================================================================
日本堆積学会　メールマガジン　◆2018年10月25日（837号）
================================================================

日本堆積学会ー石油技術協会砂岩分科会共催講演会 (Hannah Brooks博士)
(産学双方向セミナー)のお知らせ

下記の要領で，日本堆積学会ー石油技術協会探鉱技術委員会砂岩分科会共催
講演会を開催します。内容は，現在千葉大学に在籍のHannah Brooks博士が
英国Leeds大学在学中から研究されてきた「南アフリカのKaroo堆積盆の大規
模な地表露頭を用いた堆積システムと堆積盆埋積様式」についての研究成果
概要です。皆様，奮ってご参加ください。

なお、本講演会は，日本堆積学会の産官学連携推進委員会が進める「産学双
方向セミナー」の一環として行われます（今回は，学→産方向のセミナー）。
また，石油技術協会としては，「2018年度第2回砂岩分科会」として開催され
ます。

会場へは入館手続が必要になります。あらかじめ入館登録を行いますので、
参加希望者は11月16日までに、JAPEX戸田数馬（kazuma.todajapex.co.jp）
までメールにてお申し込みください。当日終了後に懇親会を同所別室にて行
います（会費4000円程度予定）。懇親会参加希望有無もお伝えください。

日時：2018年11月26日(月)15:00から17:30
場所：石油資源開発(株)(JAPEX) 本社　19 階 1901 会議室
　　（東京都千代田区丸の内1-7-12サピアタワー（JR東京駅日本橋口横））
入館方法：サピアタワー3階総合受付にて氏名用件を告げてカードキーを受け
取り、ゲート通過後、エレベータで19階へ。

講演者： Hannah Brooks 博士（千葉大学）
演題：An overview of the depositional environments of the Permian Karoo
Basin, South Africa: with focus on the 1.8 km progradational fill of the
Laingsberg depocenter, from basin plain to deltas.
講演要旨：
The Karoo Supergroup comprises of 5500 m of deep marine to fluvial deposits
that span from Late Carboniferous to Triassic. The Late Carboniferous to
early Permian period (300 - 280 Ma) was marked regionally by large scale
subsidence, producing a series of interconnected basins (Visser and Praekelt,
1996). The evolution and fill of two of these sub-basins, the Laingsburg and
Tanqua depocenters have been the focus of study by the Stratigraphy (STRAT)
group based at the Universities of Leeds and Manchester (and formally Liverpool)
in the UK for several decades. Field work and behind outcrop cores in the Tanqua
and Laingsburg depocentres (Karoo Basin, South Africa) have generated a dataset
covering some 7500 km2, comparable in extent to exploration datasets used in the
hydrocarbon industry. The Slope 4 project used this as a framework in order to
assess the spatial distribution of depositional environments and architecture,
from basin floor to continental systems, and at the larger scale increase
understanding of subsidence mechanisms leading to deposition within the Karoo
Basin. This talk will outline the work undertaken  by myself and colleagues
throughout the Karoo basin, with a focus on the Ecca Group, in the Laingsburg
depocenter, a 1800 m thick progradational succession from basin-floor deposits
(Vischkuil and Laingsburg formations; Sixsmith et al., 2004; van der Merwe et
al., 2010), channelized submarine slope (Fort Brown Fm.; Hodgson et al., 2011;
Di Celma et al., 2011; Flint et al., 2011) to shelf-edge and shelf deltas
(Waterford Fm.; Jones et al., 2015; Poyatos-Mor？ et al., 2016). More
specifically I will discuss the Laingsburg and Fort Brown formations, consisting
of multiple large sand-rich systems (Units A-F) which have been mapped from
entrenched slope valleys, through channel-levee systems, to basin-floor lobe
complexes over a 2500 km2 area. As well as three thinner (typically <5 m),
less extensive units (A/B, B/C and D/E) which suggest seabed topography was
present early during deep-water sedimentation and was maintained in a similar
area that ultimately developed to form a stepped slope profile (Brooks et al.,
2018). The stepped slope profile evolved through 3 key stages of development:
Phase 1, where sediment supply exceeded deformation rate, causing thickness
changes within basin floor lobe complexes; Phase 2, where sediment supply was on
average equal to deformation rate, resulting in channel complex entrenchment and
basin floor lobe thickness; and Phase 3, where deformation rate outpaced sediment
supply, to form intraslope lobes and sediment bypass-dominated zones.
This study demonstrates that stepped slope profiles can form progressively in
passive margin settings without influence of mobile substrate, and that thin
sandstone units are more sensitive records of seabed topography.


================================================================

＃　不達メールアドレスは随時配信リストより削除します．
＃　メルマガのバックナンバーは堆積学会ホームページからご覧いただけます．

■■■■■■■■■■■■■■■■■■■■■■■■■■■■■

日本堆積学会　事務局
〒814-0180　福岡県福岡市城南区七隈8-19-1
福岡大学理学部地球圏科学科地球科学分野（石原与四郎）内
メールアドレス：　
ホームページURL：　http://sediment.jp/

■■■■■■■■■■■■■■■■■■■■■■■■■■■■■