The Devon Karst Research Society
and Karst Evolutionary Development.
updated 21 June 2016.
This aspect of the Society's karst research activities in Devon is instrinsically linked with the Karst Geomorphological Mapping Programme and in particular, with the Karst Rock-head Profiling Programme,.which is directed by the developments and results of our core Karst Morphogenetical Research. This work is one of the Society's more important areas of karst research.
Before we consider karst morphogenesis in some detail, it is necessary to review some definitions. We begin with the "Concept of Karst" .......

1.1.1...Karst is a stage in the natural development or evolution of dominantly limestone (carbonate) landmasses and which, together with a characteristic appearance, is the result of the corrosion of such a landmass by a series of natural chemical reactions culminating in its aqueous hydrogen-carbonate dissolution.

This is the prime, fundamental aspect of the karst process.

1.1.2...The ordinary base process of simple aqueous solution of the carbonate landmass in itself does not represent the karst process but is obviously an intrinsic part of that process.
It is necessary to state that there continues to be an unhealthy trend in the application of the word "karst" to any solutional environment. The Karst Process is clearly limited to the corrosional or chemical evolution of carbonate landmasses via the complex process of aqueous hydrogen-carbonate dissolution.
The active process is referred to as karstification.
Karstification of the carbonate deposits can take place at any time, including during (or soon after) the process of deposition. This is known as syngenetic karst.
1.1.3...The aqueous hydrogen-carbonate dissolutional process is both assisted by, or may be the direct result of a dynamic interplay between various chemical, physical, biological, hydrological, geological, geographical, climatological and other authigenic environmental processes on and throughout the 3-dimensional volume or body of the carbonate landmass, resulting in a characteristic (dissolutional) surface landscape (exokarst) and an attendant characteristic underground landscape (endokarst).
The complex reactions and inter-reactions, together with the multitudinous effects of the environmental variants mentioned above, separately and collectively in their infinite varying contributive proportions and combinations with each other, on and throughout the entire 3-dimensional volume of the karstic landmass, can seriously influence the dynamism of karstification.
In this respect, it would be generally true to state that the variation, fluctuation, or alteration, however caused, in any one of the prevailing component processes of karstification, would lead to an appropriate variation etc. in at least some of the other component processes. As all these processes are of the natural environment, they are changing, varying or fluctuating minute by minute, year in and year out  continuously through time - the fourth dimension.
It should be noted that the evolution or development of both the exokarst and endokarst landscapes are subject to the parallel physical processes of abrasion and corrasion. This can often enhance the appearance of the original dissolutional effects and the dynamism of karst evolution as a whole.
However, when the karst environment is subject to the additional influences or input of allogenic variants from adjacent non-karst environments, the increase in the dynamism of karst evolution can be staggering.
1.1.4...Karst landscapes are usually characterised by being devoid of integrated surface drainage systems. Allogenic surface water crossing into a karstic environment would usually soon disappear into the karst underground or endokarst. Atmospheric precipitation would also usually be absorbed directly into the karst.
1.1.5...All carbonate landmasses are karstifiable, ie. have the potential to become karstified, if the environmental conditions support this development. However, it should be noted that not all carbonate landmasses have become karst environments. Carbonates represent approximately 80% of all known "soluble" rock types and represent about 10% of the Earth's crust. 
Under similar effects and conditions, carbonate landmasses composed of CHALK and DOLOMITE will also undergo karstification, as outlined above, although for different reasons in each case, less so than for LIMESTONE, DOLOMITIC LIMESTONE and MAGNESIAN LIMESTONE.
[Furthermore, landscapes composed of GYPSUM, ANHYDRITE, ROCK SALT or HALITE and certain SILICATES will also undergo a certain amount of solutional development. However, such solutional development in most of these cases is mainly due to simple aqueous solution and is not due to hydrogen-carbonate dissolution. Where such non-carbonate solutional environments occur, they are referred to as pseudo-karsts.in the literature. However, the Society does not accept these as being pseudo-karsts but rather as totally non-karst environments.]
1.1.6...There are other significant chemical corrosion processes which can contribute to apparent karstification. In particular is the generation of sulphuric and other mineral acids by microbial and bacterial ecosystems within or adjacent to carbonate landmasses and which are responsible for excreting or producing waste products including hydrogen sulphide. Such microbes and bacteria often attack specific minerals within the carbonate mass, such as the iron or manganese constituents leading to the production of sulphuric and other mineral acids which then corrosively dissolve the carbonate landmass producing caves. There are specific examples of these bio-mineral ecosystems in the Guadelope Mountains of New Mexico, USA. and in Mexico and Romania. Such cave development often results in the massive deposition of crystalline gypsum within the caves.
It should be remembered that these processes are not the karst process but are what the Society accepts as being true pseudo-karst processes; ie. the corrosion of carbonate strata by chemical / bio-chemical processes which are not of the form given in para 1.1.1. above.

1.1.7...There are various types of karst environment, classified according to the system used, eg. Morphological Classification, Climatological Classification etc. as well as various sub-types. Even within a specific karst environment, there are further classification systems defining specified 3-dimensional spatial zones, such as epikarst, contact karst, the various karst hydrological zones etc.
1.1.8...There are further classification systems dealing with all exokarst and endokarst landforms and features and other systems that classify further according to their functionality or the observed status of a particular observed karst environment.

It is an observed fact that the more spectacular an environment is in appearance, the more dynamic are the processes that created it.









The term "Karst" is not an easy one to define in simple terms in one sentence. Much qualification is needed of other terms used in the course of the prime definition.

a)...General :
The word "karst" is the Germanic form of the Slovene word "kras" meaning bare, stoney ground (in limestone areas) and has been typified by the Classical Karst region of Slovenia. The word has been abstracted into a general environmental conceptual term of physical geography. The scientific study of karst is known as karstology and embodies all the earth-science disciplines as applied to the study of karst in the four dimensions. By definition, this includes the multi-disciplinary speleo-sciences (cave sciences) or speleology.
b)...Semantic Origin, Development and Use of the word "Karst" :
The exact origins of the word "karst" are difficult to determine due to perpetual language developments. In researching the origin of the word "kras", Gams (1973, 1988), has reported that it has pre-Indo-European origins and that in different forms and meanings, it has been adopted into the word-stock of many Indo-European Languages. In the remaining living languages, he reports that one of its earliest forms is preserved in the Celtic Language as "kara" or "karra" (=stone).

Karst landscapes are usually more rocky than those of other rock types. Often, this difference is pronounced at the margins of the karst near or at the physical contact with the adjacent non-karst strata. In Slovenia, the name "Kras" as a Proper Noun or Toponym, has contemporary use in those areas where the Dinaric Karst Plateaux protrude most visibly near the non-karst areas in the Region which is now almost universally known as the [Slovene] Classical Karst and the Trieste Karst.
In recent Slovene literature, there are several other names also used for various parts of this Region; ie..Divaško-Komenski kras; Tržaško-Komenski kras; Sežanski kras; Tržaški kras. Gams is of the opinion however, that "Kras" should be sufficient for the Slovene Classical Karst and its constituent sub-Regions.
Old maps from the 12th Century and before, indicate that the name KRAS was marked mostly on the north-west part of the region in Slovenia called DOLENJI (=lower) KRAS and can evidence that the Slovenes started to refer to the inhabitants from this rocky plateau firstly as KRAŠEVEC (= karst dwellers) on or near the Soča Plain. Even this term has been accepted into other Slavic Languages, as for example in the Slovak term KRASOVEC, attributed to a person who lives in karst areas.
In many places in Slovenia, the word KRAS can be met with as a toponym for some of the more rocky areas, though as a village name it is rarely found, but is often reserved for that part of a settlement constructed on a more rocky surface.

The extension in the use of the word from that of an ordinary noun to being an international term of physical geography was probably via the route of its use as an adjective.


The term "Karst Morphogenetics" is the result of a formal conceptual joining of the component terms karst, morphology and genesis and means the science of the origin of karst forms. It is a part of Karst Geomorphology, the science of karst landforms and, in a wider sense, of Physical Geography.


The term "Speleogenesis" is a formal conceptual joining of the component terms speleology and genesis and means the science of the origin of caves. It is a part of Speleology, the multi-disciplinary science of caves. The science can only be understood and applied within the wider context of Karst Morphogenetics, of which it is an intrinsic part. 

1.5.   OVERVIEW :

The application of Karst Morphogenetic Theories enables the observer of the karst landscape to predict specific environmental scenarios in given locations, a practise in which the Society has become particularly adept. The application of this compound-science has been of extraordinary use in identifying specific types of concealed karstic limestone landscapes in Devon which, for the most part, are buried and masked to greater or lesser degrees beneath younger sediments.
We have observed far too many engineering geologists struggling to try and understand what they often encounter as unexpected "problem limestone areas" during construction projects in South Devon. If they had any understanding of karst morphogenesis, problems, for example, such as those encountered along the construction route of parts of the A38 Dual Carriageway (eg. at Caton Cross, Ashburton, Devon) and along the construction route of the A380 Dual Carriageway (eg. at Humber Lane, Kingsteignton), not only could have been predicted but could have been subsequently avoided by appropriate changes at the early planning stages.




Many attempts have been made over the course of the last five or six decades to systematically describe and classify the various karst environmental situations that occur across our Planet. Attempts have also been made to determine the precise mechanisms of, and the resultant phenomena associated with the Karst Process. The importance of recognizing the different contributions made by authigenic and allogenic water sources upon karstification has been described by Pitty in "An Approach to the Study of Karst Water". However, there has been little international recognition of the remarkable efforts of the late Hungarian Academic, Professor Dr László Jakucs, who, in the course of his detailed study entitled "Morphogenetics of Karst Regions - Variants of Karst Evolution", made the first serious and very successful attempt to analyse the whole spectrum of environmental causes for and variants of karstification; then to link these variously with the resultant observed karst phenomena. From many years of personal study of karst scenarios in his native Hungary and throughout Eastern Europe, he brought his experiences and observations together in a book "Morphogenetics of Karst Regions - Variants of Karst Evolution".
What he describes is not "rocket science" but simple deductive reasoning and arguments for the on-going developmental processes behind many of the karst landscapes we see in evidence today. His observations are of the obvious inter-relationships between the geological, hydrological, orogenic, topographic and climatological variants prevailing in any karst environmental situation, together with a detailed assessment of any existing karst-environmental evidence which would indicate past changes in the inter-relationships of these variants. He was able to describe those conditions or combination of conditions, which most favoured karstification and those which controlled it rate of development. He proposed two distinctive types or modes of karstification; (A-Type) Authigenic and (B-Type) Allogenic 

The present mode of karstification or karst evolution [ie. either Allogenic (B-Type) by definition normally found associated at or with contact karst areas, or Authigenic (A-Type)] of any karst landscape can be accurately determined by identifying the topographic, hydrologic and orogenic relationships between the karst and adjacent non-karst landmasses.
By carefully studying a karst area, both on the surface and underground in its caves, it should also be possible to broadly determine its karst evolutionary history.

1.6.1.  Authigenic [A-Type] Mode of Karstification or Karst Evolution ....
is essentially the "pure" type of karst evolution involving processes solely restricted to, on and within the karst landmass itself and without any contribution from adjacent non-karst areas.
For such a situation to arise, the karst landmass must be elevated above or entirely isolated from adjacent non-karst areas, preventing any hydrological connection with non-karst areas. Such scenarios are rare in Devon. It is not unusual to find zones within a karst landmass which are undergoing A-Type development. This Type or Mode of Karstification is the least dynamic of the two Types.

1.6.2.  Allogenic [B-Type] Mode of Karstification or Karst Evolution ....
is where the processes confined to or within the karst landmass are combined with those of adjacent non-karst areas, ie. contact karst zones.
For such a situation to arise, the karst landmass must not only be contiguous with a non-karst area, but must also be either at the same or at a lower topographic elevation than the non-karst area.
This is the situation normally encountered in Devon and indicates a significant hydrological connection to adjacent allogenic (non-karst) water supplies. The most spectacular endokarst karst development has, or is taking place where Allogenic (B-Type) processes dominate.



Our most successful practical application of the theories of karst morphogenesis has been in identifying the location of hydrologically-active ponor zones, which occur as "Buried Karst Doline Fields" in many karstic locations in South Devon and then determining their evolutionary history. Individually, these "Buried Karst Doline Fields" represent the largest, in areal extent, of all the karst geomorphological features in Devon's karst.
Buried Karst Doline Fields must be considered as being Karst Geohazard Zones as they present areas at high risk of catastrophic (sudden) collapse, general subsidence and other ground movement. They are thus classified as mature karst areas containing many of the classic karst landforms. They are usually drained underground by a master karst conduit-aquifer into which intermittently active or permanently active ponors (swallow holes) and their cave-stream passages feed their individual water flows.

The general problem in South Devon is that the exokarst has become buried in the post-glacial period, masking and partly filling many of the classic karst features. One of the most problematic type of karst geohazards in these areas is that of buried karst shafts. Example areas 1., 2., 4. and 7. below exemplify such problems.  Examples 4. and 7. have been particularly impacted by limestone quarrying in their vicinity. 
Living or working on such hazardous karst environments presents risk to property and to human well-being.  Any impact to such areas caused by interference to natural land drainage, excavation, hedge removal or quarrying can have (and has had) devastating environmental effects, which can take place far beyond the location of the activity itself.
Such negative environmental impact is not related to the size of the Buried Karst Doline Field itself but rather to the level of karst hydrological activity within the Buried Karst Doline Field.
Further information and images of specific examples of the karst environmental scenarios in Devon's karst can be obtained in the future by clicking on the Links given below, when they become active.

1.    The Shute Buried Karst Doline Field / Ponor Zone (BKDF-01), Denbury, S. Devon.
..........A medium sized feature but in karst hydrological terms, this is extremely active and is constantly monitored by the Society for ground movement.
.......This unstable area contains one master karst conduit-aquifer fed by 3 permanently active ponor caves and by an additional 7 intermittently active ponor caves.
.......It contains one very large buried karst shaft at its epicentre and numerous others radiating outwards from the epicentre. A second large karst shaft is located offset at one end with other associated smaller ones nearby.
2.    The Wrenwell Farm Buried Karst Doline Field / Ponor Zone (BKDF-02), Denbury, S. Devon.
..........One of the smallest sized such features in S. Devon but in karst hydrological terms, this is extremely active and is constantly monitored by the Society for ground movement.
.......This unstable area contains one master karst conduit-aquifer fed by 1 permanently active ponor cave.
.......It contains one very large buried karst shaft at its epicentre.
3.    The Rydon Farm Buried Karst Doline Field / Ponor Zone (BKDF-03), Dornafield, S. Devon.
..........One of the smallest sized such features in S. Devon but in karst hydrological terms, this is active and is occasionally monitored by the Society for ground movement.
.......It contains one very large buried karst shaft at its epicentre and an unknown number of others radiating outwards from the epicentre.
4.    The Haye Farm Buried Karst Doline Field / Ponor Zone (BKDF-04), Elburton, S.W. Devon.
..........A medium sized feature but in karst hydrological terms, this is extremely active. Due to access problems, this cannot be monitored by the Society.
.......This contains one master karst conduit-aquifer fed by 5 permanently active ponor caves.
5.    The Tornewton Buried Karst Doline Field / Ponor Zone (BKDF-05), Tornewton, S. Devon.
..........A medium sized feature but in karst hydrological terms, this is extremely active and is constantly monitored by the Society for ground movement.
.......This contains one master karst conduit-aquifer fed by 3 permanently active ponor caves.
6.    The Elburton Buried Karst Doline Field / Ponor Zone (BKDF-06), Elburton, Plymouth, S.W. Devon.
..........[Now destroyed by quarrying.]
7.    The Alston Cross / Caton Cross Buried Karst Doline Field / Ponor Zone (BKDF-07), Ashburton, S. Devon.
..........The largest sized such feature in S. Devon and in karst hydrological terms, this is extremely active. This very unstable area is monitored by the Society for ground movement both 
..........directly, (where access permits) and remotely (where access does not permit). 
..........For convenience of study and research, this Buried Karst Doline Field is divided into 3 principal sections; 
..........- The Alston Cross Buried Karst Doline Field; forming the surviving western section,
..........- The Caton Cross Buried Karst Doline Field, forming the central section,
..........- The Goodstone Cross Buried Karst Doline Field, forming the eastern section.
..........The whole area is bisected east to west by the Exeter to Plymouth A38 Trunk Road.
..........The presence of a limestone quarry (Linhay Hill Quarry) at Ashburton, within the former western section (North side) of the Alston Cross area, has caused and continues to cause predictable instability across
........across the whole of this Buried Karst Doline Field, with regular catastrophic ground collapses and subsidences.
........It contains numerous very large buried karst shafts at localised epicentres and numerous others radiating outwards from each epicentre.
........The Alston Cross section (South side) also contains the principal active master conduit-aquifer for this Buried Karst Doline Field.
..........The Caton Cross Section also contains a small area of naturally occurring exokarst in the form of small-scale Pinnacle Karst - a very rare example of this form of exposed karst in Devon.
8.    The Ashwell Buried Karst Doline Field / Ponor Zone (BKDF-08), Ashwell, S. Devon.
..........A small sized feature but in karst hydrological terms, this is active and is rarely monitored by the Society for ground movement.
.......It contains one very large buried karst shaft at its epicentre.
The above list is not exhaustive.
Most of these areas include specific geomorphological features strongly suggestive of their origin, ie. morphogenesis. An understanding of the morphogenesis and subsequent landform development can lead to a better understanding of the extant karst geohazards and in being able to predict where they may occur in the future.

[Note:  The present considerable delay in our activating the above Links has been due to the problem of presenting information without causing unecessary problems for the respective land-owners. When gaining access to private land in the past in order to carry out karst research, assurances have been given in good faith by the Society to many property owners, whereby the specific identity and location of "at risk" properties (houses & other buildings) would never be revealed. As a consequence, we are having some difficulty in finding a form in which to present the information without compromising these assurances. However, we are working on the problem and the above Links will be activated to present some very interesting karst-environmental information.]

[ * signifies a stock item in the Society's Reference Library.]
Jakucs, L. (1977) *....."Morphogenetics of Karst Regions - Variants of Karst Evolution".
..................................Published in separate English Language Editions by Adam Hilger (Bristol) & Akadémiai Kiadó (Budapest). 284.pp.
Pitty, A. (1966) *........."An Approach to the Study of Karst Water".
..................................Published by University of Hull, UK. 70.pp.
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