Mineralogical Survey Research Articles

Applied Science in Latin American Countries: The Case of the 'Geological and Mineralogical Survey of Brazil', 1906-1934

Applied Science in Latin American Countries: The Case of the 'Geological and Mineralogical Survey of Brazil', 1906-1934

The Mineralogy of Bronze Age Copper Ores from the British Isles: Implications for the Composition of Early Metalwork

Numerous analytical studies during the latter half of this century have contributed to the compilation of a large compositional database of Early to Middle Bronze Age copper‐based artefacts revealing distinctive impurity patterns which appear to change over time. However, attempts to relate these data to copper ore sources proved problematic in the absence of firm evidence for the location of prehistoric copper mines. Over the last fifteen years this situation has changed dramatically with the discovery of numerous Early and Middle Bronze Age copper mines in England and Wales. This study is the first attempt at a comprehensive mineralogical survey of the principal mines investigated to date in order to define the likely composition of the copper ores as mined in antiquity for comparison with the artefact database. The study suggests that the majority of these mines can only have produced essentially pure copper. Only one mine, Ross Island, is likely to have produced copper with a significant level of impurities. The relative purity of the known ore sources is contrasted with significant levels of various metallic impurities among the analysed artefacts, leading to the conclusion that metal circulation and mixing may have been more extensive than previously thought even during the earliest part of the Bronze Age.

Charles Frederic Hartt and the ‘Geological Commission of Brazil’ (1875-1877)

The Geological Commission of Brazil (GCB) was created on April 30, 1875, within the Ministry of Agriculture in order to promote a systematic survey of Brazilian territory. Despite the fact that other scientific traditions were already present in Brazilian geology-e.g., the German and the French ones-the GCB model was inspired by the North American Geological Surveys. As the North American Surveys usually combined geology, topography, and agriculture, this model fit very well into Brazilian needs at that moment, for the country was experiencing intense economic development caused by the coffee agriculture boom, creating a strong demand for land with the appropriate soil for growing coffee. For the organization of the GCB the Brazilian government accepted a proposal made by the Canadian-born Charles Frederic Hartt (Fredericton, New Brunswick 1840-Rio de Janeiro, 1878), who was familiar both with Brazil and the North American Geological Surveys. Hartt had visited Brazil in 1865 as a member of the Thayer Expedition with Louis Agassiz. During the 32 month existence of the Commission, Hartt and the GCB staff covered a large part of the Brazilian Empire, collecting thousands of samples and preparing dozens of papers and reports most of which, unfortunately, remained unpublished. The demise of the GCB was ordered in 1878 by a new ministry for budgetary reasons. Nevertheless, it provided an institutional model which inspired the later Geographical and Geological Commission of Sao Paulo (1886) as well as the Geological and Mineralogical Survey of Brazil (1907), which, in various manifestations, has continued to the present day.

Mineralogy of chondritic interplanetary dust particles

From a mineralogical survey of approximately 30 chondritic micrometeorites collected from the lower stratosphere and studied in detail using current electron microscopy techniques, it is concluded that these particles represent a unique group of extraterrestrial materials. These micrometeorites differ significantly in form and texture from components of carbonaceous chondrites and contain some mineral assemblages which do not occur in any meteorite class. Electron microscope investigations of chondritic micrometeorites have established that these materials (1) are extraterrestrial in origin, (2) existed in space as small objects, (3) endured minimal alteration by planetary processes since formation, and (4) can suffer minimal pulse heating (<600°C) on entering earth's atmosphere. The probable sources for chondritic interplanetary dust particles (IDPs) are cometary and asteroidal debris and, perhaps to a lesser extent, interstellar regions. These sources have not been conclusively linked to any specific mineralogical subset of IDP, although the chondritic porous (CP) aggregate is considered of likely cometary origin. Chondritic IDPs occur in two predominant mineral assemblages: (1) carbonaceous phases and phyllosilicates and (2) carbonaceous phases and nesosilicates or inosilicates, although particles with both types of silicate assemblages are observed. Olivines, pyroxenes, layer silicates, and carbon‐rich phases are the most commonly occurring minerals in many chondritic IDPs. Other phases often observed in variable proportions include sulphides, spinels, metals, metal carbides, carbonates, and minor amounts of sulphates and phosphates. Individual mineral grain sizes range from micrometers (primarily pyroxenes and olivines) to nanometers, with the predominant size for all phases less than 100 nm. Specific mineral characteristics for particular chondritic IDPs provide an indication of processes which may have occurred prior to collection in the earth's stratosphere. For example, pyroxene mineralogy in some chondritic aggregates is consistent with condensation from a vapor phase and, we consider, with condensation in a turbulent solar nebula at relatively low temperatures (<1000°C). Carbonaceous phases present in other CP aggregates have been used to imply low‐temperature formation processes such as Fischer‐Tropsch synthesis (∼530°C) or carbonization and graphitization (∼315°C). Alteration processes have been implicated in the formation of some layer silicates in CP aggregates and may have involved hydrocryogenic alteration at <0°C. In general, interpretations of transformation processes on submicrometer‐size minerals in chondritic IDPs are consistent with formation at a radius equivalent to the asteroid belt or greater during the later stages of solar nebula evolution using currently available models.

The Mineralogy of Castleguard Cave, Columbia Icefields, Alberta, Canada

A mineralogical survey at Castleguard Cave has revealed complex suites of carbonate and sulfate minerals, plus seasonal and permanent ice. Carbonate minerals observed (and number of occurrences in 55 samples) are as follows: calcite (43), huntite (15), hydromagnesite (6), aragonite (4), monohydrocalcite (1). Sulfate minerals observed (number of occurrences in 10 samples) are: gypsum (9), thenardite/mirabilite (2), epsomite (1). Ancient massive dripstone and flowstone deposits consist only of calcite. Smaller dripstones, chalky coatings on dripstone, thin flowstone crusts, erratics, and pasty wall deposits (moonmilk) were commonly combinations of calcite plus huntite. Aragonite occurs mainly as crystalline wall concretions associated with deposits and as small anthodites. Hydromagnesite and monohydrocalcite are only found as dry, crusty, moonmilk wall deposits. Distribution of carbonate and sulfate minerals is related to the thermal regime and presence of discrete seepage inputs. Small calcite speleothems occur to some extent throughout the cave. Massive dripstones and abundant decoration are restricted to sites of present or past seepage concentration. Sulfate mineralization and basic and hydrated carbonates are confined to warm, drier portions of the central cave. Chemical and stable isotope data indicate that calcite is precipitated at constant CO2 partial pressure. Evaporation is the primary process responsible for the presence of the diverse sulfate and exotic carbonate minerals in the cave.

Arthur Aikin's Mineralogical Survey of Shropshire 1796–1816, and the contemporary audience for geological publications

It has become almost traditional for historians of geology to claim that Roderick Murchison (1792–1871) ‘opened to view for the first time’ the fossiliferous rocks below the Old Red Sandstone which Murchison described in his monumental workThe Silurian Systempublished in 1839. Murchison himself claimed in the introduction to this work ‘no-one was previously aware of the existence below the Old Red Sandstone of a regular series of deposits, containing peculiar organic remains’. Professor John Phillips expressed the traditional view well when he wrote of the larger area of which Shropshire forms a part: ‘practically before the Summer of 1831 the whole field of the ancient rocks and fossils… was unexplored but then arose two men… Adam Sedgwick and Roderick Murchison and simultaneously set to work to cultivate what had been left a desert’. Against this we must set the statement of George B. Greenough (1778–1855), first president of the Geological Society of London, as reported in 1841. He had ‘frequently expressed a conviction, as a result of his own observations…, that adequate enquiry alone was wanting to prove the existence of a succession of strata in the west of England, and in Wales—not less regular than that which had been demonstrated in the centre and east of the Island.’

Comments regarding ore genesis at Silver Reef, Utah

Discussion of a paper by Paul Dean Proctor [Geology of the Silver Reef (Harrisburg) Mining District, Utah Geological and Mineralogical Survey, Bulletin 44, 1953]. Proctor9s list of 11 points favoring a syngenetic origin is reproduced and criticized in detail. An epigenetic origin is favored on the basis that mineralization in the area is structurally controlled and because ore-bearing sandstones are altered to a lighter color than adjacent zones.

Influence of Continuous Cropping on the Fixation and Release of Potassium in Three Pennsylvania Soils

AbstractThe fixation and release of potassium by three Pennsylvania soils was studied under greenhouse conditions using ryegrass as the indicator crop. The soils studied were representative of the two types of clay mineral distributions determined by a previous mineralogical survey of the soils of Pennsylvania.The potassium fixed by the soils during the greenhouse experiment was measured two ways: the fixation of exchangeable potassium as nonexchangeable, and the fixation of acid soluble potassium as acid insoluble. The amounts of potassium fixed as nonexchangeable and as acid insoluble potassium were approximately the same. The potassium fixed under moist greenhouse conditions was less than that fixed by repeated wetting and drying the soils at 75°C. The difference in the potassium fixation capacities of the soils was related to the physical characteristics of the vermiculite contained in the respective soils.The release of potassium by the soils during the greenhouse experiment was again measured two ways: the release of acid insoluble potassium as acid soluble, and the release of acid soluble potassium as exchangeable. The best indicator of the rate of release of potassium was the acid soluble potassium. The different rates of release of potassium by the soils were related to the hydrous mica content and were responsible for the significant differences in the ryegrass yield of the three soils.

Societies and Academies

LONDON. Geological Society, Mar. 20.-Sir Douglas Mawson: Some South Australian algal limestones in process of formation. A record of three different types of limestone, now actually in process of formation under the influence of plant-growth, occurring in the southeastern region of South Australia. In each of the localities examined, whether inundated in winter only or permanently inundated, the formation of limestone is being determined by blue-green algae.-Arthur W. Groves: The unroofing of the Dartmoor granite, and an outline of the distribution of its detritus in the sediments of southern England. A systematic outline mineralogical survey has been made of the sediments of southern England, from the base of the Permian in Devon (Watcombe Clay) up to the Lenham Beds of the North Downs. The minor intrusions above the granite were being rapidly eroded in Permo-Triassic times, but there is no evidence of the actual granite being exposed at that period. No proof has been obtained of direct derivation of detritus from theDartmoor granite in the Jurassic rocks. The earliest evidence of the exposure of the granite is in late Wealden times. Throughout Upper Cretaceous times-particularly during the Selbornian epoch-the Dartmoor granite contributed enormous quantities of detritus to the sediments of southern England, reaching as far afield as Kent and Oxfordshire, and perhaps farther. The Cornish Pliocene was largely derived from the Cornish granites. The St. Keverne outlier is mainly derived from the Falmouth and Bodmin masses, and yields no evidence of Dartmoor detritus. A number of new occurrences of dumortierite are recorded.

Oil-shales and Petroleum Prospects in Brazil

In view of the frequent occurrence of petroleum in other parts of the world, it seems odd that so large an area as is contained within the borders of Brazilshould be without this product. This apparent deficiency may be due, however, to our ignorance of the regions in which it may exist. In some places, indications point to the probable existence of petroleum in ages gone by; andwhile the presence of petroleum pools may be problematic, in several regionsconditions not unfavorable to their occurrence exist. Yet, Brazil has enormous oil resources in the rich oil-shales in differentparts of the country. Many of these shales are very rich and only suitableprocesses for the extraction of the oil are lacking. At the present time, onlya few small experimental plants are producing oil by distillation from theseshales. These plants have been the subject of recent investigations by theGeological and Mineralogical Survey, a preliminary report of which is in thehands of the printer. The only regions where studies have not been made are theupper Amazon, the Acre, the Rio Negro, and the Peruvian frontier, which reallyseems to be the most promising field for explorations of any in thecountry. In the vast plateau region of the interior north of the 20th parallel oflatitude, granites, gneiss, mica schists, and very old metamorphosedsedimentaries predominate. Later, sedimentaries occupy a minor position and, where found in the interior, represent a thin veneering resting on the olderrocks. At several places near the coast they have a greater development andcontain considerable beds of oil-shale and may, in some cases, offer conditionsfavorable for the occurrence of oil. Such deposits are found in the Permianrocks of central and southern Maranhao; in the Tertiary and Cretaceous bedsalong the coast of Alagoas Sergipe, Bahia, and perhaps farther south inEspirito Santo; and in the Parahyba embayment north of Cape Frio and in theinterior Tertiary basin of eastern Sao Paulo. AIME 065–11

VIII.—Note On Some Post - Tertiary Mollusca From Ceylon

Some marine shells, associated with crab-remains,1 Balani, and small thread-like annelid tubes, from the Post-Pliocene deposits of north-eastern Ceylon, have been entrusted to me for determination by Dr. H. Woodward, F.K.S. They were collected by Mr. A. K. Coomaraswamy, B.Sc, Director of the Mineralogical Survey of Ceylon, and his description of the deposits containing the fossils forms the preface of this communication. Lithologically it is observable that there are two sets of specimens-those that occur in hard, water-worn nodules of clay, and others that were obtained from soft, dark, clayey beds found in situ. The fossils found in the clayey material may perhaps be rather older than those found in the nodules, but as two of the shells are common to each, viz. Placuna placenta and Potamides fluvialilis, it is certain that no great distinction in age is to be recognised.An examination of the species represented in the collection goes to prove that they belong to the existing fauna of the Indian Ocean, being similar to the life which is found in the creeks and back-watersof that sea, and consequently bearing a littoral or an estuarine facies.It is interesting to know of the presence of corresponding Post-Tertiary deposits crowded with shells forming the coastal areas of the Madras Presidency of India, particularly at Pondicherry, Cuddalore, Tangore, etc., for the history of which we are mainly indebted to the late Mr. H. F. Blanford (Mem. Geol. Surv. India, 1862, vol. iv, pt. 1, pp. 192,193). So numerous are the mollusca of these beds that they are utilised by the natives for the manufacture of lime.

XXXVI. Geological and mineralogical survey of part of the Yorkshire coast

XXXVI. <i>Geological and mineralogical survey of part of the Yorkshire coast</i>

XXX. Notice concerning the Shropshire Witherite.

The Witherite or native carbonate of barytes, still continues to be one of the rarer productions of the mineral kingdom. The only thoroughly ascertained locality of this substance, according to Professor Jameson, (System of Mineralogy, I. 575,) is Anglesark in the county of Lancaster, where it was first discovered by Mr. James Watt. It is here found in veins traversing the independent coal formation, and accompanied by blende, galena, calamine and heavy-spar. To this locality however may be added, on the authority of Klaproth, (Analytical Essays, I. 389,) a mine near Neuberg in Upper Stiria, where this mineral occurs in a bed of spathose iron ore. The mine at Anglesark is, I understand, abandoned: it may therefore be a matter of some interest to the members of the Geological Society, to state that my researches during the last summer in pursuance of my mineralogical survey of Shropshire, have made me acquainted with a mine, within the bounds of that county, in which witherite occurs very abundantly. The most hilly district of Shropshire extends from the borders of Montgomeryshire to the town of Church Stretton, having the broad valley of the Severn for its northern boundary, and stretching as far south as the parallel of Bishopscastle. The general elevation of this tract” above the Severn varies from 800 to above 1500 feet. It is completely intersected by two strait and simple vallies, the direction of which is about north-east and south-west, and several smaller ones parallel to the larger descend from