizes under intense heat and pressure. This transformation makes the size of the mineral grains bigger and segregates them into many different bands, this formation also

The overall sequence consist entirely of mafic lavas which are futher sub-divided into different series which are low in Ti and Zr and also ones hing in both Ti and Zr. I will denote the low Ti and Zr as LTZ.L and the hing in Ti and Zr as LTZ.H. The LTZ.H consist of magnesum, alkaline to tholetiitic lavas, with a great amount of oliv + cpx phenecryst assembledge. They are a results of a possible occurrence of a mantle plum melts. (Ewart et al, 1998) The LTZ.H, on the other hand, contains much less magnesium and are tholeiltic consisting of largely cpx ± oliv +plag+Fe-Ti oxides phenecryst assemblege and also contain groundmass containing aguite and pigeonite. (Ewart et al, 1998)

SB-3 lies in grainstones in Blowfire-1 and is dated approximately 33 Ma. After this boundary sedimentation starts with photozoans, but with the increasing sea levels, algae and benthic foraminifera become abundant that shows a transition in the carbonate factory, where MFS-3 is also observed. The deposits overlaying SB-3 start with photozoans that are micrite dominated and continues with a transition to heterozoans. In upper sections, sedimentation continues with algae and benthic foraminifera dominated carbonates. Also, common dolomitization in this section marks an unconformity as the characteristics of this dolomitization represents a subaerial exposure after deposition of this stack of carbonates.

Spaced and continuous cleavages are the most common S1foliations in the Bila area. The intensity of rocks affected by foliations are controlled by the type of the rock and degree of metamorphism/deformation occurred during their formation. This S1 foliations are mostly developed in the metasedimentary and metaultramafic (talc schist) rock groups. Petrographic analysis also show the presence of well aligned minerals such as chlorite, mica, feldspar, actinolite and talc which were define the development of strong S1foliations in the most rocks of the area (Fig.4.3C and D). Foliation (S1) in the area is mostly striking NNE to NE with gently to vertical dipping WNW and SE as shown in the stereographic projection (Fig.4.4). Most of the time the (S1) foliation in this area was parallel to the axial plane of F1 folding in the area.