The Buttle Lake Camp is a major Paleozoic volcanogenic massive sulphide district in which the relationships between massive sulphide mineralization and associated volcanism are best explained if the ore deposits and associated lithologic units formed in a rift basin generated by rifting in an island arc system. This setting accounts for the marked linear distribution of the massive sulphide bodies, and the presence and distribution of volcanic products from four distinct source areas: a volcanic arc region, a back-arc (or intra-arc) rifting region, and two seamount areas. These interpretations were achieved largely through detailed mapping (1: 2400) of the Price Hillside and the relogging of pertinent drill core. Geology of the Buttle Lake Camp consists of newly proposed, four lowermost formations of the Paleozoic Sicker Group in the Buttle Lake uplift (in order of decreasing age): (1) the Price Formation, a thick sequence of basaltic andesite flows and related breccias; (2) the massive sulphide-bearing Myra Formation, consisting of mainly volcanic and volcaniclastic units; (3) the Thelwood Formations bedded sequence of siliceous tuffaceous sediments, subaqueous pyroclastic deposits and mafic sills; and (4) the Flower Ridge Formation, largely comprising coarse mafic pyroclastic deposits. Significant units within the Myra Formation are the lowermost, largely felsic H-W Horizon which hosts the large H-W deposit; the Lynx-Myra-Price Horizon, which contains two massive sulphide mineralized felsic volcanic units; the ultramafic G-Flow unit; and the uppermost, basaltic Upper Mafic unit. Zircon U-Pb dating yielded a Late Devonian age of 370 Ma for the Myra Formation. Volcanic units in the Price and Myra Formations are grouped into five volcanic series: two mafic to intermediate volcanic series, two felsic volcanic series, and an ultramafic to mafic volcanic series. These volcanic series are the result of at least three distinct and partly contemporaneous magmatic lineages. Source region for the ultramafic to intermediate parental magmas was an upper mantle peridotite variably enriched in large ion lithophile elements but depleted in high field strength elements (relative to N-type MORB). The felsic volcanic series were generated from two distinct sources. One series is from evolved andesitic magma whereas the other is from magma formed by partial melting of lower crustal material.' The Price and Myra Formations represent a general sequence of repeated events comprising: mafic to intermediate arc volcanism; rifting and sulphide mineralization; felsic arc.volcanism; ultramafic to mafic rift volcanism; and volcanogenic sedimentation. The sequence was repeated twice and formed two mineralized horizons (H-W and Lynx-Myra-Price). The Thelwood and Flower Ridge Formations indicate a major change in depositional style and environment from the two underlying units. The Thelwood Formation is a sediment-sill complex underlying mafic volcanic rocks of the Flower Ridge Formation. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

In the summer of 1964 a study was carried out on the impounded Buttle and Lower Campbell Lakes located on Vancouver Island, British Columbia. An attempt was made to determine the effects of increased water level fluctuation on the limnology, particularly the bottom fauna, in areas with different substrate types. All data from two pre-impoundment studies were examined, and additional sampling carried out to provide a basis for comparison. In addition, several stations were chosen in each lake according to specific substrate types. These different bottom conditions were formed from the combined effects of erosion by water level fluctuation and wave action, over areas where different methods of pre-impoundment clearing of vegetation had been employed. The stations chosen were the shallow onshore areas which were exposed to the air during the winter months of minimum water level, the unexposed area immediately below the minimum drawdown level, and the pre-impoundment littoral zones in each study lake. A single pre-impoundment river channel station was located in Buttle Lake. In addition to bottom dredgings, funnel traps and nocturnal surface tows were used to sample the emerging insect fauna from each station. The total seasonal chironomid catch indicated significantly different total emergence between the several stations sampled. The pre-impoundment river station in Buttle Lake produced the highest total chironomid catch. Among the other stations the unexposed area immediately below the drawdown level was most productive. In Buttle Lake where the greatest seasonal fluctuation occurred and where the completely cleared littoral area was least protected from wave action, the total seasonal emergence over the exposed littoral area was very low. But in Lower Campbell Lake which received a much smaller seasonal water level fluctuation, total emergence was much higher over the exposed littoral. This area was cleared completely in this lake and the irregular shoreline afforded considerable protection from wind action. An inverted bathymetric distribution of the fauna was apparent with the greatest concentration occurring immediately below the drawdown limit in the unexposed littoral zone. The effects of water level changes were therefore considered the most important single factors influencing the bottom fauna distribution in each lake. / Science, Faculty of / Zoology, Department of / Graduate