Like Jcmanin says, my geology confuses the hell out of him, I guess the more i read it appears Sans puzzle still remains a puzzle..San has different geologies at work here and i guess finding the traps and catch the gold is the most important thing. I find it interesting to look at past history and try to see San as a package. .....The Ross River quartz dioritic pluton intruded the Rice Lake Group prior to the deposition of the San Antonio Formation.The plutonic rocks of the Rice Lake greenstone belt are mostly large masses of granodioritic or tonalitic rock of different ages. There are "basement" rocks, gneissic intrusions with ages greater than 3.0 Ga, Mesoarchaean intrusions with ages of about 2.85 Ga, older Neoarchean intrusions with ages of about 2.72 Ga and younger, "synorogenic" Neoarchean intrusions with ages of about 2.70 Ga. The older intrusions, those that belong to the first two groups, are confined to the North Caribou Terrane, north of the Rice Lake greenstone belt. The North Caribou Terrane also includes a high proportion of intrusions that belong to the third, 2.72 Ga, group, in particular, the Wanipigow River Plutonic Complex. The Wanipigow River Plutonic Complex is of batholithic size, and may represent an Andean continental margin magmatic arc. The center of the Rice Lake greenstone belt is occupied by a large pluton, the Ross River pluton that also belongs to the 2.72 Ga group. The Ross River pluton is therefore about the same age as the felsic volcaniclastic rocks that it intrudes (the Bidou assemblage), and it appears to be cogenetic.

The gabbroic sills that intrude the epiclastic sequence are all compositionally

layered. Ames (1988) used petrographic and geochemical data to show that the sill

which hosts the San Antonio deposit is composed of three different types of gabbro:

fine grained gabbro of normal basaltic composition occupies the upper and lower

margins of the sill; melagabbro, enriched in MgO, FeO and Ni, comprises

approximately the lower one-third of the sill; and, leucogabbro that is relatively enriched

in AI203 and Ti02 occupies the upper two-thirds. Similar patterns of magmatic

differentiation were noted in a sill south of the Mine and in a large body of gabbro east

of Rice Lake (Fig. 4).

The most intense effects of deformation are found in ductile shear zones that are

common throughout the area. These zones are typically heavily carbonatized and

include two types: those, such as the Normandy Creek and footwall shears (Fig. 12)

that are concordant with lithological layering and those, such as the Rice Lake shear,

that are discordant. Although definitive evidence is lacking, the presence of "down-dip"

lineation and the fact that the Rice Lake shear places Rice Lake Group volcanic rocks

over younger arenites, indicate that at least some of these structures are dominantly

reverse faults (Fig. 12)..........................................................................................................

The latest stratigraphic, structural, and geochronological

evidence suggests that the Rice Lake belt also is composed of two or more

fundamentally dissimilar volcanic sequences. In particular, komatiites occur with

magnesian and tholeiitic basalts, oxide facies iron formation, quartzites and carbonates

(Wallace Lake) and felsic pyroclastic rocks (Garner Lake): this association of rock

types is identical in most respects to that in the pre-2800 Ma Balmer, Ball and Bruce

Channel assemblages at Red Lake. These units are distintive from, but in uncertain

contact with, the more voluminous circa 2730 Ma volcanics of the Bidou Lake and Gem

Lake Subgroups.

Given the inferred similarity with Red Lake geology and considerable new data,

it is possible to view the supracrustal rocks of the Rice Lake also to be composed of

several distinctive "tectonic assemblages" in the same way that Stott and Corfu (1991)

have divided the Uchi Subprovince in Ontario. This is done, not so much as an

endorsement of the assemblage concept, but rather as an effective means of making

geological comparisons across the Ontario-Manitoba border. Using such an approach

we are able to identify several tectonic assemblages, using nomenclature that is as

consistent as possible with past lithostratigraphic nomenclature. The main

characteristics of the assemblages, their age constraints and their mutual contact

relationships are outlined in Table 3 and their distribution is shown in their present

configuration (Fig. 15).

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