reconnaissance geophysical surveys vincent township 2.9546 reconnaissance geophysical surveys

Download RECONNAISSANCE GEOPHYSICAL SURVEYS VINCENT TOWNSHIP   2.9546 reconnaissance geophysical surveys

Post on 01-May-2018




1 download

Embed Size (px)


  • 0102.9546


  • -1-

    I INTRODUCTION; The following pages are a concise attempt to

    present the results of Geophysical surveys completed on Claims

    #845986 to #845990 inclusive,within Vincent Township. Included

    here is the location and present holders of the property,instruments

    used,with a brief explaination of field procedures,previous surveys

    done on the property,and finally an interpretation of the results.

    Also enclosed with this report are seperate profiles of each

    line,as well as a complete map of each survey.

  • -2-

    HOLDERS of CLAIMS; The, report presented here was written by

    the technical personal of the Cayuga Syndicate,which is

    headquartered at 360 Main St. ,V/innipeg,Manitoba. This organization

    are the present holders of this property.

    LOCATION: The claims surveyed are located in the north-east

    sector of Vincent Township(NTS Map 42E12) and are registered as

    #8/15986 to #845990 respectively,within the Thunder Bay Mining

    District(Fig.l). The claims are accessible by way of Highway #11 and

    various foot trails.

    EQUIPMENT and PROCEDURE; The geophysical methods used on

    these claims were of the reconnaissance type,that is ground based

    magnetometer and VLF-EM. The surveys were conducted between June

    and August 1986.

    The instruments used were a Geometrics portable proton

    magnetometer,model G-8l6 and a Geonics EM16 VLF-EM system.

    Specifications for both instruments are given in figures 2 and 3.

    A Geometrics G-856B portable magnetometer was used as a magnetic

    base station.

    As this report is concerned basically with recording data

    for assessment purposes,no attempt will be made to probe the

    theoretical aspects of the Magnetic or Electromagnetic methodology

    or equipment design. A list of suitable references is supplied to

    the reader wishing to pursue this line of thought.

    A brief procedure used in these surveys is as follows.

    For the magnetic survey,the first step is to get the base station

    functioning. The base station is necessary to correct for diurnal

    and micropulsation time variations. The base station is tuned in

    order to acquire the best magnetic signal. This magnetic base was

  • -3-

    found to be 60300 Gammas. The sychronization of the base clock

    with the operators field clock and a time interval for readings

    is then established. This interval was 60 seconds. Finally the

    Auto switch is activated and the diurnal station monitor is

    operational. The operator then proceeds down the line,takes and

    records a reading at the station to the nearest minute. The

    stations are at 25 meter intervals along north-south trending

    lines,which are 100 meters apart. The total number of stations

    for all five claims is 331.

    The VLF-EM survey is performed by first orientating the

    instrument perpendicular to the survey line in order to establish

    a transmitting station for the best coupling effect. In this case

    the transmitter is NAA originating from Cutler,Maine at a

    frequency of 2^.0 kHz. The transmitter direction is determined

    when the sound intensity is at a minimum. The next move is to

    orientate the reference coil along magnetic lines,by slowly

    moving the instrument back and forth until minimum sound intensity

    and adjust the Out of Phase(Quadrature) component dial to further

    minimize the sound. Read and record the number on the inclinometer

    and the Out of Phase component dial. The operator must always face

    north or in the case of north-south trending strike,one must face

    west. This is necessary in order for the polarities to remain

    constant through every line.

    PREVIOUS WORK: As far as can be ascertained no published

    evidence is available of prior work executed on these particular

    claims. In the field however,there is evidence that some trenching

    was done some time ago.

  • -i).-

    I INTERPRETATION; The magnetic profiles (Fig. 4-2?) indicate

    in general,a low magnetic response. There are points which show

    major peaks both high and low. The magnetic anomalies that are

    present imply that the structure causing them,is narrow and steeply

    dipping. The structure seems to trend along strike,that is in a

    east-west direction and is located,in general between lines 0+00

    and 18+00 West,covering a width of 100 meters,from stations 0+00

    to 1+00 South. There is a southern magnetic anomaly located between

    stations 4+00 and 5+00 South,along lines 18+00 to 23+00 West. The

    magnetic anomalies do not correspond exactly to the VLF conductors

    noted below,but they are adjacent and thus they are most likly the

    result of the same geological structure.

    The VLF survey shows two conductive bodies trending

    roughly in a east-west direction. The northern response is found

    from line 0+00 and trends north-westerly to line 18+00 West and

    probably continues further beyond the boundary of these claims in

    the same general direction. This conductor seems to weaken toward

    the eastern portion of the property.

    The southern conductor is found between lines 14+00

    and 23+00 West (Fig.28-43). It trends in a east-west direction and

    most likly continues further east. The two conductors are

    approximately 200 meters apart. These conductors are very similar

    in response,in that both the Inphase and Out Phase components show

    in general,a complementary repetative pattern through all lines. The

    profiles also suggest that the dip of the southern conducting

    structure is relatively steep and to the north. The response

    signal is in general of moderate strength and sharp,hinting at a

    shallow structure in depth. The northern conductor has relatively

  • -5-

    physical characteristics as the southern response,implying

    that both conductors are the result of parallel geologic features.

    From the geological evidence,there seems to be,contained

    within the volcanic flows a thin belt of Iron Formation. This zone

    is observable at random locations on surface between line 10+00 and

    17+00 West and approximatly between stations 50 to 100 South. This

    formation contains some sulphides but its magnetic susceptibility

    is low. A few meters south of these exposures is found,again at

    random shear zones containing up to 53d pyrite. These shear zones

    are in line with an apparent topographic lineament. Both of these

    structures may account for the geophysical responses encountered

    on the northern portion of these claims. Therefore a possible fault

    structure trending in general in a east-west direction maybe

    contained within this property.

    The southern conductor is not quite as obvious. Some

    Carbonized Iron rich rock was observed near station J++00 South on

    line 16+00 West. This may have some strike length to it. There are

    also many intrusive rocks within this southern region,and the

    anomaly may be a result of a lithological change.

    CONCLUSIONS; The anomalous zones within these claims

    will be explored in more detail in up coming field seasons. This

    v/ill involve trenching and X-ray drilling. It seems however that

    a major concentration of economic minerals is not likly in this

    type of environment,as the large discoveries seem to occur in

    general near volcanic-sedimentary contacts. This property is near

    some major showings and it is for this reason that it v/ill also be

    examined in future exploration programs.

    Respectively Submitted

  • 2M

    4w4^^^^ * G^V^VmS' i

    Scale: l cm. s 7.84 M.(A) .s 13.7 km.,___________ ^"'^ J1 fX * j.......*""* \ J-^J1 ri r ___ __ __ JBJ.

    showing position of Vincent Township J ~ Mining district and location of claims

    [within, township. ^^^^

    Map within


  • Fig 2


    Sensitivity: 1 gamma throughout range

    Range: 20,000 to 90,000 gammas (worldwide)

    Tuning: Multi-position switch with signal amplitude indi cator light on display

    Gradient Exceeds 300 gammas/ft (increased gradient to!- Tolerance: erance to 800 gammas/ft upon request)

    Sampling Rate: Manual push-button, one reading each 6 seconds

    Output: 5 digit numeric display with readout directly in gammas

    Power Requirements:

    Temperature Range:

    Accuracy (Total Field):

    Twelve self-contained 1.5 volt "O" cell, univer sally available flashlight-type batteries. Charge state or replacement signified by flashing indi cator light on display.

    Battery TypeAlkalinePremium Carbon ZincStandard Flashlight

    Number of Readings over 10,000 over 4,000 over 1,500

    NOTE: Battery life decreases with low temper ature operation.

    Console and sensor: -40" to *850 C

    Battery Pack: O" to *50"C (limited use to -15 0 C; lower tempera ture battery belt opera tion optional)

    l gamma through O0 to *50"C temperature range

    Sensor: High signal, noise cancelling, interchangeably mounted on separate staff or attached to carry ing harness

    Size: Console: 3.5 x 7 x 10.5 inches (9 x 18 x 27 cm) Sensor: 4.5 x 6 inches (11 x 15 cm) Staff: l inch diameter x 8 tt lenght

    (3 cm x 2.44 m)

    Weight:Console (w/barteries): Sensor A signal cable: Aluminum staff:.

    Lbs. 5,5 4

    Total: 11.5



  • Fig 3


View more >