The role of the stress regime on microseismicity induced by overpressure and cooling in geologic carbon storage

Fluid injection in deep geological formations usually induces microseismicity. In particular, industrial‐scale injection of CO₂ may induce a large number of microseismic events. Since CO₂ is likely to reach the storage formation at a lower temperature than that corresponding to the geothermal gradient, both overpressure and cooling decrease the effective stresses and may induce microseismicity. Here, we investigate the effect of the stress regime on the effective stress evolution and fracture stability when injecting cold CO₂ through a horizontal well in a deep saline formation. Simulation results show that when only overpressure occurs, the vertical total stress remains practically constant, but the horizontal total stresses increase proportionally to overpressure. These hydro‐mechanical stress changes result in a slight improvement in fracture stability in normal faulting stress regimes because the decrease in deviatoric stress offsets the decrease in effective stresses produced by overpressure. However, fracture stability significantly decreases in reverse faulting stress regimes because the size of the Mohr circle increases in addition to being displaced towards failure conditions. Fracture stability also decreases in strike slip stress regimes because the Mohr circle maintains its size and is shifted towards the yield surface a magnitude equal to overpressure minus the increase in the horizontal total stresses. Additionally, cooling induces a thermal stress reduction in all directions, but larger in the out‐of‐plane direction. This stress anisotropy causes, apart from a displacement of the Mohr circle towards the yield surface, an increase in the size of the Mohr circle. These two effects decrease fracture stability, resulting in the strike slip being the least stable stress regime when cooling occurs, followed by the reverse faulting and the normal faulting stress regimes. Thus, characterizing the stress state is crucial to determine the maximum sustainable injection pressure and maximum temperature drop to safely inject CO₂.     

Sourcing temper sands in ancient ceramics with U–Pb ages of detrital zircons: a southwest Pacific test case

Through use of methodology common in sedimentary geology, we apply U–Pb ages of detrital zircons to source nonlocal temper sand in an ancient ceramic assemblage recovered from Roviana Lagoon of the New Georgia Group in the Solomon Islands. Most potsherds from the Roviana Lagoon contain local volcanic sand as temper, but a small number of sherds contain anomalous granitic temper sand that does not appear to be local. To determine the origin of the anomalous temper, ages of zircons from the anomalous Roviana sherds are compared with ages of zircons in materials from Lizard Island off the Queensland coast and in sand from Muyuw Island in the Solomon Sea where generically similar granitic sands occur. U–Pb analyses of grains from the Roviana sherds yield Middle Miocene ages, while analyses of grains from Lizard Island granitic bedrock, sand, and local potsherds yield much older Permian-Triassic ages, disproving any possibility that the Roviana sherds were derived from Lizard Island, but suggesting local production of the Lizard Island sherds. Ages of grains in a sand sample from Muyuw Island are nearly identical to the ages of grains in the Roviana sherds. All grains in the Muyuw sand are Middle Miocene in age, overlapping closely with the Roviana age population. This strong similarity in detrital zircon signals indicates that the Roviana temper was likely derived from Muyuw Island sands. Our test case for the use of U–Pb ages of detrital zircons in sourcing temper sands is of only regional significance, and not of intrinsic global interest. The methodology, however, should find wide applicability for sourcing temper sands in many parts of the world, for it provides more specific data for the origins of tempers than either petrographic or chemical analysis.     

Simulation of the impact of faults on CO2 injection into sandstone reservoirs

Numerical simulations of multiphase CO₂ behavior within faulted sandstone reservoirs examine the impact of fractures and faults on CO₂ migration in potential subsurface injection systems. In southeastern Utah, some natural CO₂ reservoirs are breached and CO₂‐charged water flows to the surface along permeable damage zones adjacent to faults; in other sites, faulted sandstones form barriers to flow and large CO₂‐filled reservoirs result. These end‐members serve as the guides for our modeling, both at sites where nature offers ‘successful’ storage and at sites where leakage has occurred. We consider two end‐member fault types: low‐permeability faults dominated by deformation‐band networks and high‐permeability faults dominated by fracture networks in damage zones adjacent to clay‐rich gouge. Equivalent permeability (k) values for the fault zones can range from <10^?14 m² for deformation‐band‐dominated faults to >10^?12 m² for fracture‐dominated faults regardless of the permeability of unfaulted sandstone. Water–CO₂ fluid‐flow simulations model the injection of CO₂ into high‐k sandstone (5 × 10^?13 m²) with low‐k (5 × 10^?17 m²) or high‐k (5 × 10^?12 m²) fault zones that correspond to deformation‐band‐ or fracture‐dominated faults, respectively. After 500 days, CO₂ rises to produce an inverted cone of free and dissolved CO₂ that spreads laterally away from the injection well. Free CO₂ fills no more than 41% of the pore space behind the advancing CO₂ front, where dissolved CO₂ is at or near geochemical saturation. The low‐k fault zone exerts the greatest impact on the shape of the advancing CO₂ front and restricts the bulk of the dissolved and free CO₂ to the region upstream of the fault barrier. In the high‐k aquifer, the high‐k fault zone exerts a small influence on the shape of the advancing CO₂ front. We also model stacked reservoir seal pairs, and the fracture‐dominated fault acts as a vertical bypass, allowing upward movement of CO₂ into overlying strata. High‐permeability fault zones are important pathways for CO₂ to bypass unfaulted sandstone, which leads to reduce sequestration efficiency. Aquifer compartmentalization by low‐permeability fault barriers leads to improved storativity because the barriers restrict lateral CO₂ migration and maximize the volume and pressure of CO₂ that might be emplaced in each fault‐bound compartment. As much as a 3.5‐MPa pressure increase may develop in the injected reservoir in this model domain, which under certain conditions may lead to pressures close to the fracture pressure of the top seal.     

Coire a’ Cheud‐chnoic,the ‘hummocky moraine’ of Glen Torridon

EUROPE

France; A Geographical Survey. By P. Pinchemel, translated by C. Trollope and A. J. Hunt. 454 pp. Illustrations, Tables, Bibliography. Bell, London, 1969. 100s.

Italy. By George Kish. 8 × 5 1/4. 125 pp. 12 figures and index. Van Nostrand, New York, 1969. $1.lb95.

AFRICA

A Historical Geography of Ghana. By Kwamima B. Dickson. 15#lb5 × 23.lb5 cms. xiv + 379 pp., 58 maps and diagrams, 7 tables, appendices, bibliography, index. Cambridge U.P., London, 1969. 150s.

The Soil Resources of Tropical Africa. Edited by R. P. Moss. 8 1/2 × 5 1/2. Cambridge University Press, 1968. £2.

ASIA

Afghanistan. By Ludolph Fischer. Geomedical Monograph Series No. 2, 12 × 8 1/2. Text (German and English), 16 plates and 10 maps. Springer‐Verlag, Berlin, Heidelberg and New York, 1968. DM48, $12.lb00.

GEOLOGY AND GEOMORPHOLOGY

Readings in the Earth Sciences, Vols. 1 and 2. 11 1/4 × 8 1/2 Published W. H. Freeman, San Francisco, 1969. 94s. each.

Fife and Angus Geology. By A. R. MacGregor. 266 pp. Blackwood, Edinburgh and London, 1968. 21s.

METEOROLOGY

Essentials of Meteorology. By D. H. McIntosh and A. S. Thorn. 8 1/2 × 5 1/2. xv + 239 pp., numerous illustrations, answers to problems. Taylor and Francis, London. 20s.

ECONOMIC GEOGRAPHY

Industrial Britain: The North West. By David M. Smith. 10 × 6 1/4, 271 pp., 36 figures, 31 plates, bibliography and statistical appendix. David and Charles, Newton Abbot, 1969. 95s.

Industrial Demand for Water: A study of South East England. By Judith Anne Rees. 8 1/2 × 5 1/2 L.S.E. Research Monographs 3, xiv + 194 pp., Weidenfeld and Nicolson, 1969, London. 65s.

CARTOGRAPHY AND MAPS

The Antonine Wall. Ordnance Survey 2 1/2 Inch Map. 1969. 11s.

Maps and Air Photographs. By G. C. Dickinson. 10 × 17 1/2. xiv + 286 pp. Edward Arnold, London, 1969. 45s.

Atlas Four. 10 1/2 × 8 1/2. 115pages, + index 60 pages. Collins/Longmans, 1969. 15s.

EDUCATIONAL

Learning Through the Environment. By Muriel F. S. Hopkins. 7 3/4 × 5 1/8. 151 pages, 26 figures. Longmans, London. 1969. 15s.

Investigating Geography. By J. Philip Dodd. 9 3/4 × 7 1/4. 214 pp., 192 figures. Heinemann, London, 1969. 15s.

The London Regional Geographies. Book 3: Asia. By Leonard Hadlow and Reginald Abbott. 8 1/2 × 5 1/2. 294 pp., 145 figs. U. of London Press, 1969. 18s.

A Geography of Manufacturing. By H. R. Jarrett. 8 3/4 × 5 3/4. xvii + 349 pp. 67 illustrations. Macdonald &; Evans, 1969, London. 35s.

The Mediterranean Lands. By J. Brannigan and H. R. Jarrett. The New Certificate Geography Series: Advanced Level. 9 × 5l. xiv + 620, 150 illustrations. Macdonald and Evans Ltd., 1969. 38s.     

An Early Islamic Inter-Settlement Agroecosystem in the Coastal Sand of the Yavneh Dunefield,Israel

This study examines the remains of an agricultural complex found in the Yavneh coastal dunefield, central Israel. Known as a plot-and-berm agroecosystem, the complex consisted of earthworks in a crisscross pattern of sand berms and sunken agricultural plots that were used for groundwater harvesting. The plots, which provided easy access to the high groundwater table and the berms around them, are overlaid by a gray sand unit covered by pottery sherds and artifacts. This gray sand is more fertile than the underlying sand, suggesting refuse enrichment. Artifactual similarity of the finds to those of inland (Tel) Yavneh suggests that Yavneh was the main source for the refuse additive. Based on artifacts and OSL ages it seems that this agroecosystem was active during the 10th to early 12th centuries a.d. The agroecosystem demonstrates an early example of an Early Islamic agrotechnological attempt in marginal and sandy regions of the Mediterranean basin.     

Glass and glass production in the Oman peninsula in antiquity reconsidered – chemical and mineralogical investigation of sands

A batch of green‐ and amber‐coloured glass chunks and unguentaria dating from the first century CE was found in 2007 at Dibba al Hisn, a site on the Arabian Sea coast of the United Arab Emirates (UAE). Its elemental and isotopic composition revealed the glass to be of a previously unknown plant ash glass type, different from known contemporary Roman, Mesopotamian, and Indian glass. The Sr isotopic composition of the glass corresponds to locally available plants, pointing to the possible existence of a first‐century CE local glass production centre. To explore this possibility, sands from around the UAE were analysed to establish their suitability for glass making and correspondence with the Dibba finds. This paper presents the results of the elemental analysis of fourteen sands. The analysis, performed using inductively coupled plasma optical emission spectroscopy (ICP‐OES), revealed all sands to be rich in lime and alumina. X‐ray diffraction revealed the presence of calcite and other carbonate minerals, as well as antigorite and quartz. Comparison of the sand compositions to average first‐century CE non‐Roman glass found at Dibba showed them to be unsuitable as raw material for producing the glass of Dibba. The evidence thus identifies this glass batch as imported, contrary to what was suggested before. This paper also reviews the occurrence of thick‐walled unguentaria in the region.     

Significance of large-scale sand injectites as long-term fluid conduits: evidence from seismic data

Sand injectites and related features that are interpreted to have formed by large‐scale, often sudden, fluid escape in the shallow (typically <500 m) crust are readily imaged on modern seismic data. Many of the features have geometrical similarity to igneous dykes and sills and cross‐cut the depositional stratigraphy. Sand injectites may be multiphase and form connected, high‐permeability networks that transect kilometre‐scale intervals of otherwise fine‐grained, low‐permeability strata. North Sea examples often form significant hydrocarbon reservoirs and typically contain degraded, low‐gravity crude oil. Fluid inclusion and stable isotope data from cements in sand injectites record a mixing of aqueous fluids of deep and shallow origin.     

La mobilité forcée des personnes utilisatrices de drogue par injection et inhalation en situation d'itinérance à Montréal

This article focuses on the various actors in the urban setting who contribute to the increase in the forced mobility of homeless injection drug users and crack smokers in Montréal, Canada. The objective is to analyze who these actors are and how they contribute to increasing this forced mobility from the perspective of homeless injection drug users and crack smokers in relation to three needs : basic needs, acquisition of financial resources, and drug use. One hundred and six semi-structured interviews were conducted among this population. The results indicate that various actors—police officers, community organization, peers, municipal administration, storekeepers, and residents—contribute to the forced mobility of this population in their daily activities. As for their needs, it is when they use drugs, sleep, or loiter that they are more likely to experience events of forced mobility. Police officers are by far the actors who contribute the most to this, often in a repressive way. The role of the municipality is also a determining factor in the daily activities of homeless injection drug users and crack smokers.     

Obituary

EUROPE

The Future of Scotland. By James A. Bowie, M.A., D.Litt. London and Edinburgh : W. and R. Chambers, Ltd., 1939. Price 7s. 6d.

Hebridean Journey. By Halliday Sutherland. London : Geoffrey Bles Ltd., 1939. Price 10s. 6d.

The Islands of Scotland. By Hugh MacDiarmid. London : B. T. Batsford Ltd., 1939. Price 10s. 6d.

To Introduce the Orkneys and Shetlands. By Iain F. Anderson. London : James Clarke and Co. Ltd., 1939. Price 7s. 6d.

My Kingdom for a Horse. By Margaret Leigh. London : Macmillan and Co. Ltd., 1939. Price 7s. 6d.

North Cape. By F. D. Ommanney. London : Longmans, Green and Co. Ltd., 1939. Price 10s. 6d.

The Land of France. By Ralph Dutton and Lord Holden. London : B. T. Batsford Ltd., 1939. Price 8s. 6d.

Greek Earth. By Sidney W. Hopper. London: Michael Joseph Ltd., 1939. Price 12s. 6d.

The Mirrors of Versailles. By Elisabeth Kyle. London : Constable and Co. Ltd., 1939. Price 10s.

Towns and People of Modern Poland. By Robert McBride. London : Jarrolds Ltd., 1939. Price 10s. 6d.

ASIA

Minaret and Pipe‐Line: Yesterday and To‐day in the Near East. By Margret Boveri. Translated by L. M. Sieveking. London : Humphrey Milford at the Oxford University Press, 1939. Price 21s.

Settlements in the Lower Indus Basin (Sind), Parts I and II ; and Sind's Changing Map. By Professor M. B. Pithawalla. Karachi: The author. Prices Rs. 5 and Rs. 2 respectively.

REVIEWS OF BOOKS

Peaks and Lamas. By Marco Pallis. London : Cassell and Co. Ltd., 1939. Price 18s.

Eastern Journey. By J. H. MacCullum Scott. London : The Travel Book Club, 1939. Price 3s. 6d.

The Naked Nagas. By C. von Fürer‐Haimendorf. London : Methuen and Co. Ltd., 1939. Price 15s.

Karakoro: At Home in Japan. By Henry Noël. Tokyo : The Hokuseido Press, 1939. Price 6s. 6d.

I went to the Soviet Arctic. By Ruth Gruber. London : Victor Gollancz Ltd., 1939. Price 10s. 6d.

AFRICA

Afrique Équatoriale, Orientale et Australe (Géographie Universelle, vol. XII). By Fernand Maurette. Paris : Librairie Armand Colin, 1938. Price, 150 francs.

Ethiopia: An Empire in the Making. By Ferdinando Quaranta. London : P. S. King and Son Ltd., 1939. Price 7s. 6d.

By Bus to the Sahara. By Gordon West. London : The Travel Book Club, 1939. Price 3s. 6d.

Dark Subjects : Twenty‐four Adventurous Years in Nigeria. By H. L. Ward Price. London : Jarrolds Ltd., 1939. Price 15s.

AMERICA

Journey to the World's End. By Hakon Mielche. Edinburgh and London : William Hodge and Co. Ltd., 1939. Price 12s. 6d.

AUSTRALIA

A Voyage to New Holland. By William Dampier. Edited, with Introduction, Notes and Illustrative Documents, by James A. Williamson, D.Litt. London : The Argonaut Press, 1939. Price 12s. 6d.

Australian Journey. By Paul McGuire. London : William Heinemann Ltd., 1939. Price 12s. 6d.

POLAR REGIONS

Polar Exploration (” Epics of the Twentieth Century “). By Andrew Croft. London : A. and C. Black Ltd., 1939. Price 7s. 6d.

Sir John Franklin's Last Arctic Expedition. By Richard J. Cyriax. London : Methuen and Co. Ltd., 1939. Price 12s. 6d.

GENERAL

Admiralty Weather Manual, 1938. By Order of the Lords Commissioners of the Admiralty. London: H.M.S.O., for the Hydrographic Department, Admiralty, 1938. Price 10s. 6d.

White Settlers in the Tropics. By A. Grenfell Price, with additional notes by R. G. Stone. New York: American Geographical Society, Special Publication No. 23, 1939. Price $4.00.

BIOGRAPHY

Livingstone et l'Exploration de l'Afrique. By René Maran. Paris : Gallimard. Eighth Edition, 1938. Price 25. francs.

I Was There. By Edith Tyrrell. Toronto : The Ryerson Press, 1938. Price $2.00.

EDUCATIONAL TEXT‐BOOKS

Memorandum on the Teaching of Geography. Issued by the Incorporated Association of Assistant Masters in Secondary Schools. London : George Philip and Son Ltd. Second Edition Revised 1939. Price 8s. 6d.

The World of Man. Book IV. Europe, The British Isles and the World. By C. C. Carter and E. C. Marchant. London : Christophers Ltd. Price 3s. 9d.

Geography for To‐day : North America and Asia (also issued separately) : Europe and the British Isles (also issued separately). By a Committee including L. Dudley Stamp and L. S. Suggate. London : Longmans, Green and Co. Ltd., 1939. Price, 4s. each, or 3s., 2s. 6d., 2s. 9d. and 2s. 9d. respectively.     

Petrography of ancient Indian lime plaster

Samples of ancient Indian lime plaster have not previously been analysed. Excavation of a seventh century AD baked brick structure provided the necessary samples for a detailed laboratory examination of plaster. The plaster samples were studied by chemical and petrographic methods. The probable sources of lime and sand were indicated by the mineralogy.