Introduction – Early Finds – 2007 Survey
Archaeology cont...
Long Island 2007 field survey
Survey methodology
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The survey methodology was to use a Fugro Omnistar 8300HP DGPS to fix all control, transect, and anomaly points with an accuracy of a few centimetres in horizontal plane. During the 2005 survey, information was provided by Barry Humfrey (Humfrey Land Developments) for existing survey marks on the island CPLI01 (Control Point Long Island 01) and CPLI02 (Control Point Long Island 02). These points were relocated for 2007 Long Island Survey and the total station was positioned on CPLI01—the northern-most survey mark. Survey point CPLI02 was used to orient the total station survey.
A 100m fibreglass tape was used to lay the baseline down and two 30m tapes were placed perpendicular to the baseline three to five metres apart. These tape transects marked the metal detecting survey ‘lanes’ and were set at right angle from the baseline with a compass. After each 100m baseline area was surveyed, the baseline tape would be moved in line from north to south along the island. In total, five 100m baselines (BL01-05) were laid down and surveyed. Endpoints of these baselines are referred to as ‘BL01S’ and BL01N (for ‘Baseline 01 South Datum’ and ‘Baseline 01 North Datum’). Transect line endpoints were recorded as e.g.; T01W-T01E (Transect 01 West – Transect 01 East). Artefacts or anomalies were recorded as A001, A002 etc. Baseline, transect line and anomalies were fixed using the DGPS during the first three days and using the total station on the last day (as the DGPS antenna did not pick up enough satellites to provide accurate data.)
As in previous surveys of Long Island, one person acted as surveyor operating the DGPS to measure in the points of the baselines and transects, and to record the positions of any anomalies or artefacts found. Another person operated the metal detector to locate artefacts assisted by two persons who would help to locate targets, and move and offset tapes of transect and baselines as the detector moved along the island.
Total station points were measured in by one of the metal detecting assistants and the surveyor. Communication between the operator of the total station and their assistant was facilitated by using hand-held UHF radios. According to survey instructions, the metal detector operator walked along either side of the transect lines moving the detector head coil from side to side to cover a 1.5m transect area approximately 10cm above the ground surface. This detection method and the previously described surveying method theoretically ensures a full coverage of the survey area, with an average 10 to 20 cm overlap between transects to guarantee full coverage. At the end of each day, the survey data was downloaded from the DGPS or total station and imported into Arcview GIS software.
It should be kept in mind, however, that neither visual survey nor the use of a metal detector will provide conclusive evidence to answer the questions listed above as both methods are not capable of detecting buried organic remains, such as wood or skeletal material. Therefore, possible burial sites on Long Island may remain undiscovered using the current exploration method. Furthermore, organic materials are unlikely to have survived if exposed to the elements on the surface.
Survey constraints
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a)Environmental.
Sandy sections along the high ridge of the island are occupied by nesting shearwaters. It was necessary to operate the metal detector very carefully through these highly sensitive areas in order to avoid treading on and collapsing burrows, thereby slowing the survey process.
In addition, in some areas the island’s vegetation was too high or dense, particularly in those areas along the highest ridge of Long Island. Here, the metal detector head coil could not be held at a distance of 10 cm or less from the ground. Coverage of these areas cannot be regarded as sufficient or accurate. Moreover, young chicks of nesting birds used these bushes as a hiding place at the time of survey. It was, therefore, decided not to include these areas in order to leave the flora and fauna of the island undisturbed.
Furthermore, the sandy beach and deposition of coral rubble directly inshore from it were not included in the Long Island survey as this area is continuously disturbed by dynamic wave action and tidal changes. It is highly unlikely that any historic cultural remains would have been preserved in this area.
b)Equipment.
The metal detector used for the 2007 Long Island Survey is capable of detecting small, buried objects at a range of 10–30 cm. However, small isolated artefacts situated between the coral shingles or in soil at a depth greater than 30 cm, or below a bush greater than 30 cm height could not be detected.
c)Time.
Time restraints did not allow the completion of a systematic survey of the southern-most area of Long Island (approx. 250m in length). This area remains un-investigated to date and it is recommended that the archaeological survey be completed in the near future.
Introduction – Early Finds – 2007 Survey
