Monday, December 22, 2008

Looking back to 2008 and Merry Christmas!

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Last night I returned home from my mapping project for Christmas and New Year vacations. So finally I have a chance to reflect on what happened in the last year in the last post for 2008. Take a look at the posts that I find myself most rewarding, fun or informative.

January

On January 7th, 2008 I made my first post on this blog.
Minerals from Berlin - searching for heavy minerals in a close-by lake.
Not very informative but my eye-opener that I am not alone.
My first time participating at Where on (Google) Earth.

February saw little activity...

March

I visited the Rhinefalls at Schaffhausen.
Geotripper's geologists facing death lead me to write about "..facing the tides".
The post about the Hohentwiel volcanoe I liked a lot.
Then I wrote about my seminar paper on microfossils within phyllitic rocks.
Also I discovered my interest in Nonsulfide Zn-Pb deposits.

April

It was time to create a feed on German Geo-blogs...
...and I wrote about a Peruvian VMS deposit.
Free and open access geo-journals followed.

May

First I jumped on the tag cloud band waggon.
Second I began thinking and deciding about going to XIV Congreso Peruano de Geologia.
Followed by worrying about gastropods for several times.
The Accretionary Wedge allowed me to write about that Everything is inter-connected.
Last but not least I was musing a little on Nonsulfide Zn-Pb deposits again.

June

Geology in Art was the theme of the 10th Accretionary Wedge.

July

A little roadside geology from Romania of the Pestera Ursilor karst cave...
...and some ancient and modern beaches at Costinesti.
I really decided to go to Lima.

August
I was playing with OneGeology...
...and geological maps in Google Earth.

September

I became a Painting Geologist.
The Rhumequelle, a karst spring, fascinated me.
The 86th Annual Meeting of the German Mineralogical Society was my first congress participation.
The geology of the Lima coast also got my fascinated.

October

I had a wonderful time in Lima and met some great Geobloggers!
A follow-up on geology at Lima with Travertines along the Lima coast.
Field work preparations began.

November

Sharing my long list of Geology bookmarks 1, 2, 3, 4 and 5.
Writing about the Hauptrogenstein-Formation.
Starting my series on Sequence Stratigraphy and Industrial Mineral exploration (I promise part 3 will come in January).
And first field impressions.

December

I was searching my quarries.
Writing about carbonate sedimentology.
In the end snow won.

This is the end for 2008! I hope you will be following and commenting (I always like comments) just as actively in the new year. Last but not least let me wish you all a...

---

Merry Christmas
and a
Happy New Year!

---


Wednesday, December 17, 2008

Snow wins

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Originally I had planed to take measurements of joints and faults in a number of quarries in the southern part of my mapping area. However, the weather god is against me. It started snowing heavily this morning and half-way to the first quarry I decided to turn around and go back. Road conditions are bad, snow and ice covering the access roads and some quarries are completely inaccessible by now. Great! If you ever plan to be mapping in Germany in winter - don't! Unfortunately I didn't have a choice.



Above you can see the view I currently have from my room. It is still snowing big flakes. I really should move to the Caribbean. Stupid winter snow!

A carbonate tempestite?

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UPDATE: I managed to make a polished section of this specimen and in order to avoid confusing my visitors I would like to point out that this is not a tempestite, as previously thought, but most likely nothing more than a coarse sheet of unconsolidated and resedimented lime sand.

Today while measuring joints in a quarry I also took a few samples. One of the samples I took includes a wonderful shell horizon with upward decreasing grain size and an erosive base that I interprete as a storm deposit/tempestite. To let you form your own opinion I included both the edited and unedited image.


without comment


image including description

You will notice the sharp base contact and the concentration of shells and larger grains towards the lower contact and a decrease in grain size towards the top. While the lower part is a relatively finer-grained oolite (average 0.5mm) with only few bioclasts the storm deposit is composed of larger grains (2mm and more), mainly shell fragments, oncoids and larger ooids, few aggregate grains and few crinoid columnals among other, unidentifyable bioclastic debris. At the base I believe to recognise a clast of the underlying finer-grained oolite. Unfortunately I was unable to also extract the uppermost centimeter of this. The varied composition of the coarser grained layer leads me to assume that most particles were transported into the site of deposition from other parts of the carbonate platform.

Tempestites form when up-stirred sediments is deposited from storm aggitated water when the storm subsides or the suspension reaches water below the storm-wave base. That's very generalised of course and you may find more information also on how to distinguish tempestites from turbidites here.

Monday, December 15, 2008

Geologist's 100-things meme

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A geology styled meme started by Geotripper. What have I done or seen?

1. See an erupting volcano

2. See a glacier

3. See an active geyser such as those in Yellowstone, New Zealand or Iceland

4. Visit the Cretaceous/Tertiary (KT) Boundary. Possible locations include Gubbio, Italy, Stevns Klint, Denmark, the Red Deer River Valley near Drumheller, Alberta.

5. Observe (from a safe distance) a river whose discharge is above bankful stage

6. Explore a limestone cave. Try Carlsbad Caverns in New Mexico, Lehman Caves in Great Basin National Park, or the caves of Kentucky, Tennessee, Alabama, and Georgia.(Pestera Ursilor in the Apuseni mountains, Romania, and others in Germany that I do not recall the name)

7. Tour an open pit mine, such as those in Butte, Montana, Bingham Canyon, Utah, Summitville, Colorado, Globe or Morenci, Arizona, or Chuquicamata, Chile. (Worked in the lignite mine of Garzweiler, west of Cologne)

8. Explore a subsurface mine. (several. Historical mines in the hercynian mountains like Rammelsberg and B├╝cherberg, the active Salt mine in Berchtesgaden, etc.)

9. See an ophiolite, such as the ophiolite complex in Oman or the Troodos complex on the Island Cyprus.

10. An anorthosite complex, such as those in Labrador, the Adirondacks, and Niger.

11. A slot canyon. Many of these amazing canyons are less than 3 feet wide and over 100 feet deep. They reside on the Colorado Plateau.

12. Varves, whether you see the type section in Sweden or examples elsewhere

13. An exfoliation dome

14. A layered igneous intrusion, such as the Stillwater complex in Montana or the Skaergaard Complex in Eastern Greenland.

15. Coastlines along the leading and trailing edge of a tectonic plate.

16. A gingko tree, which is the lone survivor of an ancient group of softwoods that covered much of the Northern Hemisphere in the Mesozoic. (In the botanical garden)

17. Living and fossilized stromatolites.

18. A field of glacial erratics. (Northern Germany)

19. A caldera (Laacher See and Tharandter Wald, Germany).

20. A sand dune more than 200 feet high. (Southern Peru close to the ocean)

21. A fjord.

22. A recently formed fault scarp.

23. A megabreccia.

24. An actively accreting river delta.

25. A natural bridge.

26. A large sinkhole. (In the Apuseni Mountains, Romania)

27. A glacial outwash plain. (Sander in Northern germany)

28. A sea stack.

29. A house-sized glacial erratic.

30. An underground lake or river. (artificial ones in the Berchtesgaden Salt Mine)

31. The continental divide. (The Alpes)

32. Fluorescent and phosphorescent minerals.

33. Petrified trees (not whole trees, just pieces)

34. Lava tubes

35. The Grand Canyon. All the way down. And back.

36. Meteor Crater, Arizona, also known as the Barringer Crater, to see an impact crater on a scale that is comprehensible.

37. The Great Barrier Reef, northeastern Australia, to see the largest coral reef in the world.

38. The Bay of Fundy, New Brunswick and Nova Scotia, Canada, to see the highest tides in the world (up to 16m)

39. The Waterpocket Fold, Utah, to see well exposed folds on a massive scale.

40. The Banded Iron Formation, Michigan, to better appreciate the air you breathe.

41. The Snows of Kilimanjaro, Tanzania

42. Lake Baikal, Siberia, to see the deepest lake in the world (1,620 m) with 20 percent of the Earth’s fresh water.

43. Ayers Rock (known now by the Aboriginal name of Uluru), Australia. This inselberg of nearly vertical Precambrian strata is about 2.5 kilometers long and more than 350 meters high

44. Devil’s Tower, northeastern Wyoming, to see a classic example of columnar jointing

45. The Alps. (Germany, Austria, Switzerland)

46. Telescope Peak, in Death Valley National Park. From this spectacular summit you can look down onto the floor of Death Valley - 11,330 feet below.

47. The Li River, China, to see the fantastic tower karst that appears in much Chinese art

48. The Dalmation Coast of Croatia, to see the original Karst.

49. The Gorge of Bhagirathi, one of the sacred headwaters of the Ganges, in the Indian Himalayas, where the river flows from an ice tunnel beneath the Gangatori Glacier into a deep gorge.
50. The Goosenecks of the San Juan River, Utah, an impressive series of entrenched meanders.

51. Shiprock, New Mexico, to see a large volcanic neck

52. Land’s End, Cornwall, Great Britain, for fractured granites that have feldspar crystals bigger than your fist.

53. Tierra del Fuego, Chile and Argentina, to see the Straights of Magellan and the southernmost tip of South America.

54. Mount St. Helens, Washington, to see the results of recent explosive volcanism.

55. The Giant’s Causeway and the Antrim Plateau, Northern Ireland, to see polygonally fractured basaltic flows.

56. The Great Rift Valley in Africa.

57. The Matterhorn, along the Swiss/Italian border, to see the classic “horn”.

58. The Carolina Bays, along the Carolinian and Georgian coastal plain

59. The Mima Mounds near Olympia, Washington

60. Siccar Point, Berwickshire, Scotland, where James Hutton (the “father” of modern geology) observed the classic unconformity.

61. The moving rocks of Racetrack Playa in Death Valley

62. Yosemite Valley

63. Landscape Arch (or Delicate Arch) in Utah

64. The Burgess Shale in British Columbia

65. The Channeled Scablands of central Washington

66. Bryce Canyon

67. Grand Prismatic Spring at Yellowstone

68. Monument Valley

69. The San Andreas fault

70. The dinosaur footprints in La Rioja, Spain

71. The volcanic landscapes of the Canary Islands (Lanzarote).

72. The Pyrennees Mountains

73. The Lime Caves at Karamea on the West Coast of New Zealand

74. Denali (an orogeny in progress)

75. A catastrophic mass wasting event

76. The giant crossbeds visible at Zion National Park

77. The black sand beaches in Hawaii.

78. Barton Springs in Texas

79. Hells Canyon in Idaho

80. The Black Canyon of the Gunnison in Colorado

81. The Tunguska Impact site in Siberia

82. Feel an earthquake with a magnitude greater than 5.0.

83. Find dinosaur footprints in situ.

84. Find a trilobite (or a dinosaur bone or any other fossil). (Trilobite head from the Eifel region, ammonites from Holzmaden)

85. Find gold, however small the flake (unfortunately not myself)

86. Find a meteorite fragment

87. Experience a volcanic ashfall

88. Experience a sandstorm

89. See a tsunami

90. Witness a total solar eclipse (not a total one at least)

91. Witness a tornado firsthand.

92. Witness a meteor storm, a term used to describe a particularly intense (1000+ per minute) meteor shower

93. View Saturn and its moons through a respectable telescope.

94. See the Aurora borealis, otherwise known as the northern lights.

95. View a great naked-eye comet, an opportunity which occurs only a few times per century. (I saw several but I forgot their names)

96. See a lunar eclipse

97. View a distant galaxy through a large telescope (Andomeda galaxay)

98. Experience a hurricane

99. See noctilucent clouds

100. See the green flash

Friday, December 12, 2008

Ooids in Oolites

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Another nice example from carbonate sedimentology, specifically carbonate grains. In this example, that I have from one of the quarries that I am documenting, the ooids are almost white even in a fresh exposure surface (the image may not show it that well though). I put a few comments into the image. A few ooids can be seen very well rounded, some others are broken and the core nucleus can be seen. The diameter of the ooids is 0.5 to 1.0 mm. The shell fragments are part of the frequent shell layers that occur within the Hauptrogenstein-Formation. I am unable to decide without a thin section what kind of ooids these are - meaning if tangential or radial, one or multiple laminae or if micritised or not.


Ooids with shell fragments

Marine ooids occur in intertidal and subtidal marine environments like shoals, tidal bars or tidal deltas. They usually form in wave-agitated water or in areas of strong currents in generally warm temperatures. Other controlling factors are the presence of nuclei (i.e. small siliciclastic input), sufficient agitation to move grains (waves or current), supersaturated water and a process of water renewal - among others of course. Very important is the long underestimated influence of organic matter and the activity of microbes.

I would call it an oolitic packstone with shell fragments. BTW, the image approximately resembles a bedding plane surface - more or less. Otherwise you could see that the shells are in a distinct layer.

For more information take a look at the excellent USC Sequence Stratigraphy Web.

Wednesday, December 10, 2008

Good morning snow!

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I just took this foto a few minutes ago. It is the view from my door across the street.

Hmm....great...



Now if the roads are covered with ice...

...and it is still snowing.

Tuesday, December 9, 2008

Where's my quarry?!

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Not too many words. A few impression from today trying to find a quarry. BTW, I parked my car less than 100m away from it - it still took half an hour to find it.


In the jungle...


...feeling a bit of lost here...


...hmm...a first directional clue...


...finally! Found it!

Naturally the GPS was totally uselsss in the woods and the map was just as useless, as well. Sigh.