Sedimentationsprocesser och avlagringsmiljö för en kantrygg kring platåleran vid Rydsgårds gods i backlandskapet söder om Romeleåsen, Skåne
(2000) In Examensarbeten i geologi vid Lunds universitetDepartment of Geology
- Abstract (Swedish)
- Populärvetenskaplig sammanfattning: Platåleror utgör ett markant inslag i det inre backlandskapet söder om Romeleåsen i Skåne. De är kvadratkilometer stora, cirkulära lerområden, med en svagt undulerande yta som täcker landskapets högsta kullformer. Runt platålerorna ligger oftast s k kantryggar som huvudsakligen består av grus och sand. I snart hundra år har bildningsmiljön för platålerorna och kantryggarna diskuterats.
I mitt examensarbete har jag studerat en skärning i en kantrygg, som omgärdar en platålera vid Rydsgårds gods. Syftet var att rekonstruera avlagringarnas bildning och bildningsmiljö.
Sedimenten i skärningen blir grövre uppåt, med en successiv övergång från laminerad siltig lera i botten till sand och grus överst.... (More) - Populärvetenskaplig sammanfattning: Platåleror utgör ett markant inslag i det inre backlandskapet söder om Romeleåsen i Skåne. De är kvadratkilometer stora, cirkulära lerområden, med en svagt undulerande yta som täcker landskapets högsta kullformer. Runt platålerorna ligger oftast s k kantryggar som huvudsakligen består av grus och sand. I snart hundra år har bildningsmiljön för platålerorna och kantryggarna diskuterats.
I mitt examensarbete har jag studerat en skärning i en kantrygg, som omgärdar en platålera vid Rydsgårds gods. Syftet var att rekonstruera avlagringarnas bildning och bildningsmiljö.
Sedimenten i skärningen blir grövre uppåt, med en successiv övergång från laminerad siltig lera i botten till sand och grus överst. Lagren i den undre halvan är tunna, med flera och täta övergångar mellan olika lagringstyper. I de övre delarna finns tjockare lager av grövre och mera osorterade sediment. Vattenmättat och urtvättat morän material, som smält ut från glaciären, har runnit som sedimentationsströmmar på isytan, ner mot en sjö.
Sedimenten har huvudsakligen avsatts under vattenytan, de grövre lagren nära stranden och de finkorniga silt- och lerlagren längre ut i sjön. Genom successiv utbyggnad av stranden, kom grus- och sandlagren att avlagras ovanpå leran. Sjöbassängen utgjordes av en smältvattensjö uppe på en flack glaciäryta. Genom isens smältning tappades sjön och när all is slutligen smält bort kom bassängsedimenten att draperas över ett topografiskt ojämnt underlag. (Less) - Abstract
- Plateau-clays are significant features in the hummocky moraine area south of Romeleåsen ridge, Skåne, southern Sweden. The plateau clays are smoothly undulating circular areas of glaciolacustrine clay, which drape the highest hummocks in the landscape. Rim ridges often surround the plateau-clays. During the last hundred years the formation of these plateau clays has been studied and discussed. In this study a section in a rim ridge was investigated. The rim ridge surrounds a plateau clay near Rydsgård. The aim of the study was to reconstruct depositional processes and the sedimentary environment of the rim ridge and to study the lateral transition into the plateau clay. The section was investigated by detailed drawing, by lithofacies... (More)
- Plateau-clays are significant features in the hummocky moraine area south of Romeleåsen ridge, Skåne, southern Sweden. The plateau clays are smoothly undulating circular areas of glaciolacustrine clay, which drape the highest hummocks in the landscape. Rim ridges often surround the plateau-clays. During the last hundred years the formation of these plateau clays has been studied and discussed. In this study a section in a rim ridge was investigated. The rim ridge surrounds a plateau clay near Rydsgård. The aim of the study was to reconstruct depositional processes and the sedimentary environment of the rim ridge and to study the lateral transition into the plateau clay. The section was investigated by detailed drawing, by lithofacies classification and by sampling for grain size analyses, clast lithology composition and analyses of clast shape and roundness. The sediments in the section show a coarsening upward sequence, starting with laminated silty clay and grading into sand and gravel. The beds in the lower half of the sections are thin, with several, rapid transitions between massive silt, massive normally graded sand and ripple laminated sand. In the upper half there are thicker beds of massive, matrix supported gravel and gravely sand and diamict beds. These lithofacies sometimes wedge out and transform into fine grained, better sorted lithofacies. The sedimentological analysis shows that the main depositional processes were a range of sediment gravity flows from debris flows to turbidity flows. The study also shows that the depositional environment was subaqueous. Sedimentary facies from a proximal, near shore environment can be followed into distal facies out in the basin. A prograding shoreline indicates a constant lake level or a slight level fall. The sedimentary basin was a supraglacial melt-water lake on a flat surface of stagnated ice. During melting of the ice masses the lake was rapidly drained. When the ice finally wasted, the sediments in the basin were draped on an undulating substratum. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/2343941
- author
- Sundberg, Sven Birger
- supervisor
- organization
- alternative title
- Sedimentation processes and depositional environment of a rim ridge surrounding a plateau clay in the hummocky terrain of southern Sweden, Skåne
- year
- 2000
- type
- H1 - Master's Degree (One Year)
- subject
- keywords
- Quaternary, ice-walled lake plain, rim-ridge, debris flow, turbidite, subaquatic, supraglacial, hummocky
- publication/series
- Examensarbeten i geologi vid Lunds universitet
- report number
- 124
- language
- Swedish
- id
- 2343941
- date added to LUP
- 2012-11-05 11:01:39
- date last changed
- 2012-11-05 11:01:39
@misc{2343941,
abstract = {{Plateau-clays are significant features in the hummocky moraine area south of Romeleåsen ridge, Skåne, southern Sweden. The plateau clays are smoothly undulating circular areas of glaciolacustrine clay, which drape the highest hummocks in the landscape. Rim ridges often surround the plateau-clays. During the last hundred years the formation of these plateau clays has been studied and discussed. In this study a section in a rim ridge was investigated. The rim ridge surrounds a plateau clay near Rydsgård. The aim of the study was to reconstruct depositional processes and the sedimentary environment of the rim ridge and to study the lateral transition into the plateau clay. The section was investigated by detailed drawing, by lithofacies classification and by sampling for grain size analyses, clast lithology composition and analyses of clast shape and roundness. The sediments in the section show a coarsening upward sequence, starting with laminated silty clay and grading into sand and gravel. The beds in the lower half of the sections are thin, with several, rapid transitions between massive silt, massive normally graded sand and ripple laminated sand. In the upper half there are thicker beds of massive, matrix supported gravel and gravely sand and diamict beds. These lithofacies sometimes wedge out and transform into fine grained, better sorted lithofacies. The sedimentological analysis shows that the main depositional processes were a range of sediment gravity flows from debris flows to turbidity flows. The study also shows that the depositional environment was subaqueous. Sedimentary facies from a proximal, near shore environment can be followed into distal facies out in the basin. A prograding shoreline indicates a constant lake level or a slight level fall. The sedimentary basin was a supraglacial melt-water lake on a flat surface of stagnated ice. During melting of the ice masses the lake was rapidly drained. When the ice finally wasted, the sediments in the basin were draped on an undulating substratum.}},
author = {{Sundberg, Sven Birger}},
language = {{swe}},
note = {{Student Paper}},
series = {{Examensarbeten i geologi vid Lunds universitet}},
title = {{Sedimentationsprocesser och avlagringsmiljö för en kantrygg kring platåleran vid Rydsgårds gods i backlandskapet söder om Romeleåsen, Skåne}},
year = {{2000}},
}