geographia - Studia

I. MAC, N. HODOR, MARIA HOSU
f) low altitude (maximum 823 m in Piatra Vişcului peak and minimum 200 m at
the contact with Someş Plain);
g) increased geomorphologic complexity due to the geologic background features;
h) aggressive modeling through differential erosion, fostered by the structural and
petrographic variations;
i) closeness to the regional base level (Tisa Valley) that encouraged an accelerated
regressive erosion;
j) the possible development of the modeling processes on more temporal phases, if
considering the Mio-pliocene age of this volcanic unit;
k) the significant human impact upon the natural components.
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4. ENVIRONMENTAL GEOMORPHOLOGIC STATES
In general terms, the environmental state is considered as an outcome of the
„quality and depth of the environmental functional processes” (I. Mac, 1996). A state is
defined as a way in which a system develops in time and space under the impulse or motion
of input and output variables. In the case of the Oaş environmental volcanic system, the
environmental states compose a large specter, a differentiation being possible on criteria as
location, geologic-geomorphologic features and, in subsidiary, hydro-atmospheric factors
and the biotic component (especially the phytomass).
4. 1. Temporality states
They appear under the form of some geologic-geomorphologic memories and are
mirrored in three main territorial types:
− states and forms with increased stability, within which the resistance forces (rocks,
structures’ youngness) contributed to the preservation of some Pliocene-Pleistocene volcanic
structures in their original form (Osoi, Fraşin and Sivoki stratovolcanos in the Northwestern part
of the Oaş Mountains and the lava plateau in the South of the TurŃ Gulf). Many of these
structures still keep the complete volcanic apparatus, being thus very well preserved;
− residual forms and states, represented by intensely eroded volcanic structures
(necks) as the two twin hummocks (Geamăna Mare -648 m and Geamăna Mică – 553 m) or
the Frăsinaşu Volcano near the locality of Cămârzana;
− relict forms and states, conditioned by an active evolution in Prepontian when
the modeling processes destroyed almost completely the existing structures and forms,
conditioned by an active evolution in Prepontian, when the modeling processes up to their
root, while the subsequent transgressions partially flooded them (for example the Măguriciu
knoll, near Bixad). Nowadays, this kind of structures are not easily to be identified, but only
hinted;
− inherited states and forms within which the geographic conditions and processes
keep the same geomorphologic direction. The most explicit example in this respect is
provided by the glacises developed at the base of the volcanic structures. Although they are
intermediate landforms between the volcanic structures (cones, plateaus etc.) and the local
base levels (channels, river flats), their continuous, never-ceasing evolution determines
their development to the detriment of the first mentioned landforms (volcanic);
− actual states and forms that could be described by two main manifesting directions:
(1) degradation (denudation) by various agents, processes and mechanisms (specific forms of