20 December, 2009

End of the year reflections.


The holiday season is very near and christmas just waiting around the corner. December has been pretty quiet here and will most likely continue to be so for the rest of 2009. In the year that is now passing I have been and still am very busy with my graduation work. All geological travel this year was directly related to it either for my diploma mapping project in the beginning of 2009 or thesis fieldwork closer to the end of 2009. The mapping project as been brought to a successful end and even though I am still waiting to receive my official grade both examiners have hinted that there is nothing I need to be worried about.

As my planing goes I will travel to the Southwest of Germany in January or February again. The regional geological survey offered me to examine two new cores of Jurassic limestone for my thesis. This will be a welcome supplement to highlight the regional aspects of my study which is so far focused on Eastern France. The coring will be done in January. So they'll be very fresh. The core locations are directly based on my diploma mapping work by the way.

I realise the activity here has been a bit low in the recent weeks or months. That is mainly due to my thesis stress which simply doesn't leave me with enough peace of mind to author high-quality blog-posts on geology. I tried filling the gaps with some interesting news and geological tools. Also, being engulfed in my thesis, I hardly find the time to read or write something that has not to do with my thesis. Because my thesis is company sponsored there are also some aspects and results which I cannot openly publish online. I hope you understand.

Next year, with the thin-section completed, I hope to make a few good posts on microfacies and diagenesis of limestones. The half-done sections already seem to promise good photographic illustrations. We will see.
 
As this will most likely be the last post for this year I already want to wish everyone of my readers a wonderful christmas time and a happy new year!


10 December, 2009

Instructional video on how to use a Geologic Compass

In my last post I showed you a geologic compass in the Freiberg version. Below is a link on how to use a geological compass in the field. The compass used in the video is a Breithaupt model but usage is basicly identical. The only difference is the location of the dip scale which is not located on the sides of the joint but on the inside above the compass circle, as you will see in the video. Unfortunately there is no such video in English language. The video here is exclusively in German.

How to use a geological compass (Gefügekompass)

04 December, 2009

Early Christmas Gift


Wednesday I ordered with my first, own, hard earned money (the Internship wages don't count as I was just standing in the way and being useless really) a high-quality geologist compass, a UV lamp and some boxes for thin-sections. To my great surprise the parcel arrived today already! Usually it takes up to two weeks! So today I had a bit of an early geologist's christmas feeling that resulted in running around the house and examining everything with the UV lamp and the compass (in lack of any near-by outcrops the kitchen was measured). I can now confirm that the walls are indeed all standing vertical and are well aligned. On the foto I added a simple description. The compass is a 360° compass after Clar, Freiberg Modell, that I learned with and still consider one of the best. Neither the Brunton (which broke after 1 day of use), nor some Breithaupt Models (which lacked some marks) or the recently used, cheap imitation (which resulted in daily injuries of my fingers because of the extremely sharp edges and lose screws) of the Freiberg version were able to convince me. This one should last a lifetime though.



I will post some instructions on how to correctly use it sometime soon.

02 December, 2009

Tools and Tricks of the Trade - the GPS

Ahead of fieldwork for my thesis I asked what kind of GPS device is recommmendable. A number of fellow geobloggers replied with valuable advise. I actually went and bought a GPS ahead of fieldwork. Now I am a proud owner of a GPSmap 60CSx.  The device has fullfilled all expectations in terms of durability, endurance and accuracy under not perfect conditions. The batteries last for 3 days of work or more. Dropping it on rock doesn't cause a scratch and signal reception under dense tree cover is excellent. As a matter of fact I still had a signal when entering underground caves. Well, at least for the first two or three meters. But I don't want to make a commercial here. Fellow geobloggers will know, non-trained readers might wonder though what I do with a GPS device. The idea is pretty simple. It allows to rapidly map and document geological relationships in the field with sufficient accuracy. Mapping lithological borders i.e. becomes a piece of cake. Find the contact in 3 or 4 locations, take a measurement of Easting and Northing, if possible also take a dip measurement with your geologists compass, and you are done. At least in principle. You don't necessarily need the expensive GPS device I decided to buy. A price of 260 Euros is not cheap. There are cheaper alternatives or even more expensive ones with a great variety of additional gadgets.

 
The GPSmap 60CSx operating inside

Using a GPS is easy. If you do not get training at University the documentation should allow you to catch on easily. The basic steps are simple. When the accurate position is your main or only interest, as it may be for most geological fieldwork, there is not much to do. After activating the device give it a moment to acquire a satellite signal. Depending on the location and ground conditions this should not take longer than 1 minute with a good device. Next select the position format and map datum. Usually these are hidden in the units or settings options of your device. In the most simpliest sense the position format determines the way how you write down your coordinates. As the Earth is an irregular globe your need a projection to realistically depict the surface in a flat, 2D map. One of the most common formats is the UTM (Universal Transverse Mercator) format that devides the surface into boxes. The map datum is the reference system. Because our planet is not a perfect globe you need a different model of the surface depending on your position. A model that best fits the real shape of the planet. A commonly used datum is the WGS84. Depending on your location you may wish to use another format and datum. In Germany you will still frequently encounter the Gauss-Krüger-coordinate system combined with the Potsdam-Datum or the Bessel-Ellipsoid (Bessel 1841). It fits the Geoid in Europe exceptionally well.

Having decided on your position format and map datum you can start mapping. Either simply noting the coordinates into your fieldbook or saving way points for download in the evening. When using way points remember to always save the way point and not to forget one. When working on large areas way points will make it easier to track back your movements.

29 November, 2009

ByeBye Twitter

I have been on Twitter since June. Even though a lot of other geobloggers are also active there and even though there are quite some people following me, and me following them, I see no point in it. Never have and after several months of giving it a chance it is time to quit. The only thing it successfully does it waste a little more of my time while reading tweets. Time better invested in either blog posts or working on my thesis. No worries though. The blog will not be affected by it. I just decided to declutter my online life a bit. Twitter is the 2nd activity to go. Last week I stopped using and deleted my account for one of the various social networking sites I used to be registered on. Now I need to learn how to effectively use the won time. I think I forgot some real life competence. Should be fun to re-learn them!

21 November, 2009

Fun with a Triangle

Today I got the results of the geochemical analysis of the samples that I took during fieldwork in France. Plotting the CaCO3 (top), MgCO3 (left) and Impurities (right) into a triangle gives a...well...boring but good result. Totally depending what you want to do with these rocks. But what else to expect from shallow-marine non-skeletal pack- and grainstones? I hope you can recognise the tiny dots at the top.


08 November, 2009

Mineral Deposits Studies Group (MDSG): Annual Meeting - University of Glasgow

The 33rd Annual Winter Meeting of the Mineral Deposits Studies Group (MDSG) of the Geological Society will be held from the 5th to 7th of January 2010 at the University of Glasgow. The MDSG is a group within the Geological Society of London. It focuses on the study and promotion of research on mineral deposits and mineralisation processes. The 2010 meeting is sponsored by the Society of Geology Applied to Mineral Deposits (SGA). Although the full scientific programm will only be available after the abstract deadline three known geologist will be presenting as keynote speakers. These will be Prof. Jake Lowenstern talking about Magma intrusion, degassing, and hydrothermal setting of the Yellowstone Caldera, Prof. Dick Tosdale presenting Tectonic transitions in the porphyry-epithermal environment and Prof. Gaston Giuliani updating about Academic and economic geology of precious colored gemstones : an update. The size of this meeting is rather small in nature. The 2008 meeting has seen around 100 delegates from various countries, mining companies, students and academics.

Considering my absence from the last two conferences including symposia on mineral deposits I feel very tempted to drop-by in Glasgow for a couple of day this winter - time and especially money permitting.

Are any of you Geobloggers situated close to Glasgow? Any additional reason to go would be great.

26 October, 2009

New Geoblog: Chiemgau Impact

Robert has taken-up the task to author a new blog devoted primarily to the discussion of the controversial Chiemgau impact in historic time. The issue has created some debate within the geological community in the past due to contradictory evidence. Hence also the blog name: Chiemgau Impact? The blog was added to my German Geoblogosphere feed as one of the few German written blogs on geology.

Thanks to Ole and his blogging effort that alerted me to this new blog.

22 October, 2009

Dispatches from the Field #4

The Final Days

The last days of fieldwork were dedicated to sampling outcrops, measured sections and other outstanding features. In total I collected around 45 samples for thin sections and another 35 sections for geochemical investigations. The geochemical samples are, of course, the counter-parts to the respective samples for the thin-sections to allow direct comparison. Sampling required a lot of manual work with the hammer and chisle. Many locations have a very hard limestone that required intensive hammering, this way taking 4 samples could easily consume more than an hour until a largely unaltered sampled could be obtained. Also, an advise for anyone hammering away in quarries and outcrops, use a helmet! Mine proved to be a valuable addition to my equipment as it was hit two times by falling rock - that otherwise probably would have required a visit to the local hospital. Having survived sampling and last minute observations I headed to Northern Bavaria to drop-off the geochemical samples in the office of my financing company. They will hopefully be able to provide the results in a few weeks. Now I am heading home. Fieldwork is over!

12 October, 2009

Urgent call for Participation in the Geoblogosphere Survey 2009

Lutz has alerted me that, dispite the wide-spread news about the Geoblogosphere Survey 2009 the participation be you, the bloggers, is very low! The Geoblogosphere encompassed more than 200 blogs but only around 50 have participated in this community effort. Please go to the Survey and fill out the short form. I could do it, and I am in the middle of a fieldwork campagne for my Master degree with horribly bad internet connection. It takes only a few minutes. It is available in several languages, as well!

10 October, 2009

Dispatches from the Field #3

The internet connection here has gotten really...a matter of chance...each day. So here is the summary of the last few days.

Day 8 to 12:

In the last days I managed to document all profiles in the useful outcrops. The weather has unfortunately worsened and the last three days got me soacking wet every time. I did manage to begin measuring the outcrops for dip, palaeoflow (not much to see sadly) and faults. The compass only arrived thursday, my supervisor had forgotton to bring it. Well, I do get to see every spot at least twice this way. Though it does not really lift my spirits. I found a tiny veinlet with pyrite, chalcopyrite and calcite in the quarry today. The next one and a half hours I spend looking for more and examing the really tiny crystals in more detail. I'm still an ore geology guy by heart I noticed, and how hard it was to leave them and get back to documenting the boring quarry with its very monotonous succession. I am very much looking forward to going home. I can feel that I am doing the 3rd or 4th choice kind of project. I want my ores...

08 October, 2009

SedLog: A tool for drawing graphic logs.

Today's work literally got drowned by continued rain. The unvoluntary idle time could not be filld entirely with continuing the map thus I spent some time surfing the digital waves, and behold, what did I find?! Something certainly not only useful for my thesis project, but just as well to anyone else out there needing to compile sedimentary graphic logs. I stumbled upon an article (SedLog: A shareware program for drawing graphic logs and log data manipulation) published just recently in Computers & Geosciences by Zervas et al. It appears to be great and easy to use tool that I downloaded. Runs fine on my Win XP. The tool has its own webpage here.

05 October, 2009

Geoblogosphere Survey 2009

Lutz has kindly asked me to to highlight the Geoblogosphere Survey 2009. Please go here to take the survey. I already did and it only takes a few minutes and is easy to answer! The survey is open for participation until 1st of November.

Dispatches from the Field #2

Mapping complete and fighting with making a good profile

Day 5:

Today was a good day. Dispite sleeping-in late and getting lost on the road - it's really confusing to drive on these tiny French roads - I did what I wanted. The point making my day good was that I found a couple of locations with big calcite veins within 50 to 100 m of where I was expecting to find some clue for a big fault that I had been hypothesing upon the day before. Left and right side of the veins are off-set by at least a few meters. Great! There also is an old quarry that I discoverd today in which can be seen some nicely folded and layered limestone beds. The base of the formation of my interest - I think. It seems like the very old geologic map that I am basing my work on is correct in all its details. Tomorrow I will inspect the last two places of my field area. If there are no unexpected surprises here mapping will be done tomorrow and I can draw the working version of the map. Three days for 2 square km sounds pretty good. If all goes well tomorrow I might also begin with the first profile and selecting some preliminary and random samples. The only downside so far has been that the Mumienbank, a wonderful oncoid bed that would enable a rough stratigraphic positioning, seems to gone. Only some occasional float from the lower most part of the oncoid bed or the underlaying grainstones can be found here and there. To end the day with a positive expression: After taking a few dip measurements it will by a piece of cake to construct the Isoline Map! The morphology here delivers very good clues on where the hard limestones begin even when the lower contact is not exposed.

Day 6:


Today went well. Found another few spots with calcite veins just in the right location for fault lines. The morphology also screams "fault"! The entire area is mapped now and I think I found all useful outcrops as well. The evening was best, when putting everything onto the map and get confirmation that all veins, silified rock and similiar stuff is really where I suspected that it should be. Good!

Day 7:

A slow day. Wasn't really motivated. I managed to speak to the owner of the active quarry and I can come friday to pick-up the keys so I can access it on the coming weekend. I hope two days will be enough to make the profile, measure it and take enough samples. Aside of that I spent a very long time in an old quarry trying to make sense of it. The bedding is really a mess. Most of it is simply an extreme version of stylo-bedding in my opinion. I grouped these stylobeds into a "bed" when they were identical macroscopical. I got 12 beds this way in a 20m high quarry wall. Still, lazy, I hope the other places will go quicker than all day long.

04 October, 2009

Dispatches from the Field #1

After some internetless time I found some way to access it. The connection is horribly bad, so no pictures unless necesarry. Some stories about my Diplom degree fieldwork. 

Getting there and first impressions

Day 1:

Having spent the last two days packing everything that I might possible need I left home around lunch time. The traffic on the highways was a disaster and one construction site followed the other. I only arrived around 7pm at my half-way stop in Hessen. The pension was nothing special, actually the room was stinking terribly like cigarette smoke and it was awfully noisy. I don't think I slept more than 3 to 4 hours till the next morning. Luckily I did manage to get a nice Tagliatelle a la Pirata at a local restaurant. I didn't feel like eating in the pension.

Day 2:

Construction sites the 2nd day. Today also accompanied by traffic jams for a long way! Drinking awfully much Cola to fight my sleepiness I arrived in Bad Krozingen, a nice thermal bath, around 5pm. Here I spent the night in a, this time, very nice pension. Too bad I had no time for vacation!

Day 3:

Not entirely rested I met the quarry manager and the chief geologist of the company I am doing my thesis at. After an organisational meeting and talking about how to drive we took-off and drove some 90km south-west to the southern most end of Alsace. On the road we found out that the French don't understand the same under "Fast Food" as we do. The Kebab took forever. But it gave us time to talk. After having arrived on the site of interest we took a short hike to the next outcrop, a former quarry, and discussed some of the work that would be ahead of me. I took a short walk after that to see some more of my work area and then drove to my room. It's very nice by the way. Sadly, very bad WLAN internet and only three TV channels - all French! The shopping tour in the local supermarket also made me realise that I am very out of place here with my virtually non-existing French language skills. Feels very embarassing when I can't even ask what they are selling at the meat, cheese or fish stand. Very exhausted I fall to sleep in my bed later on. Finally a really good night!

Day 4:

I drove to an active quarry to ask the owner for permission to access it to do my stuff there. He ain't there. Need to come back on Monday. Good the guy at the door also spoke Alsatian dialect - something inbetween French and Swiss-German. Then I drove horribly long till I found a parking place for todays checking-out of the field. The hill is very steep! Impossible to walk lines. Will just follow the forest tracks and check if the geologic map from....very, very old...matches reality somehow, as agreed with my supervisor. Then I will pick sites for profiling and sampling. Today I already found two or three potential sites. One is small and the other a German bunker from WW 1 that has been built into an artificially extended cave. Carrying the flashlight and helmet all day came in very handy. First impression: Very confused. Too much vegetation. Worse than in the Amazonas. Sigh. Did I mention this hill is a huge, overturned fold that has consecutively been faulted, up- and down-lifted? It has, well better said had, a stone age fort on top. Together with the WW 1 bunker all kinds of imaginable rocks now all lay happily united and scattered all over the hill. The steep slopes do the rest to spread float to every possible and impossible corner. Did I volunteer for this????

27 September, 2009

Time for Fieldwork!

Thuesday will be the day I head due South to France. Starting October 1st I will be doing a little bit of mapping, measuring sections and taking plenty of samples for my Diplom thesis. The long-term weather forecasts look promising and with some luck I will be enjoying two weeks of perfect outdoor weather in the Alsatian Jura in the eastern-most part of France. I will be delving into the realm of shallow-marine carbonates, in particular oolites and oncolites. Internet access will be severely limited, in contrast to the last time I was on fieldwork. There should be enough material to make a few nice posts about fieldwork, carbonate sedimentology or karstification, I hope. It will be quiet here till mid-October.

26 September, 2009

The Lost Geologist interviewed on the Reef Tank

As I announced a few days earlier I have been sent some Q&A by Ava from the Reef Tank. The resulting interview on my own activities and their connection to marine geology is now up and available on their site. Here is a link directly to their blog. You can find me right on top at the moment. I hope you will find it interesting to read and I would welcome any feedback and so, I am sure, would Ava.

23 September, 2009

Upcoming interview on The Reef Tank

I've been asked by Ava from The Reef Tank if I would be willing to answer a few question about marine geology and my connection to it. It seems to be a very interesting site not only for aquarist but as well for those interested in reefs and the marine. Currently they are trying to build a new section on marine geology. So I gladly answered the short Q&A. The interview will most likely be published within the next few days on their site. I'm curious about the responds.

20 September, 2009

New Geology Feeds on Economic Geology and Sedimentology

The "Fachzeitschriften" feed for geology journals has been removed from the sidebar because I thought that it is too cluttered with all the geology related journal feeds in one place. On the very end of the sidebar I now included two different feeds focused on "Economic Geology" and on "Sedimentology" respectively. This move also reflects my personal focus on these issues and will enhance finding relevant information more easily, I hope. The previous feed of all journals has not ceased to exist though. If you wish to use it click here to access its page but I will no longer be maintaining it on a regular basis.

The "Economic Geology" feed includes Chemical Geology, Geofluids, Journal of Geochemical Exploration, Mineralium Deposita, Ore Geology Reviews and Resource Geology. It is the journals that offer a feed for new articles and which I regularly check for news.

The "Sedimentology" Feed includes Basin Research, Facies, International Journal of Earth Sciences, Marine and Petroleum Geology, Marine Geology, Palaeogeography-Palaeoclimatology-Palaeoecology, Sedimentary Geology and Sedimentology. I tried limiting it to journals that have articles on sedimentology frequently.

If you have any suggestions for adding journals to these two feeds feel welcome to contact me.

18 September, 2009

GPS - which one do you recommend?

I am pondering for some time now to get my own GPS device. For the upcoming field work (starting Sept. 29th) I will definitly need one, and no one seems to be able to lend me one. Our 10 or so university GPS are all broken. What GPS would you recommend for geological field work and mapping? I figure I need one that is quite accurate even under light tree cover, and also one that is able to display different projections, like UTM, Gauss-Krüger and other widely used methods. Do they still use Lambert in France? Most of my work I do in Europe - Germany, France and Switzerland and other central European states.

What do you think about the Garmin Colorado 300, the GPS 60 or the GPSmap 60 series? Price is really an issue for me.

16 September, 2009

8th Freiberg Short Course: Metallogeny and Exploration of Uranium Deposits

If you are interested in Uranium, its metallogeny and exploration, then I can recommend this years 8th Freiberg Short Course on Economic Geology at the Technical University of Freiberg, Germany. The almost one week long course will be presented by Professor Michel Cuney and others. All relevant kinds of Uranium deposits will be discussed and presented, including a field trip to the Uranium Ore collection of the WISMUT AG in Aue, the site of the former Uranium mining operation in communist times. One of the local organisers and presenters will be Dr. Thomas Seifert, an able and friendly mineral deposits expert of the Freiberg University whom I remember from various classes that I listened to in my Freiberg time. The course will be held from December 7th-12th in Freiberg.

Freiberg is not so far, perhaps 3 hours by train. If I will attend the course myself is still unclear, as I will be in the middle of my diploma thesis in december and probably stuck in a big pile of work.

09 September, 2009

Congress season

UPDATE: Unfortunately I got a very bad throat infection, high fever and lymph nodes as big as golf balls and hard as granite. My doctor ordered me to stay at home. Such a big disappointment! I was looking forward to meeting a lot of interesting people...

It has been going around in the Geoblogosphere that congress season has begun. I will be using the opportunity of having a lot of free time to attend the The 87th Meeting of the German Mineralogical Association at the Martin-Luther-University of Halle-Wittenberg. The meeting from the 13th till 16th of september will be covering a wide range of mineralogical and geological issues, also including archeology. My personal main interest will of course be to attend the symposia on mineral deposits and exploration in which will be presented a number of, I hope interesting, topics of mineral exploration in Germany. The most recent programm can be downloaded here.

08 September, 2009

Finally!

Finally my diploma mapping project and report are completely off my desk! Monday I handed in the report at the examination office and today I gave a copy of it, and the map, to the two supervisors. Whatever comes now - it's out of my hands and I can't change it. And that's good! No more worries! I hope to have the results and grade within a few weeks, before I go to field work on my diploma thesis in France. I hope to also find a bit more time for blogging in september, now that my desk is empty again.

01 September, 2009

Gastropod fossils from the Hauptrogenstein

In my previous post I promised Aydin to post a few fotos of gastropod fossils that I came across during my mapping project. So follow-up on my promise here are four examples of fossil snails that one may come across in the oolithic Hauptrogenstein. My palaeontology isn't so great, and this was a mapping aimed at lime production, so we didn't bother so much about what these are exactly. If you can share some clues, feel free to contribute.


Sample from the Mumienbank, the top bed of the Middle Hauptrogenstein.
Oncoid with a gastropod nucleus. Probably a nerinea.



Detail from a polished slap of the Middle Hauptrogenstein. Somewhere from the "cross-stratified, oolithic complex" or coral-bearing Hauptrogenstein. Shells are 3 to 4 mm in size. Unidentified.


Gastropod sample from the coral-bearing Hauptrogenstein in close association with abundant coral debris (not recognisable in foto). A nerinean?


Wonderful 3D preservation of an archaeogastropoda(?) in close association with well-preserved, probably in-situ occurence, of branching corals (see below).


Branching-coral associated with the above mentioned gastropod fossil. Possibly encrusted with coraline algae?

25 August, 2009

One end, one beginning and very vague ponderings about the future.

Today I had a last moment battle with finishing my diploma mapping report while trying to get it printed. That problem is solved and tomorrow I can pick-up several copies of the report. So, basicly, I am done and will hand it in to the examination office probably first week of september. Done.

At the same time I am starting the next project - my actual diploma thesis (about the same as a Master thesis). The planing for the field work has already begun and I found a cheap but practically located place to stay in the south-eastern most corner of France. Field work will be two weeks in the first half of october. There are some issues that need to be resolved, still, but in generall it's all settled.

I don't know if I can really reveal what exactly I will be doing, where exactly and for whom exactly but it is safe to tell you that I will again be working on limestones. As the planing is now I will be comparing the carbonate depositional environment to the quality of the limestone. The theme is cooperation with a large, German manufacturer of construction materials. Plus some other stuff. By the end of my thesis I will probably run away screaming from any limestone I see...haha...

So the end of the end seems near. Sometime first half next year, the latest, I will in the happy posession of a diploma degree in geology. If you followed my blog you may have noticed my contacts with the Industrial Minerals, Economic Geology and Sedimentology. There are some important decisions to be taken by me in the next six months. I need to decide if I want to find a good job and work in the industry or if I rather try my luck and find a nice PhD position. Especially the later also means to find a topic I really love and find enough motivation for to survive 3 to 5 years of investigating. Don't ask what I have in mine. My head is full of vague ideas about carbonate-hosted Pb-Zn or supergene Pb-Zn deposits, tantalum-niobium deposits, phosphorite deposits, shallow-marine carbonates and some exotic stuff.

Of course this will also affect my blogging. Most important I need to find out what is good to blog - and what to leave out of here.

I will see, and you, perhaps, too.

24 August, 2009

Book recommendation: Paleokarst

Occasionally I recommend books that I personally like. In the previous book recommendations I wrote about Carbonate Sedimentology by Tucker & Wright and Microfacies of Carbonate Rocks by Flügel. Today I have a slightly different theme that also related to carbonates. The title of today's book is Paleokarst by James & Choquette (Eds.). I have at several times consulted this book in the course of my diploma mapping project and, sadly only at one occasion, cited from it. It's a very interesting book when you are interested in how to recognise karstification in ancient environments and when you need to distinguish Paleokarst from modern Karst. The volume is a collection of papers and reports of the 1985 symposium on "Paleokarst Systems and Unconformities - Characteristics and Significance". Published in 1988 this book is, dispite its age, in my opinion a good collection to introduce the interested reader into the Paleokarst and Karst field. Some basic knowledge of carbonates and karst is totally sufficient to understand this volume. The book itself is two parted: At first there is a discussion in several papers of general karst and paleokarst features, such as caves, meteoric diagenesis or even carbonate-hosted lead-zinc deposits. At second examples of paleokarst terranes are presented dealing with different aspects. The book is supported by a great number of black-and-white sketches and images. Personally I do prefer good black-and-white grafics over fancy grafics that are too full to recognise what's really important. So I do not consider this to be a negative point. Sadly this great books seems to be out of print and is no longer on stock. It might be hard to find - luckily I seem to be the only one in my university library who uses the only copy.

In short: this book covers a wide range of karst features of both ancient and modern context and touches issues of different fields, such as but not limited to caves, diagenesis, ore deposits and paleoclimate.


Paleokarst front cover

08 August, 2009

Who can share research and work experience on aggregate and industrial minerals?

As my choices for my diploma thesis have boiled down to diving into the world of shallow-marine limestones (again) used for making burnt lime with a large German manufacturer of construction materials I am wondering how many geos and perhaps mining engineers we have in the geoblogosphere who can share some experiences. Mining for metal ores and precious stones has a much wider exposure than the industrial minerals, however, in Germany, if you want to work on mineral deposits (in the wider sense) industrial minerals and aggregate will be your first choice right after coal or salt.

I've been wondering. Please excuse the very vague questioning. What are the pros and cons in your opinion and what do you think about the career aspects in these fields of mineral production? I am still pondering to also persue a PhD sometime after my graduation. What affect will my focus on limestones (by necessity) have on the chances of persuing a PhD related to metalic ore deposits?

Any shared experiences are highly welcome!

Check-out WoGE #169!

I am not sure how many people normally come across Peter's photography collection where he is also hosting the next WoGE everytime he wins, therefore, I thought it to be a good idea to point you all to WoGE #169 (click here). Maybe we can re-instill a bit more life into the contest and increase it's exposure.

05 August, 2009

Where on (Google) Earth #168!!!

Recently, I was able to finally resolve the long, long waiting WoGE #167 chosen by Rod and posted on Ron Schott's Home Companion. The Rules are simple: Identify the location shown, give latitude and longitude and post some information about the geological significance of the location shown. If you win you get to host the next WoGE! If you don't happen to have a blog you can chose who may host your next WoGE.

To speed-up the next WoGE I will not invoke the Schott rule. Anyone may reply the moment they can identify and describe the target. Perhaps the veterans who already won several times can wait for a few hours before posting in order to give the new participants a chance.

Below you will find the new WoGE #168. Good luck in the hunt!


Click image to enlarge!

23 July, 2009

Oncolite Rudstone from the "Mumienbank"

I am not getting ahead fast with my diploma mapping report and it keeps being a pain in the...well, you can imagine - a lot of headache. So there isn't much around that I have time or nervs to make some serious posting about. For your entertainment I decided to share another polished slab I made that will be part of my report. It is a piece of the "Mumienbank" - an oncolitic Rudstone from the Jurassic limestones that I am working on. You can observe some lovely oncolites, nucleus and laminae intact, bored and re-filled, some deformation on the grain contacts that are partially filled with some iron minerals (the black stuff) - guess haematite or stuff. Didn't yet have time to look at it with a binocular or microscope but the black stuff is actually quite shiny in the sun.


Oncolite Rudstone of the "Mumienbank"

10 July, 2009

Flowstone, cut and polished

Another of the samples I cut and polished: This flowstone originates from an exposed karst cavity. The sample is taken from the floor of the former cave that is now infilled with flowstone and other sediments. These deposits form where water flows over rock walls or floors. Looks pretty cool, no?


Flowstone deposit. Upside is down.

09 July, 2009

Two polished carbonate slabs

There is no time to write great posts these days because of my continued work on my diploma mapping report. Though I can share some stuff. Today I cut and polished a number of samples to enhance the illustration of my report. I didn't manage to polish them all but a few samples are done and I want to share two of the more spectacular ones.

First, I cut and polished a sample I already discussed here. Back then I thought it to be a carbonate tempestive with an erosive base. Right now I am not that sure. Either way the cement is entirely sparitic from the shells upward. Below one can also find micritic and sparitic cement. Very few ooids are cut and truncated by shells. So maybe it is still a storm layer or a very proximal debris flow of carbonate sand. You can find a wild mixture of grains from shells, snails, foraminifera even, ooids, coated grains, aggregate grains, etc.


Event layer? The upside is up in the image.

Second is a cut sample of an oncoid bed that I also discussed earlier. These wonderful and easy to recognise oncoids show a great, irregular laminae, one as a gastropod as a nucleus and two of them are obviously bored with internal boring sediment. I am not so sure how to interpret the contacts between the oncoids. First I thought them to be slightly deformed by each other. Meaning they would have been still soft enough for that to happen. Some partial laminae seem to have broken off. But then some contacts look a little like pressure solution seams and the laminae are abrubtly truncated. The matrix is a carbonate mud with shells, snails and other stuff that I didn't bother to check out, yet.

(My excuses, I accidentally messed-up the scale. The scale in the oncoid image is suppossed to be 4 cm not 6 cm.)


Bored oncoids with snail nucleus

06 July, 2009

Finally some pages...

I don't quite know what changed but today I finally managed to overcome my week-long writing blockade and succeeded in writing 3 and a half pages of outcrop descriptions. That's six outcrops described in detail - without images and rose diagramms, yet. Cross your fingers for me that I manage to keep up this daily routine and perhaps even increase it a little. Once I caught-up on my writing some good ideas to blog about will most likely return, too.

02 July, 2009

Why it is so quiet here...

Studying at an under-funded university that abandoned their department of economic geology just when I got here is highly unsatisfactory. Sadly changing places again is out of the option - I do not want to lose another semester or two or three. I don't even want to think of the financial problems that would come with that.

The recent lack of posting is somehow related to that. I am fighting with my motivation to get the diploma mapping report done. Gladly I do not have problems with the material itself but working without having any goal to work for is a fairly demotivating task. Unfortunately the only professor interested in and willing to help me with a thesis in economic geology (something with ore!) has no funds to work with. Remember we don't have a department anymore, thus no funds, no research, etc. I applied in the industry but only got two offers that are even worth considering as a thesis. None of them will bring me any closer to what I really want. Actually they'll be leading me right in the other direction. Limestones are nice and it's a resource but, well, where is my ore?

Please excuse the current lack of posting. It might continue for a while until I find something worthwhile to do.

21 June, 2009

What's your daily writing pensum?

For all those of you who have to write papers, reports, thesis or your PhD. You may know I am currently writing my Diploma Mapping Report. The maps are done and with my supervisor (who liked them very much) since early June. Since then I should have been writing the report. But I didn't have much progress. Gladly I am still out of problems reach concerning my supervisors and I would like to keep it that way.

I want to set myself some strict goals, i.e. a numer of words or pages I must write every day no matter how stupid it looks like. This is mainly to get some content down and would probably be a good morale boost to see that there is something, even if quality may, yet, be lacking.

So I am curious about how you do it:

How do you get yourself to write that paper or report that you really don't feel like writing?

What is the average span of words or pages a day that you consider good?

I believe the trouble is that it is the first time I am working completely alone. Before I always had at least one fellow student or friend as co-worker. Telling your friend that you will be done with chapter X by monday makes quite a difference for writing. No one wants to disappoint his friends, right?

Also I was unlucky in terms of writing location. I didn't manage to get a room at university to work in. We simply don't have enough for every student. The library came to mind but offers too much distraction both in terms of other people looking for books and in the form of said interesting books. Additionally I don't feel like carrying all my books, papers, samples and notebook to it every day.

There is no other location at my university that I could use. So I am stuck in my own, small room at home.

What is your advice?

16 June, 2009

Geology Rocks! A true rock song!

Thanks to cottontree from the Geoversum geology forum for posting a link to this incredible rock music video! Geology Rocks! :-)

Geology Rocks Video on Youtube

15 June, 2009

Accretionary Wedge #17 is up!!!

The Accretionary Wedge #17: Let's do a Time Warp is up on Outside the Interzone from Lockwood! In this geologic web carneval we will be actively travelling though time to investigate some of the most intriguing events of Earth, otherworldly and pre-univers history. It promised to be an exiting trip with a reasonable chance I suppose to meet Jurassic critters (don't feed them!) and other strange forms of life and more importantly - rocks! So now head over to Lockwood before there are no more free seats! There are plenty of participants!

13 June, 2009

The Accretionary Wedge #17: The Time Warp!

One of the main problems in ore geology just like in most other subdivisions of geology is that we always and only see the final result. We are never there watching it from start to end. A very displeasing obstacle to really understand what happened.

But now - thanks to Lockwoord from Outside the Interzone - I have the tool I need to solve what bothers me: A Time Warp generated by the lastest edition of the Accretionary Wedge!

There are plenty of places, events and processes that would be fantastic to watch with my own eyes as they unfold. I'd really love to see if Snowball Earth really was a snowball or sample the very first living cell to probably roam the oceans. Also a small detour to early Mars while it was still warm and wet and friendly to life would sound like a great destination.

But actually I want to go elsewhere. I want to watch an ore deposit form. I want to see it from start to end. To narrow it down I want to be there while the Silesian Mississippi Valley Type district forms. This is not only the largest MVT Pb-Zn district of the planet with 730 Mt of ore but also there is evidence that the largest district of its kind was formed in an increadibly short amount of time! In the hypogenic karst cavities of the Silesian deposits you can find speleothems (see image) growing up and downwards. The point is they don't grow vertically up and down - they show indication of growing into the direction of fluid flow! You heard it right. These dripstones are made from Galenit, Spalerite and other ore minerals growing inside a pipe that the hydrothermal fluid must have been rushing through. There are estimates that the entire ore district formed in less than 50.000 years with some investigators arguing the time of formation could be as little as 5.000 years or less. Certain parts must have literally formed in the course of days and hours with giant streams of hydrothermal metal-rich fluids moving through the cracks and fissures of the host-rocks.


Sulfide speleothem from the Olkuze mine
(Source: Scanned from Conference handout SEG workshop on the Geology of Pb-Zn Ore Deposits, Lima, Peru, 2008. Image from chapters of David Leach)


That would be so cool. To sit right in those caves in a dry spot and literally watch galenite and sphalerite stalacties and stalagmites grow over night.

Not to forget I also want to take a look above ground. You may know there is a relationship between the palaeogeographic position, the palaeoclimate, mountain building processes and the formation of large carbonate-hosted MVT deposits. A hydrological test with tracers would be cool. Seeing where does the water really come from. What is the real flowpath? How are the precipating ores replacing the surrounding carbonates? I want to see and feel it first hand on.

Thats why I want a time warp.

12 June, 2009

200th Post!

Woohohohooo!!! This is the 200th post since I began blogging one and a half years ago! Time moves so fast, doesn't it? I should have planed this ahead to have a fascinating celebration post ready - as you can see I didn't. Shame on me....

However, instead I can tell you that I am planing to continue blogging for at least another 200 posts (thats probably sometime around the new year of 2010/11).

Also I've been pondering for a while to make major re-construction of my entire blog. I would like to write more focused and more in depth on what really interests me. Additionally I want to move to a more professional look. I don't quite like the options blogger provides. For now all of this is still brewing in my head while I am working on my diploma mapping report and searching a cool diploma thesis topic.

Last but not least I like to thank all the loyal and active followers of my blog. Your thoughts are always a great enrichment of this blog. Thank you!

P.S. I'm on Twitter now but I didn't quite figure out what I am supposed to do there, yet.

11 June, 2009

Another blog: Ancient Shore

Yesterday while surfing the web I came across this nice to read blog by Graham Young called Ancient Shore. Graham is writing from Canada, it's geology and his impressions - usually always somehow connected to the sea-side and the shore. I like the narrative writing style of his. Check it out!

10 June, 2009

Cool samples from fieldwork #04

This samples that I took during fieldwork is an ideal example of the Humphriesi-Oolite from the Middle Jurassic. The Bajocian Humphriesi-Oolite is an iron-ooid rich sandy limestone with ooids of up to 2 mm in diameter. According to the available literature it has been mined as an iron ore in the Dark Ages but lost its significance since then. Sadly there is not a single outcrop of this in my entire mapping area. This sample is one of the few good pieces (mostly it looks more like a boring marl with few ooids) of float that can be encountered occasionally. It can be confused with the Aalenian Murchisonae-Oolite which, however, has much smaller oolites and is sparry, marly and can often be found as small plates, unlike the Humphriesi-Oolite.


Iron-oolite with red-brown ooids of up to 2 mm

This sample is cool because the ooids are so wonderfully preserved and can be easily observed even without a magnifying glas!

09 June, 2009

Gold!

Lutz from the Geoberg.de-Blog reminded me that there still are some treasures in Germany to be found. Even if they are not as luxurious as the media may be believing. I'm not even half as excited but it sure sounds interesting. Although it is not big news to those working or researching on ore deposits in Germany and especially the Ore Mountains around Freiberg I suppose. Apparently the news has leaked out again that precious metals like Gold can actually be found in the Ore Mountains. Such a nice story for the newspapers...

06 June, 2009

Back from relaxing

Yesterday I came back from relaxing a couple of days after completing my diploma mapping project maps. I really needed a break. The first three days I was completely exhausted and could physically feel some stress falling off. Now I have a bit more energy again to write the report to accompany the maps. To my great relief my supervisor found nothing to complain about and is very pleased about my work done so far. Nice! From his mouth that's a very big "job well done"!

Also for the real news: I just mailed my poster abstract to contribute to Geodresden 2009. It is this year's meeting and congress of the DGG (German Geological Association). So my very first conference presentation is on it's way! Woohohooo! Now I have a few months to make a cool poster and hopefull some additional and enhanced thin-sections.

My poster will be about organic microfossils from certain metamorphic rocks I worked on a year ago. I might post more about it closer to the meeting.

28 May, 2009

One step closer

Finally! Yesterday I finally wrapped-up my maps and mailed them to my supervisor! I'm a big step closer to completing my diploma mapping project. Yes, writing the report remains but a big worry is off my head now and I have my mind free now to write something good. The maps were driving me insane recently and I am so glad they are finally gone. Time to take a few days off and then return with full strength for a month of report writing and interpretating. A few days off will also benefit my blogging now that I have less to worry about.

23 May, 2009

What the Lost Geologist is busy with...

My university is a wonderful place. Really is! We have all kinds of wonderful stuff - except the really useful one. Instead of finding a way to let students use Corel or other specialised software to do important things they found a better way - let the student figure it out by himself (I won't even start with all the other things that don't work - I'm in a good mood still!). That's why I am currently developing a tennis elbow while playing around with various free graphic softwares to design a good, vertical profile of my mapping area.


Screenshot of what I do

I'm busy for two days now with what you can see above. By now I believe I am too perfectionist and should just have scribbled something on a piece of with some pencils. *sigh*

When I am done with it, then it'll deserve a place in an art gallery!

21 May, 2009

What happened to the Accretionary Wedge?

Did it already fall to the fate of complete subduction? The site lists #17 for March but I haven't seen nor heard anything about it ever since. Was there one for April? What about May? Or am I just becoming blind and didn't notice? Maybe I'm not the most active contributer but I loved ready each edition.

What happened?

20 May, 2009

More about RSS feeds for geoscience journals

Brian from the Clastic Detritus blog wrote about RSS feeds for geoscience journals. I'm glad I could help out with a few more feed adresses. I figured I might just as well share my article feed that I compiled recently of all the journals that I browse for something interesting. Below is a list of the 28 journals I have on my feed. Not all journals seem to have RSS feeds. Those I check manually, i.e. Economic Geology. Blogger doesn't allow me to include the article feed in a blog post so I will add it to my side-bar. You need to scroll down a bit. (I need to do some side-bar cleaning I believe)

P.S.: I forgot to also list the individual RSS feeds. Will update that later today (or tomorrow).
  • Chemical Geology
  • Earth-Science Reviews
  • Earth and Planetary Science Letters
  • Geochimica et Cosmochimica Acta
  • Journal of African Earth Sciences
  • Journal of Geochemical Exploration
  • Journal of Geodynamics
  • Journal of South American Earth Sciences
  • Journal of Structural Geology
  • Lithos
  • Marine Geology
  • Marine and Petroleum Geology
  • Palaeogeography, Palaeoclimatology, Palaeoecology
  • Sedimentary Geology
  • Tectonophysics
  • Ore Geology Reviews
  • Journal of Petroleum Geology
  • Basin Research
  • Sedimentology
  • International Journal of Earth Sciences
  • Mineralium Deposita
  • Facies
  • Journal of Geosciences
  • Geofluids
  • Palaeontology
  • Lethaia
  • Terra Nova
  • Resource Geology

16 May, 2009

Cool samples from fieldwork #03

Another great find from my work is an extraordinary large calcite crystal that I managed to recover from one location. Outcrops are really worth checking out in the really unaccessible parts. This one required some climbing and I do have to admit that I did not have the courage to return to the location a second time. I suppose this one formed either by diagenetic processes or karstification in general. Didn't get around, yet, to review my notes on this location. It is a really cool find though! From the same location I also managed to recover a few very tiny fluorite crystals within a boxwork of calcite blades. Perhaps I managed to make fotos of those, too.


Large calcite crystals

By the way: Please excuse the lack of substantial blogging. The diploma mapping report and maps are keeping me occupied more than I want them to.

13 May, 2009

Cool samples from fieldwork #02

Here is the biggest belemnite I ever found! Dispite the fact that both ends are missing this is an interesting find especially because of its large size of about 15 cm! I will need some expert advise to correctly identify this one - can't know everything. Poor palaeontology prof will imagine he didn't teach me anything...


Jurassic (Bajocian) belemnite from SW-Germany

10 May, 2009

Cool samples from fieldwork #01

During fieldwork I came across a number of really cool fossil and rock samples. For my report I need a couple of good images to illustrate my finds and conclusions. So I had a small foto session today and made some fotos. One of my coolest finds is a plate covered with a lot of crinoid stems and arm fragments that I identified as Isocrinus nicoleti. Since my palaeontology is not so good I will get another opinion from one of the experts at my university though. Anyways, enjoy some nice fotos!


Plate with crinoid stems


Close-up of large stem and arm fragments


Close-up and cross-view of stem fragment. Note the typical star-like appearance.

07 May, 2009

Should I...?

...or should I not? Perhaps you remember some early post of mine about a seminar paper discussion chitinozoan finds in phyllites of the Erzgebirge. At the end of september this year there will be a conference - GeoDresden2009 - of the DGG (German Geological Association) in Dresden. Beautiful town by the way! The theme of my seminar paper would fit perfectly to the regional theme of the conference in my opinion though I am a litte...actually very nervous about attending and having a poster. I never did that before and I don't know if my little "investigation" is thorough enough and of sufficient quality. There are only 5 thin-sections and only one of them has a handful of microfossils in them. Being burried in work for my diploma mapping and hopefully in 1 month in my thesis I won't have time to go back to the samples and make new sections. So I basicly need to use what's in my seminar paper unless I get a hold of some old papers I've been looking for for months. Deadline for submission is May 31st.

Any advice?

01 May, 2009

Geoblog: Carbonate Sedimentology

I didn't realise it until now but there is a new geoblog out there. Neuwendao is blogging from China about his research interest in carbonate sedimentology, its sedimentation and diagenesis as he describes it. The Carbonate Sedimentology blog was born April 18th and I am keen on seeing more from this new geoblogger who apparently shares a common interest of mine with carbonates.

30 April, 2009

Book recommendation: Microfacies of Carbonate Rocks

A while ago I recommended "Carbonate Sedimentology" by M. Tucker for all those interested in carbonate rocks. I would like to add another wonderful work on carbonate sedimentology. While "Carbonate Sedimentology" by Tucker is more focused on the macroscopic aspects of carbonate sediments Erik Flügel has written an all-encompassing work on any kind of carbonate microfacies. His probably well known book titled "Microfacies of Carbonate Rocks" is filled with more than 900 pages of very well researched knowledge combined with many useful microfotographs of many different kinds of carbonates under the microscope. Nineteen chapters will guide you from the introduction to carbonates through any aspect you may imagine. Methods and microfacies data are explained, diagenesis, porosity and classification discussed, the biological origin is highlighted and fossils in thin sections examplefied. Microfacies types are explained, you will learn how to interpret palaeoenvironment, depositional models and read about basin analysis. Also contrains and processes are reflected upon before a discussion of reservoir and host rocks of economic commodities. Last but not least even a link to archaeology is presented followed by an enormous list of references that is even expanded upon in the accompanying CD. Quite a good book - I just wish I had the time to actually read it for real!


Cover of the last edition (2004) of Microfacies of Carbonate Rocks

29 April, 2009

Karst Webpages

To re-start blogging after my unwanted hiatus I would like to share a few informative sources on karst and karstification with you. As you may be aware karst is an often re-occuring problem in soluble rocks. Usually found in carbonates (esp. pure limestones) it can also be observed in sulfates or evaporites. Besides influencing limestone resource quality and playing a role the formation of Mississippi-Valley-type deposits (hence my interest) it also is a very important aspect in hydrology and groundwater flow and is recognised as a potential geohazard in the form of sinkholes. Last but not least it can influence petroleum reservoirs.

Karst and the USGS

Speleogenesis

Karst Information Portal

Karst Home Page

Karst - A potential Geohazard and Reservoir

Introduction to carbonates

19 April, 2009

Computer problems

UPDATE: The internet is working again at home but I am still missing my own computer. Should be here and working by thuesday. So I should be back to blogging sometime next week.

I wanted my readers to know, especially those of you who are commenting, that I am currently unable to make replies. My computer broke and I am completely cut-off. Thank God I made a complete back-up of my mapping data and everything just a day before the breakdown. No data is lost but I cannot work nor go online with it. So please be patient. I activated the comment moderation again so spam doesn't got out of control. The internet cafe here is quite expensive and I think it will be the only time that I will use it to post. So stay tuned for improvement sometime in the next week or two.

16 April, 2009

An online forum for Geology

An online forum for geology - does it exist? In the many years that I use the internet, email and discussion forums of various kinds I have failed to find any good and useful online discussion forum in english language on geology. That doesn't mean there aren't any but they are either of extremely low quality, specialised to a single expert topic, not used and half dead or share some or all of these negative points. There are a few good exception like the Geoversum which I frequent daily and find a great source of information - it is entirely German language. It's audience is limited to those capable of German; even though most people there also understand English. Nevertheless I love that place and met some, by now, real-life friends there. There is another forum specialised on carbonates in the form of the Carbonate Network which seems to be good on quality but is rather specialised and not very active.

Perhaps I missed the good one stop location in terms of geology forums, yet, I have I feeling I didn't. (If there is please point me to it)

There have been a couple of ideas going around in the geobloggosphere in the recent months. So perhaps it is time to add one more: To create a good quality and active online forum for geology. I could imagine such a place to be a great place for amateurs and those interested to ask question and find answer on geology, to meet like-minded people that don't want or don't have time to frequent the great variety of Geoblogs, also it might be a good place for us Earth Scientist (to also include geophysics, mineralogy, palaeontology, etc.) to talk and discuss ideas totally at ease or simply share anecdotes and information we don't feel like turning into a blog post.

There have been some ideas to expand on the Accretionary Wedge (sorry for not finding the appropiate links right now). Maybe it might be worth to include such a forum in there somehow?

I would be more than happy to share some thought with you on this issue. What are your opinions on this?

Geoblogs: Kreidefossilien and Nig-eosyncline

Today I discovered thanks to Lutz over at the Geoberg-Blog and to the latest version of Accretionary Wedge two Geoblogs or better said one geo-related site with a blog and one true Geoblog that are new to me.

One is a German site called kreidefossilien.de a website devoted to Cretaceous fossils and geology. It is very comprehensive and I found a new source of interesting and local geology information.

The other is Nig-eosyncline by Ikenna Okonkwo from Nigeria! I am very glad to have found especially the later one because Africa is so far a truly under-represented continent on the Geobloggosphere!

12 April, 2009

Happy Easter!

I would like to wish everyone a Happy Easter today and that you may pass a wonderful holiday!

11 April, 2009

Oncoids/Oncolites

After returning from fieldwork, partaking in a course on "Organic Petrology and Geochemistry of Petroleum Source Rocks" together with MapleLeaf and spending some days relaxing (finally!) I want to share with you a very nice example of some oncoids from the German Middle Jurassic that I found during my diploma mapping project in the Upper Rhine Graben. The image below is a neat cross-section through one of the many oncoids I found. It's not cut nor polished but simply splitt with a well aimed blow of the rock hammer.


Bored oncoid with shell nucleus

On top of the Middle Hauptrogenstein is a layer called Mumienbank (Mummy Bed) that consist almost entirely of oncoids of up to 6 cm in diameter. The first geologists to work on this coined the term because this layer is unusually rich in gastropod shells (Nerinea sp. most commonly) as nucleus of the oncoids. The below sample is a wonderful example of the nucleus forming gastropods picked from another location within my mapping area.


Oncoids with gastropod shells as nucleus

There is one really cool outcrop of the Mumienbank in the southern half of my mapping area that should get even the most reluctant to utter some equivalent of "cool" or "wow". It is even better when standing right in front of it of course. The lower layer is one of the usual Oo-Pack-/Grainstones that are so abundant in my mapping area. In the middle is a layer of smaller oncoids of up to 2 cm diameter. In the upper layer oncoids are 2 to 5 cm in diameter.


Outcrop of the Mumienbank with upward increasing oncoid size

So what's an oncoid? How do we recognise one in the field and why does it matter?

An oncoid is in the most basic sense nothing but nodular coated grain. A nucleus that can be of diverse origin is encursted by microbes, algae or other encrusting organisms, i.e. foraminifera. They are unattached, rounded and up to several cm in size. There are both calcerous and non-calcerous nodules of more or less concentric nature and with partially overlapping laminae around a bio- or lithoclast as nucleus. In America the term pisoid is also still in use for oncoid. They are most common in limestones and marls. Best way to recognise them is size and the irregular, concentric and partially overlapping laminae around a nucleus.

So why does it matter? It matters because they are in contrast to most other carbonate grains very good indicators of palaeoenvironment, sea-level changes and depositional settings. They appear from tropical to arctic environments, depending on the encrusting organisms. Even though they can be found even in basinal deposits most fossil oncoids appear in shallow environments and peritidal carbonates. Beware - they are not exclusively marine and can be found in freshwater and saline waters in lacustrine and fluvial environments from the Precambrian until today.

So why does that matter to me when I map potential lime resources? Two reasons: First, they are very easy to recognise in the field without any special equipment. The oncolite horizons form excellent stratigraphic orientation marks in the field, indicating the very top of a several 10s of meters thick and very pure limestone succession. Second, while mapping I noticed marly clay inbetween the oncoids at least in some areas. That's undesirable considering your resource requirements and has to be considered.

There exist a wide range of oncoids that I don't have the time to detailledly explain here. I recommend taking a look into Carbonate Sedimentology by Maurice E. Tucker and V. Paul Wright (take a look at my post about Wright's Revised Classification of Limestones) or Microfacies of Carbonate Rocks by Erik Flügel. If you are more a fan of the internet take a look into the USC Sequence Stratigraphy Web.

02 April, 2009

(Almost) Done!

The last few days were pretty intense. I was in the last steps of completing my self-set mapping programm and drafting the new geological map of the region. Quite amazing that I managed to map 16 square kilometers in 6 weeks. Especially considering the partially awful weather and unfavourable terrain. Yesterday's field tour with my supervisor and the good results in my supervisor's opinion were (and are) a great relief. Today I quickly mapped two minor areas that deserved another look. So now I am done with fieldwork - and ready for some vacations actually. Before I return homewards there will be another short visit to the office in Freiburg to return some of the equipment I had borrowed. Then, on saturday, it's finally time to go home! I will take a short rest there before I start to compile the actual map that I will be delivered to the geological survey. Also I need to write my diploma mapping report for university. So I will have plenty to do for the next two months! But before that I will be attending an - I hope interesting - short course (6th to 9th of April) on Coal Geology and Organic Geochemistry of Petroleum Deposits held at my local university by Professor Kalkreuth who is an expert working at the Federal University of Rio Grande do Sul in Porto Alegre, Brazil.

01 April, 2009

1200 degrees Celsius

Today was an important day. Field tour with my diploma mapping supervisor and the future geologist respondsible for compiling the mineral resource map of the region. The supervisor was very satisfied with the map and me very relieved about that. In the 2nd half of the day we drove north to visit a limestone quarry. A cool visit - especially the view into the fires of hell of the oven in which the limestone is burnt. 1200 degrees Celsius viewed with the bare eye after the seal and window was opened for us. A cool view - and very warm!


1200 degrees Celsius!

23 March, 2009

A geologist fully equipped for fieldwork

Work is ok. Still a bit stressed but now putting data points on the maps. Once that is done I'll return outside in 3 or 4 days to document in more details some good outcrops.

The foto is me fully equipped for work outside when there is good weather. Sorry for erasing my face. I'm not that extroverted, yet. How do you look like fully equipped?


Me ready to go to work

19 March, 2009

Flowers of spring

The weather this week has been very nice. The first signs of spring have definitly arrived. Here are some fotos I shot in the last two days of some nice flowers.


Yellow


Pink


White

P.S. I don't know much about botany, I don't know their names nor what exactly they are. Any ideas?

15 March, 2009

A day off

Sunday. No work. Basicly I should be outside using the good weather to map but I've been walking on my last leg in the recent days. So not to get totally exhausted I'm going to make sunday a free day today. Maybe just do some small things for the map working on the desk. Like adding more points and compiling a content for the report or visit the local town museum that has a small but nice exhibition on the local geology. On the side of the good news is that I received an confirmation email that I am now an official Student Member of the Society of Economic Geologists! Yay! That makes me the only one at my entire university - I think.

12 March, 2009

Blogging hiatus

Fieldwork is currently keeping me pretty stressed with a lot of work. A lot of good days are lost due to bad weather which totally ruins my workplan. I do not expect to be posting much in the next seven days either. There is a lot of ground left to be covered. Please accepts my excuses. Here is a wonderful image to make-up a little.


06 March, 2009

Did I mention I hate snow?

Did I? I think so. It has been raining and snowing since yesterday but I was still able to do some mapping. Tonight the snowline dropped far below 400 m combined with continued rain and snow since yesterday. Great! Forecasts predicted up to 46 liters of precipitation in the form of rain and snow within 24 hours. I hate snow! Maybe saturday will be better but imagine how everything will have turned into mud by then. My work trousers already changed their color from green to mud brown, the car is also speckled with mud from the forest tracks.


Today's view from my room.

03 March, 2009

Work conditions and a goat

Work conditions are not always so perfect here. The outcrops are usually of decent quality but moving only 5 to 10 m away quickly changes the situation. Rare float is the best one gets but not even that is easy to find. Apart of that all I map is dirt; brown clay. Very ugly stuff especially when wet after a rain shower. The limestone here has, at least close to the quarries, about 0.5 to 1 m of dirt on top of it. A meter is usually enough to not find any float anymore. Well, my brain is pretty drained after today's tour. Some fotos of the work conditions...


The woods

The upper part of the topsoil. Not a single rock to be found. The pebble you see is from the road cover.


Upper soil profile

A curious goat kept me company for some minutes. Very curious about my work and kind enough to let me take a foto for memory.


A goat

02 March, 2009

A View East

While mapping I also take a lot of unrelated fotos as I am advancing. Saturday when having reached the southern most point of that day's route the below view unfolded for me. The little town is nestled in a valley of the foothills of the Rhine Valley. The mountains of the Black Forrest can be seen as beautiful scenery in the background.



Sunday I took a day off to relax and visit a castle and town close-by. I had a great view into the French Vosges mountains arising behind the Rhine river on the horizon. So far I mapped a bit more than 3 km2 on Friday and Saturday. Today was rather rainy and after documenting a previously missed-out quarry I quickly headed back into my flat again - the weather was just too awful.

On a side note my motivation still needs treatment on the intensive care station but doctors believe it is going to live on though recovering may take a few more weeks or month. Maybe I will apply for doing a thesis with a company. It's a bit tricky as I don't like to buy the pig in the poke but someone recommended applying with Knauf Gips (a large producer of limestone and gypsum for construction purposes) and other companies of the branch. We will see...