PRINSIP GEOLOGI SEBAGAI KERANGKA PEMIKIRAN MANAJEMEN STRATEGI

Convention Bandung 2004 (CB2004)
The 33rd Annual Convention & Exhibition 2004

Indonesian Association of Geologist
Horizon Hotel, 29-30 Nov, 1 Dec 2004, Bandung

PRINSIP GEOLOGI SEBAGAI KERANGKA
PEMIKIRAN MANAJEMEN STRATEGI

Djoko Sunarjanto dan M.Husen

PPPTMGB ”LEMIGAS”
djoko@lemigas.esdm.go.id; husenm@lemigas.esdm.go.id

Abstract

Many geological aspects can be used as idea to solve the problems. Using the basic
principle of geology is able support the development of strategic management which
need an adjustment and new cases in order to achieve required goal. Priciples of
stratigraphy has relevance with body or structure of organizations which able to
handle situation and conditions, objectives and multi goal. As an analogy,
stratigraphy of SouthEast Wyoming can accommodate restructurization
organizations as a agency of research and development or agency of education and
training is multi functions. So approach of an analytical processes value change has
relevance with rock sedimentary pattern.

For discussion, the study of geological principle as strategic management
framework idea related to the activity and trends to fluctuate can be analogue with
natural cycle. The specific case with strategic characteristics that need alternative
solving was selected such as financial share balancing to mineral and oil and gas
solution can be discovered using geological approach as present technical
parameters and also can be applied to new scenario in order to optimize the
implementation of policy and management between central and region government.

Abstrak

Banyak aspek geologi dapat dijadikan sebagai ide yang digunakan untuk membantu
pemecahan masalah. Menggunakan prinsip dasar geologi mampu mendukung
pengembangan manajemen strategi yang memerlukan penyempurnaan dan hal-hal
baru guna mencapai tujuan (goal) yang diinginkan. Prinsip dalam stratigrafi terdapat
relevansi yang berkaitan dengan bentuk susunan atau struktur organisasi yang
mampu menampung situasi kondisi, kepentingan dan banyak tujuan. Suatu analogi,
stratigrafi South East Wyoming mampu mengakomodasi restrukturisasi organisasi
Badan/Pusat Penelitian dan Pengembangan (Research & Development) ataupun
Pendidikan dan Latihan (Education and Training) yang kaya fungsi. Demikian juga
suatu pendekatan analisis proses perubahan nilai strategis terdapat relevansinya
dengan pola sedimentasi batuan.

Diskusi tentang prinsip geologi sebagai kerangka pemikiran dalam manajemen
strategi terkait dengan aktivitas yang cenderung selalu berubah mampu
dianalogikan dengan siklus di alam. Hal khusus bersifat strategis yang memerlukan
alternatif keputusan seperti opsi perimbangan keuangan hasil bagi pendapatan dari
mineral dan migas, dapat dikaji kembali dengan pendekatan geologi sebagai
parameter teknis yang baru sekaligus diaplikasikan untuk lebih mengoptimalkan
pelaksanaan kebijakan dan manajemen bagi hasil antara pemerintah pusat dan
daerah.

Key words : Geology and Strategic Management

»»  read more

STRUKTUR PADA BATUAN SERPENTINIT DI SEPANJANG SEMPADAN JALUR TENGAH DAN JALUR BARAT SEMENANJUNG MALAYSIA

Convention Bandung 2004 (CB2004)
The 33rd Annual Convention & Exhibition 2004

Indonesian Association of Geologist
Horizon Hotel, 29-30 Nov, 1 Oct 2004, Bandung

STRUKTUR PADA BATUAN SERPENTINIT DI
SEPANJANG SEMPADAN JALUR TENGAH DAN
JALUR BARAT SEMENANJUNG MALAYSIA

Jatmika Setiawan1), Ibrahim Adullah2), Zaiton Harun2)
jatmikasetiawan855@hotmail.com, iba@pkrisc.cc.ukm.my, zaiton@pkrisc.cc.ukm.my

1) Jurusan Teknik Geologi, Fakultas Teknologi Mineral, UPN “Veteran Yogyakarta
2) Program Geologi, Fakulti Sains dan Teknologi, Universitas Kebangsaan Malaysia

Abstrak

Di sepanjang sempadan (batas) Jalur Tengah dan Jalur Barat Semenanjung
Malaysia, yang dikenali sebagai Garisan Bentong-Raub atau Sutura Bentong,
tersingkap beberapa jasad serpentinit yang berjajaran pada arah antara N340oEN350oE.
Singkapan-singkapan tersebut dipercayai mewakili batuan ultramafik yang
dahulunya merejah batuan Devon Bawah dan kemudiannya telah berubah menjadi
serpentinit. Batuan serpentinit tersebut tersingkap di Bukit Rokan Barat, Kampung
Selaru, Petasih (Negeri Sembilan); Cheruh-Bentong (Negeri Pahang) dan Kelantan
Barat (Negeri Kelantan). Seterusnya kajian struktur di batuan serpentinit dapat
digunakan untuk menjelaskan sejarah canggaan (deformasi) yang telah berlaku di
sepanjang sempadan Jalur Barat dan Jalur Tengah Semenanjung Malaysia.

Observasi lapangan pada singkapan-singkapan serpentinit dijumpai struktur foliasi,
telerang, jalur ricih dan sesar. Foliasi umumnya berjurus utara-baratlaut (UBL),
kecuali di Petasih dan Cheruh yang berjurus barat-baratlaut (BBL). Deformasi
pertama berarah arah NNW hingga NNE, menghasilkan sesar songsang (naik) geser
kanan (SSGK) dengan jurus sesar SE-NW dan kemiringan antara 70o-80o.
Deformasi kedua dengan tegasan berarah NE-SW, menghasilkan sesar SSGK
berjurus antara N340oE-N350oE atau N160oE-N170oE dan kemiringan antara 70o85o.
Deformasi ketiga dengan tegasan kompresi berarah NEE-SWW, menghasilkan
sesar mendatar kanan normal (SMKN) dengan jurus dan kemiringan N20oE/70o atau
N130oE/70o. Deformasi terakhir dengan tegasan timurlaut-baratdaya (TL-BD),
menghsilkan sesar songsang geser kiri (SSGK) dengan jurus dan kemiringan
N270oE/85o.Hasil kajian petrografi dari semua sayatan nipis mendapati bahawa
batuan asal ultramafik telah terubah menjadi mineral serpentin. Kecuali di daerah
Cheruh-Bentong masih terlihat batuan asalan serpentinit adalah batuan igneus
Peridotit

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MINERAL RESOURCE ASSESSMENT OF PORPHYRY COPPER DEPOSITS IN INDONESIA USING THE USGS 3-PART ASSESSMENT METHOD

Convention Bandung 2004 (CB2004)
The 33rd Annual Convention & Exhibition 2004

Indonesian Association of Geologist
Horizon Hotel, 29-30 Nov, 1 Dec 2004, Bandung

MINERAL RESOURCE ASSESSMENT OF
PORPHYRY COPPER DEPOSITS IN INDONESIA
USING THE USGS 3-PART ASSESSMENT
METHOD

Bambang Tjahjono Setiabudi

Directorate of Mineral Resources Inventory
E-mail: BTSetiabudi@hotmail.com

ABSTRACT

Mineral Resource Assessment is a field of research and application of
quantitative appraisal methods to evaluate potential mineral resources.
Principally it describes mineral deposits, measures their grade and tonnage,
estimate the occurrence of the undiscovered deposits and estimates mineral
resources in the permissive tracts. The main objectives are to outline the
principal areas in Indonesia that have potential for selected undiscovered
mineral resources and to estimate the probable amounts of those mineral
resources to a depth of 1 km below the earth's surface. The assessment is
carried out using the USGS 3-Part Quantitative Mineral Resource Assessment
Method. The 3-part method consists of firstly, delineating tracts for commodities
and porphyry Cu deposit types based on the geology of the ore deposits,
secondly, estimating the amount of resources contained in the undiscovered
deposits using appropriate ore characteristics and metal contents based on
grade and tonnage models and thirdly, estimating number of undiscovered
deposits of each type for each delineated area. Overview of porphyry copper
resources in Indonesia as the results of mineral assessment includes
standardized database for known mineral deposits and occurrences, digital
regional-scale maps of tracts permissive for current known deposits as well as
undiscovered mineral resources, and estimates of undiscovered mineral
resources within permissive tracts for copper (copper-gold).

SARI

Penilaian Sumber Daya Mineral adalah suatu bidang penelitian dan aplikasi
metode kuantitatif untuk mengevaluasi potensi sumber daya mineral. Metoda ini
menjelaskan endapan mineral, menentukan kadar dan tonase, memperkirakan
keterdapatan endapan yang belum ditemukan dan memperkirakan jumlah
sumber daya mineral di daerah tersebut. Tujuan utamanya adalah untuk
menentukan daerah-daerah utama di Indonesia yang memiliki potensi sumber
daya mineral tertentu yang belum ditemukan dan untuk memperkirakan jumlah
sumber daya mineral tersebut sampai batas kedalaman 1 km dibawah
permukaan bumi. Penilaian ini menggunakan USGS 3-Part Quantitative Mineral
Resource Assessment Method. Metoda ini terdiri atas 3 bagian, yaitu (1)
menentukan tract untuk komoditas dan endapan tembaga porfiri berdasarkan
geologi endapan bijih, (2) memperkirakan jumlah sumber daya yang terkandung
dalam jenis endapan yang belum ditemukan dengan menggunakan karakteristik
endapan dan kandungan logam berdasarkan model kadar dan tonase, dan (3)
memperkirakan jumlah endapan yang belum ditemukan untuk setiap jenis di
daerah yang telah ditentukan. Pengkajian sumber daya tembaga porfiri di
Indonesia sebagai hasil penilaian sumber daya mineral ini meliputi database
standard untuk endapan mineral yang prospek maupun yang berupa indikasi,
peta digital regional dan tabel data daerah (tract) untuk endapan yang prospek
maupun yang belum ditemukan, estimasi sumber daya mineral yang belum
ditemukan dalam suatu tract untuk endapan tembaga (tembaga-emas).

»»  read more

ORGANIC PETROLOGY OF SELECTED TERTIARY KALIMANTAN COALS

Convention Bandung 2004 (CB2004)
The 33Convention Bandung 2004 (CB2004)
The 33AnnualConvention & Exhibition 2004

Indonesian Association ofGeologist
Horizon Hotel, 29-30 Nov, 1 Oct 2004, Bandung

ORGANIC PETROLOGY OF SELECTED TERTIARY
KALIMANTAN COALS

By :

Binarko Santoso and Bukin Daulay

R and D Centre for Mineral and Coal TechnologyJalan Jenderal Sudirman 623 Bandung 40211Ph. 022-6030483, fax. 022-6003373, email binarkos@tekmira.esdm.go.id

ABSTRACT

Study on organic petrology was carried out on both East and South Kalimantan Palaeogene andNeogene coals. West and Central Kalimantan coals are ignored in the study, because their
geological conditions are not favourable and the seams are usually thin and generally rich inargillaceous or arenaceous mineral matter.

Similarities and differences in type and rank characteristics in the coals reflect their geologicalsetting. Rank and type variation of the coals were assessed by petrographic examination of 40samples. The coals are dominated by vitrinite, common exinite and rare inertinite and mineralmatter. The type differences reflect climatic influence and differences in peat conditions.

Rank of the coals depends largely on the geological age and the level of temperature under
confining pressure (burial depth). Increased depth of burial and increased temperature andpressure over a period of time, consequently result in higher rank. Reflectance measurements on
the coals indicate that there is a substantial difference in rank between Palaeogene and Neogenecoals. The Palaeogene coals are sub-bituminous to high volatile bituminous rank (Rvmax of 0.53-
0.67%), whereas Neogene coals are brown to sub-bituminous rank (Rvmax of 0.30-0.57%),
according to the Australian classification.

SARI

Studi petrologi organik telah dilakukan terhadap batubara Paleogen dan Neogen diKalimantanTimur dan Selatan. Batubara Kalimantan Barat dan Tengah tidak termasuk dalam studi ini, sebabtatanan geologisnya kurang menarik dan lapisan-lapisan batubaranya umumnya tipis dan banyak
mengandung mineral berpartikel lempung dan pasir.

Kesamaan dan perbedaan karakteristik jenis dan peringkat batubara di daerah penelitian
mencerminkan tatanan geologisnya. Variasi jenis dan peringkat batubara tersebut diteliti di bawahpengujian petrografis terhadap 40 buah contoh. Batubara Kalimantan didominasi olehvitrinit,
eksinit dan sedikit inertinit dan mineral. Perbedaan jenis batubara tersebut mencerminkanpengaruh cuaca dan perbedaan lingkungan pembentukan gambutnya.

Peringkat batubara Kalimantan terkontrol oleh umur geologis, suhu dan ketebalan lapisanpenutupnya. Semakin tebal lapisan penutup, suhu dan tekanan pada suatu periode waktu tertentu,
menghasilkan peringkat yang lebih tinggi. Pengukuran reflektansi vitrinitnya menunjukkanperbedaan penting peringkat antara batubara Paleogen dan Neogen. Batubara Paleogen tersebutberperingkat subbituminus-bituminus zat terbang tinggi (Rvmax 0.53-0.67%), sedangkan batubaraNeogennya adalahbatubara coklat-subbituminus (Rvmax 0.30-0.57%), berdasarkan klasifikasiAustralia.

»»  read more

MINERAL RESOURCE ASSESSMENT OF PORPHYRY COPPER DEPOSITS IN INDONESIA USING THE USGS 3-PART ASSESSMENT METHOD

 

Bambang Tjahjono Setiabudi

Directorate of Mineral Resources Inventory

E-mail: BTSetiabudi@hotmail.com

 

ABSTRACT

Mineral Resource Assessment is a field of research and application of quantitative appraisal methods to evaluate potential mineral resources. Principally it describes mineral deposits, measures their grade and tonnage, estimate the occurrence of the undiscovered deposits and estimates mineral resources in the permissive tracts. The main objectives are to outline the principal areas in Indonesia that have potential for selected undiscovered mineral resources and to estimate the probable amounts of those mineral resources to a depth of 1 km below the earth's surface. The assessment is carried out using the USGS 3-Part Quantitative Mineral Resource Assessment Method. The 3-part method consists of firstly, delineating tracts for commodities and porphyry Cu deposit types based on the geology of the ore deposits, secondly, estimating the amount of resources contained in the undiscovered deposits using appropriate ore characteristics and metal contents based on grade and tonnage models and thirdly, estimating number of undiscovered deposits of each type for each delineated area. Overview of porphyry copper resources in Indonesia as the results of mineral assessment includes standardized database for known mineral deposits and occurrences, digital regional-scale maps of tracts permissive for current known deposits as well as undiscovered mineral resources, and estimates of undiscovered mineral resources within permissive tracts for copper (copper-gold).

SARI

Penilaian Sumber Daya Mineral adalah suatu bidang penelitian dan aplikasi metode kuantitatif untuk mengevaluasi potensi sumber daya mineral. Metoda ini menjelaskan endapan mineral, menentukan kadar dan tonase, memperkirakan keterdapatan endapan yang belum ditemukan dan memperkirakan jumlah sumber daya mineral di daerah tersebut. Tujuan utamanya adalah untuk menentukan daerah-daerah utama di Indonesia yang memiliki potensi sumber daya mineral tertentu yang belum ditemukan dan untuk memperkirakan jumlah sumber daya mineral tersebut sampai batas kedalaman 1 km dibawah permukaan bumi. Penilaian ini menggunakan USGS 3-Part Quantitative Mineral Resource Assessment Method. Metoda ini terdiri atas 3 bagian, yaitu (1) menentukan tract untuk komoditas dan endapan tembaga porfiri berdasarkan geologi endapan bijih, (2) memperkirakan jumlah sumber daya yang terkandung dalam jenis endapan yang belum ditemukan dengan menggunakan karakteristik endapan dan kandungan logam berdasarkan model kadar dan tonase, dan (3) memperkirakan jumlah endapan yang belum ditemukan untuk setiap jenis di daerah yang telah ditentukan. Pengkajian sumber daya tembaga porfiri di Indonesia sebagai hasil penilaian sumber daya mineral ini meliputi database standard untuk endapan mineral yang prospek maupun yang berupa indikasi, peta digital regional dan tabel data daerah (tract) untuk endapan yang prospek maupun yang belum ditemukan, estimasi sumber daya mineral yang belum ditemukan dalam suatu tract untuk endapan tembaga (tembaga-emas).

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TUNGSTEN AND GOLD MINERALIZATION IN THE LATUPA AREA, LUWU DISTRICT, SOUTH SULAWESI

 

Bambang Nugroho Widi* ), Sudarsono**)

*) Direktorat Inventarisasi Sumber Daya Mineral, Bandung

**)Puslitabang Geo-Teknologi LIPI, Bandung

 

Abstract

Tungsten mineralization occurrences in the Suguntu area, Latupa form an unique mineralization to study, particularly in the Indonesia Archipelago geological setting. It is usually occurred commonly in the continental or cratonic environment granitic rock. The presence of gold and a number of other sulfide- oxide minerals such as arsenopyrite, chalcopyrite and mangan as mineral association make the mineralization become more interesting and important in this region. Mineralization in this area is indicated by the presence of tungsten mineral (wolframite) bearing quartz vein intruding the granitic and metasediment host rocks. The vein trend is generally of about N 170 ° E to 190° with dip of about 70° to 90° with thickness from few centimeters to nearly 20 centimeters. Altered rocks type present in this area involve argilitization, propylitization, seritization (phyllic). Silicification found locally, particularly near to the vein. Based on the physical appearrence on the specimens, minerals association recognized are cahalcopyrite, pyrite, magnetite, hematiti and mangan. It seem mineralization formed in the mesothermal environment, at depth lower than epithermal zone (more than 500 meters below the paleosurface) with temperature formation > 300°. However, in order to ensure this suggestion, study on geochemistry, ore microscopy, fluid inclusion, petrography, pima, etc, are hughly needed to obtain an imaginationclearly in connection to know the relationship between tungsten (wolfram) and gold mineralization.

 

Sari

Keterdapatan mineralisasi tungsten di daerah Siguntu, Latupa merupakan bentuk mineralisasi yang unik untuk di pelajari khususnya pada tatanan geologi kepulauan di Indonesia. Hal ini biasa terjadi umumnya pada lingkungan kontinen atau batuan bersifat granitik. Kehadiran mineral emas dan mineral sulfida serta oksida lainnya seperti arsenopirit, kalkopirit , magnetit dan mangan menjadikan mineralisasi ini lebih menarik dan penting di kawasan ini. Mineralisasi di kawasa ini ditandai oleh hadirnya urat kuarsa mengandung mineral tungsten (wolframit) yang menerobos batuan metasedimen dan batuan granit. Pada umumnya arah urat adalah hampir uatara selatan (N 170 – 190°) dengan kemiringan antara 70 ~ 90° dan ketebalan urat dari beberapa sentimeter hingga mendekati 20 sentimeter. Batuan alterasi yang muncul adalah argilitisasi, propilitisasi, seritisasi dan setempat silisifikasi terutama dekat urat. Berdasarkan kenampakan fisik yang dikenal pada hand spesimen mineral assosiasinya adalah arsenopirit, wolframit, kalkopirit, pirit dan mangan. Agaknya mineralisasi terbentuk pada lingkungan mesotermal dengan kedalaman yang lebih dalam dari zona epitermal (lebih dari 500 m di bawah permukaan dengan temperatur pembentukan > 300°) Untuk memastikan dugaan ini studi geokimia, mikroskop bijih, petrografi, inklusi fluida, PIMA dan lain sebagianya sangat diperlukan guna mendapatkan gambaran secara lebih jelas dalam kaitannya untukmengetahui hubungan antara mineralisasi tungsten dan emas.

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LATERAL CONTINUITY PREDICTION OF LATERITE NICKEL DEPOSIT BETWEEN TWO DRILL BY USING GEOLOGICAL AND STATISTICAL APPROACH AT SOROWAKO AREA SOUTH SULAWESI PROVINCE

Asran Ilyas, Adi Tonggiroh, Agustinus T*

Geological Engineering, Hasanuddin University, Makassar, South Sulawesi, INDONESIA

asran_ilyas@yahoo.com, adi_unhas@yahoo.com

ABSTRACT

On mining process in the ore zone of laterite nickel deposit in Sorowako area then needed the prediction of the deposit in lateral continuity in underground. This prediction is very important in order to create the section of lateral continuity of laterite nickel deposit in underground between the nearest of two drill points in order to get the mining process effectively and efficiently. One of the prediction technique that could be develope is by using the minerals content series from top to bottom from the outcome of the logging data's between the nearest of two drill points by using geological and statistical approach. From the outcome of the prediction, it is get that this prediction technique is good enough and could be applied and developed for the mining process needed and developing of science and technology in the future.

Keywords : prediction, minerals content series, geological and statistical approach.

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HYDRAULIC CONDUCTIVITY BEHAVIORAL DEVELOPMENT ON ARTIFICIAL VEGETATION SUBSTRATES (made by coal fly ash, gravel G5 and clay) FOR THE COAL MINING RECLAMATION PROJECT „OBERDORF“ GKB-Bergbau GmbHKÖFLACH AUSTRIA

 

by :

 

Anggoro Tri Mursito

 

Research Centre for Geotechnology

Indonesian Institute of Sciences (LIPI)

Jl. Sangkuriang, Komplek LIPI Gedung 70, Bandung 40135

anggoro@geotek.lipi.go.id

 

abstract

 

An artificial soil mixed made out of electrical-coal power plant wastes (fly ash) and

material from the coal mine sites (clay and gravel G5) has been created for the

reclamation of open pit mine site. Physico-chemical properties were measured over

time to examine them in a chronosequence of 22 plots (each 400m2) with

systematically changing mixtures (1,2 and 3 components of varying proportions were

established and planted. In the field plots, available nutrient content was initially high

but established only for some of plots. Due to ecological function measurement,

physical parameter, which is hydraulic conductivity, is one of several physic

properties will have to be monitored and analysed.

 

According to the development value of the year of 2003 (spring) shows that

increasing of water permeability classes (class 6) is leaning to the direction of fly ash

and tegel (clay) composition. Class 5 are only in the trial plot number 5 and 9. Only in

one trial plot which is drop in class 4 (trial plot 16), but it is still classified into "good"

class (according to "Arbeitskreis Standortskartierung, 1996"). The trial plot number 1

has also classified into class 6, because the substrate composition in this trial is only

100% of gravel. It has to be the highest class, but it is not always the highest value of

water permeability. All the trial plots are classified into high to very-very high.

Compared results between initial (spring, 2000) and recent measurement (spring,

2003) is shown that extremely increased in the trial plot 3 and 13. In the year of 2003,

in trial plot number 3 and 13 are suddently flare up to 4 classes (from class 2 to 6).

As also analysed by Computed Tomography images of one component substrate

(100 % of tegel) shows that cracked structures clearly appear as a results of

decreasing precipitation in the last winter and also highly increasing of temperature

as well. High percentage of cracked means that water can easily flows. Most of the

trial plots are increasing of classes due to the season differences. The others (trial

plot number 1, 5, 6 and 9) remain in the same class.

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Local zonation of foraminifera in the North West Java Basin

Abstrac
Role of analysis foraminifera in North West Java Basin is importance because it can be determine age and depositional environment very well. This research observes foraminifers’ that emerging at the age Miocene in North West Java Basin. Research data is result of biostratigraphic analysis from 6 chosen well representing some fields oil and gas property of XXXXX which ahead done by group of Stratigraphy PPPTMGB "LEMIGAS" through service. The purpose is analyze and makes local of zonation foraminiferal that later earns as reference at the time of determination of zonation or age other well in North West Java Basin.

The age Miocene of planktonic foraminifers is enough abundance especially in the Upper Cibulakan and Parigi Formation, but unable to grow in the Talangakar and Baturaja Formation. The growth of bentonic foraminifers is good enough started from Talang Akar until Parigi Formation. Based on some literature and calibrated with nannoplankton and palinomorf, the benthonic foraminiferal earn also determine age. This thing based from first or last appearance of larger and smaller benthonic foraminiferal. The marker species of planktonic foraminifers are composed of Globorotalia tumida, Globorotalia merotumida, Globorotalia plesiotumida, Globorotalia acostansis, Globorotalia siakensis, Orbulina universa, Globigerinoides subquadratus, Globorotalia fohsi robusta, Globorotalia fohsi fohsi, Globigerinoides bisphaericus and Globigerinoides diminutus. The larger benthonic foraminiferal species is Lepidocyclina (T) orientalis, Borelis melo, Lepidocyclina (N) inflata, Lepidocyclina (N) tournoueri, Spiroclypeus sp. and Miogypsina sp. The age diagnostic species of the benthonic foraminifera of rotaliid group covers Pseudorotalia catiliformis, Pseudorotalia indopacifica, Pseudorotalia shcroeteriana angusta, Cavarotalia annecten, Asterorotalia yabei and Ammonia umbonata.

Result of this research is the form of 3 column of local zonation foraminiferal Miocene covering planktonic foraminiferal, larger benthonic foraminiferal and smaller benthonic foraminiferal (rotaliid group) zonation. Benthonic foraminiferal zonation only as complement when marker species of planktonic foraminifers unable to grow.

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Geochronology

From Wikipedia, the free encyclopedia

In the natural sciences under the umbrella of natural history, Geochronology is the science of determining the absolute age of rocks, fossils, and sediments, within a certain degree of uncertainty inherent within the method used. A variety of dating methods are used by geologists to achieve this.

Geochronology is different in application from biostratigraphy, which is the science of assigning sedimentary rocks to a known geological period via describing, cataloguing and comparing fossil floral and faunal assemblages. Biostratigraphy does not directly provide an absolute age determination of a rock, merely places it within an interval of time at which that fossil assemblage is known to have coexisted. Both disciplines work together hand in hand however, to the point they share the same system of naming rock layers and the time spans utilized to classify layers within a strata. (See table at right for terminology.)

For instance, with reference to the Geologic time scale, the Upper Permian (Lopingian) lasted from 270.6 +/- 0.7 Ma (Ma = millions of years ago) until somewhere between 250.1 +/- 0.4 Ma (oldest known Triassic) and 260.4 +/- 0.7 Ma (youngest known Lopingian) - a gap in known, dated fossil assemblages of nearly 10 Ma. While the biostratigraphic age of an Upper Permian bed may be shown to be Lopingian, the true date of the bed could be anywhere from 270 to 251 Ma.

On the other hand, a granite which is dated at 259.5 +/- 0.5 Ma can reasonably safely be called "Permian", or most properly, to have intruded in the Permian.
The science of geochronology is the prime tool used in the discipline of chronostratigraphy, which attempts to derive absolute age dates for all fossil assemblages and determine the geologic history of the Earth and extraterrestrial bodies.

Dating methods
• Radiometric techniques measure the decay of radioactive isotopes, and other radiogenic activity.
• Incremental techniques measure the regular addition of material to sediments or organisms.
• Correlation of marker horizons allow age-equivalence to be established between different sites.

Radiometric dating
By measuring the amount of radiocative decay of a radioactive isotope with a known half-life, geologists can establish the absolute age of the parent material. A number of radioactive isotopes are used for this purpose, and depending on the rate of decay, are used for dating different geological periods.
• Radiocarbon dating. This technique measures the decay of Carbon-14 in organic material (e.g. plant macrofossils), and can be applied to samples younger than about 50,000 years.
• Uranium-lead dating. This technique measures the ratio of two lead isotopes (Pb-206 and Pb-207) to the amount of uranium in a mineral or rock. Often applied to the trace mineral zircon in igneous rocks, this method is one of the two most commonly used (along with argon-argon dating) for geologic dating. Uranium-lead dating is applied to samples older than about 1 million years.
• Uranium-thorium dating. This technique is used to date speleothems, corals, carbonates, and fossil bones. Its range is from a few years to about 700,000 years.
• Potassium-argon dating and argon-argon dating. These techniques date metamorphic, igneous and volcanic rocks. They are also used to date volcanic ash layers within or overlying paleoanthropologic sites. The younger limit of the argon-argon method is a few thousand years.

Other radiogenic dating techniques include:
• Fission track dating
• Cosmogenic isotope dating
• Rubidium-strontium dating
• Samarium-neodymium dating
• Rhenium-osmium dating
• Lutetium-hafnium dating
• Paleomagnetic dating
• Thermo-luminescence dating (quartz exposure to heat)

Luminescence dating
Luminescence dating techniques observe 'light' emitted from materials such as quartz, diamond, feldspar, and calcite. Many types of luminescence techniques are utilized in geology, including optically stimulated luminescence (OSL), cathodoluminescence (CL), and thermoluminescence (TL). Thermoluminescence and optically stimulated luminescence are used in archaeology to date 'fired' objects such as pottery or cooking stones, and can be used to observe sand migration.

Incremental dating
Incremental dating techniques allow the construction of year-by-year annual chronologies, which can be fixed (i.e. linked to the present day and thus calendar or sidereal time) or floating.
• Dendrochronology
• Ice cores
• Lichenometry
• Varves

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Environmental Geology

From Wikipedia, the free encyclopedia

Environmental geology, like hydrogeology, is a multidisciplinary field of applied science and is closely related to engineering geology and somewhat related to environmental geography. They all involve the study of the interaction of humans with the geologic environment including the biosphere, the lithosphere, the hydrosphere, and to some extent the atmosphere,. It includes:
• managing geological and hydrogeological resources such as fossil fuels, minerals, water (surface and ground water), and land use.
• defining and mitigating exposure of natural hazards on humans
• managing industrial and domestic waste disposal and minimizing or eliminating effects of pollution, and
• performing associated activities, often involving litigation

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Enginering Geology

From Wikipedia, the free encyclopedia

Engineering Geology is the application of the geologic sciences to engineering practice for the purpose of assuring that the geologic factors affecting the location, design, construction, operation and maintenance of engineering works are recognized and adequately provided for. Engineering geologists investigate and provide geologic and geotechnical recommendations, analysis, and design. Engineering geologic studies may be performed during the planning, environmental impact analysis, civil engineering design, value engineering and construction phases of public and private works projects, and during post-construction and forensic phases of projects. Works completed by engineering geologists include; geologic hazards, geotechnical, material properties, landslide and slope stability, erosion, flooding, dewatering, and seismic investigations, etc. Engineering geologic studies are performed by a geologist or engineering geologist educated, professionally trained and skilled at the recognition and analysis of geologic hazards and adverse geologic conditions. Their overall objective is the protection of life and property against damage and the solution of geologic problems.

Engineering geologic studies may be performed:
• for residential, commercial and industrial developments;
• for governmental and military installations;
• for public works such as a power plant, wind turbine, transmission line, sewage treatment plant, water treatment plant, pipeline (aqueduct, sewer, outfall), tunnel, trenchless construction, canal, dam, reservoir, building, railroad, transit, highway, bridge, seismic retrofit, airport and park;
• for mine and quarry excavations, mine tailing dam, mine reclamation and mine tunneling;
• for wetland and habitat restoration programs;
• for coastal engineering, sand replenishment, bluff or sea cliff stability, harbor, pier and waterfront development;
• for offshore outfall, drilling platform and sub-sea pipeline, sub-sea cable; and
• for other types of facilities.
Geohazards and adverse geo-conditions
Typical geohazards or other adverse conditions evaluated by an engineering geologist include:
• fault rupture on seismically active faults ;
• seismic and earthquake hazards (ground shaking, liquefaction, lurching,lateral spreading, tsunami and seiche events);
• landslide, mudflow, rock fall and avalanche hazards ;
• unstable slopes and slope stability;
• erosion;
• slaking and heave of geologic formations;
• ground subsidence (such as due to ground water withdrawal, sinkhole collapse, cave collapse, decomposition of organic soils, and tectonic movement);
• volcanic hazards (volcanic eruptions, hot springs, pyroclastic flows, debris flows, debris avalanche, gas emissions, volcanic earthquakes);
• non-rippable or marginally rippable rock requiring heavy ripping or blasting;
• weak and collapsible soils;
• shallow ground water/seepage; and
• other types of geologic constraints.
An engineering geologist or geophysicist may be called upon to evaluate the excavatability (i.e. rippability) of earth (rock) materials to assess the need for pre-blasting during earthwork construction, as well as associated impacts due to vibration during blasting on projects.

Methods and reporting
The methods used by engineering geologists in their studies include
• geologic field mapping of geologic structures, geologic formations, soil units and hazards;
• the review of geologic literature, geologic maps, geotechnical reports, engineering plans, environmental reports, stereoscopic aerial photographs, remote sensing data, Global Positioning System (GPS) data, topographic maps and satellite imagery;
• the excavation, sampling and logging of earth/rock materials in drilled borings, backhoe test pits and trenches, fault trenching, and bulldozer pits;
• geophysical surveys (such as seismic refraction traverses, resistivity surveys, ground penetrating radar (GPR) surveys, magnetometer surveys, electromagnetic surveys, high-resolution sub-bottom profiling, and other geophysical methods);
• deformation monitoring as the systematic measurement and tracking of the alteration in the shape or dimensions of an object as a result of the application of stress to it manually or with an automatic deformation monitoring system; and
• other methods.

The field work is typically culminated in analysis of the data and the preparation of an engineering geologic report, geotechnical report, fault hazard or seismic hazard report, geophysical report, ground water resource report or hydrogeologic report. The engineering geologic report is often prepared in conjunction with a geotechnical report, but commonly provide geotechnical analysis and design recommendations independent of a geotechnical report. An engineering geologic report describes the objectives, methodology, references cited, tests performed, findings and recommendations for development. Engineering geologists also provide geologic data on topograpic maps, aerial photographs, geologic maps, Geographic Information System (GIS) maps, or other map bases.

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Major subdisciplines in petroleum geology

Several major subdisciplines exist in petroleum geology specifically to study the seven key elements discussed above.

Analysis of source rocks
In terms of source rock analysis, several facts need to be established. Firstly, the question of whether there actually is any source rock in the area must be answered. Delineation and identification of potential source rocks depends on studies of the local stratigraphy, palaeogeography and sedimentology to determine the likelihood of organic-rich sediments having been deposited in the past.
If the likelihood of there being a source rock is thought to be high, the next matter to address is the state of thermal maturity of the source, and the timing of maturation. Maturation of source rocks (see diagenesis and fossil fuels) depends strongly on temperature, such that the majority of oil generation occurs in the 60° to 120°C range. Gas generation starts at similar temperatures, but may continue up beyond this range, perhaps as high as 200°C. In order to determine the likelihood of oil/gas generation, therefore, the thermal history of the source rock must be calculated. This is performed with a combination of geochemical analysis of the source rock (to determine the type of kerogens present and their maturation characteristics) and basin modelling methods, such as back-stripping, to model the thermal gradient in the sedimentary column.

Analysis of reservoir
The existence of a reservoir rock (typically, sandstones and fractured limestones) is determined through a combination of regional studies (i.e. analysis of other wells in the area), stratigraphy and sedimentology (to quantify the pattern and extent of sedimentation) and seismic interpretation. Once a possible hydrocarbon reservoir is identified, the key physical characteristics of a reservoir that are of interest to a hydrocarbon explorationist are its porosity and permeability. Traditionally, these were determined through the study of hand specimens, contiguous parts of the reservoir that outcrop at the surface and by the technique of formation evaluation using wireline tools passed down the well itself. Modern advances in seismic data acquisition and processing have meant that seismic attributes of subsurface rocks are readily available and can be used to infer physical/sedimentary properties of the rocks themselves.

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Petroleum Geology

From Wikipedia, the free encyclopedia

Petroleum geology is principally concerned with the evaluation of seven key elements in sedimentary basins:

A structural trap, where a fault has juxtaposed a porous and permeable reservoir against an impermeable seal. Oil (shown in red) accumulates against the seal, to the depth of the base of the seal. Any further oil migrating in from the source will escape to the surface and seep.
• Source
• Reservoir
• Seal
• Trap
• Timing
• Maturation
• Migration

In general, all these elements must be assessed via a limited 'window' into the subsurface world, provided by one (or possibly more) exploration wells. These wells present only a 1-dimensional segment through the Earth and the skill of inferring 3-dimensional characteristics from them is one of the most fundamental in petroleum geology. Recently, the availability of cheap and high quality 3D seismic data (from reflection seismology) has greatly aided the accuracy of such interpretation. The following section discusses these elements in brief. For a more in-depth treatise, see the second half of this article below.

Evaluation of the source uses the methods of geochemistry to quantify the nature of organic-rich rocks which contain the precursors to hydrocarbons, such that the type and quality of expelled hydrocarbon can be assessed.

The reservoir is a porous and permeable lithological unit or set of units that holds the hydrocarbon reserves. Analysis of reservoirs at the simplest level requires an assessment of their porosity (to calculate the volume of in situ hydrocarbons) and their permeability (to calculate how easily hydrocarbons will flow out of them). Some of the key disciplines used in reservoir analysis are the fields of stratigraphy, sedimentology, and reservoir engineering.

The seal, or cap rock, is a unit with low permeability that impedes the escape of hydrocarbons from the reservoir rock. Common seals include evaporites, chalks and shales. Analysis of seals involves assessment of their thickness and extent, such that their effectiveness can be quantified.

The trap is the stratigraphic or structural feature that ensures the juxtaposition of reservoir and seal such that hydrocarbons remain trapped in the subsurface, rather than escaping (due to their natural buoyancy) and being lost.
Analysis of maturation involves assessing the thermal history of the source rock in order to make predictions of the amount and timing of hydrocarbon generation and expulsion.
Finally, careful studies of migration reveal information on how hydrocarbons move from source to reservoir and help quantify the source (or kitchen) of hydrocarbons in a particular area.

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Introduction Mining

Mining is the extraction of valuable minerals or other geological materials from the earth, usually (but not always) from an ore body, vein or (coal) seam. Materials recovered by mining include bauxite, coal, copper, gold, silver, diamonds, iron, precious metals, lead, limestone, magnesite, nickel, phosphate, oil shale, rock salt, tin, uranium and molybdenum. Any material that cannot be grown from agricultural processes, or created artificially in a laboratory or factory, is usually mined. Mining in a wider sense comprises extraction of any non-renewable resource (e.g., petroleum, natural gas, or even water).

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Economic Geology

From Wikipedia

Economic geology is concerned with earth materials that can be utilized for economic and/or industrial purposes. These materials include precious and base metals, nonmetallic minerals, construction-grade stone, petroleum minerals, coal, and water. The term commonly refers to metallic mineral deposits and mineral resources. The techniques employed by other earth science disciplines (such as geochemistry, mineralogy, geophysics, and structural geology) might all be used to understand, describe, and exploit an ore deposit.
Economic geology is studied and practiced by geologists; however it is of prime interest to investment bankers, stock analysts and other professions such as engineers, environmental scientists and conservationists because of the far-reaching impact which extractive industries have upon society, the economy and the environment.

Mineral resources
Mineral resources are concentrations of minerals which are of note for current and future societal needs. Ore is classified as mineralization economically and technically feasible for extraction. Not all mineralization meets these criteria for various reasons. The specific categories of mineralization in an economic sense are:
• mineral occurrences or prospects which are of geological interest but may not be economic interest
• mineral resources, include those which are potentially economically and technically feasible, and those which are not
• ore reserves, must be economically and technically feasible to extract

Ore geology
Geologists are involved in the study of ore deposits, which includes the study of ore genesis and the processes within the Earth's crust which form and concentrate ore minerals into economically viable quantities.
Study of metallic ore deposits involves the use of structural geology, geochemistry, the study of metamorphism and its processes, as well as understanding metasomatism and other processes related to ore genesis.
Ore deposits are delineated by mineral exploration, which utilizes geochemical prospecting, drilling and resource estimation via geostatistics to quantify economic ore bodies. The ultimate aim of this process is mining.

Coal and petroleum geology
The study of sedimentology is of prime importance to the delineation of economic reserves of petroleum and coal energy resources

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Tectonics

From Wikipedia, the free encyclopedia

Tectonics, (from the Greek for "builder", tekton), is a field of study within geology concerned generally with the structures within the crust of the Earth (or other planets) and particularly with the forces and movements that have operated in a region to create these structures.

Tectonics is concerned with the orogenies and tectonic development of cratons and tectonic terranes as well as the earthquake and volcanic belts which directly affect much of the global population. Tectonic studies are also important for understanding erosion patterns in geomorphology and as guides for the economic geologist searching for petroleum and metallic ores.

A subfield of tectonics that deals with tectonic phenomena in the geologically recent period is called neotectonics.

Tectonic studies have application to lunar and planetary studies, whether or not those bodies have active tectonic plate systems.

Since the 1960s, plate tectonics has become by far the dominant theory to explain the origin and forces responsible for the tectonic features of the continents and ocean basins.
There are three main types of tectonic regime
• Extensional tectonics
• Thrust (Contractional) tectonics
• Strike-slip tectonics
Extensional tectonics is concerned with the structures formed, and the tectonic processes associated with, the stretching of the crust or lithosphere.
Areas of extensional tectonics are typically associated with:
• The development of continental rifts, with or without the effects of mantle upwelling
• The gravitational spreading of zones of thickened crust formed during continent-continent collision
• Tensional flexures along strike-slip faults
• On passive margins where an effective basal detachment layer is present at the upper end of a linked system

Extensional structures
The main structures formed in areas of extensional tectonics are normal faults and graben structures.
Prominent examples include:
• The East African Rift, a major continental rift system
• The Basin and Range province of western North America
• The global mid-ocean ridge system
• The Dead Sea basin formed at a releasing bend along a continental transform boundary

Thrust tectonics is concerned with the structures formed, and the tectonic processes associated with, the shortening of the crust or lithosphere.
Areas of thrust tectonics are typically associated with:
• The collision of two continents or a continent and an island arc at a destructive plate boundary
• Restraining bends on strike-slip faults
• On passive margins, balancing up-dip extension, where an effective detachment layer is present

Strike-slip tectonics is concerned with the structures formed by, and the tectonic processes associated with, zones of lateral displacement within the crust or lithosphere.
Areas of strike-slip tectonics are associated with
• Continental transform (conservative) plate boundaries
• Lateral ramps in areas of extensional or contractional tectonics accommodating lateral offsets between major extensional or thrust faults
• Zones of oblique continent-continent collision
• The deforming foreland of a zone of continent-continent collision, a process sometimes known as escape tectonics

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Important Principles of Geology

There are a number of important principles in geology. Many of these involve the ability to provide the relative ages of strata or the manner in which they were formed.
The principle of intrusive relationships concerns crosscutting intrusions. In geology, when an igneous intrusion cuts across a formation of sedimentary rock, it can be determined that the igneous intrusion is younger than the sedimentary rock. There are a number of different types of intrusions, including stocks, laccoliths, batholiths, sills and dikes.

The principle of cross-cutting relationships pertains to the formation of faults and the age of the sequences through which they cut. Faults are younger than the rocks they cut; accordingly, if a fault is found that penetrates some formations but not those on top of it, then the formations that were cut are older than the fault, and the ones that are not cut must be younger than the fault. Finding the key bed in these situations may help determine whether the fault is a normal fault or a thrust fault.

The principle of inclusions and components states that, with sedimentary rocks, if inclusions (or clasts) are found in a formation, then the inclusions must be older than the formation that contains them. For example, in sedimentary rocks, it is common for gravel from an older formation to be ripped up and included in a newer layer. A similar situation with igneous rocks occurs when xenoliths are found. These foreign bodies are picked up as magma or lava flows, and are incorporated, later to cool in the matrix. As a result, xenoliths are older than the rock which contains them.

The principle of uniformitarianism states that the geologic processes observed in operation that modify the Earth's crust at present have worked in much the same way over geologic time. A fundamental principle of geology advanced by the 18th century Scottish physician and geologist James Hutton, is that "the present is the key to the past." In Hutton's words: "the past history of our globe must be explained by what can be seen to be happening now."

The principle of original horizontality states that the deposition of sediments occurs as essentially horizontal beds. Observation of modern marine and non-marine sediments in a wide variety of environments supports this generalization (although cross-bedding is inclined, the overall orientation of cross-bedded units is horizontal).

The principle of superposition states that a sedimentary rock layer in a tectonically undisturbed sequence is younger than the one beneath it and older than the one above it. Logically a younger layer cannot slip beneath a layer previously deposited. This principle allows sedimentary layers to be viewed as a form of vertical time line, a partial or complete record of the time elapsed from deposition of the lowest layer to deposition of the highest bed.

The principle of faunal succession is based on the appearance of fossils in sedimentary rocks. As organisms exist at the same time period throughout the world, their presence or (sometimes) absence may be used to provide a relative age of the formations in which they are found. Based on principles laid out by William Smith almost a hundred years before the publication of Charles Darwin's theory of evolution, the principles of succession were developed independently of evolutionary thought. The principle becomes quite complex, however, given the uncertainties of fossilization, the localization of fossil types due to lateral changes in habitat (facies change in sedimentary strata), and that not all fossils may be found globally at the same time.

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History of Geology

A mosquito and a fly in this Baltic amber necklace are between 40 and 60 million years old
The work Peri Lithon (On Stones) by Theophrastus (372-287 BC), a student of Aristotle, remained authoritative for millennia. Peri Lithon was translated into Latin and some other foreign languages. Its interpretation of fossils was the most dominant theory in classical Antiquity and the early Middle Ages, until it was replaced by Avicenna's theory of petrifying fluids (succus lapidificatus) in the late Middle Ages.[2][3] In the Roman period, Pliny the Elder produced a very extensive discussion of many more minerals and metals then widely used for practical ends. He is among the first to correctly identify the origin of amber as a fossilized resin from pine trees by the observation of insects trapped within some pieces. He also laid the basis of crystallography by recognising the octahedral habit of diamond.

Some modern scholars, such as Fielding H. Garrison, are of the opinion that modern geology began in the medieval Islamic world.[4] Abu al-Rayhan al-Biruni (973-1048 AD) was one of the earliest Muslim geologists, whose works included the earliest writings on the geology of India, hypothesizing that the Indian subcontinent was once a sea.[5] Ibn Sina (Avicenna, 981-1037), in particular, made significant contributions to geology and the natural sciences (which he called Attabieyat) along with other natural philosophers such as Ikhwan AI-Safa and many others. He wrote an encyclopaedic work entitled “Kitab al-Shifa” (the Book of Cure, Healing or Remedy from ignorance), in which Part 2, Section 5, contains his essay on Mineralogy and Meteorology, in six chapters: Formation of mountains, The advantages of mountains in the formation of clouds; Sources of water; Origin of earthquakes; Formation of minerals; The diversity of earth’s terrain. These principles were later known in the Renaissance of Europe as the law of superposition of strata, the concept of catastrophism, and the doctrine of uniformitarianism. These concepts were also embodied in the Theory of the Earth by James Hutton in the Eighteenth century C.E. Academics such as Toulmin and Goodfield (1965), commented on Avicenna's contribution: "Around A.D. 1000, Avicenna was already suggesting a hypothesis about the origin of mountain ranges, which in the Christian world, would still have been considered quite radical eight hundred years later".[6] Avicenna's scientific methodology of field observation was also original in the Earth sciences, and remains an essential part of modern geological investigations.[3]

In China, the polymath Shen Kua (1031-1095) formulated a hypothesis for the process of land formation: based on his observation of fossil animal shells in a geological stratum in a mountain hundreds of miles from the ocean, he inferred that the land was formed by erosion of the mountains and by deposition of silt.

Georg Agricola (1494-1555), a physician, wrote the first systematic treatise about mining and smelting works, De re metallica libri XII, with an appendix Buch von den Lebewesen unter Tage (Book of the Creatures Beneath the Earth). He covered subjects like wind energy, hydrodynamic power, melting cookers, transport of ores, extraction of soda, sulfur and alum, and administrative issues. The book was published in 1556. Nicolas Steno (1638-1686) is credited with the law of superposition, the principle of original horizontality, and the principle of lateral continuity: three defining principles of stratigraphy. Previous attempts at such statements met accusations of heresy from the Church.[citation needed]

By the 1700s Jean-Étienne Guettard and Nicolas Desmarest hiked central France and recorded their observations on geological maps; Guettard recorded the first observation of the volcanic origins of this part of France.

William Smith (1769-1839) drew some of the first geological maps and began the process of ordering rock strata (layers) by examining the fossils contained in them.

James Hutton is often viewed as the first modern geologist. In 1785 he presented a paper entitled Theory of the Earth to the Royal Society of Edinburgh. In his paper, he explained his theory that the Earth must be much older than had previously been supposed in order to allow enough time for mountains to be eroded and for sediments to form new rocks at the bottom of the sea, which in turn were raised up to become dry land. Hutton published a two-volume version of his ideas in 1795 (Vol. 1, Vol. 2).

Followers of Hutton were known as Plutonists because they believed that some rocks were formed by vulcanism which is the deposition of lava from volcanoes, as opposed to the Neptunists, who believed that all rocks had settled out of a large ocean whose level gradually dropped over time.

In 1811 Georges Cuvier and Alexandre Brongniart published their explanation of the antiquity of the Earth, inspired by Cuvier's discovery of fossil elephant bones in Paris. To prove this, they formulated the principle of stratigraphic succession of the layers of the earth. They were independently anticipated by William Smith's stratigraphic studies on England and Scotland.

Sir Charles Lyell first published his famous book, Principles of Geology, in 1830. Lyell continued to publish new revisions until he died in 1875. The book, which influenced the thought of Charles Darwin, successfully promoted the doctrine of uniformitarianism. This theory states that slow geological processes have occurred throughout the Earth's history and are still occurring today. In contrast, catastrophism is the theory that Earth's features formed in single, catastrophic events and remained unchanged thereafter. Though Hutton believed in uniformitarianism, the idea was not widely accepted at the time.

Plate tectonics - seafloor spreading and continental drift illustrated on relief globe of the Field Museum

19th century geology revolved around the question of the Earth's exact age. Estimates varied from a few 100,000 to billions of years. The most significant advance in 20th century geology has been the development of the theory of plate tectonics in the 1960s. Plate tectonic theory arose out of two separate geological observations: seafloor spreading and continental drift. The theory revolutionized the Earth sciences.
The theory of continental drift was proposed by Frank Bursley Taylor in 1908, expanded by Alfred Wegener in 1912 and by Arthur Holmes, but wasn't broadly accepted until the late 1960s when the theory of plate tectonics was developed.

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Geology Definition

From Wikipedia, the free encyclopedia
Geology (from Greek: γη, gê, "earth"; and λόγος, logos, "speech" lit. to talk about the earth) is the science and study of the solid matter that constitutes the Earth. Encompassing such things as rocks, soil, and gemstones, geology studies the composition, structure, physical properties, history, and the processes that shape Earth's components. It is one of the Earth sciences. Geologists have established the age of the Earth at about 4.6 billion (4.6x109) years, and have determined that the Earth's lithosphere, which includes the crust, is fragmented into tectonic plates that move over a rheic upper mantle (asthenosphere) via processes that are collectively referred to as plate tectonics. Geologists help locate and manage the Earth's natural resources, such as petroleum and coal, as well as metals such as iron, copper, and uranium. Additional economic interests include gemstones and many minerals such as asbestos, perlite, mica, phosphates, zeolites, clay, pumice, quartz, and silica, as well as elements such as sulfur, chlorine, and helium. Geology is also of great importance in the applied fields of civil engineering, soil mechanics, hydrology, environmental engineering and geohazards.
Planetary geology (sometimes known as Astrogeology) refers to the application of geologic principles to other bodies of the solar system. Specialised terms such as selenology (studies of the moon), areology (of Mars), etc., are also in use. Colloquially, geology is most often used with another noun when indicating extra-Earth bodies (e.g. "the geology of Mars").
The word "geology" was first used by Jean-André Deluc in the year 1778 and introduced as a fixed term by Horace-Bénédict de Saussure in the year 1779. The science was not included in Encyclopædia Britannica's third edition completed in 1797, but had a lengthy entry in the fourth edition completed by 1809.[1] An older meaning of the word was first used by Richard de Bury to distinguish between earthly and theological jurisprudence.

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