The purpose of the Harrisburg Area Geological Society (HAGS) is to stimulate geologic thought, advance and disseminate geologic knowledge, and provide fellowship amongst area individuals interested in earth sciences. Monthly meetings present a realm of geologic topics, ranging from tectonics, coal, carbonate groundwater geochemistry, geomorphology, engineering geophysics, and ore mineralogy. Field trips allow members to visit geologic sites within and beyond Pennsylvania. All events are open to the public and free unless otherwise stated. 


Meetings are held on Zoom at 6:30 PM on the second Thursday of the month, except summer months. Please email the HAGS secretary to be added to the email list and with any questions.


Kent Littlefield


Bill Bruck


Mike Meyer


Amy Randolph


A Round-Robin of Local University Student Research Projects

Presented by:  Several local student researchers!


Meeting Date:  Thursday, December 9, 2021

Meeting Time:  6:30 - 7:30 p.m.

Meeting Location:  Zoom

RSVP:  Email the HAGS secretary by noonish on the day of the meeting to RSVP and for Zoom meeting details. 

Presentation Summary: A showcase of local university student researchers.

Speaker Bios: 


Aleksandra Dimova in the Environmental Engineering program at Penn State Harrisburg will give a presentation on “Long – Term Effectiveness of Restoration Activities on Streams in the Lititz Run Watershed”.  Aleksandra’s research addresses the question of the long-term effectiveness of stream restoration activities by evaluating water quality and biotic integrity above and below several restorations on Lititz Run and its major tributary Santo Domingo Creek as part of a linear system of stream restoration projects. The restorations are at least 5 – 10 years old and have been the subject of several citizen science data collection efforts for the past 20 years. Therefore, an abundance of historical data exists as a framework for current sampling. Moreover, these streams pass through both urban and rural areas. Urban area restorations typically are primarily stabilization activities due to limited land space while agricultural restorations mostly involve floodplain restoration. The outcomes will provide insight into the temporality of the restoration effectiveness in the stream reach and the cumulative effects of these restorations on downstream water quality.

For each restoration, water testing was conducted upstream, in the middle and further downstream of the restoration, along with potential inputs just above or in the restoration areas. Preliminary results show that the restored vegetation around the floodplain and in the main channel is helpful in reducing the levels of the analyzed chemicals. For instance, at one of the restored locations, at New Street Ecological Park, we observed high concentrations of ammonia and phosphate just below two sewer manholes, indicating that there is a leak in the sewer system. However, 70 feet downstream of the location the levels are significantly lower. In addition, the fall 2019 macroinvertebrate sampling highlights the poorer biotic integrity in urban area restorations where bank armoring was the primary technique. The summer/fall 2020 and spring 2021 results are added to this initial assessment and to the historical data that has been collected on this multi-site restoration of several miles of stream.

Aaron Stone, a student at Harrisburg University will present, “Reuse of Construction and Demolition Waste Reuse: Utilizing C&D Waste as a Sustainable Growth Media”.  His research is a literature review evaluating the perception of urban waste recycling, the status of urban waste recycling, and the equitability and distribution of urban greenspace within developing countries.  This research works towards hypothesizing about the potential of construction and demolition waste as a growth media/synthetic soil process converting waste into synthetic soil. This review was conducted to provide a potential solution to urban waste disposal and provide healthy, equitable greenspace to developing countries and urbanizing areas.

Dakota Cleary, also a student at Harrisburg University, will give a presentation on “Trail Use on Water Quality”.  Dakota’s research includes a literature review, the purpose of which is to investigate the negative impacts of trail use on water quality in preparation for research in Michaux State Forest. Recent years have seen an increased amount of outdoor recreational activity resulting in having greater traffic on trails that is impacting trail-adjacent vegetative and soil properties generating greater erosion and runoff rates that negatively impacts water quality. Therefore, the reviewed literature in this research focused on measuring trail impact by quantifying soil compaction, trail characteristics, trail-use types, pollution, macroinvertebrates, and water chemistry across multiple locations. However, research on impacts of trail use is minimal, preventing effective Best Management Practices to be put into place. Regarding conservation efforts, it is imperative to consider the impacts these factors have on the ecosystem for land managers to best implement mitigation efforts to balance recreational interest and a healthy, balanced ecosystem.

Sarah Ryan, Pennsylvania State University, will present her talk on, “Impact of Precipitation on Deicing Salt Transport in a Bioretention Basin”.  During late fall, winter, and early spring, Central Pennsylvania in the Mid-Atlantic region of the United States is subject to mixed precipitation events that range from rain to freezing rain or sleet to snow, sometimes all occurring in one storm event. Due to the desire to keep streets free from ice and snow accumulations that would preclude vehicle travel, roadway clearing efforts are aggressively pursued to ensure deicing occurs through the application of road salt and, if snow begins to accumulate, plowing. Anti-skid is occasionally applied, but the method of choice to keep road surfaces free from ice accumulation, and, therefore, passable, is typically road salt application. The variety of precipitation types along with the temperature variations above and below freezing throughout these months has generated data that reveals the impact of this weather cycling on the salinity of water entering the soil of a bioretention basin in the city of Lancaster, Pennsylvania, as measured by soil conductivity, water flow meters, and local precipitation tracking. In the 3-month winter period, multiple snow and wintry precipitation storm events occurred with three of them resulting in deicing salt application to the nearby roadway and sidewalk.


The results showed that, during periods of snow and cold temperatures, when no substantial water flow entered the basin, as measured by flow meters, the soil conductivity (salinity) did not change in the top 8 inches of the soil. Precipitation in the form of rain, however, had a significant effect on the soil salinity. When rain followed a deicing salt application, soil conductivity (salinity) increased substantially. In instances when the precipitation events occurred as rain, but temperatures were far enough above freezing that deicing methods were not used, rain washed the salt out of the soil pores, resulting in a decrease in soil conductivity (salinity). Over the course of the winter of 2020-2021, the conductivity (salinity concentrations) of the soil increased after every deicing salt application with conductivity decreasing as rain intensity and air temperature increased. At the end of winter, soil conductivity (salinity) measurements in this sandier soil took over 60 days after the end of the last recorded salt application to decrease to baseline concentrations.

HAGS Guidebooks are available for download below. To purchase a hardcopy guidebook, contact the HAGS secretary.

Annual Field Trips

1st Annual Field Trip‐ Geology in the South Mountain area, Pennsylvania, Noel Potter, Jr., editor, April 24, 1982, Reprinted 1992. 37 p.

2nd Annual Field Trip‐ Geology along the Susquehanna River, south‐central Pennsylvania, J. Ronald Mowery, editor, April 16, 1983, 55 p.

3rd Annual Field Trip‐ Stratigraphy, structural style, and economic geology of the York‐Hanover Valley, G. Robert Ganis and David Hopkins, April 28,1984, 51 p.

4th Annual Field Trip‐ Pennsylvania’s polygenetic landscape, William D. Sevon, April 27, 1985, Reprinted 1992, 55 p.

5th Annual Field Trip‐ Selected geology of Dauphin and Northumberland Counties, Pennsylvania, by W. D. Sevon, W. E. Edmunds, G. R. Ganis, and J. P. Wilshusen, May 17, 1986, 22 p.

6th Annual Field Trip‐ Lower Jurassic diabase and the Battle of Gettysburg, D. T. Hoff, J. R. Mowery, and G. R. Ganis, April 25, 1987,17 p. plus appendices. 

7th Annual Field Trip‐ The geology of the Lower Susquehanna River area, a new look at some old answers, Glenn H. Thompson, Jr., editor, May 7,1988, 56 p.

8th Annual Field Trip‐ Karst development and environmental geology in the carbonate rocks of the Lehigh and Lebanon Valleys, William E. Kochanov, April 29, 1989, 33 p.

10th Annual Field Trip‐ The Ridge and Valley Physiographic Province and the East Broad Top Railroad, William D. Sevon, June 1, 1991, 24 p.

11th Annual Field Trip‐ Paleozoic geology of the Paw Paw‐Hancock area of Maryland and West Virginia, Marcus M. Key and Noel Potter, Jr., May 9,1992, 25 p.

12th Annual Field Trip‐ South Mountain and the Triassic in Adams County, Pennsylvania, Raymond Britcher, editor, May 22, 1993, 41 p.

13th Annual Field Trip‐ Geology of the Lebanon Valley and western end of the Reading Prong, Charles Scharnberger, editor, April 23. 1994, 68 p.

14th Annual Field Trip‐ Geology of the Rohrer Quarry and Binkley and Ober Quarry near East Petersburg, Lancaster County, PA, Richard P. Nickelsen, Donald U. Wise, Richard Clouser, April 29, 1995, 27 p.

15th Annual Field Trip‐ Pseudo‐Morainic Topography of the Allentown Area of Eastern Pennsylvania, Duane D. Braun and William E. Kochanov, May 4, 1996, 28 p.

16th Annual Field Trip‐ Notes on the Hamburg Klippe: biostratigraphy, ash layers, olistostromes, and “exotics,” G. Robert Ganis, April 26, 1997, 52 p.

17th Annual Field Trip‐ Geomorphology in the Northern Cumberland Valley, PA, including the Carlisle Deluge of 1779, Noel Potter, Jr., Donald Hartman, and Helen Delano, April 18, 1998, 49 p.

18th Annual Field Trip‐ The Cove Syncline by canoe, William M. Roman and Michael A. Knight, May 15, 1999, 16 p. plus maps, Out of Print

19th Annual Field Trip‐ Geology of the Kishacoquillas Valley and vicinity, Mifflin County, Pennsylvania, Michael A. Knight and William M. Roman, May 20, 2000, 18 p. plus maps and sections.

20th Annual Field Trip‐ Geology and Geomorphology of the South Mountain Area, Cumberland and Franklin Counties, Pennsylvania, Noel Potter, Jr., and William D. Sevon, May 14, 2011, 64 p.

21st Annual Field Trip‐ Shermans Creek from Dellville to Duncannon, Perry County, Pennsylvania, William Roman, May 12, 2012, 48 pages, color.

22nd Annual Field Trip‐ Some geological aspects of the north side of the Cumberland Valley in Cumberland County, PA, Bill Sevon, May 4, 2013, 33 pages, large font, color photos.


No formal guidebooks were prepared for the 9th (1990) and 14th (1995) Field Trips. The 2001 trip was a repeat of the 2000 trip.

Other Field Trips

In cooperation with the 20th annual Binghamton Geomorphology Symposium at Dickinson College‐ The rivers and valleys of Pennsylvania, then and now, by William D. Sevon, October 20, 1989, 59 p.

Anthracite Region Field Trip‐ Harrisburg Area Geological Society Field Trip Guidebook Anthracite Region, James E. Baxter and Keith Brady, May 2002, 24 p.

Halloween Limestone Adventure‐ Limestones of Snyder and Centre Counties, PA, Bill Kochanov, Rose-Anna Behr, and Bill Roman, October 22, 2011 May 2002, 25 p.