U.S. Geological Survey Karst Interest Group Proceedings, Carlsbad, New Mexico, April 29-May 2, 2014. Karst aquifer systems are present throughout parts of the United States and some of its territories, and have developed in carbonate rocks (primarily limestone and dolomite) that span an interval of time encompassing more than 550 million years.
Rates of dolomite dissolution can be used to test the concept, based on geomorphologic evidence, that a major part of the Edwards aquifer could have formed within the Holocene, a timeframe of approximately 10,000 years. During formation of the aquifer in the Edwards limestone (Cretaceous, Albian) of the Balcones fault zone, dolomite dissolution and porosity development were synchronous and the ...
Geologic units containing Dolostone. Earth material. Sedimentary rock. Carbonate rock. Dolostone. A carbonate sedimentary rock of which more than 50% by weight or by areal percentages under the microscope consists of the mineral dolomite. This category is also used for dolomite and dolostone (dolomite) .
Geologic unit mapped in Ohio: Peebles Dolomite, bluish gray weathers light gray; planar to irregular, thick to massive bedded; 0 to 120 feet thick; vuggy to cavernous porosity; cliffs former. Lilley Formation, dolomite with minor limestone, chert, and shale; bluish gray to gray weathers reddish gray to gray; planar to irregular, thin to thick bedded; 20 to 80 feet thick; fossiliferous.
In a comparison of limestone and granite, higher increase in porosity was found for limestone than for granite, porosity being lower in limestone [73]. On the other hand, there is at least one study explaining the slight impact of thermal shock on a limestone by the low porosity of this rock [18] Besides the total amount of pores, the ...
The neutron-density porosity overlay in conjunction with the gamma-ray log gives an excellent first look at lithologies. However, it has its limitations because the amount of information to be gained is restricted by the number of inputs - in this case, three logs. The gamma-ray log is …
Porosity measurements by borehole gravity meter in subsurface Cenozoic carbonates of south Florida reveal an extremely porous mass of limestone and dolomite which is transitional in total pore volume between typical porosity values for modern carbonate sediments and ancient carbonate rocks. A persistent decrease of porosity with depth, similar to that of chalks of the Gulf Coast, occurs in ...
Porosity % 10% Comparison of neutron-density and sonic porosity logs in a Pennsylvanian section in Mesa Leathersland#l-14 NE-SE 14-30!+34W. Notice the oomoldic porosity zone in the upper part of the Bethany Falls Limestone. 10
Reservoirs: Reservoir rocks are mainly crystalline cherty dolomite and limestone of Ordovician through Mississippian age, which have solution and vuggy porosity and are fractured and faulted. Lower Paleozoic rocks were deposited in a shallow-marine environment in the gently subsiding ancestral
Graphs showing comparison of porosity values estimated by geophysical methods and by laboratory core analysis for: ... the U.S. Geological Survey began a regional aquifer systems analysis (UCRASA) of this area in 1981 (Taylor and others, 1983). ... These formations are homogeneous deposits of limestone and dolomite.
Because of its low ductility relative to limestone (and sandstone), the reservoir characteristics of dolomite often are enhanced by fracturing. Secondary dolomitization may create porosity and permeability by post-burial diagenesis closely preceding or …
2. Thickness and percentage of Madison Limestone marker intervals cored in U.S. Geological Survey test wells 1, 2, and 3 C4 3. Percentage of major rock types in the Madison Limestone in U.S. Geological Survey test wells 1, 2, and 3 5 4. Porosity and permeability of rock types in the Madison Limestone 7 5.
Porosity measurements of Wisconsin rocks. The porosities of the rocks measured vary from 2% to more than 30%.Much of this variation is due to lithology (rock type). The data table lists the porosities of the tested samples and the figure at right shows the range and distribution of porosities by lithology. The dolomites have the lowest porosities (2–6%), the shales have the widest range of ...
Year Published: 2017 U.S. Geological Survey Karst Interest Group Proceedings, San Antonio, Texas, May 16–18, 2017. Introduction and AcknowledgmentsKarst aquifer systems are present throughout parts of the United States and some of its territories, and have developed in carbonate rocks (primarily limestone and dolomite) and evaporites (gypsum, anhydrite, and halite) that span an interval of ...
Geological vs. Commercial Definition of Limestone: There is an academic, geological definition and a practical, commercial definition of limestone. The geological definition of limestone is a sedimentary rock consisting of at least 50% calcite and dolomite, with less than 50% other rock materials.