Induced and remanent magnetic properties of marine sediments as indicators of depositional processes

1980 ◽  
Vol 38 (1-3) ◽  
pp. 233-244 ◽  
Author(s):  
Brooks B. Ellwood
Author(s):  
Т.Д. Гараева

В статье приводятся результаты палеомагнитных исследований разрезов континентальных и морских отложений Каспийского моря и их корреляция. Палеомагнитные исследования проводились на восемнадцати разрезах: в Среднекуринской депрессии разрез г. Дуздаг, хребты Боздаг и Караджа, Нафталан; в Нижнекуринской депрессии разрез хр. Малый Харами; на Абшеронском полуострове – разрез г. Бакинский ярус и в Каспийском море: острова Булла-Дениз, Гарасу и Камень Персиянина. Расчленены плейстоценовые осадки Каспийского моря и депрессионных зон Азербайджана, проведена межрегиональная корреляция и датированы выделенные геологические события по палеомагнитным данным. In this paper we present the results of paleomagnetic studies of the sections of continental and marine sediments of the Caspian Sea and their correlation. Paleomagnetic studies have been conducted on 18 sections: in a middle Kura depression section of them. Duzdag, Bozdag range, Karadja range, Naftalan; in a lower Kura depression Lesser Harami range; in Absheron peninsula – section of Baku stage and in Caspian Sea: is. Bulla- Deniz, is. Qarasu and is. Kamen Persianina. Separated Pleistocene sediments of the Caspian Sea and depression zones of Azerbaijan, conducted interregional correlations and dated selected geological events according to paleonagnetic data.


Radiocarbon ◽  
1991 ◽  
Vol 33 (3) ◽  
pp. 283-289 ◽  
Author(s):  
Peter S. Roy

The dating of palimpsest marine sediments using broken shell fragments (shell hash) is considered to be a necessary but unreliable technique because of the mixed age of the fragments. An analysis of geological mixing models and radiocarbon data on shell hash from sandy sediments on the southeast Australian coast and shelf are used to examine the possibility for simulating the depositional processes, and thus, to better understand the age structure of the deposits.


2016 ◽  
Vol 23 (0) ◽  
pp. 41-51 ◽  
Author(s):  
Noriko Kawamura ◽  
Naoto Ishikawa ◽  
Atsushi Kurasawa

2020 ◽  
Author(s):  
Jonas Kristensen Kimerud ◽  
Maarten Felix

<p>This project examines organic rich black shales from the Upper Jurassic on the Norwegian shelf. The aim is to investigate the relationship between the depositional environment as determined from facies descriptions and the magnetic properties of the black shale. An additional aim is to relate cyclicity in the magnetic measurements to the Milankovitch cycles using time series analysis techniques. Cores from four different location on the Norwegian shelf were investigated using sedimentological description, facies analysis, and measuring of bulk magnetic susceptibility. The cores were drilled in the Skagerrak Region in the North Sea (core 13/01-U-01), Møre-Trøndelag Region of the Norwegian Sea (core 6307/07-U-03 A), Lofoten Region of the Norwegian Sea (core 6814/04-U-02), and the Nordkapp Basin in the NE Barents Sea (core 7230/05-U-02).</p><p>Based on preliminary results from the sedimentological description and facies analysis, the sediments were separated into facies: (1) massive black mudstone, (2) siderite cemented mudstone, (3) lenticular laminated sandy mudstone, (4) flaser laminated muddy sandstone with silt clasts, (5) heavily bioturbated silty sandstone, and (6) sandstone. Deposits like high-density turbidites, debrites and slump deposits, as well as post depositional processes like bioturbation, pyrite- and siderite-cementation were found in the cores. Deposits from mass movements can be thick, but they are deposited over a short time interval. It is therefore important to remove the mass movement deposits in the cyclostratigraphic analysis. The high iron content in the siderite and pyrite cemented deposits must be taken into account in regard to the magnetic susceptibility measurements. The magnetic susceptibility data will be used to correlate the cores in the homogeneous black shale sections.</p>


2020 ◽  
Author(s):  
Myriam Kars ◽  
Tetsuya Fukuta ◽  
Carina Becker

<p><span>The Nankai Trough is an accretionary complex which extends over several thousands of kilometers along the Japanese Pacific coast. Many ocean scientific drilling expeditions have taken place in this zone to better understand the mechanisms of big earthquakes and generation of devastating tsunamis. Offshore Cape Muroto, Shikoku Island, is one of investigated zones. A recent International Ocean Discovery Program (IODP) expedition (IODP Expedition 370) in the area has focused on the temperature limit of life in deep subseafloor sediments. Here we present paleomagnetic and rock magnetic preliminary results on two neighboring sites in this zone drilled during two former Ocean Drilling Program (ODP) legs: Site 808 of ODP Leg 131 and Site 1174 of ODP Leg 190. At all sites, shipboard magnetostratigraphy was challenging because of a strong diagenetic alteration of the magnetic mineral assemblages. Four main downcore magnetic zones, characterized by specific magnetic properties and mineralogy, are identified. At Site 808, catagenesis of the organic matter has been proposed to explain the downcore rock magnetic properties. This explanation however could not stand for Site 1174. We present here a first attempt of a comparative paleomagnetic and rock magnetic study in high temperature marine sediments, off Cape Muroto. </span></p>


2021 ◽  
Vol 750 (1) ◽  
pp. 012040
Author(s):  
R Zuraida ◽  
I Adhirana ◽  
G Lattuputty ◽  
U Hernawan ◽  
L Gustiantini ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document