Ordovician rocks

Metallogeny of the gold-enriched Cambro-Ordovician rocks in the Annidale area, south-central New Brunswick, Canada... 

Neoproterozoic to Early Paleozoic rocks of the Annidale area are interpreted to mark the southeastern margin of Ganderia in the New Brunswick segment of the northern Appalachians (Johnson et al. 2009). The area is underlain by Late Cambrian to Early Ordovician rocks of the Annidale Group and Late Neoproterozoic to Early Cambrian rocks of the Belleisle Bay Group, which are juxtaposed along a major tectonic boundary marked by the Taylor Brook Fault (Fig. 1). 

Janssens, A. 1973. Stratigraphy of the Cambrian and Lower Ordovician Rocks of Ohio. Ohio Department of Natural Resources, Division of the Geological Survey, 64, Columbus, OH, USA, 197. 

Total Carbohydrates. The results of the phenol-sulfuric acid tests for total carbohydrates are listed in Table 1. The Lower and Middle Ordovician dolomites and limestones of this area did not yield detectable total carbohydrates, either because they are absent or because of metamorphic degradation. Palacas (5) and Palacas, Swain, and Smith (6), on the other hand, found traces of glucose and other sugars in Lower and Middle Ordovician rocks of Franklin County, Pa. southeast of the Mt. Union area. It appears that the early and medial Ordovician seas of the Mt. Union area may neither have been receiving much carbohydrate material from the lands nor was much being contributed by organisms to the bottom sediments. 

Periglacial paleosols, unknown in Cambrian and Early to Middle Ordovician rocks, are found again... 

In this way, the Shackleton Range completes a trend that began in the Thiel Mountains and continued in the Pensacola Mountains both of which are inCTeasingly displaced from the subduction zone along which the Ross Orogen formed by compression from east to west at about 500 Ma. However, Clarkson (1982) reported that the Cambro-Ordovician rocks at the western end of the Shackleton Range strike north and south. 

The Ordovician rocks of the eastern-most part of the Baltic palaeocontinent were deposited in a remarkable epicontinental basin with no apparent modern analogues. Sediment rates were very low, in the order of 1-3 mm per 1,000 years and predominantly carbonates. The seafloor had little topography and the eastern part of the basin, at least, was tectonically stable for much of its history. Carbonate sediments were generated across much of the continent during most of the period. In the East Baltic the Ordovician succession reaches a thickness of up to 250 m in the central part of the region, in west Latvia. To the west, however, in the Oslo Region, thicker successions, in the order of 1.5 km, are characterised by the significant input of siliciclastic material from the adjacent Caledonian mountain belt (Bruton and Harper, 1988). 

Drucker, 1., (agent). Postal card, 1878, Collections of the Century House Historical Society. Fisher, D. W., Correlation of the Ordovician Rocks of New York State, New York State Museum Map and Chart Series, Vol. 3, 1962. 

The crystalline host rocks are covered by Palaeozoic sediments of the Western Interior Basin. These consist of Ordovician... 

The Halfmile Lake deposit consists of massive, breccia, and stockwork Zn-Pb-Cu sulfide mineralization hosted by volcanic and sedimentary rocks of the Ordovician Tetagouche Group (Mireku Stanley 2006 Adair 1992). The main sulphide minerals in the deposit are... 

VMS deposits of the BMC occur within a Middle-Ordovician bimodal volcanic and sedimentary sequence in the northern Appalachians of New Brunswick, Canada (Goodfellow McCutcheon 2003). Volcanic rocks were emplaced between 472 and 455 Ma within an intra-continental back-arc basin (the Tetagouche-Exploits basin) at the eastern margin of the proto-Atlantic (lapetus) Ocean (van Staal et al. 2003). 

Geological Setting The IRAC is hosted in folded and faulted sedimentary rocks of Cambrian to lower Ordovician age (Currie 1975). These units are the slaty-limestone of the McKay Group (Cambro-Ordovician), massive limestone of the Ottertail Formation (Cambrian), and the sheared argillaceous rocks of the Cambrian Chanceller Formation (Allan 1914, Aitken Norford 1967). 

The BSC (part of the Dunnage tectonic Zone) formed in Late Ordovician to Early Silurian (i.e., during the Salinic Orogeny), and contains the accreted and subducted remnants of the Middle to Late Ordovician Tetagouche-Exploits back-arc basin. Consequently, the rocks of the BSC have... 

Winchester, J.A. 1998. Geochemical and isotopic (Nd, O) data from Ordovician felsic Plutonic and volcanic rocks of the Miramichi highlands petrogenetic and metallogenic implications for the Bathurst Mining Camp. Canadian Journal of Earth Sciences, 3, 237-252. 

The northern part of the Bendigo-Baiiarat zone consists of an Ordovician fiysch sequence which has been complexly deformed and intruded by late Devonian granitoids. In the south-western part of the study area Tertiary basalt overlies much of the Ordovician sedimentary sequence. Practically all known goldfields and mineralized zones have been discovered in areas where Ordovician sedimentary rocks crop out. 

The aim of the investigation was to outline the most promising areas for gold exploration in Ordovician host rock lying under more recent basalts. According to preliminary data, the thickness of the basalt cover is between 100 and 300 m. 

Orogen (Williams 1995). The Meguma Terrane is made up primarily of Cambro-Ordovician metasedimentary rocks of the Meguma Group and approximately one third of the terrane has been intruded by Late Devonian granitoid batholiths, the largest of which is the South Mountain Batholith (MacDonald 2001). These basement rocks are overlain by the sedimentary rocks of the Maritimes Basin. 

Lithogeochemistry of Ordovician Sedimentary Rocks Implications for VMS Exploration in the Bathurst Mining Camp (BMC), Canada... 

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