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A. D. Duerr

Publications and source records attributed to A. D. Duerr.

At least 19 recordsLinked to original sources
USGS2001

Potentiometric surfaces of the intermediate aquifer system, west-central Florida, September 2000

The intermediate aquifer system underlies a 5,000-square-mile area within the Southwest Florida Water Management District including De Soto, Sarasota, Hardee, Manatee, and parts of Charlotte, Hillsborough, Highlands, Polk, and Lee Counties. The intermediate aquifer system is overlain by the surficial aquifer system and is underlain by the Floridan aquifer system. The intermediate aquifer system consists of layers of sand, shell, clay, calcareous clay, limestone, and dolomite of the Tamiami Formation and Hawthorn Group of Oligocene to Pleistocene age (Wingard and others, 1995). The intermediate aquifer system contains one or more water-bearing units separated by discontinuous confining units. The intermediate aquifer system is the principal source of potable water in the southwestern part of the study area and is widely used as a source of water where wells are open to the intermediate aquifer system or to both the intermediate and Floridan aquifer systems. Yields of individual wells open to the intermediate aquifer system vary from a few gallons to several hundred gallons per minute. The volume of water withdrawn from the intermediate aquifer system is considerably less than that withdrawn from the Floridan aquifer system in the study area (Duerr and others, 1988).

Florida↗
USGS1995

Exploring storm surge

This video provides a thorough discussion of storm surge, one of the most dangerous elements of hurricanes and major storms. This video illustrates basic storm surge principles, shows actual footage of storm surge damage and relates high-water level data collection by the U.S. Geological Survey to the task of recreating the storm surge event.

Open-File Report↗
USGS1995

Types of secondary porosity of carbonate rocks in injection and test wells in southern peninsular Florida

The types of secondary porosity present in carbonate injection intervals and in the overlying carbonate rocks were determined at 11 injection well sites and 3 test well sites in southern peninsular Florida. The hydrogeologic system consists of a thick sequence of carbonate rocks overlain by clastic deposits. Principal hydrogeologic units are the surficial aquifer system, the intermediate aquifer system or the intermediate confining unit,the Floridan aquifer system, and the sub-Floridan confining unit.The concept of apparent secondary porosity was used in this study because the secondary porosity features observed in a borehole television survey could have been caused by geologic processes as well as by drilling activities. The secondary porosity features identified in a television survey were evaluated using driller's comments and caliper, flowmeter, and temperature logs. Borehole intervals that produced or received detectable amounts of flow, as shown by flowmeter and temperature logs, provided evidence that the secondary porosity of the interval was spatially distributed and interconnected beyond the immediate vicinity of a borehole and, thus, was related to geologic processes. Features associated with interconnected secondary porosity were identified as effective secondary porosity. Fracture porosity was identified as the most common type of effective secondary porosity and was observed predominantly in dolomite and dolomitic limestone. Cavity porosity was the least common type of effective secondary porosity at the study sites. In fact, of the more than 17,500 feet of borehole studied a total of only three cavities constituting effective secondary porosity were identified at only two sites. These cavities were detected in dolomite rocks. Most apparent cavities were caused by drilling-induced collapse of naturally fractured borehole walls. Also, fractures usually were observed above and below cavities. The majority of vugs observed in the television surveys did not constitute effective secondary porosity. No effective secondary porosity was evident in the limestone or dolomitic limestone in the 300-foot interval immediately above the injection interval at six sites on the southeastern coast of Florida. Injection wells commonly are cased through the 300-foot interval. Fractures or cavities that contribute to effective secondary porosity may be present in this interval, but were not detectable with the methods used. Widely dispersed, inter- connected fractures or cavities can be present beyond the rock column intersected by the borehole and can provide local pathways for vertical migration of injected wastewater or the displaced saltwater. In the interval between the top of the Floridan aquifer system and a point 300 feet above the top of the injection interval, fractured rocks having effective secondary porosity were observed at five of six sites along the southeastern coast. Borehole characteristics usually are related to the drilling characteristics of the rock type. In limestone, borehole diameters are consistently larger than the bit diameter whereas in dolomite, borehole diameters are intermittently larger than the bit diameter. The large borehole diameters associated with dredging probably are caused by the presence of intensively fractured dolomite which collapses during drilling.

Water-Resources Investigations Report↗
USGS1988

Geohydrology and 1985 water withdrawals of the aquifer systems in southwest Florida, with emphasis on the intermediate aquifer system

In southwest Florida, principal hydrogeologic units include the surficial aquifer system, the intermediate aquifer system, and the Floridan aquifer system. The Floridan aquifer system consists of the Upper and Lower Floridan aquifers separated by a middle confining unit. The intermediate aquifer system includes all water-bearing units and confining units between the overlying surficial aquifer system and the underlying Floridan aquifer system. Thickness of the surficial aquifer system ranges from 25 to 250 ft and thickness of the intermediate aquifer system ranges from less than 100 to more than 800 ft. Transmissivity of the intermediate aquifer system ranges from less than 200 to about 12,000 sq ft/day. In the northern part of the study area, the potentiometric surface of the intermediate aquifer system is higher than the potentiometric surface of the underlying Upper Floridan aquifer. Water is transmitted downward through the confining unit and recharges the Upper Floridan aquifer. The gradient in head reverses in the southern part of the study area. In 1985, an estimated 808 million gal/day of freshwater was withdrawn from all aquifers in the study area for irrigation, public and rural supply, and industrial use. Of this total, an estimated 68.9 million gal/day was withdrawn from the intermediate aquifer system. (USGS)

Water-Resources Investigations Report↗