Non-skeletal Constituents-Carbonate Petrology

Coated grains

Ooids
– Size: 0.25 mm to 2 mm diameter
– Identification: clear nucleus or site of the nucleus. Several (not always) concentric cortical layers. Cortical layers are continuous (no overlapping). Generally larger than peloids but much smaller than oncoids. When the stage is rotated under XPL, they will undergo pseudo-uniaxial cross type extinction.
– Microfabric: tangential, radial and/or random crystals in each cortical layer.
– Rocks that predominantly made of ooids known as oolite.

Pisoids
– Size: > 2 mm to < 10 mm diameter - Identification: very similar (or rather same except the size) to ooids. Can the nucleus be observed???? - Rocks that predominantly made of pisoids are known as pisolite.

Note: Oooids and Pisoids both have nucleus. However, often pisoids nucleuses are harder to identify. Each layer of these two types of grains are known as cortical layers the boundaries of cortical layers are known as cortex.

Oncoids
– Size: > 2 mm; the outline of oncoids usually can be observed on thin sections with naked eye. Larger than peloids and ooids.
– Formed as a result of building layers on biological or lithological clastic nucleus.
– Found in all forms of water conditions (fresh/brackish/marine).
– Identification: irregular in shape with cortical layers of variable thickness. Overlapping discontinuous and irregular laminae. Alternating organic (dark) and microspar (light) layers. Overall shape can be described as rather a deformed circular one (asymmetric) as opposed to perfect circular patterns on ooids/pisoids.

Others

Pellets
– Size: 0.03 mm to 0.30 mm
– Identification: lacks internal structures but uniform shape and size.

Peloids
– Size: ~ 30 mm to 100 um; most commonly < 200 um - Modern peloids can be found in low energy environments such as shallow tidal and subtidal platforms. - Identification: lacks morphological structure (not always). In a sample, they are often widely varies in size and shape. - Rocks that predominantly made of peloids are peloidal packstones or wackestones. - Can be described as degraded pellets that have been moved causing mud rip-ups/broken tissues.

Aggregates

There are no universally accepted rules in the Geological community on how to separate grapestones from lumps. In fact, a grains aggregate can be classified as a grapestone by one petrologist and may be successfully disputed by another. However, generally grapestones are tightly packed together or touch each other. They often have the shape of the grains in their outer boundary. Lumps are generally full of “matrix” hence they lacks contact between the grains.

Clasts

Lithoclasts is a general term used to describe sedimentary clasts of pre-existing consolidated carbonate rock types (intra- or extraclasts). Intraclasts are fragmented lithofied or partially lithofied carbonate fragments. Extraclasts are fragmented carbonates particles.

Skeletal Microstructures-Carbonate Petrology

Homogeneous Prismatic

– Size: 1 um wide and 5 – 20 um long.
– Use high power magnification in petrographic microscope.
– Identification: sweeping extinction. Microgranular: Dark coloured in ppl. Opaque in reflected light. Porcelaneous: dark or amber in ppl. Shiny white in xpl. Hyaline: speckled colours in xpl.
– Primary characteristic of foraminifera, molluscs (bivalve).
– Secondary characteristic of trilobites, ostracodes.

Normal Prismatic

– Size: ~ 10s to ~ 100s um long
– Use high power magnification in petrographic microscope, but may also be visible under low power.
– Identification: rod-like crystals that undergo unit extinction.
– Primary characteristic of brachiopods outer layer.
– Secondary characteristic of molluscs.

Complex Prismatic

– Size: < 100 um width. - Identification: rod-like structures with radiating fiber-like crystals. These radiations will make a V-shaped pattern within the rod. When the stage is rotated, the extinction will move across each rod-like structure (move across to one end and move back to the other end). - Primary characteristic of molluscs ONLY.

Composite Prismatic

– Size: ~250 um(?) in width.
– Identification: elongated/rectangular structures with fan-like radiations pointing in the elongation direction.
– Primary characteristic of molluscs ONLY.

Foliated and Nacrerous

– Foliated term is used on calcitic shells while nacreous term is used on aragonitic shells.
– Size: 0.1 – 0.5 um thickness, 4 – 20 um long and 2 – 4 um width
– Foliated identification: long thin lamination-like structures that are near parallel or parallel to the shell surface or short irregular fiber-like inclined structures.
– Primary characteristic of brachiopods.
– Secondary characteristic of molluscs, bryozoans, worm tubes.

– Nacrerous identification: almost similar to foliated but more polygonal and aragonites may be separated by a films of conchiolin
– Primary characteristic of molluscs ONLY.

Single-crystal

– Size: relatively larger than other microstructures.
– Identification: since these fragments are made of a single (usually calcite) crystal, they will undergo unit extinction. Typical calcite twining may observe (~ 60/120 type crosses) on the surface. In some samples it may look like a calcite crystal. In others you may observe some morphological features such as an outline of an echinoderm.
– Primary characteristic of echinoderms.
– Secondary characteristic of molluscs, fenestrate bryozoans, sponge spicules.

Crossed-lamellar

– Size: few mm or 100 um
– These are wedges made of 1st and 2nd order lamellae
– Identification: ridge-like elongated structures. Not to be confused with complex prismatic because they could look very very similar.
– Primary characteristic of molluscs (bivalve) ONLY.

Fascicular fibrous structure

– Size: fibers are very thin, but often found in large quantities (may be observed under low power).
– Identification: elongated fiber-like crystals that stacked around coalesced (side-by-side). They may have a bit of circular radiation pattern. Transverse sections will have fan-like growth lines.
– Primary characteristic of corals; Tabulata corals (may also be normal to tabulae). Rugose corals. Scleractinia: (trabecular structures in septal walls, crystals radiating out and upwards)

Installing web applications

There are two major platforms used commercially for web development; Microsoft Windows Server and Linux based OS versions such as Red Hat Enterprise. You could also get a fully operational free version of Linux Operating Systems for personal or small business use. Out of the two main platforms, the most popular one among large companies is Microsoft Windows Server. I will demonstrate how to install a Web Application using the Microsoft Web Platform Installer (version 4.6 to be exact).

Web Applications

Web Applications, Scripts or web modules are programs that can be installed on a server to manage web based media. It can be databases such as SQL, or server side languages such as PHP, or web Content Management Systems (CMS) such as WordPress and Drupal. Some of these programs depend on others. Drupal and WordPress depend on PHP database so a server must have the PHP module installed to support them.

Microsoft Web Platform Installer (Web PI)

Web PI is a free software package (yep… it is legally free) developed and distributed by Microsoft. You can download it here. In includes a large repository of free web applications for web development and deployment. To install it, you need a Windows based operating system. It could be a server type OS or a regular desktop OS like Windows XP, 7, 8, etc. Check their website for supported systems.

I will use the Web PI 4.6 installed on Windows Server 2012 Datacenter OS for my examples. But the process is the same/similar regardless of the Operating System. Please note that this article explains the Server Administer side installation process. The client side installation process, which you usually get through a web hosting company, has a completely different installation process (on shared hosting).

Installing WordPress Web App

WordPress is the most popular platform for blogging for awhile. Recently full-blown websites have been built on it. The WordPress platform became popular because it has an easy to use user interface and a streamline update system. Naturally, I will use the WordPress Web Application as an example. But you can install any other program or application using Web PI following the same steps.

1) After installing Web PI, select “Products” tab from the top. Install “ISS XX.XX Express” and “ISS Recommended Configuration”. You may have already installed these on your server during the initial setup of the system.

MS Web PI Products Tab. Make sure the key components are installed.
MS Web PI Products Tab. Make sure the key components are installed-Click to enlarge.

If the PHP module is not installed, you will be prompt to install during the install of applications that depends on it. Since we are going to install WordPress, you may also install the PHP module now.

2) Select “Applications” tab and “Add” all the Web Apps you would like to install. You may install more than one at a time. After adding, press “Install”.

MS Web PI Applications Tab. Add for installation.
MS Web PI Applications Tab. Add for installation-Click to enlarge.

In this particular example, I will be installing one application; WordPress for Windows. Other options include variety of CMS such as Drupal, Joomla, Orchard, .NET, etc and web programs such as Moodle, Gallery Server Pro, etc.

3) The PREREQUISITES Window will check for all dependencies. If a dependency such as SQL or PHP is not installed, this will add those to the installation process. Accept for installation. Depend on the speed of your computer components, it will be installed in few seconds to a few minus period.

Prerequisites for WordPress Web Application.
Prerequisites for WordPress Web Application-Click to enlarge.

Application installation process.
Application installation process-Click to enlarge.

4) Once installation is completed, you will be greeted with the CONFIGURE Window. Select the location of install in your system from “Web Site” drop-down. The “application name” will determine the folder in which the installation will be done. In this case I choose “wp” as my application name. Hence the final access will be at http://localhost:80/wp and you may change the root folder of the site later. Keep reading this article for more information on how to do that.

WordPress installation server location setup.
WordPress installation server location setup-Click to enlarge.

5) The next CONFIGURE Window has a form which user should edit. Do not panic! All those “Keys” can be confusing. Just enter either a random set of numbers and letter or something meaningful to you. It does not matter what you enter. I usually use the exact same set of characters for all of the options. Press “Continue”.

Web Application Configuration Window. Type several characters for each option (key).
Web Application Configuration Window. Type several characters for each option (key)-Click to enlarge.

6) Record all the “Password Settings” information under the FINISH Window. You may “Copy to clipboard” and paste it somewhere for saving as well. I usually save in a Text file.

Password Settings for WordPress app Install.
Password Settings for WordPress app Install-Click to enlarge.

Now you may visit the site by selecting “Launch WordPress” or you may simply type the location address in Step 4 on a Internet window. Close the windows by pressing “Finish”. The first thing you will see on the Internet window is a setup page. Each Web App has its’ own setup page. In this particular example, it will be a WordPress CMS setup page. This is the final step!

WordPress CMS setup page.
WordPress CMS setup page-Click to enlarge.

Additional options

We setup the Web App in a folder named “wp” in Step 4. But let’s say your client insists that their website should not have “wp” as prefix (http://example.com/wp). You do not have to reinstall everything. You do not have to relocate the folders on the server either. What you need to do is to go to the domain settings and make “wp” your root folder. Now the http://example.com/wp will be http://example.com/. Another way to do this is through domain registrar options. You can point the domain name to wp folder from there as a root.

As mention before, you may install any of the Web Applications on a single server. They very lightweight programs, that they will not effect the performance of the server (but the traffic flow will). I highly recommend using different folders for each Web Application. This will avoid conflicts between them.

By default, all web applications take Port 80 (HTTP port) over others. However, you may also change this to whatever the port you want. You may ask, why would you want to use non-standard port? One reason would be that you are a developer or a student. If your ISP blocked access to Port 80, then you can bypass this by using a different port and utilizing port forwarding.