Request for Proposals for Geophysical Survey Specialist

TheTexas Historical Commission (THC) is preparing to conduct archaeologicalinvestigations-Geophysical Survey Specialist Services, at Pass Cavallo tolocate the encampments and abandoned shipwrecks associated with Louis MichelAury’s occupation of Matagorda in May and June of 1817. Along with GalvestonIsland, Matagorda served as the revolutionary headquarters of the Republic ofMexico from 1816–1817, with Aury as the governor during the Mexican War forIndependence.Theunderwater archaeological survey will cover 4,113 acres under Texas AntiquitiesPermit No. 32185 and will be conducted in two stages: a traditionalremote-sensing survey using the agency's 25-ft SeaArk VC Commander Anomaly IIand a micro-shallow water survey using an autonomous survey vessel (ASV). Thisrequest for proposals (RFP) pertains to the traditional underwaterarchaeological survey for which the THC Marine Archaeology Program is seeking aremote-sensing survey specialist to assist with data acquisition aboard AnomalyII. This task includes post-processing and interpretation of the field data.Thisproject is made possible, in part, through grant support from the National ParkService (NPS). The primary objective of the overall project is to discover theshipwrecks and settlements associated with Aury’s tenure in Matagorda. However,unrelated archaeological sites may also be discovered during the fieldwork.Pass Cavallo serves as the historical commercial entrance to Matagorda Bay,prior to the creation of the Matagorda Ship Channel through Matagorda Peninsulain 1966. The historical inlet has not undergone large-scale modifications,giving it a high potential to contain undiscovered underwater archaeologicalsites. According to THC data, nearly a hundred reported, unverified shipwrecksare located in the vicinity of the project area.Thetraditional remote-sensing survey on board Anomaly II will utilize a GeometricsG-882 marine magnetometer and EdgeTech 4125 dual-frequency side-scan sonar fordata acquisition. The purpose of this investigation is to detect targets thatrepresent submerged cultural resources. The survey will be conducted inaccordance with agency requirements outlined in the Texas Administrative Code,Title 13, Part 2, Rule §28.6. It will be performed at 20-meter surveyintervals, with significant remote-sensing targets also undergoing close-orderrefinement survey. As part of the fieldwork, previously detected shipwrecks andsignificant remote-sensing targets from earlier archaeological studies withinthe project area will be re-examined. All magnetic data will be processed andpresented as contour isolines according to state survey standards (13 TAC§28.9). The data will be evaluated using standard underwater archaeologyinterpretative models, including the North-Alignment Model. Verified magnetictargets identified as shipwreck archaeological sites will be included in theproprietary database developed in conjunction with this model.Theremote-sensing specialist will assist in the mobilization and deployment of thesurvey vessel and equipment. The respondent will be responsible for supervisingfield data acquisition and post-fieldwork data processing, with a specificfocus on magnetic data. As part of the project, verified shipwreckarchaeological sites will be incorporated into the North-Alignment Modeldatabase, so the respondent must have access to this proprietary study andproduct. The respondent must meet the minimum professional qualifications foran underwater archaeologist as presented in 13 TAC §26.4. Previous experienceconducting underwater archaeological investigations at Pass Cavallo ispreferred.Proposalsshould be emailed to responses@thc.texas.gov and clearly labeled with the RFP number.For further inquiries, please contact Christi Duve at christi.duve@thc.texas.gov