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Springs, seen and interpreted in the context of groundwater flow-systems (a suggested hydrogeological approach to subsurface sounding)

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Special Paper no. 1, National Cave and Karst Research Institute, Carlsbad, NM, U.S.A.160 p. ... interpreted and used for practical and scientific purposes in ... – PowerPoint PPT presentation

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Title: Springs, seen and interpreted in the context of groundwater flow-systems (a suggested hydrogeological approach to subsurface sounding)


1
Springs, seen and interpreted in the context of
groundwater flow-systems(a suggested
hydrogeological approach to subsurface sounding)
  • J. Tóth
  • 50 Years of Hydrogeology at GSA Looking Back
    and Looking Forward
  • GSA Annual Meeting
  • October 18-21, 2009
  • Portland, Oregon, U.S.A.

2
KEY POINTS OF THE TALK(not an Outline)
  • Looking back Hydrogeology Division and
    Groundwater Flow Systems
  • Looking around, I see Flow Systems without
    Springs and Springs without Flow Systems
  • Looking forward, I suggest the Virtual Spring,
  • or,
  • Springs in the context of Flow Systems, because
  • Virtual Spring Flow Systems
  • Subsurface (Hydrogeological) Sounding

3
Hydrogeology Division and Flow Systems
  • Looking back
  • The founding of GSAs Hydrogeology Division
    (1959) and the recognition of gravity-driven
    groundwater flow-systems (early 1960s) were,
    closely timed. A fortuitous and fortunate timing.
  • Fortuitous the two events were totally
    independent.
  • Fortunate The O. E. Meinzer Award drew attention
    to the concept, and high caliber researchers kept
    developing it further. It has thus turned out to
    be the starting point for many new fields of
    hydrogeologically related inquiry.

4
Drainage ditch (line sink in thalweg)
The Unit Basin(area-sink all lower half)
Composite basin(multiple sinkslocal
depressions) (Hubbert, 1940, Fig. 45. Tóth,
1962, Fig. 3 1963, Fig. 3, courtesy T. Winter)
FLOW SYSTEMS without SPRINGS (system concept
was born within 3 to 4 years from creation of
GSAs Hydrogeology Division)
5
Acting Chairman Stan Lohman, of GSAs
Hydrogeology Division presents the Divisions
first O.E. Meinzer Award given for the theory of
gravity-driven groundwater flow- systems (without
springs!),Kansas City, November 6, 1965.M.
King Hubbert liked it. After all, it all started
with? gh gz p/?. (Photos courtesy GSA,
1965)
6
Looking around (i. e., the present)SPRINGS
without FLOW SYSTEMS
  • Studies of various spring attributes abound (rock
    type, orifice morphology, volume, temperature,
    discharge rate, periodicity, flora, fauna, etc.)
    Their purpose is chiefly utilitarian and
    management issues (water supply, water balance,
    health, recreation, mineral water, mineral
    resource, etc.).
  • They do not pay attention to the feeding (i.e.
    parent) flow-systems. Yet!
  • (E.g., Stevens and Meretsky, 2008)

7
YET SPRINGS FLOW SYSTEMSThe Effects of the
Hydrogeologic Environment on springs depend on
the springs parent flow-systems, i.e., the
springs bear imprints of their subsurface
environment..(Tóth, 1971, Fig. 2.)
frequent rainfall events
rare rainfall events
8
Looking forward, I suggestThe Virtual
Spring a conceptual entity defined asAll
discharge phenomena considered together as one
single entity in the terminal area of a
groundwater flow-system(Springs
phreatophytes, all plant types ,soil/rock
mechanics, soil salinity/mineral deposits, swamps
and their water chemistry, well-water
temperature, etc.)
9
Effects and manifestations of regional
groundwater flow The Virtual Spring
(modified from Tóth, 1980)
Virtual springs
10
Virtual spring, Norris Geyser Basin,
Yellowstone Park, comprisingsprings, seeps,
steam, salts, gases, mud-boils, high pressure,
heat, phreatophytes, minerals (iron, travertine,
etc), bacteriaall, plus others, due to
groundwater discharge. (Photo Tóth, 1967)
11
The flow-system concept used to explain the place
of provenance of thermal spring water from
environmental isotope composition, Montecatini
Terme, Italy(One of, if not, the first explicit
applications of the flow-system theory combined
with isotopes Fritz, 1968)
local system
regional flow system
12
Field of geothermal heat modeled without and with
groundwater flow, Tongue Creek watershed,
Coloradonote dependence of springs
temperature on flow-system order (Lazear, 2006,
Figs. 14, 16)
Areal distribution of spring-water temperature
fits flow-systems context
13
? Modeled changes, (anomalies) in temperature
due to groundwater flow? Spring locations vs.
flow patterns i) at change in slope below
ridges, ii) at concentration of flow (Lazear,
2006, Figs. 18, 12)
14
Simulated groundwater flow-systems, calibrated
to springs, phreatophytes, runoff, Grote-Nete
drainage basin, N.E. Belgium.Legend numbers
1-18 flow system solid line flow-system
boundary (demarcation) gray scale discharge
areas and flow times in years (time determined by
capture-zone modeling, increases toward lighter
shades, resp. lt10, 10-50, 50-100, gt100 (Batelaan
et al., 2003, Fig. 10)
15
Fig. 1. Epigenic and hypogenic karst in the
context of basinal groundwater flow. (Klimchouk,
2007, Adopted and modified from Tóth, 1999)
(Klimchouk, A.B., 2007 Hypogene Speleogenesis
Hydrogeological and Morphogenetic Perspective.
Special Paper no. 1, National Cave and Karst
Research Institute, Carlsbad, NM, U.S.A.160
p.)(Klimchouk distinguishes between epi- and
hypo-genic karst based on chemical,
mineralogical and geothermal signatures found in
caves and attributed by him to flow systems of
different order)
16
Conceptual model of groundwater flow-system and
geochemical processes (left) causing high radon
content of St. Placidus spring, Switzerland
(right) (Figs. 6.1, Gaignon, 2008 and 8,
Gaignon et al., 2007)
Recharge area
Discharge area
hydraulic mid line
Eh
238U
222Rn FeOOH
Redox front
238U
Eh
226Ra
226Ra
Eh-
Fe, Mn
17
CONCLUSION
  • An expanded spring concept, the Virtual Spring,
    is defined and proposed as all discharge
    phenomena taken together as one single entity in
    the terminal areas of groundwater flow-systems
  • The virtual spring reflects the subsurface
    conditions of its parent flow-system. It thus
    facilitates inferences of the hydrologic,
    hydraulic, thermal and chemical attributes of the
    systems rock body in one or two specific ways,
    i.e.
  • i) by explaining features of the virtual spring
    from known properties of the rock body, or/and
  • ii) by inferring attributes of the rock body
    from observed features of the virtual spring
  • Springs can thus be seen, interpreted and used
    for practical and scientific purposes in the
    context of groundwater flow-systems.
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