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In Halifax, Nova Scotia, 149 victims of the 1912 sinking of the Titanic lie beneath petrologically identical "black granite" headstones. Those headstones, supplied by the White Star Line, arrived in Halifax in late 1912, but no known historical document reveals their source. They consist of medium- to coarse-grained olivine-bearing gabbro, with cumulus phases consisting of randomly oriented euhedral plagioclase laths, corroded olivine, and titaniferous magnetite, and intercumulus material consisting of augite with reaction rims of hornblende, both of which are variably altered to actinolite and biotite. Three types of forensic evidence [quantitative - radiometric age of 422.1 ±1.3 Ma (n = 17), mean olivine FeO/(FeO + MgO) values ranging from 0.43 to 0.46, augite rim traceelement compositions (35 elements), and whole-rock chemical compositions (48 elements), including statistical analysis of all these data showing no significant differences between the headstones and their putative source quarry; qualitative - mineral assemblages, modal proportions, textural parameters, style and degree of alteration; and circumstantial - regional reputation, quarrying history, local logistics, regional transportation, McGrattan marker] connect the Titanic headstones to the Saint George Batholith in southwestern New Brunswick. Precise matching of any dimension stone to its source quarry is problematic, because that material connects only to a void in the quarry. Ideally, all physical-chemical-temporal properties of the dimension stone and source quarry should match, both quantitatively and qualitatively, but in reality only the ages must almost certainly match. Thus it is remotely possible for the right quarry to mismatch most of the properties of the dimension stone, and for a wrong quarry to match most of the properties of the dimension stone. However, in the case of the Titanic headstones, the cumulative weight of all the quantitative, qualitative, and circumstantial evidence, combined with a process of elimination and application of Ockham's razor, indicate that the Charles Hanson quarry near Bocabec, southwestern New Brunswick, is the likely source for the gabbroic Titanic headstones in Halifax, Nova Scotia. [ABSTRACT FROM AUTHOR]

The Late Silurian to Late Devonian Saint George Batholith in southwestern New Brunswick is a large composite intrusion (2000 km2) emplaced into the continental margin of the peri-Gondwanan microcontinent of Ganderia. The batholith includes: (1) Bocabec Gabbro; (2) equigranular Utopia and Wellington Lake biotite granites; (3) Welsford, Jake Lee Mountain, and Parks Brook peralkaline granites; (4) two-mica John Lee Brook Granite; (6) Jimmy Hill and Magaguadavic megacrystic granites; and (6) rapakivi Mount Douglas Granite. New LA ICP-MS in situ analyses of six samples from the Saint George Batholith are as follows: (1) U-Pb monazite crystallization age of 425.5 ± 2.1 Ma for the Utopia Granite in the western part of the batholith (2) U-Pb zircon crystallization ages of 420.4 ± 2.4 Ma and 420.0 ± 3.5 Ma for two samples of the Utopia Granite from the central part of the batholith; (3) U-Pb zircon crystallization age of 418.0 ± 2.3 Ma for the Jake Lee Mountain Granite; (4) U-Pb zircon crystallization age of 415.5 ± 2.1 Ma for the Wellington Lake Granite; and (5) U-Pb monazite crystallization age of 413.3 ± 2.1 Ma for the John Lee Brook Granite. The new geochronological together with new and existing geochemical data suggest that the protracted magmatic evolution of the Late Silurian to Early Devonian plutonic rocks is related to the transition of the Silurian Kingston arc-Mascarene backarc system from an extensional to compressional tectonic environment during collision of the Avalonian microcontinent with Laurentia followed by slab break-off. [ABSTRACT FROM AUTHOR]

The Cape Spencer gold deposit, located approximately 15 km southeast of Saint John, has an inferred mineral resource estimate of 151 000 oz. The Cape Spencer area presents polyphase fold and thrust style deformation of the rock units related to the docking and adjustment of the Meguma terrane, as documented through different movements along the Minas Fault Zone between the Late Devonian and Late Carboniferous. The deposit presents characteristics of orogenic-style gold systems in which Au is hosted in quartz ± carbonate ± plagioclase ± pyrite ± specularite veins that vary from several millimetres to several decimetres in width and within sericitized (illite-carbonate ± quartz ± pyrite ± specularite), pyrite-rich rocks along the thrust faults and folds. The timing of gold deposition is bracketed by the age of the youngest unit affected by the alteration and displaying the ductile to brittle fabrics associated with gold mineralization, the Lancaster Formation (Bashkirian), and the emplacement of aplitic dikes (273.7 ± 1.3 Ma) that crosscut the fabrics of the host rocks. White micas (illite) collected from both the Cape Spencer Formation and the Millican Lake Granite were dated via in situ 40Ar/39Ar to establish a minimum age of the alteration event associated with the gold deposition. The illites define a foliation Sa related to a first episode of deformation within the polyphase fold and thrust belt. The in situ 40Ar/39Ar ages vary from 260.2 ± 4.9 to 300.6 ± 6.4 Ma and reflect continuous mica crystallization, recrystallization, and/or fluid migration along a strongly sheared and brittle faulted area leading to isotopic resetting below the closure temperature. These data also attest to the near-contemporaneous nature of deformational events that produced overprinting relationships of folds and cleavages. This resulted in sub-microscopic and lattice defects associated with deformational microstructures that could have substantially contributed to Ar diffusion release. [ABSTRACT FROM AUTHOR]