Name: sediment core extrusion method at millimeter resolution using a calibrated, threaded-rod
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这项研究是由来自英国石油公司的赠款部分成为可能/墨西哥研究计划，C-IMAGE，DEEP-C和部分由海洋的英国石油/佛罗里达协会（BP / FIO）-Gulf防漏油海湾，响应和恢复资助计划。作者感谢尼科Zenzola他在此过程中开发的投入。作者还感谢第r / V Weatherbird II的船员实地计划期间他们的帮助。 https://data.gulfresearchinitiative.org/（数据/ R1.x135.119:0004 /），（数据/ Y1.x031.000:0003 /），（数据/ Y1数据可以在GRIIDC网站进行访问。 x031.000:0006 /），（R1.x135.120:0004）。

1.收集沉积岩心<ol><li>收集使用多核水产沉积岩芯，芯盒制芯，活塞核心等 4,7,12,14。确保核心部为1微米或更小。 </li><li>插入聚碳酸酯或丙烯酸冰球到芯的底部。确保冰球是与芯管的内直径相一致。插入在冰球的最外直径的橡胶垫圈保留沉积物芯的全部。 </li><li>在核心的检索，立即或挤压包运​​输和储存（见步骤储存和运输1.4〜1.6）。 </li><li>插入泡沫或丙烯酸冰球到芯管的表面，并轻轻按下直至泡沫或丙烯酸刚好高于沉积物界面保持运输和贮存过程中的沉积物 - 水界面的完整性。 </li><li>放置在芯管的顶帽并用绝缘带密封。放在芯管的底盖和密封ELECTRICA升胶带。标签与必要的项目和样品标识顶盖。 </li><li>根据所需的分析在所需温度商店芯。 注意:例如，用于有机化学分析或生物分析芯可以冷冻（-20℃），而短寿命放射性同位素核可以在室温下储存（〜20-25℃）。 </li></ol> 2.准备子样容器和工具<ol><li>标签子样本器皿项目名称，核心部位和增量（ 例如，罐，袋或烧杯）（ 例如 ，项目NAME_CORE SITE_0 - 2mm）的，与任何其他相关身份信息 （ 如日期，核心型）一起。 </li><li>组装和消毒（甲醇）必要的切割工具（如丙烯酸桨，油灰刀等 ）和个人防护装备（如手套，实验室外套等 ）。 注意:这些工具和它们的灭菌程序将取决于类型分析的要对每个子样品进行。例如，使用金属和丙烯酸器具（相对于塑料）为有机化学分析，而丙烯酸和塑料器具（相对于金属）必要必须用于无机微量元素分析。 </li></ol> 3.准备沉积物柱挤压<ol><li>如果核心已存储或保藏的，先卸下底盖。要做到这一点切底盖关闭用刀片，并允许顶帽，以保持真空，保持该沉淀在管而转移到挤出机（挤出冰球必须已在保留芯的底部插入）（ 图1）。 </li><li>当在收集立即挤出，将挤出的冰球到芯的底部。然后轻轻地设置芯管到活塞并拧紧核心用卡的挤出机。 </li><li>确保有芯管剩余ABOV的至少5cmE对于采样领最上面的夹子。 </li><li>卸下顶盖。 </li><li>放置在芯管的顶部取样衣领。确保套环坐在平齐与芯管的最上部程度，以避免任何的样品损失。 </li><li>样品（或丢弃如果不需要）使用注射器沉积物以上的水在此时或者虹吸。 </li><li>提取后的水，开始转动活塞对准表面最沉积物与采样轴环的表面上。 </li></ol> 4.挤压<ol><li>转活塞到所需的采样分辨率（通常为1-2毫米，1完整的旋转= 2毫米子样）（ 图1）。 </li></ol><img alt="图1" src="/files/ftp_upload/54363/54363fig1.jpg" /> 图 1: 挤出机的照片限定活塞（1）在挤出机的照片，耦合（2），螺纹杆（3），挤出机底座（4），夹具（5），芯管（6），SAMPLING领（7）和橡胶带（8）。 <a href="https://www.jove.com/files/ftp_upload/54363/54363fig1large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <ol start="2"><li>使用丙烯酸板（切到采样轴环的内径），以使初始样品切。接着移动子样品朝向采样环的边缘缓慢而定位采样领口下方的相应取样容器中。 </li><li>开始到样品推入取样器。后大多数样品是在容器中，使用较小的工具（ 例如 ，油灰刀）至在采样衣领到取样容器移动任何剩余样品。 </li><li>使用较小的实现从丙烯酸板和任何其他采样表面进入取样容器清洗样品的剩余量。 </li><li>一旦样品完全从采样衣领转移到容器中，清洁采样吨ools用去离子水，实验室纸巾和/或其它灭菌流体（ 例如 ，甲醇）。与实验室湿巾，去离子水等消毒液清洗相应采样衣领。 </li><li>密封样品容器和挤出准备下一个样品容器。重复步骤4.1至4.5为每个子样本。 </li></ol> 5.重置挤出机<ol><li>手动复位挤出机。使用钻头和橡胶带，以加快活塞复位到螺纹杆的底部的过程。 </li><li>放置橡胶带基为最稳定邻近所述活塞周围。 </li><li>拉伸橡胶带围绕钻头的头部，并设置钻头的方向到向下旋转活塞。 </li><li>上使用的钻头的低速，直到它到达挤压机的基部上方的期望高度旋转活塞。 注意:此高度是基于芯的长度被挤压和期望采样HEIGHT。 </li></ol>

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The authors have nothing to disclose.

挤出机可以进行修改，以容纳芯管的多个直径。如果芯直径被改变，则活塞，冰球，和钳位直径必须进行相应调整。此修改允许在湖泊和海洋沉积物收集广泛的应用前景。该沉积岩芯也可以在现场或在实验室中挤出。一个常见的​​修改，以减轻这一挤出系统的发货是建立在它的两个部分;下部区段（基和活塞）然后可联接到上部（夹具）。 有这种挤出方法有一些限制。其中的第一个是，每一个核心，或核心部分，必须削减到一米长或更小。正如任何挤出法，还有难免有些压缩。但是，引起此方法压实是最小的。在这种方式中挤出的多个记录重现为2-4毫米范围内。这种重复性估计各种之间的比较收集了八核的多核系统的同一部署记录（微量金属元素，有机地球化学，底栖有孔虫，沉积）。这种挤出方法也最适合于那些主要（&gt; 50％）淤泥和粘土尺寸的颗粒沉积。滓主要（&gt; 50％）组成的砂尺寸的颗粒趋于结合，造成额外的压实，由于较高的摩擦系数。与此方法相关联的最终限制是沉积物可从在毫米级分辨率每个增量的量。这种方法提供了约15-20克湿质量，并以2 mm的分辨率，这可能是限制对于某些分析方案3-10克干质量。 在墨西哥湾北部的深水地平线事件的沉积记录证明毫米级二次采样的功效。首先，234钍约会不会未经毫米级频带分割是不可能的。此约会米ethod只能在某些情况下，这将进一步讨论4被应用。油絮状物质以下的深水地平线事件的脉冲满足了这些条件，在6-12个月内，在墨西哥湾北部的某些部位沉积到材料8毫米。如果没有毫米标抽检，本次活动的年代学不会得到解决的分年度规模（ 表2和表 3）。除了​​234钍记录，氧化还原敏感的微量金属，底栖有孔虫密度，并且该事件的有机地球化学记录将被限制于在表面厘米一个数据点（ 见表3）。相反，如果使用毫米级次抽样提供的MOSSFA事件的详细和强大的（5-10数据点）记录。具体地，增加4倍（N = 18）以上在使用毫米尺度子采样总脂族预深水地平线值将被降低到2倍增加，使用厘米刻度欠采样（N = 6）。因此，在使用毫米尺度子采样的90％底栖有孔虫密度降低将被减少到使用厘米尺度子采样的60％的降低。如果没有这种高分辨率采样，锰氧化物，以及与非稳态氧化还原变化有关的沉积再浓度的变化的离散双峰不会得到解决。总体而言，这一挤出系统提供了在毫米尺度二次采样沉积物岩芯，保留了样本的整个体积并可以修改了在水生沉积物取样广泛应用的能力。这种方法的未来应用可能包括过去漏油的评估，由于与地下油发布相关的毫米标事件地层。其他应用可能包括毫米尺度的气候变化的湖泊记录。毫米级子采样已在人类活动的影响的背景下刻画事件地层被证明是有效系统。

从湖泊，河口和海洋（大陆架和斜坡）环境中的沉积物岩芯样品提供了关于十年盐度，温度，有机和无机污染物和其他许多环境参数的记录千年时间尺度1-3,6,8,13 17。在大多数情况下，标准的做法，以节这些内核在半公分或厘米间隔5,15。该决议适用于多年，十年或更高分辨率的规模在大多数情况下。需要增加挤压分辨率最近被证明在一些报道沿沉积岩芯11,16的垂直廓线检测生物标志物的沉积/代理变化在判罚尺度。在上月的时间尺度发生一年最近沉降的情况下，它是那么必要使用更精细的分辨率子采样方法（ 例如 ，毫米刻度）。这通常是由于使用到t水体沉积物挑战他未合并表层沉积物性质。 我们提出了一个沉积岩芯挤压法，提供毫米结垢子样本。然后，我们这个挤压法适用于墨西哥湾北部的以下的深水地平线（DWH）事件的沉积物。此应用程序演示毫米级分取样表征与人类活动影响的沉积体系分年度事件地层的功效。 表征短期事件地层时在沉积记录每月或分年度尺度分辨率是特别有利的。采用分年度解决环境评估是能够充分体现人类活动引起的沉降事件。 在墨西哥湾北部的沉积物所影响的深水地平线石油事件提供事件地层的例子使用毫米波充分的特点（分年度）■卡尔分辨率采样。继2010年的深水地平线（DWH）事件，墨西哥东北部海湾（恩戈姆）的大陆坡沉积物通过的絮状沉淀烃4,9,10,12,14,18数量级的增加进来与碳氢化合物接触。在沉降的增加是由海洋石油雪沉淀絮状积累（MOSSFA）事件4,9,10,12,14,18引起的。这导致大约6-10毫米的6-12个月内泥沙淤积，从2010年中期到2011年初4，这是要分样品在毫米级这些沉积岩芯，以充分体现投入，沉淀率和沉积后处理。

<table><tbody><tr><td>Extruder</td><td>Custom Fabrication</td><td></td><td>Aluminum base and clamps, steel threaded rod&amp;nbsp;</td></tr><tr><td>Piston</td><td>Custom Fabrication</td><td></td><td>PVC tubing with acrylic cap</td></tr><tr><td>Polycarbonate Core Tube</td><td>SABIC Poymershapes</td><td>68374192</td><td></td></tr><tr><td>Acrylic puck/Rubber Gasket</td><td>Custom Fabrication</td><td></td><td></td></tr><tr><td>Acrylic sampling collar</td><td>Custom Fabrication</td><td></td><td></td></tr><tr><td>Acrylic plate</td><td>Custom Fabrication</td><td></td><td>One edge bevelled at 45 degree angle</td></tr><tr><td>Putty knife</td><td>Fisher Scientific</td><td>&lt;a href=&quot;https://www.fishersci.com/shop/products/ampco-safety-putty-knives-4/19166432&quot;&gt;19-166-432&lt;/a&gt;</td><td></td></tr><tr><td>Steel/Acrylic Plates</td><td>Custom Fabrication</td><td></td><td></td></tr><tr><td>Electrical tape</td><td>McMaster Carr</td><td>76455A28</td><td></td></tr><tr><td>Siphon or Syringe</td><td>Fisher Scientific</td><td>14-176-227, 14-823-2A</td><td></td></tr><tr><td>Razor blade</td><td>Fisher Scientific</td><td>12-640</td><td></td></tr><tr><td>Drill</td><td>Ryobi</td><td>P-882</td><td></td></tr><tr><td>Thick rubber band</td><td>Staples</td><td>831636</td><td>2 - 3 cm in width, larger diameter than piston</td></tr><tr><td>Personal protection equipment</td><td>Fisher Scientific</td><td>Gloves-19-058-801C,&lt;br/&gt; lab coat- 17-100-850,&lt;br/&gt; Goggles-19-181-501</td><td>&lt;i&gt;e.g.&lt;/i&gt;, gloves, lab coat, goggles</td></tr><tr><td>Sample labels</td><td>Fisher Scientific</td><td>&lt;a href=&quot;https://www.fishersci.com/shop/products/fisherbrand-patient-id-labels-addressograph-2/15920&quot;&gt;15920&lt;/a&gt;</td><td></td></tr><tr><td>Sample vessels</td><td>Fisher Scientific</td><td>Whirlpak- 01-812-3,&lt;br/&gt; &amp;nbsp;Jar- 02-911-791</td><td>&lt;i&gt;e.g.&lt;/i&gt;, whirlpak bags, jars, &lt;em&gt;etc.&lt;/em&gt;</td></tr><tr><td>Laboratory wipes</td><td>Fisher Scientific</td><td>06-666-11</td><td>&lt;i&gt;e.g.&lt;/i&gt;, kim wipes</td></tr><tr><td>Methanol</td><td>Fisher Scientific</td><td>BP1105-1</td><td></td></tr><tr><td>Deionized water</td><td></td><td></td><td></td></tr></tbody></table>

sediment core extrusion method at millimeter resolution using a calibrated, threaded-rod

水产沉积物二次抽样是在厘米或半厘米的分辨率普遍执行。根据不同的沉降速率和沉积环境，该决议规定在年度记录十年尺度，最好的。挤出法，用校准的，螺纹杆这里提出，其允许不同直径的水生沉淀物芯的毫米级子采样。毫米波规模的二次抽样允许分年度的沉积记录，要比典型抽样方案高出一个数量级的月度分析。挤出机由2米的铝制框架和底座，两个核心管夹具，螺纹杆，以及1米活塞。沉积物芯被放置在活塞上方并夹紧在框架上。丙烯酸采样套环固定到上部5厘米芯管，并提供从其中提取的子样本的平台。活塞在校准间隔围绕所述螺纹杆旋转时，轻轻推沉淀出到芯管的对。然后将沉淀物分离进入取样衣领并置于适当的采样容器（ 例如 ，瓶或袋）。此方法也是在表面保留了松散的样品（即高孔隙水含量），提供了一个一致的取样量。这个规模毫米挤塑方法适用于在墨西哥的下深水地平线海底石油发布墨西哥湾北部收集内核。有证据表明，有必要在毫米尺度来样充分体现在每月的时间尺度大陆坡沉积物中发生的事件。

从现场DSH08的内核使用的海洋仪器MC-800多管收集在2010年12月（29°7.25&#39;，东经87°51.93&#39;W，1143米深度）。这些型芯为2mm挤出为使用上述协议的表层为15cm（或以上）。预DWH（2010年之前）和后DWH（2010）的核心区间的采用配对短命的放射性同位素（234 Th和210 Pb计）地质年代学测定4。进行其他几个分析在这个网站下面的深水地平线事件来约束沉积投入，沉积速率，和后沉积过程。除了 ​​短暂的放射性同位素分析，总脂肪含量12，氧化还原敏感的金属（锰，铼）7，总底栖有孔虫密度14进行了量化。进行这些参数的在毫米规模和规模厘米的比较（ 表图2和3，图2）。厘米级数据组成的综合，平均毫米标数据。 <table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always"><tbody><tr><td> 顶部深度（mm） </td><td> 过量 PB-210 （DPM / G） </td><td> 过量 TH-234 （DPM / G） </td><td> TH-234和铅210合并年龄模型 （年） </td><td> 总 有孔虫 密度 （indiv./cm 3） </td><td> [回覆] （纳克/克） </td><td> [锰] （毫克/克） </td><td> 总脂肪族 （纳克/克） </td></tr><tr><td> 0 </td><td> 71.81 </td><td> 6.19 </td><td> 2010.9 </td><td> 1 </td><td></td><td></td><td> 336922.6 </td></tr><tr><td> 2 </td><td> 71.81 </td><td> 5.14 </td><td> 2010.9 </td><td> 3 </td><td> 0.69 </td><td> 10.2 </td><td> 53701.4 </td></tr><tr><td> 4 </td><td> 69.91 </td><td> 2.72 </td><td> 2010.8 </td><td> 2 </td><td> 0.53 </td><td> 15.9 </td><td> 77081.2 </td></tr><tr><td> 6 </td><td> 70.32 </td><td> 1.57 </td><td> 2010.8 </td><td> 6 </td><td> 0.57 </td><td> 12.1 </td><td> 48057.4 </td></tr><tr><td> 8 </td><td> 69.67 </td><td> 1.15 </td><td> 2010.7 </td><td> 10 </td><td> 0.61 </td><td> 11.3 </td><td> 42888.0 </td></tr><tr><td> 10 </td><td> 61.39 </td><td> 0.29 </td><td> 2009.6 </td><td> 10 </td><td> 0.73 </td><td> 8.30 </td><td> 50786.4 </td></tr><tr><td> 12 </td><td> 56.50 </td><td> 0.64 </td><td> 2008.5 </td><td> 12 </td><td> 0.75 </td><td> 7.1 </td><td> 51582.9 </td></tr><tr><td> 14 </td><td> 63.31 </td><td> 0.00 </td><td> 2007.5 </td><td> 11 </td><td></td><td></td><td> 52126.8 </td></tr> &lt;TR&gt; <td> 16 </td><td> 51.55 </td><td> 0.00 </td><td> 2006.5 </td><td> 11 </td><td> 0.79 </td><td> 6.9 </td><td> 59046.6 </td></tr><tr><td> 18 </td><td> 51.69 </td><td> 0.00 </td><td> 2005.6 </td><td> 10 </td><td> 0.77 </td><td> 7.1 </td><td> 48384.8 </td></tr><tr><td> 26 </td><td> 44.26 </td><td></td><td> 2000.7 </td><td> 9 </td><td></td><td></td><td> 31774.7 </td></tr><tr><td> 32 </td><td> 38.25 </td><td></td><td> 1997.2 </td><td> 9 </td><td> 0.83 </td><td> 8.3 </td><td> 37128.4 </td></tr><tr><td> 34 </td><td> 41.57 </td><td></td><td> 1996.0 </td><td> 12 </td><td></td><td></td><td> 25849.4 </td></tr><tr><td> 38 </td><td> 39.11 </td><td></td><td> 1993.1 </td><td></td><td></td><td></td><td> 29901.6 </td></tr><tr><td> 42 </td><td> 35.18 </td><td></td><td> 1990.1 </td><td> 10 </td><td> 0.89 </td><td> 8 </td><td> 257300.4 </td></tr><tr><td> 46 </td><td> 38.80 </td><td></td><td> 1987.0 </td><td> 12 </td><td></td><td></td><td> 23159.6 </td></tr><tr><td> 48 </td><td> 32.58 </td><td></td><td> 1985.3 </td><td></td><td></td><td></td><td> 21387.0 </td></tr><tr><td> 50 </td><td> 26.71 </td><td></td><td> 1983.3 </td><td> 9 </td><td> 0.94 </td><td> 5.3 </td><td> 15331.0 </td></tr><tr><td> 70 </td><td> 17.32 </td><td></td><td> 1965.8 </td><td> 11 </td><td> 1.33 </td><td> 2.2 </td><td></td></tr><tr><td> 90 </td><td> 10.32 </td><td></td><td> 1945.9 </td><td></td><td> 2.04 </td><td> 1.3 </td><td></td></tr><tr><td> 110 </td><td> 5.36 </td><td></td><td> 1923.3 </td><td></td><td> 2.12 </td><td> 1.2 </td><td></td></tr><tr><td> 130 </td><td> 2.21 </td><td></td><td> 1899.1 </td><td></td><td></td><td></td><td></td></tr><tr><td> 140 </td><td> 1.71 </td><td></td><td> 1888.5 </td><td></td><td></td><td></td><td></td></tr></tbody></table> 表1: 从核心站点DSH08毫米级分辨率数据短命放射性同位素活动，年代学，底栖有孔虫密度，固相氧化还原敏感的金属浓度（锰，铼），并于12月采集的核心部位DSH08总脂肪含量的记录。 2010年，在2毫米增量4,7,12,14子采样。 <table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always"><tbody><tr><td> 顶部深度（mm） </td><td> 过量 PB-210 （DPM / G） </td><td> 过量 TH-234 （DPM / G） </td><td> TH-234和铅210合并年龄模型 （年） </td><td> 总 有孔虫 密度 （indiv./cm 3） </td><td> [回覆] （纳克/克） </td><td> [锰] （毫克/克） </td><td> 总脂肪族 （纳克/克） </td></tr><tr><td> 0 </td><td> 70.70 </td><td> N / A </td><td> 2010 </td><td> 4 </td><td> 0.60 </td><td> 12.4 </td><td> 111730.1 </td></tr><tr><td> 1 </td><td> 56.89 </td><td></td><td> 2006.2 </td><td> 11 </td><td> 0.76 </td><td> 7.3 </td><td> 52385.5 </td></tr><tr><td> 2 </td><td> 44.26 </td><td></td><td> 2000.5 </td><td> 9 </td><td> 0.00 </td><td></td><td> 31774.7 </td></tr><tr><td> 3 </td><td> 39.65 </td><td></td><td> 1995.5 </td><td> 12 </td><td> 0.83 </td><td> 8.3 </td><td> 30959.8 </td></tr><tr><td> 4 </td><td> 35.52 </td><td></td><td> 1989.7 </td><td> 11 </td><td> 0.89 </td><td> 8 </td><td> 22273.3 </td></tr><tr><td>五</td><td> 26.71 </td><td></td><td> 1981.9 </td><td> 9 </td><td> 0.94 </td><td> 5.3 </td><td> 15331.0 </td></tr><tr><td> 6 </td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td> 7 </td><td> 17.32 </td><td></td><td> 1967.1 </td><td> 11 </td><td> 1.33 </td><td> 2.2 </td><td></td></tr><tr><td> 8 </td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td> 9 </td><td> 10.32 </td><td></td><td> 1945.2 </td><td></td><td> 2.04 </td><td> 1.3 </td><td></td></tr><tr><td> 10 </td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td> 11 </td><td> 5.36 </td><td></td><td> 1917.6 </td><td></td><td> 2.12 </td><td> 1.2 </td><td></td></tr><tr><td> 12 </td><td></td><td></td><td></td><td></td><td></td> &lt;TD&gt; </td><td></td></tr><tr><td> 13 </td><td> 2.21 </td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td> 14 </td><td> 1.71 </td><td></td><td></td><td></td><td></td><td></td><td></td></tr></tbody></table> 表2: 厘米 -s 卡尔解决方案从核心网站DSH08数据短命放射性同位素活动，年代学，底栖有孔虫密度，固相氧化还原敏感的金属浓度（锰，铼），并在收集核心部位DSH08总脂肪含量的记录。 2010年12月，在综合1厘米增量4,7,12,14。 <img alt="图2" src="/files/ftp_upload/54363/54363fig2.jpg" /> 图2: 毫米和厘米级分辨率数据的图示 。短命的放射性同位素ACTIV伊蒂埃斯，年龄模型，底栖有孔虫密度，固相氧化还原敏感的金属浓度（锰，RE）和总脂肪含量的记录在2010年12月收集的核心部位DSH08，在2毫米增量（蓝色菱形）和一厘米的增量子采样（红色方块）4,7,11,13。 <a href="https://www.jove.com/files/ftp_upload/54363/54363fig2large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> 允许234钍毫米级子采样（和沉积条件，见4）被用作在子年度规模时计（N = 7）。在厘米刻度，该数据不会是可行的制造年代学，因为表面厘米将减少到一个测量（N = 1）。总脂肪的浓度从36,322.3纳克/克干重（预DWH）至336,922.6增加纳克/克干重（后DWH）根据毫米刻度的记录，而第Ë根据厘米大型综合平均后DWH增加111,730.1纳克/克干重。总底栖有孔虫密度从前期DWH下降（平均= 11 indiv./cm 3）到后DWH（平均= 1 indiv./cm 3）在毫米刻度（N = 17），并从预DWH（平均= 10 indiv./cm 3）到后DWH（平均在厘米刻度= 4 indiv./cm 3）（N = 7）。在铼的细微增加表层2毫米，这指示的还原条件下，也将不会在厘米的分辨率来解决。

Watch this Scientific Journal Video about Sediment Core Extrusion Method at Millimeter Resolution Using a Calibrated, Threaded-rod at JoVE.com

Sediment Core Extrusion Method at Millimeter Resolution Using a Calibrated, Threaded-rod

使用校准的螺纹杆挤出法提出，允许水产品沉积物岩芯的规模毫米的二次抽样。毫米级采样是必要的沉积物记录完全表征近期事件地层。

沉积物核心挤压法在毫米的分辨率用校准，螺纹杆

Aquatic sediment core subsampling is commonly performed at cm or half-cm resolution. Depending on the sedimentation rate and depositional environment, ...

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11.2K 次观看.  University of South Florida. 使用校准的螺纹杆挤出法提出，允许水产品沉积物岩芯的规模毫米的二次抽样。毫米级采样是必要的沉积物记录完全表征近期事件地层。 

视频: Sediment Core Extrusion Method at Millimeter Resolution Using a Calibrated, Threaded-rod

Laboratory-determined Phosphorus Flux from Lake Sediments as a Measure of Internal Phosphorus Loading

Eutrophication is a water quality issue in lakes worldwide, and there is a critical need to identify and control nutrient sources. Internal phosphorus (P) loading from lake sediments can account for a substantial portion of the total P load in eutrophic, and some mesotrophic, lakes. Laboratory determination of P release rates from sediment cores is one approach for determining the role of internal P loading and guiding management decisions. Two principal alternatives to experimental determination of sediment P release exist for estimating internal load: in situ measurements of changes in hypolimnetic P over time and P mass balance. The experimental approach using laboratory-based sediment incubations to quantify internal P load is a direct method, making it a valuable tool for lake management and restoration.
Laboratory incubations of sediment cores can help determine the relative importance of internal vs. external P loads, as well as be used to answer a variety of lake management and research questions. We illustrate the use of sediment core incubations to assess the effectiveness of an aluminum sulfate (alum) treatment for reducing sediment P release. Other research questions that can be investigated using this approach include the effects of sediment resuspension and bioturbation on P release.
The approach also has limitations. Assumptions must be made with respect to: extrapolating results from sediment cores to the entire lake; deciding over what time periods to measure nutrient release; and addressing possible core tube artifacts. A comprehensive dissolved oxygen monitoring strategy to assess temporal and spatial redox status in the lake provides greater confidence in annual P loads estimated from sediment core incubations.

Lake eutrophication is a water quality issue worldwide, making the need to identify and control nutrient sources critical. Laboratory determination of phosphorus release rates from sediment cores is a valuable approach for determining the role of internal phosphorus loading and guiding management decisions.

实验室确定的磷通量湖泊沉积物作为内部磷载入一个测量

Eutrophication is a water quality issue in lakes worldwide, and there is a critical need to identify and control nutrient sources. Internal phosphorus (P) ...

科研

环境科学

Sediment Core Sectioning and Extraction of Pore Waters under Anoxic Conditions

We demonstrate a method for sectioning sediment cores and extracting pore waters while maintaining oxygen-free conditions. A simple, inexpensive system is built and can be transported to a temporary work space close to field sampling site(s) to facilitate rapid analysis. Cores are extruded into a portable glove bag, where they are sectioned and each 1-3 cm thick section (depending on core diameter) is sealed into 50 ml centrifuge tubes. Pore waters are separated with centrifugation outside of the glove bag and then returned to the glove bag for separation from the sediment. These extracted pore water samples can be analyzed immediately. Immediate analyses of redox sensitive species, such as sulfide, iron speciation, and arsenic speciation indicate that oxidation of pore waters is minimal; some samples show approximately 100% of the reduced species, e.g. 100% Fe(II) with no detectable Fe(III). Both sediment and pore water samples can be preserved to maintain chemical species for further analysis upon return to the laboratory.

A protocol for sectioning sediment cores and extracting pore waters under anoxic conditions in order to permit analysis of redox sensitive species in both solids and fluids is presented.

沉积物核心切片和孔隙水萃取缺氧条件下

We demonstrate a method for sectioning sediment cores and extracting pore waters while maintaining oxygen-free conditions. A simple, inexpensive system is ...

The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations

The measurement of sediment-water exchange of gases and solutes in aquatic sediments provides data valuable for understanding the role of sediments in nutrient and gas cycles. After cores with intact sediment-water interfaces are collected, they are submerged in incubation tanks and kept under aerobic conditions at in situ temperatures. To initiate a time course of overlying water chemistry, cores are sealed without bubbles using a top cap with a suspended stirrer. Time courses of 4-7 sample points are used to determine the rate of sediment water exchange. Artificial illumination simulates day-time conditions for shallow photosynthetic sediments, and in conjunction with dark incubations can provide net exchanges on a daily basis. The net measurement of N2 is made possible by sampling a time course of dissolved gas concentrations, with high precision mass spectrometric analysis of N2:Ar ratios providing a means to measure N2 concentrations. We have successfully applied this approach to lakes, reservoirs, estuaries, wetlands and storm water ponds, and with care, this approach provides valuable information on biogeochemical balances in aquatic ecosystems.

The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations

Here, we present small core incubations for the measurement of sediment-water gas and solute exchange. These will provide reliable measurements of sediment-water exchange that assess the role of sediment in influencing biological and biogeochemical processes in aquatic ecosystems.

Ø的底栖交易所<sub&gt; 2</sub&gt;，N<sub&gt; 2</sub&gt;和营养盐使用小的核心孵化

The measurement of sediment-water exchange of gases and solutes in aquatic sediments provides data valuable for understanding the role of sediments in ...

Soil Lysimeter Excavation for Coupled Hydrological, Geochemical, and Microbiological Investigations

Studying co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled Earth-system processes. Such knowledge is imperative in improving predictions of hydro-biogeochemical cycles, especially under climate change scenarios. We present an experimental method, designed to capture sub-surface heterogeneity of an initially homogeneous soil system. This method is based on destructive sampling of a soil lysimeter designed to simulate a small-scale hillslope. A weighing lysimeter of one cubic meter capacity was divided into sections (voxels) and was excavated layer-by-layer, with sub samples being collected from each voxel. The excavation procedure was aimed at detecting the incipient heterogeneity of the system by focusing on the spatial assessment of hydrological, geochemical, and microbiological properties of the soil. Representative results of a few physicochemical variables tested show the development of heterogeneity. Additional work to test interactions between hydrological, geochemical, and microbiological signatures is planned to interpret the observed patterns. Our study also demonstrates the possibility of carrying out similar excavations in order to observe and quantify different aspects of soil-development under varying environmental conditions and scale.

This study presents an excavation method for investigating subsurface hydrological, geochemical, and microbiological heterogeneity of a soil lysimeter. The lysimeter simulates an artificial hillslope which was initially under homogeneous condition and had been subjected to approximately 5,000 mm of water over eight cycles of irrigation in an 18-month period.

土壤蒸渗仪开挖加之水文，地球化学和微生物调查

Studying co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled ...

Resurrection of Dormant Daphnia magna: Protocol and Applications

Long-term studies enable the identification of eco-evolutionary processes that occur over extended time periods. In addition, they provide key empirical data that may be used in predictive modelling to forecast evolutionary responses of natural ecosystems to future environmental changes. However, excluding a few exceptional cases, long-term studies are scarce because of logistic difficulties associated with accessing temporal samples. Temporal dynamics are frequently studied in the laboratory or in controlled mesocosm experiments with exceptional studies that reconstruct the evolution of natural populations in the wild.
Here, a standard operating procedure (SOP) is provided to revive or resurrect dormant Daphnia magna, a widespread zooplankton keystone species in aquatic ecosystems, to dramatically advance the state-of-the-art longitudinal data collection in natural systems. The field of Resurrection Ecology was defined in 1999 by Kerfoot and co-workers, even though the first attempts at hatching diapausing zooplankton eggs date back to the late 1980s. Since Kerfoot&#39;s seminal paper, the methodology of resurrecting zooplankton species has been increasingly frequently applied, though propagated among laboratories only via direct knowledge transfer. Here, an SOP is described that provides a step-by-step protocol on the practice of resurrecting dormant Daphnia magna eggs.
Two key studies are provided in which the fitness response of resurrected Daphnia magna populations to warming is measured, capitalizing on the ability to study historical and modern populations in the same settings. Finally, the application of next generation sequencing technologies to revived or still dormant stages is discussed. These technologies provide unprecedented power in dissecting the processes and mechanisms of evolution if applied to populations that have experienced changes in selection pressure over time.

Resurrection of Dormant Daphnia magna: Protocol and Applications

Long-term studies are essential to understanding the process of evolution and the mechanisms of adaptation. Generally, these studies require commitments beyond the life-time of researchers. Here, a powerful method is described that dramatically advances state-of-the-art data collection to generate longitudinal data in natural systems.

休眠蚤的复活: 协议和应用

Long-term studies enable the identification of eco-evolutionary processes that occur over extended time periods. In addition, they provide key empirical ...

Stress Distribution During Cold Compression of Rocks and Mineral Aggregates Using Synchrotron-based X-Ray Diffraction

We report detailed procedures for performing compression experiments on rocks and mineral aggregates within a multi-anvil deformation apparatus (D-DIA) coupled with synchrotron X-radiation. A cube-shaped sample assembly is prepared and compressed, at room temperature, by a set of four X-ray transparent sintered diamond anvils and two tungsten carbide anvils, in the lateral and the vertical planes, respectively. All six anvils are housed within a 250-ton hydraulic press and driven inward simultaneously by two wedged guide blocks. A horizontal energy dispersive X-ray beam is projected through and diffracted by the sample assembly. The beam is commonly in the mode of either white or monochromatic X-ray. In the case of white X-ray, the diffracted X-rays are detected by a solid-state detector array that collects the resulting energy dispersive diffraction pattern. In the case of monochromatic X-ray, the diffracted pattern is recorded using a two-dimensional (2-D) detector, such as an imaging plate or a charge-coupled device (CCD) detector. The 2-D diffraction patterns are analyzed to derive lattice spacings. The elastic strains of the sample are derived from the atomic lattice spacing within grains. The stress is then calculated using the predetermined elastic modulus and the elastic strain. Furthermore, the stress distribution in two-dimensions allow for understanding how stress is distributed in different orientations. In addition, a scintillator in the X-ray path yields a visible light image of the sample environment, which allows for the precise measurement of sample length changes during the experiment, yielding a direct measurement of volume strain on the sample. This type of experiment can quantify the stress distribution within geomaterials, which can ultimately shed light on the mechanism responsible for compaction. Such knowledge has the potential to significantly improve our understanding of key processes in rock mechanics, geotechnical engineering, mineral physics, and material science applications where compactive processes are important.

We report detailed procedures for compression experiments on rocks and mineral aggregates within a multi-anvil deformation apparatus coupled with synchrotron X-radiation. Such experiments allow quantification of the stress distribution within samples, that ultimately sheds light on compaction processes in geomaterials.

基于同步辐射 x 射线衍射的岩石和矿物团聚体冷压缩应力分布

We report detailed procedures for performing compression experiments on rocks and mineral aggregates within a multi-anvil deformation apparatus (D-DIA) ...

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors

Denitrification is the primary biogeochemical process removing reactive nitrogen from the biosphere. The quantitative evaluation of this process has become particularly relevant for assessing the anthropogenic-altered global nitrogen cycle and the emission of greenhouse gases (i.e., N2O). Several methods are available for measuring denitrification, but none of them are completely satisfactory. Problems with existing methods include their insufficient sensitivity, and the need to modify the substrate levels or alter the physical configuration of the process using disturbed samples.This work describes a method for estimating sediment denitrification rates that combines coring, acetylene inhibition, and microsensor measurements of the accumulated N2O. The main advantages of this method are a low disturbance of the sediment structure and the collection of a continuous record of N2O accumulation; these enable estimates of reliable denitrification rates with minimum values up to 0.4-1 &#181;mol N2O m-2 h-1. The ability to manipulate key factors is an additional advantage for obtaining experimental insights. The protocol describes procedures for collecting the cores, calibrating the sensors, performing the acetylene inhibition, measuring the N2O accumulation, and calculating the denitrification rate. The method is appropriate for estimating denitrification rates in any aquatic system with retrievable sediment cores. If the N2O concentration is above the detection limit of the sensor, the acetylene inhibition step can be omitted to estimate the N2O emission instead of denitrification. We show how to estimate both actual and potential denitrification rates by increasing nitrate availability as well as the temperature dependence of the process. We illustrate the procedure using mountain lake sediments and discuss the advantages and weaknesses of the technique compared to other methods. This method can be modified for particular purposes; for instance, it can be combined with 15N tracers to assess nitrification and denitrification or field in situ measurements of denitrification rates.

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors

This method estimates sediment denitrification rates in sediment cores using the acetylene inhibition technique and microsensor measurements of the accumulated N2O. The protocol describes procedures for collecting the cores, calibrating the sensors, performing the acetylene inhibition, measuring the N2O accumulation, and calculating the denitrification rate.

利用岩体和 n 2o 微传感器估计沉积物脱氮率

Denitrification is the primary biogeochemical process removing reactive nitrogen from the biosphere. The quantitative evaluation of this process has ...

Isolation of Quartz Grains for Optically Stimulated Luminescence (OSL) Dating of Quaternary Sediments for Paleoenvironmental Research

Optically stimulated luminescence (OSL) dating quantifies the time since mineral grains were deposited and shielded from additional light or heat exposure, which effectively resets the luminescence clock. The systematics of OSL dating is based on the dosimetric properties of common minerals, like quartz and feldspar. The acquired luminescence with exposure to natural ionizing radiation after burial provides a depositional age for many Quaternary sedimentary systems, spanning the past 0.5 Ma. This contribution details the procedures for separating pure quartz grains of a known range of particle sizes to facilitate luminescence analysis with small or single grain aliquots. Specifically, protocols are given for the needed data and interpretations for effective OSL dating of terrestrial sediment cores or sample tubes from exposures. These cores, 5-20 m long in 1.2 m sections, are split lengthwise and crown-cut leaving 80% of core volume undisturbed, which facilitates sampling of light-protected sediment for OSL dating deep within the core. Sediment samples are then subjected to a series of physical separations to obtain a certain grain-size interval (e.g., 150-250 &#181;m). Magnetic minerals are removed in wet and dry states using magnets. A series of chemical digestions starts with soaking in H2O2 to remove organic matter, followed by HCl exposure to remove carbonate minerals, followed by density separation. Subsequently, grains are soaked in HF for 80 min and after in HCl to render solely quartz grains. The mineralogic purity (&#62;99%) of the quartz extract is quantified with grain petrographic assessment and Raman spectroscopy. Repeating this quartz isolation procedure may be necessary with sediment that contains &#60;15% quartz grains. Excitation of the purified quartz grains by LED-derived blue and IR light allows calculations of the fast and IR depletion ratios, which are metrics to assess the dominance of luminescence emissions from quartz.

Isolation of Quartz Grains for Optically Stimulated Luminescence OSL Dating of Quaternary Sediments for Paleoenvironmental Research

This protocol is for the isolation of quartz grains by size for luminescence dating of sediments. Outlined are physical cleansing and chemical digestions by soaking sequentially in H2O2, HCl, HF, and HCl again to isolate quartz grains. The quartz purity is quantified with microscopic assessment, Raman spectroscopy, and IR depletion ratio.

分离石英颗粒用于第四纪沉积物的光学刺激发光（OSL）测年，用于古环境研究

Optically stimulated luminescence (OSL) dating quantifies the time since mineral grains were deposited and shielded from additional light or heat ...

Advanced Workflow for Taking High-Quality Increment Cores - New Techniques and Devices

In dendroecological research, precise dating of each single growth ring is a basic requirement for all studies, focusing on ring-width variations only, chemical or isotope analyses, or wood anatomical studies. Independent of the sampling strategy for a certain study (e.g., climatology, geomorphology), the way samples are taken is crucial for their successful preparation and analyses.
Until recently, it was sufficient to use a (more or less) sharp increment corer to obtain core samples that could be sanded for further analyses. Since wood anatomical characteristics can be applied to long time series, the need to obtain high-quality increment cores has taken on a new meaning. Essentially, the corer needs to be sharp(ened) when used. When coring a tree by hand, there are some problems in handling the corer, resulting in the hidden occurrence of micro cracks along the entire core: When starting to drill by hand, the drill bit is strongly pressed against the bark and the outermost ring until the thread has fully entered the trunk. At the same time, the drill bit is moved up and down as well as sideward. Then, the corer is drilled all the way into the trunk; however, it is necessary to stop after each turn, change the grip, and turn again. All these movements, as well as the start/stop-coring, puts mechanical stress on the core. The resulting micro cracks make it impossible to create continuous micro sections, as they fall apart along all these cracks.
We present a protocol to overcome these obstacles by applying a new technique using a cordless drill to minimize these problems when coring a tree, as well as its effect on the preparation of long micro sections. This protocol includes the preparation of long micro sections, as well as a procedure to sharpen corers in the field.

Here, we present a protocol on how to avoid micro cracks in increment cores by applying a cordless drill with a torque multiplier to minimize problems when coring trees, as well as its effect on preparing long micro sections. This protocol also includes a procedure to sharpen corers in the field.

采用高质量增量核心的高级工作流程 - 新技术和设备

In dendroecological research, precise dating of each single growth ring is a basic requirement for all studies, focusing on ring-width variations only, ...

<meta charset="utf8"></head><body>树木生态学研究中田间到实验室树木年轮数字化的协议

A New Workflow for Sampling and Digitizing Increment Cores

Here we present a new workflow from taking increment cores in the field, storing and transporting them to the lab, to digitizing their tree rings for further analyses for subsequent dendroecological analyses. The procedure involves the use of new sample carriers for increment cores. These new G&#228;rtner Schneider Core (GSC) holders are designed using three-dimensional (3D) modeling software and finally printed with a 3D printer. Using these mounts from the beginning in the field, the cores can directly be cut with a core microtome, and their surface can then be digitized without further rearrangement using a new high-resolution image-capturing system. They are thus available for direct analysis. This system allows digitizing tree rings from cores and disks, and also taking images from long micro sections (up to 40 cm) using transmitted light. This feature is of special interest for dendroecological and geomorphic applications to identify the onset of any disturbance in micro sections cut with a core-microtome.

<meta charset="utf8"></head><body>作者聚焦：用于推进树木生态学和木材解剖学研究的创新设备开发

We present a protocol to use 3D-printed mounts to fix increment cores in the field without the necessity of unpacking and gluing them on wooden mounts. The new GSC holder allows placing the cores in a core microtome to cut their surface and directly transfer them to digital image capturing.

用于对增量岩芯进行采样和数字化的新工作流程 

Here we present a new workflow from taking increment cores in the field, storing and transporting them to the lab, to digitizing their tree rings for ...