メソゾイクアルプス時代 過去の緯度プレート運動の結果,アルプス層の堆積
Giovanni Muttoni1, Elisabetta Erba, Dennis V Kent
1Department of Earth Sciences, University of Milan, via Mangiagalli 34, I-20133 Milan, Italy. giovanni.muttoni1@unimi.it
Nature
|March 4, 2005
まとめ
パンゲア=パンゲア
科学分野:
- 地質学 地質学 地質学
- パレオセアノグラフィー
- プレート・テクトニクス (プレート・テクトニクス)
背景:
- アルプス・地中海地域は,パンゲアの断片化と大西洋の開裂に続く沈着パターンの大きな変化を経験しました.
- 沈殿面は,ジュラ紀・クレタセア紀の間,浅水から,石灰岩や放射性ケルトを含む,ペラジックへと移った.
- これらの面の変化に関する以前の説明は,炭酸補償深度 (CCD) の垂直の変動に焦点を当てていた.
研究 の 目的:
- ロンバルディアン盆地におけるファシ (石灰岩-放射性サーツ-石灰岩) の観測された三分化の代替説明を提案する.
- ラジオラライトの堆積を説明するモデルに水平板の動きを組み込む.
- 地中海地域と中東地域における放射性岩石の発生に関する新しい構造モデルを提供すること.
主な方法:
- イタリアのロンバルディアン盆地におけるジュラ紀・クレタセア紀のペラジック相次ぎの古磁気サンプル収集と分析.
- より広い古地理的文脈における古緯度データの分析.
- 水平板の動きを統合した構造模型の開発.
主要な成果:
- 古磁気データによると,ロンバルド流域は,赤道付近の上流地帯に向かって,そしてそこから離れていった.
- この動きは,観測された面の変化,特に放射性の堆積の主要な原動力として提案されています.
- この研究は,水平のプレートモーションコンポーネントを導入することによって,純粋に垂直のCCD変動モデルに挑戦しています.
結論:
- ロンバルド盆地におけるファシースの三分化は,赤道上の上流地帯に比べて盆地の漂流によって最もよく説明される.
- 水平板の動きは,ジュラ紀期の放射性ラライトの堆積を理解する上で重要な要因です.
- このモデルは,地中海と中東のジュラ紀の放射性ラライトの分布について,統一された説明を提供します.
関連する概念動画
Global Climate Change
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
Speciation Rates
Speciation can proceed at markedly different rates, and evolutionary biologists commonly describe these differences through the models of gradualism and punctuated equilibrium. Both patterns explain how new species arise, but they differ in the tempo and continuity of evolutionary change. In both cases, evolutionary change arises from heritable variation within populations, with natural selection often shaping traits that improve survival and reproduction under specific environmental conditions.
The Fossil Record
The fossil record documents only a small fraction of all organisms that have ever inhabited Earth. Fossilization is a rare process, and most organisms never become fossils. Moreover, the fossil record only exhibits fossils that have been discovered. Nevertheless, sedimentary rock fossils of long-lived, abundant, hard-bodied organisms dominate the fossil record. These fossils offer valuable information, such as an organism's physical form, behavior, and age. Studying the fossil record helps...
Mechanism of Lamellipodia Formation
Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for...
Diversity of Protists III
Rhizaria are a diverse group of unicellular protists characterized by their threadlike cytoplasmic extensions known as pseudopodia. These structures aid in both locomotion and feeding, giving Rhizaria an amoeboid appearance. Their amoeboid morphology once led to taxonomic confusion, but molecular phylogenetics has clarified their evolutionary placement and emphasized their shared use of pseudopodia despite divergent lineages.This clade comprises diverse lineages such as Chlorarachniophyta,...
Microbial Mats
Microbial communities forming biofilms and mats represent complex, spatially structured ecosystems where metabolic processes are stratified according to light, oxygen, and nutrient gradients. Biofilms are initial colonization stages, only a few millimeters thick, while mature microbial mats can reach centimeter-scale thickness and display intricate vertical organization. Their structural and functional heterogeneity allows microorganisms to occupy distinct ecological niches within a few...


