Subsurface Imaging in Archaeology- Geology 436
aka: Archaeological Geophysics, Near Surface Geophysics
Professor: Steve Sheriff
Syllabus, the ad, project reports, grading papers
Excel tips & exercises (free!)

Spring Semester, 2012:

1/24/2012: Introduction to course, and a basic discussion on geophysical targets and methods (magnetic, gravity, electrical, radar; Intro ppt, movies (1, 2). The latter lead to three basic questions: 1) what are you looking for?, 2) what are the physical characteristics?, and 3) what are the material contrasts?, and a flow chart for the experimental process. Introduction to gravity: Newton, spheres and trenches; my notes.

1/31/2012: Gravity over a buried sphere and horizontal cylinder (spreadsheet example). Using CSM's Java applet for modeling the gravity anomaly over a tunnel; Berkeley's gravity page (has great Java applets too); PBLOCK.EXE. Gravity with time (hours, days), elevation, and latitude; field methods (drift curve). My notes. Assignment: 1) problem with report due next week, and 2) read this abstract and the gravity section of and the paper that goes with it - the resistivity and magnetics stuff comes next! Operation of the Scintrex CG3 gravity meter.

2/7: Signal stacking & instrument sensitivity. Discussion of your bids. Introduction to DC electrical resistivity (Loke's tutorial <-6 megs & 'mathy', analog model , example). The apparent resistivity of subsurface materials is measured with a number of common arrays used both for profiling and sounding. The Syscal kid specs, depth of investigation and case studies (Coloma (figure, paper), Sandhill, (ppt), Coloma data). A good paper and my notes.

2/14: The previous assignment (accuracy-precision, and resolution). Next: pseudosections, resistivity mapping, modeling and inverting with RES2DMOD and RES2DINV demonstrates:

1. variations of resistivity in the subsurface cause different apparent resistivity values at the surface and the pseudosection depends on the array.
2. arrays have variable sensitivity (Wenner, dipole-dipole).
   
   
Assignment: For next week (2/21): find a recent professional paper using DC resistivity pertinent to your interests in archaeology or geosciences - be prepared to give us a short review of that paper next week (Your presentation outline: authors, problem, experiment, results, your thoughts - focus on the geophysics). We'll use these presentations as a basis for furthering understanding and answering questions and I'll watch for your understanding.

Due in two weeks(2/28): Here's an assignment using RES2DMOD and RES2DINV for modeling and inverting electrical resistivity profiles.

Spring Semester, 2011:

1/25/2011: Introduction to course, and a basic discussion on geophysical targets and methods (magnetic, gravity, electrical, radar; Intro ppt). The latter lead to three basic questions: 1) what are you looking for?, 2) what are the physical characteristics?, and 3) what are the material contrasts?, and a flow chart for the experimental process. Introduction to gravity: Newton, spheres and trenches; my notes.

2/1: Gravity over a buried sphere and horizontal cylinder (spreadsheet example). Using CSM's Java applet for modeling the gravity anomaly over a tunnel. Berkeley's gravity page (has great Java applets). Gravity with time (hours, days), elevation, and latitude; field methods (drift curve). My notes. Assignment: 1) problem with report due next week, and 2) read this abstract and the gravity section of and the paper that goes with it - the resistivity and magnetics stuff comes next! Operation of the Scintrex CG3 gravity meter.

2/8: Discussion of your bids. Introduction to DC electrical resistivity (Loke's tutorial <-6 megs & 'mathy', analog model , example). The apparent resistivity of subsurface materials is measured with a number of common arrays used both for profiling and sounding. The Syscal kid specs, depth of investigation and case studies (Coloma (figure, paper), Sandhill, (ppt), Coloma data). A good paper and my notes.

2/15: Resistivity mapping, modeling and inverting with RES2DMOD and RES2DINV demonstrates:

1. variations of resistivity in the subsurface cause different apparent resistivity values at the surface
2. arrays have variable sensitivity (Wenner, dipole-dipole).

Assignment: For next week (2/22): find a recent professional paper using DC resistivity pertinent to your interests in archaeology or geosciences - be prepared to give us a short review of that paper next week (Your presentation outline: authors, problem, experiment, results, your thoughts - focus on the geophysics). We'll use these presentations as a basis for furthering understanding and answering questions and I'll watch for your understanding.

Due in two weeks(3/1): Here's an assignment using RES2DMOD and RES2DINV for modeling and inverting electrical resistivity profiles.

2/22: The previous assignment (accuracy, precision, and resolution) and your presentations.

3/1: Finish up your resistivity presentations. Start magnetic exploration: example magnetic anomaly; the Schonstedt fluxgate magnetometer and Earth's magnetic field (declination, inclination, magnetic elements), D, I in Missoula.

3/8: Magnetics - as good as it gets; flux around a dipole, block model, buried dipole applet. Magnetic minerals and rock magnetism (Butler chapter 2, 3); acquisition of magnetization; my notes and an overview: Schmidt (2007). Examples & demo processing - magnetic anomalies last a long time(.ppt).

3/15: MIDTERM EXAM - take home exam due 3/31. Gridding(figure: 4 methods, data), contouring (directions), and a start to interpreting a magnetic grid using Surfer and Magpick (source) and using upward continuation to isolate equivalent sources from different depths (my notes). USGS extensions to Oasis Montaj; decorrugation (MYAP example, gridded data).

3/22: In the lab CHCB11, Surfer (gridding and contouring) and Oasis Montaj with USGS extensions.

• Make a new folder on the desktop, using your name or something distinct. Do all your downloads and calculations in this folder; it will end up with lots of files! Think about the steps below as you go through them!
• in Surfer, grid these data from Yellowstone (acquired at 5Hz with a one meter line spacing) using kriging and minimum curvature at 0.5 meter spacing and compare the results; make nice maps/images and show me the results.
• decorrugate the data from above in Oasis Montaj (Oasis/USGSV/Spatial Filtering/Decorrugate) with a couple different operator sizes and compare the results.
• use upward continuation to further smooth the data and then difference upward continuations to separate deep and shallow sources; make nice maps/images and show me the results.
• Use upward continuation of these data acquired over a visible stone ring to determine how deep you could bury them and still see the magnetic anomaly.

3/29: Gridding, Surfer, and Oasis/USGS questions? Operating the Geometrics magnetometer, data acquisition (base stations, layout, space weather, sensor orientation (typical, dead zones) and the Syscal Kid Switch 24 (see information sheets).

Assignment: find a professional paper using magnetics pertinent to your interests in archaeology or geology - be prepared to give us a short review of that paper after spring break (Your presentation outline is: authors, problem, experiment, results). We'll use these presentations as a basis for furthering understanding and answering questions.

4/5: Spring Break

4/12: Your presentations (several) and a start on GPR. Then, in the lab (room 3) download last week's mag data (using Magmap2000 from Geometrics), analyze it on your own.

Assignment: In groups of 3-4 I want you to design an interesting, local magnetic experiment, check out the magnetometer, then acquire, download, process, and interpret the data. Each individual is responsible for their own report on those data using the usual outline; limit it to 4 pages not including tables and figures - due 5/3. Ultimately you'll present these reports in class (as a group) for our joint discussion and edification. If you would rather do a resistivity experiment, that's fine too.

Here are the magnetic data from north of CHCB - see what you can do!!

4/19: Your presentations (a few), your magnetic data, then more GPR theory and acquisition, designing a GPR experiment and operating the equipment.

4/26: You acquire GPR on campus to answer questions about the magnetic data from north of CHCB.

5/3: Finish your magnetic presentations then GPR continued: processing & presentation of last week's data-it's noisy! with Reflex.

5/11: FINAL EXAM scheduled at 1:10 - 3:10, Wednesday

The 2010 course
The 2009 course
The 2008 course
The 2007 course

Relevant Links:

Relevant Journals:

Archaeological Prospection - informs archaeologists, environmental scientists, site developers, local authorities and regional environmental agencies about the wide range of scientific techniques available for the study of the near-surface environment.

Journal of Archaeological Science - is aimed at archaeologists and scientists with particular interests in advances in the application of scientific techniques and methodologies to all areas of archaeology.

Near Surface Geophysics - an international journal for the publication of research and development in geophysics applied to the near surface. It puts emphasis on geological, hydrogeological, geotechnical, environmental, engineering, mining, archaeological and other applications of geophysics as well as on physical soil and rock properties.

Geoarchaeology - an interdisciplinary journal which presents the results of original research at the methodological and theoretical interface between archaeology and the geosciences.

SAGEEP - The Environmental and Engineering Geophysical Society (EEGS) convenes the annual Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP). Proceedings (and the journal) sometimes have archaeolgical papers.

Quick comments on some texts:

Handbook Of Geophysics In Archaeology, A.J. Witten, Equinox Handbooks in Anthropological Archaeology, 2006, 343 p. This is a good, informative and readable introductory text. The organization is excellent as is the breadth of topics and case studies. It should serve well as a textbook. On the downside there are a few errors in the text, among the most glaring is the consistent use of remnant instead of remanent in the magnetics section; likely an editor's mistake rather than the late author's.

Remote Sensing in Archaeology: An Explicitly North American Perspective, J. K. Johnson ed., Univ. Alabama Press, 2006, 319 p.  This is a set of papers resulting from a meeting. All the major methods are presented and reviewed, often in the context of "cultural resource management". The are lots of good case studies but there is insufficient physical background to make this an informative reference book. Never the less, it is a worthwhile read.

Field Geophysics, John Milsom, Wiley, 2003, 3rd edition, 232 p. This book provides the basics of a large spectrum of techniques. It is not specifically archaeological in approach, but it serves as a useful, handy reference and source of facts.

GPR for Archaeology, L. Conyers, Alta Mira Press, 2004, 203 p., This is an excellent book on a specific technique for archaeology. It is well written and all the necessary background is provided in an easily digestible fashion - recommended.

Magnetometry for Archaeologists, 2008, Aspinall, A., Gaffney, C., and Schmidt, A., Alta Mira Press, 208 p. This book gives a very sound background to understanding of magnetics and why there are magnetic anomalies over many archaeological targets. The applications, data processing and visualization are directed mostly at results and conditions in Britain.