GEOPHYSICAL SURVEY OF THE ARKANSAS BAUXITE REGION

Geophysics ◽  
1944 ◽  
Vol 9 (3) ◽  
pp. 324-366 ◽  
Author(s):  
Mark C. Malamphy ◽  
James L. Vallely
Keyword(s):  
Hot Spring ◽  
Geophysical Survey ◽  
Geophysical Data ◽  
Magnetic Survey ◽  
Large Area ◽  
Clark County ◽  
Ore Bodies ◽  
Geophysical Surveys ◽  
Bauxite Ore ◽  
Geophysical Anomalies

Magnetic and gravimetric surveys were conducted over an area of approximately 1400 square miles in the bauxite district of central Arkansas. The primary purpose of these surveys was to discover any possible buried and hitherto unknown syenite masses favorable for the occurrence of bauxite and to determine the approximate position of the buried flanks of the known syenite masses which might offer conditions favorable for the discovery of new ore bodies. These surveys indicated that the various syenite outcrops are domes or bosses on a large batholith and that other similar domes occur on the batholith but do not outcrop. Drilling on the local geophysical anomalies proved the presence of 10 buried domes, but only 2 were found to project above the upper surface of the Midway clays, a requisite of conditions favorable for the occurrence of bauxite ore bodies. The geophysical data indicated the approximate configuration of the buried flanks of the known syenite outcrops, and the portions of these flanks that project above the Midway have now been outlined more accurately by drilling. The geophysical surveys have produced evidence permitting the elimination of a large area as unfavorable for the occurrence of bauxite. Magnetic surveys extending along the Midway‐Wilcox contact from Gurdon in Clark County on the southwest to Searcy in White County on the northeast have proved the improbability of the existence of other syenite masses similar to those found in Pulaski and Saline Counties. A detailed magnetic survey of the Magnet Cove area in Hot Spring County has proved that the syenite mass exposed in that locality is an isolated intrusion and entirely unrelated to those of Pulaski and Saline Counties. This syenite mass does not occur under conditions believed to be favorable for the occurrence of bauxite.

Airborne geophysical surveys in Greenland in 1998

1999 ◽  
pp. 34-38 ◽  
Author(s):  
Thorkild M. Rasmussen ◽  
Leif Thorning
Keyword(s):  
High Resolution ◽  
Geophysical Data ◽  
Digital Data ◽  
Geological Survey ◽  
Magnetic Data ◽  
Magnetic Survey ◽  
Original Series ◽  
Geophysical Surveys ◽  
The Government

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Rasmussen, T. M., & Thorning, L. (1999). Airborne geophysical surveys in Greenland in 1998. Geology of Greenland Survey Bulletin, 183, 34-38. https://doi.org/10.34194/ggub.v183.5202 _______________ Airborne geophysical surveying in Greenland during 1998 consisted of a magnetic project referred to as ‘Aeromag 1998’ and a combined electromagnetic and magnetic project referred to as ‘AEM Greenland 1998’. The Government of Greenland financed both with administration managed by the Geological Survey of Denmark and Greenland (GEUS). With the completion of the two projects, approximately 305 000 line km of regional high-resolution magnetic data and approximately 75 000 line km of detailed multiparameter data (electromagnetic, magnetic and partly radiometric) are now available from government financed projects. Figure 1 shows the location of the surveyed areas with highresolution geophysical data together with the area selected for a magnetic survey in 1999. Completion of the two projects was marked by the release of data on 1 March, 1999. The data are included in the geoscientific databases at the Survey for public use; digital data and maps may be purchased from the Survey.

Geophysical Survey and Rural Settlement Architecture on the Lower Danube at the Transition to Late Antiquity

2007 ◽  
Author(s):  
M. J. BOYD
Keyword(s):  
Late Antiquity ◽  
Settlement Patterns ◽  
Research Programme ◽  
Rural Settlement ◽  
Geophysical Survey ◽  
Total Density ◽  
Large Area ◽  
Density Distributions ◽  
Geophysical Surveys ◽  
Local Patterns

One of the key aims of the ‘Transition to Late Antiquity’ research programme has been to collect a systematic data sample in order to examine local patterns and disparities at a regional level. In this project, an understanding of inter- and intra-settlement patterns of occupation is primarily acquired by calculating total density distributions of surface material, but for the examination of individual architectural units and the relationships between them, a geophysical survey has been used because of its particular ability to provide detailed information about subsurface features over a large area without excavation. This chapter describes the approach and methodology employed in the geophysical surveys carried out to assess rural settlement patterns in Bulgaria (lower Danube) as part of the ‘Transition to Late Antiquity’ research programme. Examples of particular surveys — which in general have proved remarkably successful — are used to illustrate the results.

scholarly journals Combined Magnetic, Transient Electromagnetic, and Magnetotelluric Methods to Detect a BIF-Type Concealed Iron Ore Body: A Case Study in Gongchangling Iron Ore Concentration Area, Southern Liaoning Province, China

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1044
Author(s):  
Jianfei Fu ◽  
Sanshi Jia ◽  
Ende Wang
Keyword(s):  
Data Collection ◽  
Iron Ore ◽  
Survey Methods ◽  
Survey Method ◽  
Magnetic Survey ◽  
Iron Ores ◽  
Transient Electromagnetic ◽  
Ore Bodies ◽  
Geophysical Surveys ◽  
Iron Bearing

The detection and evaluation of concealed mineral resources deep in metallic mines and in the surrounding areas remain technically difficult. In particular, due to the complex topographic and geomorphic conditions on the surface, the detection environments in these areas limit the choices of detection equipment and data collection devices. In this study, based on metallogenic theory and the metallogenic geological characteristics of banded iron formation (BIF)-type iron ores, equipment for surface geophysical surveys (i.e., the high-precision ground magnetic survey method, the transient electromagnetic method, and the magnetotelluric method) and data collection devices capable of taking single-point continuous measurements were employed to detect the concealed iron ore bodies in the transition zone CID-1 between the Hejia and Dumu iron deposits in the Gongchangling iron ore concentration area in the Anshan-Benxi area (Liaoyang, China), a representative area of BIF-type iron ores. The results showed that an optimal combination of these geophysical survey methods accurately determined the anomalous planar spatial locations and anomalous profile morphologies of the concealed iron ore bodies. On this basis, we determined their locations, burial depths, and scales. Two anomalous zones induced by concealed iron ore bodies, YC-1 and YC-2, were discovered in zone CID-1. Two concealed iron-bearing zones, one shallow (0–150 m) and one deep (300–450 m), were found in YC-1. A 100 m scale drilling test showed that the cumulative thickness of the shallow iron-bearing zone was over 23.6 m.

Airborne geophysical surveys in Greenland – 1996 update

1997 ◽  
pp. 75-79
Author(s):  
Robert W. Stemp
Keyword(s):  
Mineral Exploration ◽  
Geological Mapping ◽  
Digital Data ◽  
Magnetic Survey ◽  
Aeromagnetic Survey ◽  
West Greenland ◽  
South West ◽  
Geophysical Surveys ◽  
The Government ◽  
Airborne Geophysical Data

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Stemp, R. W. (1997). Airborne geophysical surveys in Greenland – 1996 update. Geology of Greenland Survey Bulletin, 176, 75-79. https://doi.org/10.34194/ggub.v176.5069 _______________ Two major airborne geophysical surveys were carried out in 1996, the third year of a planned five-year electromagnetic and magnetic survey programme (project AEM Greenland 1994–1998) financed by the Government of Greenland, and the second year of an aeromagnetic survey programme (project Aeromag) jointly financed by the governments of Denmark and Greenland; both projects are managed by the Geological Survey of Denmark and Greenland (GEUS). The two 1996 surveys were: 1) Project Aeromag 1996 in South-West and southern West Greenland;2) Project AEM Greenland 1996 in South-West Greenland. All areas surveyed and planned for future surveys as of March 1997 are shown in Figure 1. Results of both the 1996 surveys were released in March 1997, as a continuation of a major effort to make high quality airborne geophysical data available for both mineral exploration and geological mapping purposes. The data acquired are included in geoscientific databases at GEUS for public use; digital data and maps may be purchased from the Survey. The main results from the 1996 surveys are described in Thorning & Stemp (1997) and Stemp (1997). Two further new airborne surveys have already been approved for data acquisition during the 1997 field season, with subsequent data release in March 1998. A summary of all surveys completed, in progress or planned since the formal inception of project AEM Greenland 1994–1998 is given in Table 1. The programme was expanded to include a separate regional aeromagnetic survey in 1995, provisionally for 1995–1996, with extension subject to annual confirmation and funding.

Aeromagnetic survey in central West Greenland: project Aeromag 2001

2002 ◽  
pp. 67-72 ◽  
Author(s):  
Thorkild M. Rasmussen
Keyword(s):  
High Resolution ◽  
Magnetic Measurements ◽  
Geophysical Data ◽  
High Quality ◽  
Aeromagnetic Survey ◽  
Original Series ◽  
West Greenland ◽  
Airborne Measurements ◽  
Geophysical Surveys ◽  
Airborne Geophysical Data

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article. Rasmussen, T. M. (1). Aeromagnetic survey in central West Greenland: project Aeromag 2001. Geology of Greenland Survey Bulletin, 191, 67-72. https://doi.org/10.34194/ggub.v191.5130 The series of government-funded geophysical surveys in Greenland was continued during the spring and summer of 2001 with a regional aeromagnetic survey north of Uummannaq, project Aeromag 2001 (Fig. 1). The survey added about 70 000 line kilometres of high-quality magnetic measurements to the existing database of modern airborne geophysical data from Greenland. This database includes both regional high-resolution aeromagnetic surveys and detailed surveys with combined electromagnetic and magnetic airborne measurements.

scholarly journals A Reconnaissance Geophysical Survey of the Kawartha Lakes and Lake Simcoe, Ontario

2007 ◽  
Vol 47 (3) ◽  
pp. 313-323 ◽  
Author(s):  
Brian J. Todd ◽  
C. F. Michael Lewis
Keyword(s):  
Geophysical Survey ◽  
Paleozoic Rock ◽  
Lower Unit ◽  
Western Lake ◽  
Strong Reflection ◽  
Geophysical Surveys ◽  
Glacier Ice ◽  
Reflection Configuration ◽  
Lake Simcoe ◽  
Tectonic Origin

ABSTRACT A marine geophysical survey program has been conducted in lakes of southern Ontario. The survey was designed to detect neotectonic features, if they exist, and to evaluate their geological importance. High-resolution single- and multichannel seismic reflection profiling were used to delineate late- and post-glacial sedimentary strata and structures, as well as the sediment/bedrock interface, in the Kawartha Lakes and Lake Simcoe. Results show that two seismostratigraphic sequences are common within the unconsolidated overburden. The lower unit exhibits a parallel reflection configuration having strong reflection amplitudes, whereas the upper unit is acoustically transparent and overlies the lower unit conformably in some places and unconformably in others. Both units vary in thickness within lakes and from lake to lake. Typical subbottom profiles of Precambrian rock surfaces are rolling; those of Paleozoic rock surfaces are smooth. At one location in Lower Buckhorn Lake, tilted rock surfaces may be faulted but disturbance of overlying glacioge-nic sediments was not observed. In western Lake Simcoe and Kempenfelt Bay, slumping into graben-like features was observed. Also in Lake Simcoe, a diapiric feature was documented. It is speculated that these disturbances most likely result from glacier ice block melting and fluid migration. A tectonic origin, however, cannot be discounted at this stage of investigation. Additional systematic marine geophysical surveys are required in the future to map features in detail to determine whether they are of neotectonic or glaciotectonic origin.

scholarly journals Magnetic Survey at the Roman Military Camp of el Benian in Mauretania Tingitana (Morocco): Results and Implications

2020 ◽  
Vol 13 (1) ◽  
pp. 28
Author(s):  
Francesco Martorella
Keyword(s):  
Roman Empire ◽  
North Africa ◽  
Geophysical Survey ◽  
Magnetic Survey ◽  
North East ◽  
The North ◽  
Military Camp ◽  
Building Activity ◽  
Economic Studies

The topic of military settlements and the role of troops in the northern provinces of North Africa during the age of the Roman Empire has recently gained a strong interest in historical, archaeological, epigraphical, and economic studies. In particular, at Mauretania Tingitana (in the north-east area of modern-day Morocco), the presence of numerous military camps in the Early and Later Roman Empire has now been assessed. In this framework, the present work deals with the geophysical survey, by means of magnetometry, at the site of el Benian, where the largest military camp is located. In particular, the magnetic survey has highlighted the organization of the camp, almost totally unknown previously. The result of the magnetic survey has confirmed intense building activity over the centuries and made it possible to identify and characterize the structures typical of a military field.

scholarly journals Prediction of Hidden Ore Bodies using Integrated Geology, Source of Fluids and Stratagem EH4 Geophysical Survey in Kuoerzhenkuola Gold Deposit in Xinjiang, China

2008 ◽  
Vol 58 (1) ◽  
pp. 52-71 ◽  
Author(s):  
Ping Shen ◽  
Yuanchao Shen ◽  
Tiebing Liu ◽  
Heping Zhu ◽  
Lijuan Wang ◽  
...  
Keyword(s):  
Gold Deposit ◽  
Geophysical Survey ◽  
Ore Bodies

GEOPHYSICAL METHODS ADAPTED TO HIGHWAY ENGINEERING PROBLEMS

Geophysics ◽  
1952 ◽  
Vol 17 (3) ◽  
pp. 505-530 ◽  
Author(s):  
R. Woodward Moore
Keyword(s):  
Seismic Refraction ◽  
Geophysical Methods ◽  
Engineering Structures ◽  
Highway Engineering ◽  
Earth Resistivity ◽  
The Earth ◽  
Ore Bodies ◽  
Geophysical Surveys ◽  
Engineering Problems ◽  
Test Use

Of the several geophysical methods used in exploration for oil and useful ore bodies, the earth‐resistivity and seismic‐refraction tests have been found to be the most adaptable to the shallow tests generally required in highway construction work. Of these, the earth‐resistivity test is the faster and has a wider range of application to highway problems than does the seismic test. Use of both methods of tests in subsurface explorations for engineering structures is expanding. The paper cites a growing need for a more thorough subsurface investigation of all engineering structure sites and gives examples of field data obtained by the Bureau of Public Roads when making preliminary geophysical surveys of proposed highway locations or structure sites. The economic aspects and the advantages and limitations of the two methods of test are discussed with particular reference to their application to highway engineering problems.

Surveying Batavia’s Graveyard: Geophysical controlled experiments and subsurface imaging of archaeological sites on an Indian Ocean coral island

Geophysics ◽  
2017 ◽  
Vol 82 (4) ◽  
pp. B147-B163 ◽  
Author(s):  
Jeffrey Shragge ◽  
David Lumley ◽  
Nader Issa ◽  
Tom Hoskin ◽  
Alistair Paterson ◽  
...  
Keyword(s):  
Sea Water ◽  
Controlled Experiments ◽  
Near Surface ◽  
Survey Techniques ◽  
Geophysical Surveys ◽  
Archaeological Materials ◽  
Coral Island ◽  
Water Saturated ◽  
Ground Penetrating ◽  
Geophysical Anomalies

We conducted geophysical surveys on Beacon Island in the Houtman Abrolhos archipelago offshore Western Australia, to investigate areas of archaeological interest related to the 1629 Batavia shipwreck, mutiny, and massacre. We used three complementary near-surface geophysical survey techniques (total magnetic intensity, electromagnetic induction mapping, and ground-penetrating radar) to identify anomalous target zones for archaeological excavation. Interpreting near-surface geophysical anomalies is often complex and nonunique, although it can be significantly improved by achieving a better understanding of site-specific factors including background conditions, natural variability, detectability limits, and the geophysical response to, and spatial resolution of, buried targets. These factors were not well-understood for Beacon Island nor indeed for the Australian coastal environment. We have evaluated the results of controlled experiments in which we bury known targets at representative depths and analyze the geophysical responses in terms of an ability to detect and resolve targets from natural background variability. The maximum depth of detectability of calibration targets on Beacon Island is limited to approximately 0.5 m due to significant variations in background physical properties between a thin ([Formula: see text]) and highly unconsolidated dry sand, shell, and coral layer of variable thickness overlying a sea-water-saturated sandy half-space. Our controlled measurements have implications for calibrating and quantifying the interpretation of geophysical anomalies in areas of archaeological interest, particularly in coastal and sandy-coral island environments. Our geophysical analyzes contributed to the discovery of archaeological materials and five historical burials associated with the 1629 Batavia shipwreck.

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