Neotectonics of Poland: An overview of active faulting

Neo tec tonic stud ies in Po land con cern mainly mani fes ta tions of those tec tonic move ments that have been ac tive in Late Neo gene and Qua ter nary times, as well as geo deti cally meas ured re cent ver ti cal and hori zon tal crus tal mo tions. Among prob lems of par ticu lar in ter est, the fol low ing should be listed: pe rio dic ity of neo tec tonic (mostly Qua ter nary) ac tiv ity, es ti ma tion of the para me tres of the neo tec tonic stress field, am pli tudes and rates of Qua ter nary and re cent move ments, de vel op ment of neo tec tonic troughs and young faults, mu tual re la tion ships among pho to linea ments, geo - logi cal struc tures and re cent seis mic ity, as well as the role of tec tonic re ac ti va tion of fault zones due to hu man ac tiv ity. Neo tec tonic faults in Po land have de vel oped in Neo gene and Qua ter nary times due to re ac ti va tion of La ramian or older struc tures, or in the Qua ter nary due to re ac ti va tion of Neo gene faults. The size of throw of Qua ter nary faults changes from 40–50 m and >100 m in the Sude tes and the Lublin Up land, to sev eral – sev eral tens of me ters in the Car - pa thi ans. The av er age rate of fault ing dur ing Qua ter nary times has been 0.02 to 0.05 mm/yr, what en ables one to in -clude these struc tures into the do mains of in ac tive or low- activity faults. A simi lar con clu sion can be drawn from the re sults of re peated pre cise lev el lings and GPS cam paigns. Strike- slip dis place ments have been pos tu lated for some of these faults. Iso lated faults in Cen tral Po land have shown mid dle Qua ter nary thrust ing of the or der of 40–50 m, and some of the Outer Car pa thian over thrusts tend to re veal young Qua ter nary ac tiv ity, as in di cated, i.a. by con cen tra tions of frac tured peb bles within the thrust zones. Epi sodes of in creased in ten sity of fault ing took place in the early Qua ter - nary, in the Ma zo vian (Hol stein ian) In ter gla cial, and dur ing or shortly af ter the Odra nian (Dren the) gla cial stage. Some of the faults have also been ac tive in Holo cene times. Re cent seis mic ac tiv ity is of ten re lated to strike- slip faults, which in the Car pa thi ans trend ENE–WSW and NE–SW, whereas out side the Car pa thi ans they are ori ented par al lel to the mar gin of the East- European Plat form and the Sudetic Mar ginal Fault. Fu ture in ves ti ga tions should put more em - pha sis on pa laeo seis mo tec tonic phe nom ena and prac ti cal ap pli ca tion of neo tec tonic re search.