scholarly journals Marine Archaeological Survey for the Webster to Seadrift Pipeline Project in Calhoun and Jackson Counties, Texas

Author(s):  
John Rawls ◽  
Michael Tuttle ◽  
Jim Hughey ◽  
Michael Quennoz

Under contract to BIO-WEST, Inc., Gray & Pape, Inc., of Houston, Texas, conducted a Phase I marine archaeological survey for the proposed Webster to Seadrift Pipeline Project in Calhoun and Jackson counties, Texas. Enterprise Products Operating LLC sponsored the archaeological survey. All marine fieldwork and reporting activities were completed with reference to state law (Antiquities Code of Texas [Title 9, Chapter 191 of the Texas Natural Resources Code] and Texas State rules found in the Texas Administrative Code [Title 13, part 2, Chapters 26 and 28]) for cultural resources investigations. Work was completed under Texas Antiquities Permit Number 9004. The United States Army Corps of Engineers, Galveston District has been identified as the lead federal agency. All project records are curated at the Center for Archaeological Studies at Texas State University in San Marcos, Texas. The Phase I underwater archaeological investigation assessed the number, locations, cultural affiliations, components, spatial distribution, data potential, and other salient characteristics of potential submerged cultural resources within the proposed project area. The linear project area includes approximately 391 hectares (967 acres) of submerged land in Calhoun and Jackson counties, Texas. The investigation included a comprehensive magnetic and acoustic remote sensing survey and target analysis designed to determine the presence or absence of potentially significant remote sensing targets that might be affected by proposed project activity. Background research revealed that there are no previously recorded sites within the Area of Potential Effects and that there have been two previous cultural resource surveys (Pearson et al. 1993; Gearhart 2016), conducted between 1993 and 2016, partially within the project Area of Potential Effects. Research also revealed that the 50-meter (164-foot) avoidance areas, as mandated by Texas Administrative Code, Title 13, Part 2, Chapter 26, for three previously recorded magnetic anomalies (Mag 7–Mag 9) identified by Gearhart (2016) are partially located within the survey area. These three magnetic anomalies were recommended for avoidance as they represent potential cultural resources. The grid for the remote sensing survey within the open waters of Lavaca Bay consisted of a total of 19 track lines (Lines 1–16, 18,19, 37, and 38) at 20-meter (65.6-foot) line spacing oriented parallel to an existing pipeline right-of-way. The remaining portions of the project area within Lavaca River and Catfish Bayou were surveyed at 20-meter (65.6-foot) line spacing (Lines 0, 17, 22–35, and 39–43) oriented perpendicular to the survey corridor. The marine field investigations consisted of a magnetometer and side-scanning sonar investigation of the proposed project area in safely navigable waters between July 29 and 30, 2019, and required approximately 60-person hours to complete. A total of 284.6 kilometers (176.9 linear survey miles) were transected utilizing the magnetometer and side-scan sonar. Comprehensive analysis of the magnetic and acoustic data recorded for this project resulted in the identification of 127 discrete magnetic anomalies, with 80 meeting or exceeding the Pearson and Linden (2014) 50-gamma/65-foot criteria. A total of 43 of the 80 anomalies that meet or exceed the 50-gamma/65-foot criteria are associated with existing pipelines. While the remaining 37 anomalies, consisting of 22 magnetic targets, meet and/or exceed the 50-gamma/65-foot criteria, they do not meet Gearhart’s 2011 magnetic orientation and spatial criteria to be considered potentially significant. They are interpreted as relic oils wells, ferrous debris scatters associated with the oil and natural gas industries and recreational and commercial fishing activities, and miscellaneous debris from previous tropical storms and hurricanes. Review of the sonar record revealed two distinct acoustic targets (SST-1 and SST-2) consisting of the remnants of a subsequent exploratory oil well and a subsided pipeline trench. Based on the applied criteria, these magnetic and acoustic targets do not exhibit any characteristics associated with historic shipwrecks and/or other significant submerged cultural resources. As such, the recommended management action for magnetic targets, Numbers 1–22, as well as acoustic targets, SST-1 and SST-2, is no further archaeological investigations. One magnetic target, Number 23, situated outside of the Area of Potential Effects, is associated with previously recorded anomaly Mag 8, which was deemed as potential historic shipwreck remains. While it is located outside of the Area of Potential Effects, it was recorded within the 50-meter (164 foot) avoidance buffer of previously recorded anomaly Mag 8. No magnetic signatures were recorded within the portion of the avoidance buffer that is within the Area of Potential Effects. The lack of any residual magnetic signatures of the anomaly within the Area of Potential Effects indicate that no portions of the ferrous source objects for Mag 8 extend into the current survey area or the construction footprint; and therefore, the submerged target or its avoidance buffer will not be impacted by the proposed activities. Additionally, no magnetic signatures associated with previously recorded anomalies Mag 7 and Mag 9 were identified in the 50-meter (164-foot) avoidance buffers within the Area of Potential Effects. The lack of any residual magnetic signatures of anomalies (Mag 7 and Mag 9) within the Area of Potential Effects indicate that no portions of the ferrous source objects for these two magnetic anomalies extend into the current survey area or the construction footprint; and therefore, the submerged targets or their avoidance buffers will not impacted by the proposed activities. The recommended management action for the portions of the 50-meter (164-foot) avoidance buffers for Mag 7, Mag 8, and Mag 9 that extend partially into the current survey area is avoidance from any bottom disturbing activities. If bottom disturbing activities within the buffer buffers cannot be avoided, additional marine archaeological investigations in the form of diver-ground-truthing will be required to determine the nature and historical significance of the source magnetic objects.

Author(s):  
Michael Quennoz ◽  
Jacob Hilton ◽  
Amanda Kloepfer ◽  
Tony Scott

Over several mobilizations between April 2018 and January 2020, Gray & Pape, Inc., of Houston, Texas, conducted an intensive pedestrian cultural resources survey of two segments (Segments GR02 and GR03) of proposed trail development along Lower Greens Bayou in the City of Houston, Harris County, Texas. The project alignment measures approximately 10.8 kilometers (6.7 miles) in length and encompasses approximately 9.6 hectares (23.7 acres) of area. Another 0.6 kilometers (0.4 miles) or 0.6 hectares (1.4 acres) of project alignment was removed from consideration. In total, approximately 11.4 kilometers (7.1 miles) or 10.2 hectares (25.1 acres) was surveyed for the project. Because the proposed trail development occurs on publicly owned properties a Texas Antiquities Code Permit was required prior to survey. All work was completed under Texas Antiquities Permit #8328, which was assigned by the Texas Historical Commission on February 14, 2018. Fieldwork and reporting activities were performed according to procedures set forth by the Texas Historical Commission and the Council of Texas Archeologists. The goals of the survey were to establish whether or not previously unidentified archaeological resources were located within the project area, also defined as the project’s Area of Potential Effects, and whether the proposed development would affect any previously identified cultural resources. Prior to fieldwork, site file and background research was conducted, including a review of historic aerial and topographic maps in an attempt to locate any historic structures associated with the Area of Potential Effects. Site file review and background research indicated that there are no previously recorded sites within the project Area of Potential Effects. Fieldwork took place between April 10, 2018 and January 7, 2020 and consisted of a combination of pedestrian survey and shovel testing. Systematic shovel testing was performed along a single transect over both project segments resulting in 131 shovel tests being excavated, of which 11 were positive for cultural material. The survey revealed that large portions of both project segments have been heavily disturbed by development and flood events, however, three new archaeological sites, 41HR1234, 41HR1235, and 41HR1236, and one historic Isolate were identified as a result of survey. Site 41HR1234 was identified as a mid-twentieth century historic trash midden. Site 41HR1235 was identified as a Late Prehistoric ephemeral campsite. Site 41HR1236 was identified as a multicomponent prehistoric campsite and historic isolate. Diagnostic artifacts were observed at all three sites; however, it is the recommendation of Gray & Pape, Inc. that only Sites 41HR1235 and 41HR1236 are significant in the materials they contain and their potential to offer additional research potential. Direct impacts to both sites have been avoided by the project alignment as currently planned. While indirect impacts such as looting are a concern, the distance between the sites and the current alignment as well the density of woods surrounding them minimizes the danger as a result of the project. Eligibility testing is recommended for the sites if they cannot be avoided by future projects. Based on the results of this survey, Gray & Pape, Inc. recommends that the no further cultural resources work be required for the project as currently planned and that the project be cleared to proceed. As specified under the conditions of Texas Antiquities Code Permit #8328, all project associated records are curated with the Center of Archaeological Studies at Texas State University in San Marcos, Texas.


Author(s):  
Robert Krause ◽  
James Hughey ◽  
Jacob Hilton

Gray & Pape, Inc., of Houston, Texas, under contract with BIO-WEST, Inc., has prepared the following report on cultural resources management activities in Fort Bend County, Texas. The project includes an archaeological survey of a total of approximately 0.93 kilometers (0.58 miles) along Buffalo Bayou between Katy-Flewellen Road and Kingsland Boulevard in Katy, Texas. The archaeological Area of Potential Effects is defined as the maintenance corridor, 30 to 60 meters (98 to 196 feet) long. The goal of this study was to assist Fort Bend County, the Texas Historical Commission, and the lead federal agency in determining whether or not intact cultural resources are present within areas for construction, and if so to provide management recommendations for these resources. All activities described herein were subject to Section 106 of the National Historic Preservation Act and issuance of an Antiquities Permit for Archeology (Permit 9319) applied for by Gray & Pape, Inc. on February 13, 2020, and issued by the Texas Historical Commission. No diagnostic or non-diagnostic artifacts were collected in the course of the current survey. As a project permitted through the Texas Historical Commission; however, Gray & Pape, Inc. submitted project records to the Center of Archaeological Studies at Texas State University. The Natural Resource Conservation Service is the lead federal agency for the project. Fieldwork was conducted between March 12 and March 16, 2020 and required approximately 40person hours to complete. Subsurface testing included a combination of systematic shovel testing and judgement sample auger probing. The site file research revealed two previously recorded archaeological sites (41FB101 and 41FB102) are located within the project area. At the beginning of the survey, an initial attempt was made to relocate previously recorded Sites 41FB101 and 41FB102 through surface inspection and limited shovel testing across the Area of Potential Effects along both sides of Buffalo Bayou. Recent disturbances from mechanical excavation along the channel slopes, the dumping of spoil across the surface of the two-track right-of-way along the bayou, and the active installation of sheet piling were photographed and mapped. Sites 41FB101 and 41FB102 could not be relocated within the Area of Potential Effects during the surface inspection, shovel testing or auger probing. No other historic or prehistoric artifacts or cultural features were identified as a result of this survey. During the initial reconnaissance, Rangia shells (n=8), including whole (closed) specimens and half shell, were observed on the surface in an area recently disturbed by heavy machinery. The shells were located east of Site 41FB101 along the two-track right-of-way and slope of the east bank of Buffalo Bayou. The majority of them were smaller than 3 centimeters (1.2 inches), with one whole specimen measuring approximately 6 centimeters (2.4 inches). Surface and subsurface inspection in the immediate area of these specimens failed to find evidence of associated cultural features or artifacts on the surface or in a buried context. A variety of modern bricks and brick fragments were also observed along the inner slopes of the east bank near the shell scatter. These same materials were later observed among the variety of riprap materials along the west bank of the bayou west of Site 41FB102 near a residential property immediately adjacent to the Area of Potential Effects. No additional cultural materials were observed on the surface with the exception of modern debris including plastics and aluminum cans. Gray & Pape, Inc. is not recommending a site designation for the Rangia shell or brick scatter observed during the survey for the foregoing reasons:1) there were no intact, buried deposits or features found; 2) there was no material that could be positively identified as artifacts; 3) the bricks observed were modern and likely deposited by landowners in attempts to prevent erosion; 4) the size, quantity, and inclusion of whole Rangia identified on the surface appear to be natural occurrences as opposed to the remains of an archaeological deposit or feature; and 5) it is impossible to determine the original location of the shell specimens at this time. Based on the results of this investigation, Sites 41FB101 and 41FB102 do not appear to extend into the existing easement belonging to the Fort Bend County Drainage District. Instead, both sites appear to be located on private property outside of the project Area of Potential Effects. As such, these sites have not been evaluated for National Register eligibility, but Gray & Pape, Inc. recommends that there will be no direct impact to these sites. It is also recommended that because the majority of project impacts will occur within sediments that have been repeatedly impacted by past channelization activities, the potential to identify intact, significant cultural resources is low. Gray & Pape, Inc. recommends the project be allowed to proceed as currently planned. As a protective measure during construction, high-visibility temporary fencing should be installed against the edge of the Area of Potential Effects in the vicinity of the two known sites. No additional cultural resources activities are recommended unless project plans change.


Author(s):  
Robert Gearhart

BOB Hydrographics, LLC conducted a marine geophysical survey and archaeological assessment of a proposed construction access channel in Galveston County, on behalf of HDR Engineering, Inc. A proposed 25-acre bay access channel would cross portions of State Mineral Lease Tracts, West Bay 59, 65 and 66 in West Galveston Bay. The channel would provide construction access to build a breakwater for the Galveston Island State Park Marsh Protection and Restoration Project, sponsored by the General Land Office. An archaeological survey was requested by the U.S. Army Corps of Engineers, Galveston District, based on their review of Permit Application SWG-1998-02298. Consultation between the Texas Historical Commission and the Galveston District concluded that archaeological survey only would be required for the channel providing access from the bay to the island and not for areas adjacent and including the proposed breakwaters. The area of potential effect encompasses 70 acres, including a 50-meter buffer mandated by the Texas Historical Commission around the proposed channel. A review of cultural background determined that 1 marine archaeological investigation and, at least, 1 wreck have been reported within 3 miles of the survey area. BOB completed a marine geophysical survey on May 9, 2019 under Texas Antiquities Permit 8906. A total of 140 acres was surveyed to provide options for adjusting the route if necessary. Water depth at the time of the survey ranged from 4 to 9 feet. BOB assessed all geophysical data to locate archaeological sites potentially affected by construction of the access channel. No artifacts were collected during the survey. No significant geophysical targets were discovered that might be potentially eligible for the State Antiquities Landmark or for the National Register of Historic Places. BOB recommends cultural resource clearance for all areas surveyed, provided that a THC-mandated 50-meter buffer is honored around the perimeter of the survey area. This study was completed in compliance with Section 106 of the National Historic Preservation Act (Public Law 89-665; 16 U.S.C. 470) and the Antiquities Code of Texas (Texas Natural Resource Code, Title 9, Chapter 191). The minimum reporting and survey requirements for marine archaeological studies conducted under a Texas Antiquities Permit are mandated by The Texas Administrative Code, Title 13, Part 2, Chapters 26 and 28, respectively. Project records are curated at the Center for Archaeological Studies at Texas State University in San Marcos.


Author(s):  
Michael C. Tuttle

Archaeological survey is fundamental to archaeological data collection. Underwater archaeology is developing and maturing as a discipline. The levels of technology available for investigations are variable depending on the objectives of surveys. Prior to entering the field, it is essential to do a complete desktop research, an in-office examination of available literature, and to develop a survey plan. This article describes different methods and the tools used for probing, which are used for examining subsurface features or defining the extent of a site. Remote sensing is an effective method to search for cultural material in a marine context. Once a general survey has located acoustic targets, magnetic anomalies, or other areas of interest, a predisturbance site survey of the targets may be conducted. Accurate positioning during a predisturbance investigation is critical. With an area survey complete or a predisturbance survey conducted, the next step in the archaeological process is excavation.


Author(s):  
Robert Gearhart

BOB Hydrographics, LLC (BOB) conducted an underwater archaeological survey for proposed dredging adjacent 16628 Market Street in Channelview, Texas. The project is located upstream of River Terrace Park on the northern bank of Old River, an oxbow channel of the San Jacinto River, in Harris County. This project was sponsored by 16628 Market Street, LLC. The project spans portions of State Mineral Lease, Old River Tract A. An area of 3.5 acres is proposed for dredging to provide consistent depths for barge fleeting. Water depths in the survey area range from 3.5 to 15 feet. Dredging will remove sediment to an approximate depth of 12 feet, including shoals along the shoreline, allowing barges and tugs to moor along the existing bulkhead. The survey area measures 8.8 acres, including navigable portions of a 50- meter buffer around the project perimeter but excluding areas where survey was prohibited by parked barges. Field investigations consisted of a marine geophysical survey, performed under Texas Antiquities Permit 8878, on May 8, 2019. The purpose of BOB’s survey was to locate potential archaeological sites that would be affected by construction activities A desktop review of the cultural background determined that 10 marine archaeological investigations, 1 archival study, and at least 27 shipwrecks have been reported within 3 miles of the survey area. Magnetometer data was inconclusive due to abundant modern anomaly sources in the vicinity. Analysis of side-scan sonar data discovered no significant targets. BOB recommends clearance of the 3.5-acre project proposed for dredging from further cultural resource requirements. This study was completed in compliance with Section 106 of the National Historic Preservation Act (Public Law 89-665; 16 U.S.C. 470) and the Antiquities Code of Texas (Texas Natural Resource Code, Title 9, Chapter 191). The minimum reporting and survey requirements for marine archaeological studies conducted under a Texas Antiquities Permit are mandated by The Texas Administrative Code, Title 13, Part 2, Chapters 26 and 28, respectively. Project records are curated at the Center for Archaeological Studies at Texas State University in San Marcos. No artifacts were collected during this survey.


Author(s):  
John Lindemuth

Gulf South Research Corporation (GSRC) personnel conducted an intensive archaeological survey of an existing footpath and detached river terrace, referred to as “No Name Island” proposed for vegetation removal on behalf of U.S. Customs and Border Protection (CBP). The project area consists of an approximately 0.25-mile-long dirt footpath, which is proposed to be widened to 16 feet to allow vehicle access (i.e., No Name Access Road), and an approximately 1.12-acre area of detached river terrace (i.e., No Name Island), for which clearing of dense vegetation is proposed. This investigation constitutes CBP’s good faith effort to take into account any adverse effects that may occur as a result of the proposed undertaking in compliance with Section 106 of the National Historic Protection Act (NHPA) (Public Law 89-665; 54 U.S.C. 300101 et seq). The intensive Phase I archaeological investigation included background research of the physical environment, cultural history of the area, previous investigations and previously reported cultural resources, and field survey. Field survey included pedestrian surface inspection supplemented with the excavation of shovel test pits (STPs). Background research revealed eight investigations have been previously conducted, three archaeological sites, and one National Register of Historic Places (NRHP)-listed historic district have been previously recorded within a 0.5-mile radius of the proposed project area. Two of these investigations overlapped with portions of the survey area. None of the previously identified archaeological sites or the NRHP-listed district overlap with either the No Name Access Road or No Name Island survey areas. During field survey, the pedestrian survey encountered no archaeological resources on the ground surface. The subsurface testing consisted of the excavation of four STPs along No Name Access Road within the 0.25 mile long, 60-foot wide project corridor and five STPs within the 1.12 acre No Name Island vegetation removal area. None of the nine STPs were positive for cultural material. As a result of this investigation, no cultural resources were identified within the proposed project area. The proposed project will have no adverse effect on cultural resources and no further work is recommended.


Author(s):  
Brett Lang ◽  
Melissa Green

In March 2020, an intensive cultural resources survey of the proposed Moore Park athletic complex in Plano, Collin County, Texas was completed in order to inventory all cultural resources. The project parcel currently lies within an open field at the southwest corner of the intersection of Chaparral Road and Cottonwood Creek. It is bounded by Chaparral Road on the north, Cottonwood Creek to the east, Bright Star Way on the south, and Cloverhaven Way on the west in a densely residential developed area. A North Texas Municipal Water District building is located in the far northwestern corner near Cottonwood Creek. The archeological area of potential effects (APE) covers an area of approximately 103 acres (42 hectares). Because the project is owned and funded by the City of Plano, a political subdivision of the State of Texas, the project is subject to the Antiquities Code of Texas (9 Texas Natural Resources Code [TNRC] 191), which requires consideration of effects on properties designated as—or eligible to be designated as—State Antiquity Landmarks (SALs), which includes archeological resources. The survey was carried out for the City of Plano, Parks and Recreation under Texas Antiquities Permit 9334 by Brett Lang (Project Archeologist) of Cox|McLain Environmental Consulting, Inc. (CMEC). Melissa M. Green was the Principal Investigator. The parcel is situated on an upper terrace above Cottonwood Creek. From the western boundary, an unnamed tributary of Cottonwood Creek flows from the northwest corner to the southwest corner of the project parcel (as the terrace slopes southeastward) into Cottonwood Creek approximately 860 meters or 2821.5 feet away. Cottonwood Creek parallels the eastern boundary of the APE. Ground surfaces within the project area parcel were mostly covered in short, ankle-high prairie grasses used for active cattle grazing allowing for some limited visibility ranging from 20 to 50 percent. A densely wooded section was observed along the eastern boundary and along part of the tributary, allowing for 30 to 80 percent ground visibility. In all, 19 shovel test units were excavated judgmentally across the project area, of which none contained cultural materials. All materials (notes, photographs, administrative documents, and other project data) generated from this work will be housed at the Center for Archeological Studies at Texas State University at San Marcos, where they will be made permanently available to future researchers per 13 Texas Administrative Code 26.16-17. If any unanticipated cultural materials or deposits are found at any stage of clearing, preparation, or construction, the work should cease and Texas Historical Commission personnel should be notified immediately. The Texas Historical Commission concurred with the findings and recommendations of this report on 8 May 2020.


Author(s):  
Michael Hogan ◽  
Jennifer Kimbell

Terracon Consultants, Inc. (Terracon) was contracted by the City of Port Arthur (client) to conduct a cultural resources survey of an approximately 54-acre project area in Port Arthur, Jefferson County, Texas in advance of the proposed expansion of an existing detention basin. Since the proposed undertaking will occur on land owned or controlled by a political subdivision of the State of Texas, and because funding for this project will come, in part, from the Federal Emergency Management Agency (FEMA), this project required compliance with the Antiquities Code of Texas (Texas Natural Resources Code Chapter 191) and its implementing rules and regulations (Texas Administrative Code Chapter 26) and Section 106 of the National Historic Preservation Act (NHPA), (54 USC § 306101) and its implementing rules and regulations, 36 CFR 800. This project was conducted under Antiquities Permit #9109. The proposed project area comprises a 54-acre tract of land located between Texas State Highway 347 and U.S. Route 69 in Port Arthur, Texas. Terracon archeologists excavated a total of eleven (11) shovel tests to a depth of 80 centimeters (cm) below surface, or to sediments inferred to predate human occupation in the area. The removed sediment was passed through ¼-inch hardware mesh to screen for artifacts. No cultural materials were identified during the survey. Additionally, to comply with Section 106 of the NRHP, adjacent parcels were evaluated to determine whether historic properties might be present and subject to visual effects from the project. No such historic properties were identified. Fieldwork was conducted between October 15 and October 17, 2019 by Michael Hogan (Staff Archeologist) and Amani Bourji (Field Technician) under the supervision of Jenni Hatchett Kimbell (Principal Investigator). The report was authored by Michael Hogan and Jenni Hatchett Kimbell. Given the absence of known prehistoric or historical-period resources within the proposed project area, Terracon recommends that the expansion of the Lake Arthur detention basin proceed as planned. Should human remains, historic properties, or buried cultural materials be encountered during construction or disturbance activities, work should cease in the immediate vicinity and Terracon, the Texas Historical Commission (THC) Archeology Division, or other proper authorities should be contacted.


Author(s):  
Robert Gearhart

BOB Hydrographics, LLC (BOB) conducted an underwater archaeological survey for proposed dredging adjacent the Russell Marine Barge Dock in Channelview, Texas. The barge dock is located upstream of River Terrace Park on the northern bank of Old River, an oxbow channel of the San Jacinto River, in Harris County. This project was sponsored by Lloyd Engineering, Inc. on behalf of Russell Marine, LLC. The project spans portions of State Mineral Lease, Old River Tract A. An area of 16 acres is proposed for dredging. The survey area measures 33 acres, including a 50-meter buffer around the project perimeter, where navigable, but excluding areas where survey was prohibited by parked barges. Water depths in the survey area ranged from 3.5 to 22 feet. Dredging will remove sediment to an approximate depth of 12 feet. Field investigations consisted of a marine geophysical survey, performed under Texas Antiquities Permit 8866, on May 8, 2019. The purpose of BOB’s survey was to locate potential archaeological sites that would be affected by construction activities. A desktop review of the cultural background determined that 10 marine archaeological investigations, 1 archival study, and at least 27 shipwrecks have been reported within 3 miles of the survey area. Magnetometer data was inconclusive due to abundant modern anomaly sources in the vicinity. Analysis of side-scan sonar data discovered no significant targets. BOB recommends clearance of the 16-acre area proposed for dredging from further cultural resource requirements. This study was completed in compliance with Section 106 of the National Historic Preservation Act (Public Law 89-665; 16 U.S.C. 470) and the Antiquities Code of Texas (Texas Natural Resource Code, Title 9, Chapter 191). The minimum reporting and survey requirements for marine archaeological studies conducted under a Texas Antiquities Permit are mandated by The Texas Administrative Code, Title 13, Part 2, Chapters 26 and 28, respectively. Project records are curated at the Center for Archaeological Studies at Texas State University in San Marcos. No artifacts were collected during this survey.


Author(s):  
Dumisani John Hlatywayo ◽  
Emmanuel Sakala

Optimum magnetic signatures for drill-hole targeting in gold exploration in Mbudzane were resolved from induced polarisation-resistivity and magnetic anomalies. Total magnetic field and a gold-in-soil map showed the area is magnetically quiet with high anomalous values along old gold workings. Induced polarisation was carried out along a grid for lines of 500m length, 50m separation and a baseline oriented at 330˚. The survey comprised a gradient array and three real sections. The magnetic survey was conducted over the same grid as the induced polarisation. Stations were set at 5m intervals for a line spacing of 50m. The results show intense anomalies that suggest different degrees of magnetic alteration and a set of conjugate lineaments and faults that possibly control the mineralisation in Mbudzane. The tilt derivative of the reduced-to-pole image resolves the separation between anomalies, giving information on the faulting. High chargeability is confined to the sheared and silicified mafic schist. The gradient resistivity image revealed contact between rock formations. Real section IP shows coincident low chargeability – low resistivity anomalies close to the surface. Chargeability intensity increases with depth, suggesting incipient development of disseminated sulphide replacement zones. A strong correlation between ground magnetic inferred contacts and apparent resistivity-chargeability anomalies forms the basis for suggesting a new drill-hole targeting. They dictate both the depth and angle at which drilling should be carried out. These results should be applicable to any region where drill-hole targeting in gold exploration may be required.


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