Metamorphic pattern of the Teplá suture: from subduction to oblique collision

• Thesis title in Czech: Metamorfní vzor tepelské sutury: od subdukce k šikmé kolizi
• Thesis title in English: Metamorphic pattern of the Teplá suture: from subduction to oblique collision
• Academic year of topic announcement: 2023/2024
• Thesis type: dissertation
• Thesis language: angličtina
• Department: Institute of Petrology and Structural Geology (31-440)
• Supervisor: doc. RNDr. Petr Jeřábek, Ph.D.
• Author: hidden - assigned and confirmed by the Study Dept.
• Date of registration: 09.10.2023
• Date of assignment: 09.10.2023
• Confirmed by Study dept. on: 09.10.2023
• Advisors: doc. Mgr. Ondrej Lexa, Ph.D.

Preliminary scope of work

Tepelská sutura byla interpretována jako hlavní tektonické rozhraní mezi spodní saxothuringickou a svrchní tepelsko-barrandienskou deskou zaznamenávající variský subdukčně kolizní vývoj. Tato disertační práce je zaměřena na geometrické aspekty subdukčně-kolizního procesu, který lze studovat za použití variací ve strukturním a metamorfním záznamu podél tohoto rozhraní. Hlavním zaměřením práce je identifikace,charakteristikaa správné časové zařazení metamorfózy spjaté se subdukčním procesem a její následné redistribuce během předpokládané šíkmé kolizní události.

Preliminary scope of work in English

The Teplá suture has been interpreted as a major tectonic boundary between the lower plate Saxothuringian and the upper plate Teplá-Barrandian domains which were amalgamated during Variscan subduction-collision process in the Bohemian Massif. This PhD project is focused on geometric aspects of the collision that can be studied through variations in tectono-metamorphic record exposed along the Teplá suture zone. The suture shows subducted-exhumed portions of oceanic crust along its N-S trending segments which were incorporated into the upper plate during the early evolution. In contrast, continental crust of the lower plate, sometimes with occurrence of ultrahigh pressure rocks, delineates generally E-W trending segments of the suture. The lower plate assembly shows evidence for transition from accretionary to orogenic wedge redistributed along the suture zone. Such geometry is likely a result of deformation partitioning between the frontal and lateral boundary of the subducting continental segment. The principal target of the thesis is to understand themetamorphic record of the early subduction as well as its distribution in acomplex geometry of the wedge.In addition the resulting metamorphic patternneed to belinkedwitha particular stage of the collision process. The project will focus on detailed characterization of the tectono-metamorphic record along the E-W trending segments of the suture including age determination. The E-W trending segments of the Teplá suture are mostly poorly documented due to rather discontinuous outcrop situation in these parts, where the suture is mostly covered by the permo-carboniferous and tertiary sediments and volcanics. On the other hand, there are few key regions where the analysis can be performed.