Blue Clay Links:

"In 1849 while constructing the first railroad between Rutland and Burlington, Vermont, workers unearthed the bones of a mysterious animal near Charlotte. Buried nearly 10 feet below the surface in a thick blue clay, these bones were unlike those of any animal previously discovered in Vermont. After consulting with experts, the bones were identified as those of a "beluga" or "white" whale, an animal that inhabits arctic and subarctic marine waters in the northern hemisphere."

They soon found the tusk and several bones including the vertebra bearing the apparent cut marks. In late September, Broster and Breitburg returned to the site and made an additional discovery: "Sticking out of the bank in the same matrix that the mastodon was in, there was a core scraper and a large flake." Broster scheduled a full-scale excavation for October and as the bones were uncovered Breitburg was able to examine them and determine the age and sex of the animal. Because the epiphyses, or end caps, of the long bones and thoracic vertebrae had not fused with the main sections of the bones, he was able to determine that the animal, though large in size, was likely between the ages of 18 and 23 when it died.

Although a small amount of the skeleton apparently was eroded away from the side of the ravine Broster believes the site contains a near-complete mastodon skeleton that lay in blue clay. Analysis of the location of individual bones suggests they have been moved short distances. "It could be from the process of butchering," Broster speculated. "That is certainly possible given the amount of lithic material we found."

Broster said the skeleton was relatively concentrated and in some anatomical order. "It's not like a washed deposit--a random scatter of bones. There's been some movement of the bones within a very restricted area." Geologists involved in the investigation, Richard Stearns and Art Reesman of Vanderbuilt University's Department of Geology, suggest that the site was a shallow pond in Pleistocene time. Discovery of the remains of a painted turtle there confirmed the likelihood of shallow, slow- moving water. Trenches the team excavated to analyze the stratigraphy indicate the a fairly extensive blue clay deposit, and that leads Broster to consider the possibility that other skeletons of Pleistocene fauna--and possibly more signs of Pleistocene humans--might be buried in the same general area.

The only excavations into this mound were conducted by Moorehead in the early 1920s. His reports do not include any maps of those excavations because material was too irregularly distributed in the mound, he said, to make a map worthwhile. His reports did include the following (Moorehead 1929:38-40): 1. Eight burials accompanied by some grave goods were located along the southern slope of the mound. 2. No burials were found in a 35-foot-long (10.7 meters), 5-foot-deep (1.5 meters) trench dug along the east side. 3. A center pit 14 by 15 feet (4.3 by 4.6 meters) wide and 16 feet (4.9 meters) deep was dug into the mound.

An auger was used to probe an additional 3.5 to 4 feet (1.1 to 1.2 meters) to a base of heavy, wet clay. That probing revealed that:

1. The mound was stratified, with strongly marked series of alternating bands of dark earth and yellow earth. The dark bands were 3 to 10 inches (7.6 to 25.4 centimeters) wide and the yellow bands were 12 to 24 inches (30.5 to 61 centimeters) wide.

2. The layers were not even. A conically formed deposit in the northwest corner dipped from the east to the southeast, whereas, according to Moorehead, 10 feet (3.05 meters) down the layers appeared to be more horizontal. It is possible that this formation represented a slope of an earlier construction stage.

3. A heavy black layer was found on the south side of the trench and auger borings on the south side of the pit showed a heavy blue clay mixed with a grayish clay. A heavy blue clay, the natural deposit just below the soil development horizon, has been found by more recent excavators throughout much of the site area. This may just be another indication that heavy blue clay is universal throughout the Cahokia site area.

4. Scattered throughout the mound were bits of pottery fragments, chips, spawls, a ceramic mammal-head effigy, an awl from a deer jaw, and a human head effigy cut from a freshwater mussel shell.

5. Moorehead's workmen found a number of disturbed burials, but no indication is given of their location. These were apparently scattered throughout the area. Since the soil was soft and disturbed, Moorehead assumed the burials were in an area where either Patrick or McAdams had dug. 6. Moorehead thought that extensive habitation areas once surrounded this mound. Black pottery

The weir became visible once again during excavation for the New England Mutual Life Insurance Company. It was during this time that further observations of the weir were made by Johnson (1942). This excavation revealed six walls formed by the wooden stakes as well as six other areas with less defined concentrations of stakes. The stakes, which were from four to seven feet (1.2-2.1 M) in length, were sharpened at the bottom and ranged from one to four inches (2.5-10 cm.) in diameter. There were groups of four to eight stakes within a square foot area as well as individual stakes. In some places, the stakes were driven into the blue clay that formed the lowest level. Some of the stakes were driven into a thin layer of peat above the clay, and other stakes were driven into the silt that had built up above the peat. The stakes had been driven about eighteen inches (46 cm.) deep. The variation in the length of the stakes may be an indication of work being done on the weir at different times. It also indicates that the area had already begun filling in with silt at the time of the weir's construction. Some of these stakes are shown in Figure 5.



AUTHOR(s): Rosen P S ; Brennikmeyer B M; Maybury L M;

PUBLICATION: Journal Of Coastal Research SPR 1993, V9, N2 Pages: 363-377

NOTES: Number of References: 38

ABSTRACT: Recent building excavations in the previously landfilled Back Bay section of Boston, Massachusetts, permitted direct observation of the Holocene estuarine stratigraphic sequence. The environmental changes that occurred during this period were a concomitant decreasing submergence rate and an increasing energy level. While the diminishing submergence rate is well-documented in the regional stratigraphy, it is believed that this sequence reflects the growth of tidal resonance in the Gulf of Maine system, resulting in a change from microtidal to mesotidal conditions.

Three major estuarine depositional units define the changing conditions at this site. The Lower Unit reflects rapid deepening and low energy depositional conditions; the Middle Unit marks sufficient tidal prism to lead to the formation of tidal channels; while the Upper Unit, with coarser material and tidalities, reflects higher energy during deposition. The 5 m thick estuarine sequence unconformably overlies a weathered surface of the Boston Blue Clay, a glacio-marine meltwater deposit (approximately 14,000 yr BP). The Lower Unit (5,630 to 3,570 yr BP) defines the beginning of the Holocene submergence of Boston Inner Harbor with a sequence grading from intertidal saltmarsh to subtidal laminated muds.

Average accumulation rates of 1 mm/yr roughly correspond to the thickness of laminations, suggesting an undisturbed annual deposit. The Middle Unit (3,570 to 3,090 yr BP) is interpreted as channel deposits based on numerous channel-bottom shell-lag layers. Initial average accumulation rates of 11.7 mm/yr diminish to 1.3 mm/yr at the top of the unit. The Upper Unit is a well-mixed sandy silt with occasional interfingered tidalities. Initial accumulation was 3 mm/yr, and diminished to 0.5 mm/yr at the top of the sequence. This is interpreted as a tidal flat environment, corresponding to historical records showing tidal flats and salt marsh in the area.

The stratigraphy concurs with archaeological observations at the Boylston Street Fishweir, a 4,400 yr old series of structures built and used over a several-hundred year period. The exposure of the weir is located in the Lower Unit of this sequence. Despite the collection of over 65,000 wooden stakes (parts of the weir) since it was discovered in 1913, no other artifacts have been found associated with it. Since modern fishweirs in New England, which have similar construction, are maintained by foot at low tide, this appeared inconsistent. However, as this was a microtidal setting at that time, the fishweir was probably a subtidal device maintained by canoe rather than on foot, as in the Chesapeake Bay during historic times.

SUBJECTS: Environmental Sciences Marine & Freshwater Biology Geosciences Estuarine Sedimentation

SUBJECTS: Boylston Street Fishweir Laminated Muds Stratigraphy Stratigraphy System Fundy


DATE ADDED: 05/07/94 TITLE: Journal of coastal research : JCR / CERF.

PUBLISHED: Fort Lauderdale, FL : Coastal Education and Re // c1985- DESCRIPTION: v. : ill. ; 26 cm.

SUBJECTS: Coasts--Periodicals. Seashore--Periodicals. Shore protection--Periodicals.

1. LOCATION: Science (3rd) CALL#: GB450.J68

Proj # 1.16.059

Dirctr Ladd, C.C.

Title Geotechnical Testing for Central Artery/Tunnel Project

Abstract: Due to the scope and unique features of underground construction in thick deposits of Boston Blue Clay for the CA/T Project, a special test program is being conducted on the deposit to better characterize its engineering properties. This includes a combination of different [cf4]in situ[cf3] and laboratory testing techniques. M.I.T. is using new automated stress path triaxial cells to assess stress history and the effects of disturbance, anisotropy and drainage conditions of strength-deformation behavior. Keywds Geotechnical Engineering Keywds Stress; Strain-Strength of Cohesive Sorts Keywds Anisotropic; Anisotropy Keywds Boston; Central Artery Tunnel Keywds Soil Properties; Boston Blue Clay ***********

Whittle, A.J., DeGroot, D.J., Ladd, C.C., and Seah, T.H. (1994). "Model Prediction ofthe Anisotropic Behavior of Boston Blue Clay." Journal of Geotechnical Engineering, American Society of Civil Engineers, Vol. 120, No. 1, pp. 199-224.

24th August 1804

Rained last night and this morning. Set out at the usual time and proceeded on the course of last night to the Commencement of a blue Clay Bluff. Those Bluffs appear to have been on fire and it is too hot for any man to bear his hand into the ground. Much coal has been seen.

Pyrites alum: Thomas Jefferson gave Meriwether Lewis instructions pertaining to the journey. He specifically asked that Lewis and Clark notice the soil and face of the country and mineral production of all kinds. Lewis and Clark did as they were instructed and listings of minerals appear throughout their journals.

fire: As late as 1877, some scientists believed that the bluff was a true volcano caused to erupt when the flooding Missouri River poured water onto the molten rock in subterranean caverns. By 1900, investigations proved that the eruptions were due to the heat of oxidation of damp pyritiferous and carbonaceous Carlile shale on fresh exposures provided by the rapid erosion of the river bluffs. This bluff was later called the "Ionia volcano" (Moulton 506).


The men of the Lewis and Clark Expedition saw many natural curiosities during their trek to the Pacific Ocean. On August 24 Captain Clark described "a blue Clay Bluff of 180 or 190 feet high. . . . Those Bluffs appear to have been laterly on fire, and at this time is too hot for a man to bear his hand in the earth at any debth." The bluff came to be known as the Ionia Volcano. Not until about 1900 did scientists learn that the heat was generated by the oxidation of shale. The bluff has since eroded into the Missouri River.

An indication of the violent nature of society is the fact that nearly all the graves of males include weapons. A well-equipped warrior had to have a sword, a wooden shield with an iron boss at its center to protect the hand, a spear, an ax, and a bow with up to 24 arrows. The helmets and coats of mail with which most Vikings are commonly portrayed in modern pictures, are extremely rare in archaeological material. Helmets with horns, ubiquitous in present-day depictions, have never been found amongst relics from the Viking period. Even in the graves with the most impressive array of weapons, we find signs of more peaceful activities: sickles, scythes, and hoes lie along side of weapons. The blacksmith was buried with his hammer, anvil, tongs, and file. The coastal farmer has kept his fishing equipment and is often buried in a boat. In women's graves we often find personal jewelry, kitchen articles and artifacts used in textile production. Women too, are often buried in boats. Wooden articles, leather goods, and textiles generally do not survive the soil, so there are many gaps in our knowledge.

In a smattering of graves, the soil-type has been more conducive to preservation. In many areas along the Oslofjord, we find blue clay directly underneath the turf, dense and nearly impermeable by water and air. A few graves are well preserved after a thousand years, and we have retained a whole spectrum of articles placed in the pit. The treasures from the enormous Viking ship graves from Oseberg, Tune, and Gokstad - which can be seen at the Viking Ship Museum at Bygdoy in Oslo - are prime examples of what gifts can be preserved for future generations, given the right soil conditions. We do not know who the dead were, but they obviously belonged to the upper echelon of their society. Perhaps they belonged to a royal family which, a few generations later, unified Norway as one nation.

The Civil Engineering department at Swansea enjoys or resource which must be shared by very few other universities, namely a beach within five minutes walk of the Engineering building. A dominant exposure on this beach is - surprise, surprise - sand! There are also exposures of Swansea blue clay and of a stiff peat which derives from the ancient forests which once covered the area. Such a resource just had to be utilised for the teaching of soil mechanics.

Inspiration which lead to greater use of the beach in practical classes given as part of an introductory soil mechanics course for second year Civil Engineers came from the national meeting of teachers of geotechnical subjects (MIGS) held in Edinburgh in the summer of 1990. At this meeting the value of experiments which allowed the students to actually see what was happening to the soil was highlighted.

To this end the oedometer and shear box tests were dropped from the laboratory test program while the 'more visible' measurement of Atterberg limits (of Swansea blue clay of course) and the triaxial test were retained. Some new experiments to be done on the beach were added. One of these, the 'sand sled' test was carried out partly in the lab. and partly on the beach. Other tests done entirely on the beach comprise the 'sand castle', 'spade', and 'hole to Australia' tests. These will now be described.

"I worked hard on my uncle's firm when I wuz a kid. Two thengs I remember often an' that wuz the cuttin' a the turf, an' aworkin' in flax tame.

"Turf, ya see, is that most people birnt (burnt) in Ireland, 'stead a wood or coal. In the sprang tame the hull family 'ould start diggin' fir it.

"Sometames underneath the ground we'd see parta what had bin an oak tree. An' down eight er ten feet where the blue clay wuz, we'd get the good stuff. It wuz soft an' slippery laike soap with oil on it and ya could cut it out like a brick. Ah! but the blue clay wuz good ta see.

"After it wuz dug we would lay it out in rows ta dry. If ' twas a rainy sason, (season), it sure would be bad luck 'cause thin it wun't dry. Bad day fir the folks in Ireland in a rainy spell when ya could not dry the turf.

"The sun would shrink it up some, and then ya would heap it up some in little chunks. Then whin it wuz rale (real) dry, it would be heaped up near the house, sometames as big as a small house itself. We'd put straw over that sa it 'ould not get wet.

"It 'ould be stacked so it 'ould come up ta a point on the top. When we started ta birn it, we'd take it from the bottom, an' every tame ya' take a piece out, another 'ould roll down.

"Sometames too, paople 'ould make turf outa bog mud. Wuzn't as good as that got near the blue clay but it burned good jest the same.

"Turf kept the houses warm an' it wuz used fir cookin' too, on the hirth (hearth). There'd be a big crane across the top a the hirth ta hang the pots on, an' in the bottom my mother'd put her bake oven. Din't she bake the good cakes an' bread in that? I remimber how good they usta taist at Christmas. An' I kin see her as she usta pile the turf aroun' the oven. Ah! that turf that wuz dug from the blue clay bed! It 'ould birn (burn) like the dickens.

Blue Clay.

This deposit lies between the overlying Greensand and the underlying Globigerina. It is the most fertile sediment on the islands and is essential to the agricultural well-being of the island. It also act as an aquifer, many of the springs on the island rise up between the Upper Coralline limestone and the Blue clay. Such locations have often attracted settlement and are very fertile and productive.

Blue Clay erodes easily when wet and mantles the underlying hillslopes, making farming possible where the gradient is not too steep. The depositional environment indicated by this sediment is open muddy water between 150 and 100 metres deep. However this erosion can be extreme and result in undercutting and cliff collapse

This is the view from the citadel on Gozo. In many parts of Gozo the Upper Coralline limestone has been almost completely denuded exposing the Blue clay which erodes very easily. Here you can see that the blue clay has mantled the hillsides in view covering the underlying Globigerina and Lower Coralline limestone. Note the terracing.

Points to consider:

How widespread is the blue clay formation on Malta/Gozo? Is this resource adequate or under threat? What steps are being taken to preserve this resource? Do buildings erected on this sediment take adequate account of the sediments properties? What is the relationship between the blue clay, the spring line and agricultural sediment? How can this sediment be stabilised to prevent or slow down cliff collapse?

The Older Glaciation on the Uplands

Thickness of the Till.-The deposit of till on the uplands varies from almost nothing to a thickness of ten or fifteen feet. Thicker deposits are generally confined to valleys and ravines. The average thickness, aside from the broad valleys, may be from one to five feet near the Ohio, and from eight to twelve feet near the Hamilton-Butler County line. This applies to the area not covered by the later drift sheet. Farther north where it is overlain by the younger till sheet, its thickness is hard to estimate because of the difficulty in distinguishing the two formations. In the more hilly sections bordering the Miami Valley from Venice to Lawrenceburg, this drift is almost as thin as on the bluffs of the Ohio.

Character of the Till.-The Illinoian till is generally a hard blue clay (yellow near the surface), containing many fragments of limestone. These fragments are generally small, many good exposures showing no fragments larger than one or two inches. However, fragments the size of a hand are common, and the dimensions may reach a foot or more. The majority of these fragments are of blue limestone, being from the same formations as those which underlie the area. Many others are of light-colored limestone, such as underlies western Ohio and eastern Indiana farther north. A very few, perhaps one or two per cent, are of igneous rocks, granite, basalt, etc., and metamorphic rocks, gneiss, quartzite, etc., derived from north of the Great Lakes. But although such stone are rare in the drift, the few large bowlders which are found on the surface are nearly all of this character.

This till or bowlder clay is generally very hard. It cannot be shoveled, even where free from large stones, and offers considerable resistance to a pick. It is generally very calcareous, effervescing freely with weak muriatic acid. In such tests, the limestones must of course be avoided. This calcareous quality is absent only within a foot or so of the surface, where the lime has been leached out in the process of weathering.

Another surface phenomenon in the till is a change of color from blue (generally very pronounced) to yellow. This is due to the complete oxidation of the iron as in case of our local limestones. This oxidation generally goes down from five to ten feet, and may go farther. The oxidized till retains its calcareous nature except very near the surface.

1964 Good Friday earthquake which devastates much of South Central Alaska doesn't cause the physical damage in Chugiak-Eagle River, where most houses are built on bedrock, that it did in areas of Anchorage underlaid with blue clay.

Horworth explained that the European eskers found across glaciated areas of Europe and Russia contained, in their uppermost layers, "stiff blue clay or...finely sifted and laminated brickearths containing, in places, [many] diatoms and marine shells, but never, so far as [he knew], freshwater debris or land mollusks." Henry H. Horworth (C), "The Asar or Osar of Scandinavia and Finland," Geological Magazine 35 (1898): 200.

"Corporate Boundaries. "Sec. 2.1. Town Boundaries. Until modified in accordance with law, the boundaries of the Town of Castle Hayne are as follows:

Lying and being in New Hanover County and beginning at the center of the Northeast Cape Fear River in the northeastern most point where Island Creek intersects the river and is the boundary of Pender County to the East, following said Island Creek southward under Holly Shelter Road, continuing South approximately 1 mile where Island Creek departs from the New Hanover/Pender line running West and South to where Island Creek meets Sidbury Road. From the South right away boundary of Sidbury Road and running at a West by West-South Westward direction along said Sidbury Road to where it intersects with Blue Clay Road, thence South by Southwest on Blue Clay Road South right-a-way to where Blue Clay Road intersects with Seaboard Railroad Track, from that point an abrupt change to a Northern direction along the East boundary of said Seaboard Coastline Railroad right-a-way to where it meets Hermitage Road, turning West along the South side of Hermitage Road to US 117 and State Road 133 turning South along Eastern side of said US 117 and State 133 to Contennial Drive at the General Electric Company South boundary, turning West and running along the South boundary of General Electric Company property to the N.E. Cape Fear River continuing North by Northwest to the Northwest point of New Hanover County and Brunswick County where they meet at center of N.E. Cape Fear Channel. Except for the change of relocating line to South boundary of General Electric property all of said boundaries are those relating to the Cape Fear 2 voting district and stated as such on the maps of New Hanover County.

Oak Island: Vital Statistics

[ Drilling Results || Artifacts Found ]

Here you'll find summaries of some of the vital information that is known about the Oak Island mystery. Hopefully this information will help you check your facts and theories.

Drilling Results

Below you'll find information about some of the major drillings that have occurred on the island.

Triton - 1967-1969 Determined that bedrock layer was at 162 +/- 10 feet Between 172 and 224 feet found china, oak buds, cement, wood, and metal Found tunnels that were cut through bedrock - under 40 feet of bedrock Found 40 feet rock, inches of wood, layer of blue clay, inches of wood and 6-7 foot void Carbon date of wood - 1575 +/- 80 years Depression from 172 to 222 feet (beneath Hadden shaft) - 30 foot in diameter filled with layers of blue clay with small stone spaced at 18 inches!!! 186 feet metal and brought up piece of brass (high impurities) 212 feet brick-like material found - it had been fired Cement found - worked by man 210 feet hard metal hit Borehole X-10 140 feet found a 4 foot cavity 160 feet found a 4 foot cavity Bedrock at 180 feet 210 feet hit a 2 foot cavity 230-237 feet a cavity Handfuls of metal found at 165 feet - low-carbon steel - prior to 1800 Spruce found at 155 feet 155 feet eight pieces of steel chain - Swedish steel made prior to 1790 Wood at 180 feet Metal in several places above and below bedrock 660 feet north-northeast of the Money Pit - 1973 - p220 110 feet a 2 inch piece of wire - dated to 1500s to 1800s A solid metal plate There are future plans to excavate

Artifacts Found

Below you'll find a listing of the artifacts found, or allegedly found, on the island. Many of the artifacts have been lost and are known only through writings left by early searchers or writers.

Copper coin, bosun's whistle, and iron ring bolt imbedded in a rock at Smith's Cover - 1795-1802 Inscribed stone Gold links - 1849 Remains of the old cofferdam Wood and end of a keg pulled out when the Pit collapsed Blue clay Parchment Anchor fluke of ancient design - 1931 - since disappeared Dump with thousands of broken pottery flasks Rock with "1704" inscribed on it. Nail, washer Scissors, heart stone Original cofferdam - logs 2 feet thick up to 65 feet long with Roman numerals marked on them. Nails and metal-straps Leather shoes 3 drilled rocks and ask piles analyzed to be burned bones!!!!!

Arsenic occurs in the rocks of the Verde Formation. Drill cuttings and outcrop samples from the Verde Formation (fig. 3) contained from 7 to 88 micrograms/gram of arsenic (table 5) and indicate that arsenic is disseminated throughout the formation rather than occurring in a particular bed of the formation. The amount of arsenic present in different beds does differ with location. A sample of the salt deposits from the Camp Verde Salt Mine contained the least amount of arsenic, 7 micrograms/gram. The white lime beds contained from 7 to 43 micrograms/gram of arsenic and averaged 19 micrograms/gram. The blue clay beds contained from 16 to 73 micrograms/gram, and the blue lime beds contained from 24 to 75 micrograms/gram; both units averaged 54 micrograms/gram of arsenic. The largest concentrations of arsenic were contained in the red clay beds near Lake Montezuma where the values were 34 and 88 micrograms/gram and averaged 61 micrograms/gram. Arsenic probably is associated with clay where arsenic ions are in the matrix of the clay particles. Arsenic concentrations are lowest in the clean white limestone and salt beds where the clay content is low.

I'm not exactly sure why Virginia City is America's favorite western town. It just isn't one place in history. Instead of a single era of development and change, there are actually four distinct and separate eras here. This makes things a bit confusing for the traveler although most people just browse around here for the better part of a day and sightsee without ever understanding the complexities.

The first phase of the town was during its discovery and early development. The second was created by the Big Bonanza and the Great Fire. The third phase was a long era of decline and survival during the beginning of the twentieth century. The fourth phase was the post-World War II tourism boom, an era that created its own imprint on what was left of the old Virginia City and continues to do so even today.

In the 1850s, gold was discovered nearby. Miners were aggravated by finding thick blue clay that clogged up their gold-washing equipment. Someone learned that the "blasted blue stuff" was silver ore laced with gold. The new place was named supposedly by James Finnimore from Virginia, who dropped a whiskey bottle and christened the place "Virgina."

The Pakri Peninsula (former Leetse Peninsula) is located on the limestone plateau of the Estonian northern coast, between Pakri (Paldiski) and Lahepere Bays, and ends in the north at Cape Pakri. The Pakri Peninsula is 12 km in length; the average width is 5 km, area, 40 km(2). Absolute elevation of the grade on Pakri Peninsula is 31 m at its highest; the average height of the Pakri cliff coast is 24-25 m. In the southern part, at Leetse, the average height is 25-26 m. Absolute elevation of the limestone cliff bank at Leetse is 14-18m.

An average geological profile of the limestone cliff is as follows:

1 m of moraine; 20 m of limestone; 3 m of dictyonema shale; 30 m of sandstone with intermediate clay layers; 65 m of blue clays; 90 m of sandstone; granite rocks at 180-190 m depth and deeper.

The Pakri Peninsula is dominated by 3 spreading aquifers: one is situated in the ordovician limestones (O); the other in Ordovician-Cambrian (O-Cm); and the third in Cambrian-Vendian (Cm-V) sandstones. The uppermost (O) aquifer has no natural protection against penetration of pollution, the second (O-Cm) is relatively protected but military objects at depths greater than 20 m and unsealed/uncapped drill wells/holes are endangering the water quality in this aquifer. The first aquifer - O - is practically unused. O-Cm aquifer in some places serves as the local water supply. Groundwater in the third - Cm-V aquifer, spreading under the blue clay layer, is well protected. The Cm-V sandstone aquifer supplies Paldiski with water. The filter parts of the drill wells open the sandstone at a depth of 90-200 m below the ground. Thus, blue clays protect the utilized groundwater from pollution.


(photo: Skara Brae)

In 1850 a ferocious storm scalped the high dune of Skara Brae in the Bay of Skaill, revealing the ruins of a 5,000 year old village preserved in an immense midden or refuse heap. The furniture, including box beds, stone seats, dressers and cupboards, was intact. Drains ran below some of the alcoves, indicating indoor lavatories, and the houses had a damp proofing course - a layer of blue clay that would have worked as well as polythene does today.

Despite these signs of civilisation, the village looked abandoned. Professor Gordon Childe, who supervised the excavations from 1927 to 1930, believed this was due to a massive sandstorm which forced the people to flee. A more recent view is that the village became depopulated over a long period of time, in which young people moved into single farmsteads and the old simply died out.

There are many soil types that redwood just doesn't occur on. One of these is the Dubakella series, a soil developed on serpentine. You wouldn't think you would find Jeffrey pine west of the redwood belt, but here we find it west of Miranda. Serpentine outcrops occur at the head of Salmon Creek and on them we find Jeffrey pine. These continue into the Mattole River drainage near the head of Salmon Creek west of Miranda (Elk Ridge) with Jeffrey pine occurring west of the main redwood belt. These particular serpentine soils have subsoil pH of 7.5, although the top soil may have a pH of about 6. Another large area of this type is on Big Red Mountain down in northern Mendocino County near Cummings. It's almost all vegetated with Ponderosa pine, Jeffrey pine, sugar pine and manzanitas, with no redwood encroaching on it. Those of you who have traveled in the redwood region quite often are familiar with the soil type that forms the blue gray landslides formed by the Yorkville soil series. This was the soil that I mentioned earlier was high in sodium and magnesium. It is a clay soil with an expanding clay called montmorillonite. When it becomes wet, the clay platelets expand like an accordion due to infiltration with water. The combination of a slippery sodium magnesium coating on the clays (absorbed cations) with the expanding clay produces the glacier-like masses of blue clay soil. This is a soil that is very unfavorable to the occurrence of redwoods.

Öpik's first publications, in 1925 and 1926, although not very voluminous, were concerned, with a wide range of problems of stratigraphic correlation, facies distribution, palaeogeography and biostratonomy of Cambrian and Early Ordovician deposits in Estonia. His very first paper, on the Cambrian 'Eophyton Sandstone' (now Pirita Formation), exhibits the broad approach to stratigraphic problems that became a hallmark of all of Öpik's later work. Through careful field work and an analysis of the sparse fossil fauna, he reconstructed the palaeogeography and conditions of sedimentation for this formation as well as its exact correlation with beds on the western side of the Baltic Sea. Another small but important publication from this period deals with the famous 'Blue Clay' (now Lontova Formation), an unconsolidated sediment of Early Cambrian Age.

The excavation of the Sears Tower was to be taken to depths of 45 to 50 feet below street grade. The soil excavated was a 15 foot crust of granular material, followed by a 40 foot layer of blue clay that extended to the hardpan layer. Beneath the hardpan layer was limestone rock. The limestone had a load bearing capacity of 100 tsf

To find your dinosaur you have to look in sedimentary rocks of the right age and type. For a rock to have any chance of containing something dinosaur-ish it must not only be the right age (200 - 65 million years old), but it must also have been laid down in fresh or brackish water. Dinosaurs did not live in the sea so their corpses are much more likely to be flushed into rivers or buried in lagoons, the sediments much later turning into sandstone, shale or clay. This brings us to the Isle of Wight of today, where a likely layer of freshwater deposits 115 million years old is exposed along southern coastal cliffs like the jam in the side of a sponge cake. As far as England goes you can see this 'dinosaur layer' at ground level on the Isle of Wight. It is hidden to the west, north and east under thick layers of younger rocks, only peeping through in the odd quarry or brick pit. The dinosaur layer is actually a series of layers hundreds of metres thick, only some of which are fossiliferous (or dinosauriferous). These strata run along the Islands coast for miles and are best displayed at Brighstone and Brook bays. Despite their great age most of the rocks have never truly solidified, but remain as a soft blue clay which the locals call 'blue slipper' on account of it's vulnerability to the erosive action of the sea. Each winter brings a series of high spring tides which combine with storm force winds to erode our tiny island at an alarming rate. Constant cliff falls, mud flows and landslips mean that the Isle of Wight is disappearing fast in geological terms and will probably vanish for good in a mere 50 thousand years. All of this will be disappointing reading for the average Isle of Wight resident but is great news for the potential fossil collector who can rely on the elements to do most of the work.

The Great Bay Estuary's abundant natural resources attracted Paleo-indians to the area 4000 to 6000 years ago. Tools, including an adze from that period and numerous artifacts from more recent American Indian occupations, were unearthed in archaeological digs at the Sandy Point Discovery Center site. Abenaki Indians of the Msquamskek tribe occupied the area during European colonization in the early 1600s. Shell middens at Adams Point confirm the presence of a base camp between 650 and 800 AD.

The extensive estuary with miles of navigable waterways made transportation by vessel easier than by wagons over roads. The early European settlers invented the gundalow, a sailing barge. From 1650s to the early 1900s, gundalows plied the waters from miles up small rivers through the bay down the great Piscataqua River 20 miles to the Atlantic Ocean at Portsmouth. The gundalows carried bricks made of Great Bay blue clay to Boston, cord wood, fish, salt marsh hay, etc.


Sunday 13th August

The Carse of Gowrie is district of low, alluvial ground, south of the Sidlaw Hills, between Perth and Dundee. It is extremely rich, arable ground, though still with morasses or stagnant pools between raised areas, or inches, until the 18th century. The soil is largely a blue clay, and this was the local building material. The Carse has as a large number of clay buildings, an 18th century farmhouse built from clamp-kiln bricks, later brickworks still exist at Errol and the use of shuttered concrete was pioneered in the UK in the Carse, at Kinfauns Castle.

One of the reasons Chicago originally developed southward was the barrier presented by the Chicago River. Though not a wide stream, it was exceptionally busy with marine commerce. Short moveable bridges were the most expedient solution, but they were open as much as a quarter of the time during the navigation season to accommodate large numbers of masted vessels.

Given the easy-to-excavate blue clay that underlies the city, and the city's success with water supply tunnels, Chicago turned to tunnels under the river. The first, at Washington Street, was built 1867-69, and was 1,605 feet long. North Side access was made easier with construction of the LaSalle St tunnel (1869-71), 2,000 feet long. The LaSalle Street tunnel had two separated lanes for vehicles, and a third tunnel for pedestrians. Brightly lit by gas, it was the wonder of the city, and was a valuable escape route only three months later, during the Great Chicago Fire, which quickly consumed the wooden bridges. These first two tunnels were simply public tunnels for the convenience of vehicles and pedestrians; they carried no horsecar lines.

Indians who hunted in the area many years ago. Saguache was named for a nearby spring which contained a blue clay, and most nearly means "water at the blue earth".

The town of Saguache is nestled at the northern most end of the San Luis Valley which is bounded on the southwest by the La Garita Mountains, and the northwest by the Cochetopa Hills, and on the east by the Sangre de Cristo Mountains.

Saguache is a rural community known for its farming and ranching. Saguache's scenic backdrop in the Rocky Mountains provides for a wide variety of outdoor recreational activities including camping, hiking, rock climbing, mountain biking, skiing, and fishing.

Undrained Shear Strength of a Glacial Clay

G. Mesri,* S. Ali University of Illinois

Stability analysis of embankments, foundations, and excavations on clays requires evaluation of the undrained shear strength mobilized along a potential surface of slip. Mode and rate of shear, as well as progressive yielding and soil disturbance, are major factors that influence evaluation of mobilized strength from laboratory measurements. Excellent quality undisturbed block specimens of Boston Blue clay are being used to investigate mobilized undrained shear strength of a glacial clay. The natural clay used in the study is being characterized by means of a complete spectrum of structural, mechanical, and hydraulic properties.


TI: Title Discoasters of the Blue Clay (middle Miocene) of Malta and Gozo

AU: Authors Hojjatzadeh, M.

AF: Author Affiliation Postgrad. Unit Micropalaeontol., Univ. Coll., Gower St., London WC1E 6BT, UK

SO: Source Geol. Mag., 115(1), 1-80, (1978)

ER: Environmental Regime Marine

AB: Abstract Twenty-three species of the Family Discoasteraceae Vekshina, 1959 recovered from 18 samples of the Blue Clay at Fort Chambray, Gozo, and 31 samples from Fomm-Ir-Rih Bay, Malta, have been studied under light and scanning electron microscopes. Fourteen Middle Miocene species are reviewed, their stratigraphical ranges and importance as marker species discussed. Nine species are described as new. On the basis of the discoaster species present, a Middle Miocene age (NN.6 Discoaster exilis Zone-NN.7 Discoaster kugleri Zone) for the Blue Clay in Malta and Gozo is suggested. LA: Language English SL: Summary Language English PY: Publication Year 1978 PT: Publication Type Journal Article DE: Descriptors Tertiary period; biostratigraphy; new species; stratigraphy; Discoasteraceae; Malta; Gozo ID: Identifiers Discoaster exilis; Discoaster kugleri; Miocene epoch; taxonomy; Discoaster TR: ASFA Input Center Number IR7806948 CL: Classification Code Q2 09273 Palaeontology SF: Subfile Name ASFA 1: Biological Sciences & Living Resources; ASFA 2: Ocean Technology Policy & Non-Living Resources

TI: Title The preservation of the shells of Sepia in the middle Miocene of Malta

AU: Authors Hewitt, R.A.; Pedley, H.M.

AF: Author Affiliation Dep. Geol. Sci., Univ. Birmingham, PO Box 363, Birmingham B15 2TT, UK SO: Source Proc. Geol. Assoc, 89(3), 227-237, (1978)

ER: Environmental Regime Marine

AB: Abstract Well preserved cuttlebones (Sepia sp., S. sepulta and S. c. harmati) are restricted to 15 out of a total of 500 m of marine Oligo-Miocene sediments exposed in the Maltese Islands. They occur at the top of the Blue Clay Formation, a series of slowly deposited offshore marls of Serravallian age. The chambers of the cuttlebones were infilled before compaction and their aragonitic shell structurs are replaced by goethite pseudomorphs after pyrite. The general scarcity of fossil Sepia results from the small range of marine environments in which they may be fossilised and the destruction of post-mortem drifted shells on shore-lines. LA: Language English SL: Summary Language English PY: Publication Year 1978 PT: Publication Type Journal Article DE: Descriptors palaeontology; palaeoenvironments; Cephalopoda; Sepia; Malta ID: Identifiers Miocene epoch TR: ASFA Input Center Number IR7814814 CL: Classification Code Q2 09273 Palaeontology; Q1 08187 Palaeontology SF: Subfile Name ASFA 1: Biological Sciences & Living Resources; ASFA 2: Ocean Technology Policy & Non-Living Resources