Evolution of the Taebaeksan Basin, Korea: II, late Paleozoic sedimentation in a retroarc foreland basin and assembly of the proto‐Korean Peninsula

Abstract

The Taebaeksan Basin comprises the lower Paleozoic Joseon Supergroup and the upper Paleozoic Pyeongan Supergroup, which are separated by a disconformity representing a 140 myr‐long hiatus. This paper deals mainly with the late Paleozoic paleogeographical and tectonic evolution of the Taebaeksan Basin on the basis of updated stratigraphy, sedimentation, and geochronology of the Pyeongan Supergroup. Late Paleozoic sedimentation in the Taebaeksan Basin recommenced at ~ 320 Ma and formed a thick siliciclastic succession of marginal marine and non‐marine alluvial deposits, the Pyeongan Supergroup. The Pyeongan Supergroup was deposited in a retroarc foreland basin formed by build‐up of a magmatic arc along the northern margin of the Sino‐Korean Craton. The formation of sedimentary deposits ceased at ~ 250 Ma due to the collision of the Sino‐Korean Craton and South China Craton that generated the Triassic Songnim orogeny in Korea. Diverse tectonic models have been proposed for assembly of the proto‐Korean Peninsula, but the indented wedge model is considered to best explain the geological features of the peninsula. The indented wedge model entails northward subduction of the central block of the Korean Peninsula (part of the South China Craton) beneath the northern block of the Korean Peninsula (part of the Sino‐Korean Craton) along the Sulu‐Imjingang Belt.

Redefinition of the boundary between the Taebaeksan Basin and the Ogcheon metamorphic belt, Korea: a remark on the South Korean Tectonic Line (SKTL)

“…The boundary between the Taebaeksan Basin and the Ogcheon metamorphic belt has been viewed differently depending on tectonic models. Although the boundary itself has long been misunderstood in terms of its width and involved rock units, the boundary should be either a local structure (Kim et al, 2001;Lee and Lee, 2003;Oh and Kusky, 2007) or a continental transform fault (Chough et al, 2000;Ree et al, 2001;Choi, 2019b). We consider two alternative models for the origin of the Taebaeksan Basin and the Ogcheon metamorphic belt which dictates structural relationship between those two domains;…”

Evolution of the Taebaeksan Basin, Korea: I, early Paleozoic sedimentation in an epeiric sea and break‐up of the Sino‐Korean Craton from Gondwana

“…In this paper and its companion paper on the late Paleozoic (Choi, ), the Paleozoic evolution of the Taebaeksan Basin will be explored on the basis of updated information on the stratigraphy, faunal assemblages, sedimentation, and geochronology. To discuss the paleogeographical and tectonic evolution of the Taebaeksan Basin, some fundamental questions should be taken into consideration: How was the basin initiated at ~ 520 Ma or what was the tectonic setting for early Paleozoic sedimentation in the basin? What caused the termination of early Paleozoic sedimentation in the basin at ~ 460 Ma? How can the Paleozoic disconformity, representing a 140 myr‐long hiatus, in the basin be explained in terms of tectonics? How did late Paleozoic sedimentation in the basin resume at ~ 320 Ma or what was the tectonic setting for late Paleozoic sedimentation in the basin? What caused the termination of late Paleozoic sedimentation in the basin? These questions are equally applicable to other Paleozoic sedimentary basins of the Sino‐Korean Craton.…”

“…In this paper and its companion paper on the late Paleozoic (Choi, 2018), the Paleozoic evolution of the Taebaeksan Basin will be explored on the basis of updated information on the stratigraphy, faunal assemblages, sedimentation, and geochronology. To discuss the paleogeographical and tectonic evolution of the Taebaeksan Basin, some fundamental questions should be taken into consideration: This paper deals primarily with the first two questions, focusing on the early Paleozoic paleogeography and tectonics of the Taebaeksan Basin.…”

The Paleozoic evolution of the Korean Peninsula and Japan: An introduction

“…Korea has a complex geological history that extends deep into the Precambrian. Two papers in this volume provide an overview of the evolution of the Paleozoic succession in the Taebaeksan Basin (Choi, , ), which occupies the mid‐eastern part of the southern Korean Peninsula and is bounded to the northwest by the Gyeonggi Massif, to the southeast by the Yeongnam Massif, and to the southwest by the Chungcheong Basin or the Ogcheon Metamorphic Belt (Cho et al, ). The Taebaeksan Basin comprises the Cambrian (Series 2) to Middle Ordovician Joseon Supergroup and the Upper Carboniferous to lowermost Triassic Pyeongan Supergroup, these two supergroups being separated by a major disconformity that is also recognized in North China.…”

“…Nevertheless, evidence from detrital zircons collected from the lower Cambrian Jangsan Formation and the younger Myobong Formation has contrasting provenance signatures, the earlier indicating a likely North China source, but the latter having a younger basement signature. The overlying Pyeongan Supergroup comprises some 1.7 km of marine and non‐marine sedimentary deposits that show arc‐related signatures likely recording a retro‐arc foreland basin along the margin of the North China Craton (Choi, ). Sedimentation ceased in the earliest Triassic due to collision between the North China and South China paleocontinents that formed the Songnim orogeny on the Korean Peninsula.…”