Дэлгэрэнгүй мэдээлэл

аман илтгэл

This review includes the results of coal petrography. Maceral compositions are calculated on mineral matter free basis. Studied Mongolian coals are vitrinertite, duroclarite, clarodurite, and clarite. Vitirinte contents range from 38.8% to 96.6%, inertinte contents vary from 2.0% to 63.0%. Liptinite content is less than 13.7%

During the last decade, significant geological studies on fossil fuels and sedimentary basins in Mongolia have been completed; e.g., more than 100 coal deposits were explored. This review includes recent advances in tectonic setting of sedimentary basins, depositional environments of fossil fuel hosting sedimentary rocks, and quality and resources of coal, oil shale and petroleum source rocks. It also covers the results of coking coal blending studies, oil shale pyrolysis and the outcome of the first evaluation of coal bed methane potential of Mongolia.

Монгол орны геологийн хөгжлийг үндсэнд нь: кембрийн өмнөх, палеозойн эхэн, палеозойн дунд ба сүүл, мезозойн, кайнозойн гэсэн таван үе шатанд хуваах боловч үе шатуудын ялгаа болон одоогийн хотгор гүдгэрт нөлөөлөх байдлыг тодорхой болгохын үүднээс кембрийн өмнө ба палеозойн эхэн үе шат, палеозойн дунд ба сүүл үе шат, мезозойн ба кайнозойн үе шат, дөрөвдөгч галавын үе шат гэж ялган үзэж болох юм. Кембрийн өмнө ба палеозойн эхэн үе шатанд Монгол орны нутаг дэвсгэрт Завханы эх газар, түүний баруун болон зүүн талаар Палео-Азийн ба Палео-Номхон далай хөгжиж байсан бол палеозойн дунд ба сүүл үе шатанд эдгээр далайнууд хаагдаж эх газрын горимд шилжсэний сацуу Монгол орны өмнө талд Палео-Тетисын далай хөгжиж эхэлжээ. Палео-Тетисын далай хаагдсанаар мезозой ба кайнозойн үе шатанд Монгол орны газар нутаг эх газрын хөгжлөөр хөгжиж өнөөг хүрч байгаа ба энэ хооронд дөрөвдөгч галавын үе шатанд их мөстлөгийн нөлөөнд автсан нь гадаргын хөгжлийн өөрчлөлтөнд томоохон нөлөөг үзүүлсэн ажээ. Монголын нутаг дэвсгэр ирээдүй хойчдоо ямар хөгжлийг дамжин ямар болох, хэрхэн орших, яаж өөрчлөгдөх асуудал цаашдын судалгааны гол сэдвүүдийн нэг юм.

Сайхан-Овоо формацын элсэн чулууны петрологи ба геохимийн судалгаар тухайн талбайн элсэн чулууны ангилал хуримтлалын орчин тархалтын зүй тогтлыг судалсан

Нарийнсухайтын ордын нүүрсний петрографийн судалгаа, хүлэр хуримтлалын орчинг тодорхойлсон

Монгол Улсад 20-р зууны хагасаас эхлэн геологи шинжилгээний ажил эрчимтэй өрнөж эхэлснээр өсөн нэмэгдэж байгаа мэргэжилтний хэрэгцээг дотоодын боловсон хүчнээр хангах шаардлага гарч ирсэн бөгөөд үндэсний геологийн сургалтыг зохион байгуулсан нь Монголын геологийн салбарын хөгжилд томоохон түлхэц болсон байна. 1960 оны 4-р сарын 11-ний өдрийн БНМАУ-ын Сайд нарын зөвлөлийн ба МАХН-ын Төв хорооны 171/112-р тогтоолын дагуу тухайн ондоо МУИС-ийн Байгалийн ухааны факультет (БУФ)-д Геологийн анги нээн хичээллүүлж эхэлснээр Монгол улсад Геологийн дээд мэргэжилтэй боловсон хүчин бэлтгэж эхлэв. 1982 онд МУИС-ийн харьяа Политехникийн дээд сургууль салснаар МУИС Геологийн ангигүй болжээ. Монгол Улсын ууган их сургууль МУИС-д Геологийн анги зайлшгүй байх шаардлагаар 1991 онд МУИС-ийн Ректорын тушаал гарч, тухайн оны 4-р сарын 1-нд БУФ-ийн дэргэд Геологийн тэнхим байгуулагдаж сургалтын ажлыг эхлүүлснээр МУИС-д геологийн мэргэжилтэн бэлтгэх хоёр дахь үе шат эхэлсэн юм. 1992 оноос Геологийн салбарын багшлах боловсон хүчин, сургалт-эрдэм шинжилгээний үйл ажиллагааг өргөжүүлэн хөгжүүлэх зорилгоор өргөн мэдлэг боловсрол, үйлдвэрлэлийн дадлага туршлагатай эрдэмтэд, судлаачдыг багшаар ажиллуулж эхэлсэн ба тэнхимийн багш нар Монголын геологи, геодинамик, тектоник, геоморфологи, ашигт малтмалын геологи, петрографийн судалгаа, палеонтологи, палеогеограф, ашигт малтмалын ордын эдийн засгийн үнэлгээ, мөн газрын доорх усны экологи, нүүрсний геологи, шатах ашигт малтмалын геохимийн чиглэлүүдээр ажиллаж, олон арван бүтээл туурвисан нь Монголын геологийн шинжлэх ухааны хөгжилд томоохон үүргийг гүйцэтгэж хөгжүүлсэн билээ.

Middle and Upper Jurassic 18 sandstone core samples from exploration borehole, drilled in Nariinsukhait coal deposit, was studied. Geochemistry of samples indicates that sandstones were derived from acidic and intermediate rocks and mixed with recycled older sedimentary rocks. Possible sources are volcano-sedimentary rocks of Mississippian Tost Formation, granite and granodiorite of Early-Late Carboniferous Tavan-Uul complex and sedimentary rocks of Middle-Upper Triassic Noyon Formation. Paleoclimate indices (C-value, Rb/Sr, Sr/Ba, 1000xRb/K2O and CIA) reflect that coal seams were accumulated in warmer and more humid climate, when paleo-weathering was intense, whereas sandstones were deposited in relatively cold and arid climate. In Late Jurassic, it is more likely that paleoclimate became more arid and cold compared with Middle Jurassic, indicated by quite low CIA and Rb/Sr. Redox condition (Th/U, Ni/Co and V/Cr) was variable, probably controlled by paleoclimate. Moreover, various discrimination diagrams suggested that Middle Jurassic coal-bearing sedimentary rocks were accumulated in foreland basin. It is consistent with previous interpretations of regional tectonic during Triassic and Jurassic time. Түлхүүр үг: элсэн чулуу, тектоник, дунд юра, нүүрс, өмнөд Mонгол, форланд

Могойн гол нүүрсний орд нь Хөвсгөл аймгийн Цэцэрлэг сумын нутагт орших бөгөөд нүүрс нь доод-дунд юрын настай Могойнгол формац (J1-2mg)-д агуулагдана. Элсэн чулуу, шаврын петрографи, геохимийн шинжилгээгээр тухайн чулуулгийн гарал үүсэл, тектоникийн нөхцөл болон тэжээгч мужийн уур амьсгал, өгөршлийн эрчим зэрэг хуримтлалын эртний орчныг тодорхойлно. Могойн голын нүүрсний орд орчим тархсан 2300 метр зузаантай дунд юрын тунамал чулуулаг нь Хойд Монголын геологийн хөгжлийн түүхийг сэргээн босгоход тодорхой хувь нэмэр болох юм . Энэ судалгаагаар дунд юрын нүүрс агуулсан Могойнгол формацын элсэн чулуу, шаврын геохимийн судалгаа хийж, нүүрс агуулсан тунамал хурдас хуримтлагдсан орчин, тектоникийн нөхцөлийг сэргээн босгохыг зорилоо.

Тавантолгойн чулуу нvvрсний орд нь Өмнөговь аймгийн Цогтцэций сумын нутагт, сумын төвөөс баруун урагш 18км-т оршдог. Улаанбаатар хотоос 560км-т буюу газар зvйн уртрагийн 105025I-105032I хойд өргөрөгийн 43035I-43039I солбилцолд далайн төвшнөөс дээш 1500-1830 м-ийн өндөрлөгт Их шанхайн массивийн төв Улааннуурын хөндийд байрладаг. Элсэн чулууны петрографи, геохимийн судалгаагаар тухайн чулуулгийн гарал үүсэл, геодинамикийн нөхцөл болон тэжээгч мужийн уур амьсгал, өгөршлийн эрчим зэрэг хурдас хуримтлалын эртний орчныг тодорхойлж болно. Тавантолгой нүүрсний орд орчим тархсан 3300 метр зузаантай пермийн хурдас нь Өмнөд Монголын пермийн хурдсын бүтэн зүсэлт гэж тооцогддог. Нөгөө талаас пермийн цаг үеийн Өмнөд Монголын геологийн хөгжлийн түүхийг сэргээн босгох нь палеозойн цаг үеийн Төв Азийн геодинамикийн түүхийг сэргээн босгоход тодорхой хувь нэмэр болох юм. Энэ судалгаагаар дунд пермийн нүүрс агуулсан Тавантолгой формацийн элсэн чулууны геохимийн судалгаа хийж, нүүрс агуулсан тунамал хурдас хуримтлагдсан орчин, тектоникийн нөхцлийг сэргээн босгохыг зорилоо.

Сайхан-Овоо формаци нь Дундговь аймгийн Сайхан-Овоо суманд оршино. Доод-дунд Юрийн настай Сайхан-Овоо формаци нь Идэрмэгийн террейнд (Г.Бадарч) харьяалагдана. Сайхан-Овоо хотгор нь Төв Монголд орших Мезо-Кайнозойн хамгийн том хотгор юм. Уг хотгор нь нүүрс, газрын тос, шатдаг занарын хувьд хэтийн төлөв сайтай ялангуяа газрын тосны хувьд маш чухал тунамал сав болно. Хотгорыг Юра, Цэрдийн тунамал хурдас дүүргэх ба эдгээр хурдсаас доод-дунд Юрийн Сайхан- Овоо формацын зузаан 2800 м хүрэх (Мөнхцэрэн нар, 2014) бөгөөд нүүрс, шатдаг занар агуулна (жишээлбэл: Цагаан-Овоо орд) (Бат-Эрдэнэ, 2012-V боть, Erdenetsogt et al., 2017). Тус формаци нь дээд ба доод мэмбэрт хуваагддаг.

Middle Jurassic (five samples from one location) and Lower Cretaceous (thirty-two samples from eight locations) lacustrine sedimentary rocks of central Mongolia were studied to determine their depositional environments and petroleum source rock potential. The Middle Jurassic shale contains sufficient organic matter (OM) with Type II/III kerogen to represent a mixed oil and gas potential source rock. Tmax and biomarker maturity indices suggest a thermally immature level. Pristane/phytane and the gammacerane index indicate that the shale accumulated in an oxic, freshwater environment. Terrigenous OM with input from algae and macrophytes was a major contributor as indicated by long-chain n-alkanes and the abundance of C29 regular steranes. The stable carbon and nitrogen isotope compositions and kerogen types agree with land plant derived OM. Lower Cretaceous shales are highly oil-prone but thermally immature, reflected by Rock-Eval data and biomarker parameters. Carbon preference index (CPI), n-alkane distributions, and C27/C29 ratios suggest that OM in Lower Cretaceous shales is a mixture of phytoplankton, macrophyte, and land plant. The contribution from algal OM is variable. Lower Cretaceous shales were deposited in stratified lakes with anoxic bottom waters and the salinity of paleolakes was variable, indicated by Pr/Ph and the gammacerane index, respectively. Organic geochemical characteristics and depositional environments of Middle Jurassic and Lower Cretaceous sedimentary rocks studied herein are similar to those of Jurassic source rocks in western Chinese basins and Lower Cretaceous source rocks in eastern Mongolian basins, respectively.

hujirt is a syncline that hosts Jurassic coal deposit in Northern Mongolia. Nine coal samples collected from exploration borehole were selected for analyses of major oxide and trace elements of coal ash. The average value of CAI for the samples is 82.8, reflecting intensive weathering in the source area. The plotted data on A-CN-K diagram displays that rocks in coal were sourced mainly from Early Permian andesite and basalt and Early Paleozoic granodiorite, which borders Khujirt syncline. It is also supported by Al2O3/TiO2 (avg. 18.4) and Ti/Zr (avg. 37.1) ratios. To infer tectonic setting, two multi-dimensional discrimination diagrams were used. The results suggest that the tectonic setting of Khujirt was foreland basin that was probably formed by closure of Mongol-Okhotsk Ocean. Low Rb/Sr (0.02-0.04) and high Sr/Cu (13.8-30.6) ratios of the studied samples indicate that arid climate condition was dominant during the deposition of Khujirt peat accumulation. This conclusion is supported by C-values. Due to arid condition, salinity was high, reflected by substantially high Sr/Ba ratio varying from 1.7 to 2.7.

Middle and Upper Jurassic 18 sandstone core samples from exploration borehole, drilled in Nariinsukhait coal deposit, was studied. Geochemistry of samples indicates that sandstones were derived from acidic and intermediate rocks and mixed with recycled older sedimentary rocks. Possible sources are volcanosedimentary rocks of Mississippian Tost Formation, granite and granodiorite of Early-Late Carboniferous Tavan-Uul complex and sedimentary rocks of MiddleUpper Triassic Noyon Formation. Paleoclimate indices (C-value, Rb/Sr, Sr/Ba, 1000xRb/K2O and CIA) reflect that coal seams were accumulated in warmer and more humid climate, when paleo-weathering was intense, whereas sandstones were deposited in relatively cold and arid climate. In Late Jurassic, it is more likely that paleoclimate became more arid and cold compared with Middle Jurassic, indicated by quite low CIA and Rb/Sr. Redox condition (Th/U, Ni/Co and V/Cr) was variable, probably controlled by paleoclimate. Moreover, various discrimination diagrams suggested that Middle Jurassic coal-bearing sedimentary rocks were accumulated in foreland basin. It is consistent with previous interpretations of regional tectonic during Triassic and Jurassic time.

Based on the geochemistry of coal samples, collected from East and West mines of Nariinsukhait deposit, provenance, tectonic settings and source areapaleoweathering and paleoclimate was reconstructed. Sediments accumulated in peat swamp were mainly from acidic rocks mixed with smaller amount of intermediate rocks, indicated by Al2O3/TiO2 and A-K-CN diagrams. Seam 5 was deposited under realtively hot climate compared with upper seams (Seam 8, 9 and 10). Seam 5 is characterized by high Sr/Cu (avg. 7.4), Sr/Ba (avg. 2.5) and inertinite content (up to 35%). For upper seams, Sr/Cu (4.8), Sr/Ba (1.5) and inertinite content (~14%) are low, indicating more humid climate and fresher water body. CIA, Ni/Co and V/Cr support the findings. In addition, сoal was deposited in foreland basin. Collision tectonic setting was dominant during Triassic and Jurassic period in southern Mongolia.

Доод-дунд Юрын настай Сайхан-Овоо формац нь Идэрмэг террейнд харьяалагдана. Энэ өгүүлэлд Сайхан-Овоо формацын элсэн чулууны хэмхдэсүүд болон цементийн найрлага, тэдгээрийн хувирал, структур, текстурыг тодорхойлж, элсэн чулууны найрлагын ангиллыг тогтоолоо. Уг формацын дээд мэмбэрийн элсэн чулуунууд нь ихэвчлэн хээрийн жоншт литик аренитын литик аренитын, доод мэмбэрийн элсэн чулуунууд нь хээрийн жоншт литик аренитын найрлагатай байна.

Нарийнсухайтын нүүрсний орд нь Өмнөговийн нүүрсний савд хамаарагдах (Д.Бат-Эрдэнэ нар, 1985) ба Өмнөговь аймгийн Гурвантэс сумын нутагт оршдог. Орд нь Нарийнсухайтын хотгорт орших ба ордын хэмжээнд дунд Юрын Оргилохбулаг (J2ob), дээд Юрын Шархотгор (J3sh), Доод Цэрдийн Өндөр-Ухаа формац (К1uu) формацууд тархсан

Лавразийн юрын нүүрс уур амьсгалын онцлогоос шалтгаалан витринитийн болон устөрөгчийн агуулга өндөр байдаг. Мөн тэлэх болон уян харимхайн чанар маш өндөр тул коксын түүхий эдийн холимогт ашиглана. Энэ нь муу коксждог, хямд үнэтэй нүүрсийг ашиглах боломж бий болгоно. Үүнээс гадна юрын нүүрс агуулсан хурдас нь газрын тосны эх хурдас гэж тооцогддог. Энэ илтгэлд Монголын юрын нүүрсний геологийн онцлогийн талаар хэлэлцэх болно.

The Tavantolgoi deposit, which has more than six billion tons of coal reserves, is situated in southern Mongolia. In 2018, more than 22Mt coal was produced from the deposit. During the exploration program completed in 2017, eighteen sandstone and two andesite samples for petrographical and geochemical analysis were collected from the upper part of coal-bearing Middle Permian Tavantolgoi Formation, which was intersected completely by 960 m deep bore hole. Petrographically, the sandstones are classified as litharenite reflecting relatively weak weathering intensity in source area, probably due to arid or semiarid climate conditions. Provenance analysis indicates that the sandstones are sourced from transitional arc and undissected arc that were probably formed during the closure of Paleoasian ocean between southern Mongolia and North China block. Geochemistry of major oxide and trace element result are summarized as below. CAI values from major oxides of the studied samples vary between 66.7 and 81.5 with an average of 77.0, reflecting weak to moderate intensity of weathering in source area. The plotted data on A-CN-K diagram displays that sandstones were sourced mainly from early Permian andesite and dacite, which are widely distributed around Tavantolgoi. It is also supported by Al2O3/TiO2 (avg. 19.6), TiO2/Zr (avg. 57.7) and petrographical study. C-value, indicator of paleoclimate, in the sandstone ranges from 0.15 to 1.3 with an average of 0.50, suggesting semiarid and semiarid to semimoist condition. However, some samples accumulated during the short period of arid and moist conditions. Rb/Sr and Sr/Cu of the studied samples are consistent with those of C-value. In addition, Sr/Ba (avg. 0.56), Th/U (avg. 2.8) and Ni/Co (avg. 2.0) of the samples suggest that the sandstones were deposited in paleoenvironment with fresh and oxic water.

The Nariin Sukhait mine is located in the southwest of Umnugobi province 50 kilometers from Mongolia's border with China at Shivee Khuren within the Nariin Sukhait deposit, which has relatively complex geological features. The most prominent feature relating to the Nariin Sukhait coal deposit is the arcuate, east-west trending Nariin Sukhait fault. The coal-bearing section, interpreted to be middle Jurassic in age, is exposed primarily in a window adjacent to this fault. The chemical composition of whole indicates (variable composition, values of the ratio Th/U > 3.8-4.2, values Th/Sc 0.3-0.8, values LaN/YbN > 5 and values Eu/Eu* 0.6-0.9) indicates components derived from the active continental margin type. The low CIA values (50–60) indicate the absence or poor chemical weathering in the source area. SEM-CL-imaging of sandstone quartz from Nariin sukhait show three types of quartz: early Q1 cementation has gray to slightly grey luminescences, postdated compaction, and reduced intergranular porosity associated with illite formed during eogenesis. Q2 is characterized by dark luminescence overgrowths and is more voluminous in the thinly bedded sandstones than in the thickly bedded sandstones filling most of the remaining pore space during mesogenesis. Q3 was formed during the early telogenesis stage fully cementing the sandstones and the fractures were filled by hydrothermal chlorite and sulfides. Significant amounts of trace elements Al, Ti, Ca, K and Fe has been detected in quartz overgrowths. Al varies consistently between each cement with averages of 1324, 1523, and 1352 ppm for the Q1, Q2, and Q3 generations, respectively. The geochemical, SEM-CL imaging and EPMA data results suggest a relatively igneous source, whit felsic composition. The sedimentary environment of the sandstone and argillite of these sedimentary rocks was the poor chemical weathering in the source area.

Middle Permian Tavantolgoi coal deposit lies in southern Mongolia and has more than 6 billion tons of coal including significant tonnage of coking coal. In 2017, exploration bore holes were drilled at Borteeg, the largest syncline of the deposit. Eighteen sandstone and two andesite samples for petrographical and geochemical analysis were collected from coal-bearing sequences that were intersected by 960 m deep bore hole. The sandstones are classified as litharenite suggesting that weathering intensity in source area was weak, probably due to short transport distance coupled with relatively arid to semiarid climate conditions. Provenance analysis (Q-F-L, Qm-F-Lt, and Qp-Lvm-Lsm diagrams) suggests that the sandstones are recycled sediments derived from transitional arc and undissected arc that were formed during the closure of Paleoasian ocean between southern Mongolia and North China block. The average value of CIA for the samples is 74.1, reflecting relatively weak intensity of weathering in source area, which is consistent with the results of petrography. The plotted data on A-CN-K diagram displays that sandstones were sourced mainly from Early Permian andesite and dacite, which are widely distributed around Tavantolgoi. It is also supported by Al2O3/TiO2 (avg. 19.6) and petrographical study. To infer tectonic setting, two multi-dimensional discrimination diagrams were used. The results suggest that the tectonic setting of Tavantolgoi syncline, in which the studied sandstone was deposited, was rift.

Seven sandstone samples were collected from Middle Jurassic Orgilokhbulag Formation distributed at Nariinsukhait coal deposit and petrographical study has been completed. According to the results of study, the sandstones are classified into subarkose, sublitharenite and feldspathic litharenite. The sandstone provenance analysis suggests that the sandstones were deposited during the late stage of development of Noyon syncline, which is a foreland basin formed due to early Mesozoic crustal shortening. In addition, MIA suggests that during middle Jurassic time, weathering intensity in the source area of Nariinsukhait sandstone was relatively high, probably due to warm and humid climate.

Middle Permian Tavantolgoi coal deposit lies in southern Mongolia and has more than 6 billion tons of coal including significant tonnage of coking coal. In 2017, exploration bore holes were drilled at Borteeg, the largest syncline of the deposit. Eighteen sandstone and two andesite samples for petrographical and geochemical analysis were collected from coal-bearing sequences that were intersected by 960 m deep bore hole. The sandstones are classified as litharenite suggesting that weathering intensity in source area was weak, probably due to short transport distance coupled with relatively arid to semiarid climate conditions. Provenance analysis (Q-F-L, Qm-F-Lt, and Qp-Lvm-Lsm diagrams) suggests that the sandstones are recycled sediments derived from transitional arc and undissected arc that were formed during the closure of Paleoasian ocean between southern Mongolia and North China block. The average value of CIA for the samples is 74.1, reflecting relatively weak intensity of weathering in source area, which is consistent with the results of petrography. The plotted data on A-CN-K diagram displays that sandstones were sourced mainly from Early Permian andesite and dacite, which are widely distributed around Tavantolgoi. It is also supported by Al2O3/TiO2 (avg. 19.6) and petrographical study. To infer tectonic setting, two multi-dimensional discrimination diagrams were used. The results suggest that the tectonic setting of Tavantolgoi syncline, in which the studied sandstone was deposited, was rift.

Seven sandstone samples were collected from Middle Jurassic Orgilokhbulag Formation distributed at Nariinsukhait coal deposit and petrographical study has been completed. According to the results of study, the sandstones are classified into subarkose, sublitharenite and feldspathic litharenite. The sandstone provenance analysis suggests that the sandstones were deposited during the late stage of development of Noyon syncline, which is a foreland basin formed due to early Mesozoic crustal shortening. In addition, MIA suggests that during middle Jurassic time, weathering intensity in the source area of Nariinsukhait sandstone was relatively high, probably due to warm and humid climate.

Ovoot coal deposit is located in northern Mongolia, Tsetserleg soum of Khuvsgul aimag and lies 180 km west of Murun city. Geologically, the deposit belongs to Orkhon-Selenge coal-bearing area. Ovoot is the most highlighted recent coal discovery (227 Mt coal reserve in accordance with Mongolian standard) hosted in Jurassic sequences not only in Orkhon-Selenge area, but also in Mongolia. In addition, the deposit is the second largest coking coal reserve after Tavantolgoi deposit in Mongolia. The Jurassic coal-bearing sequence in Ovoot is gently folded into an east-northeast – west-southwest trending syncline. Seams generally dip 6° toward the fold axis. There are three main seams Upper, Lower and OVB. The Upper Seam thickness increases from north (1.5 m) to south (50 m). The top of the upper sequence ranges in depth from 40 m to 340 m below surface. A second lower sequence of seam, Lower Seam, is present along the southern margin of the coal bearing sediments, stratigraphically below the upper sequence of seams. Thickness of the Lower seam varies between 3.6 m and 62 m. A third, and the lowermost coal sequence, known as OVB Seam with the net thickness of 20 to 40 m, is locally developed in a restricted basement low, possibly the result of a large sink hole in limestone basement. Ovoot coal has high content of vitrinite, same as other Jurassic coals in Mongolia. Vitrinite reflectance value (RoMax) ranges from 1.15% to 1.25% (average is 1.2%). Results of ultimate analysis, Ovoot coal has carbon content ranging from 89.1% to 87.1% and oxygen content ranging from 5.0% to 2.5%. Pilot scale washability test was completed at ALS lab in Australia. Result shows that at an average washing yield of 82%, a 9% ash, with 10% moisture product would be achievable. Table below shows quality of washed coal. Washed coal quality of Ovoot by pilot scale test TM A VM TS CSN MFL MD GK G Y RoMax 9% 8.1% 28.5% 1.06% 9 3.30 206% G11 88 31 mm 1.2% Note: TM – total moisture, A – ash, VM – volatile matter, TS – total sulfur, CSN – crucible swelling number, MFL –max fluidity log, MD - max dilatation, GK – Gray King coke type, G – G index, Y – sapozhnikov indices, Romax – vitrinite reflectance High vitrinite content of Ovoot coal provides high fluidity and plastic properties. In addition, the coals have very high Gray King Coke types, G11. These attributes indicate superior blend carrying capacity and when combined with its relatively high rank (RoMax) of 1.2%. Therefore, Ovoot coal is considered as a value-add blend coal – able to be blended with cheaper inert coals.

Chemical structures of five coals from Mongolia were studied using solid-state C-13 NMR and oil and gas potential as well as yields of liquefaction products of the coals have been predicted. Pennsylvanian ZG, Upper Permian TT and Lower-Middle Jurassic AT-5 coals might have more potential for gas due to abundant aliphatic and aromatic CH3 carbons. Lower-Middle Jurassic KH coal probably has more potential for oil because of its increased CH2 content. Lower Cretaceous SO-3 coal may have more potential for gas, but significant amount of non-hydrocarbon gases could also be generated simultaneously. The prediction of yields of liquefaction product shows that ZG, TT and AT-5 and KH coals could yield similar hydrocarbon gas, oil and residue. Cretaceous SO3 coal is predicted to give the lowest yields of oil, hydrocarbon gas and residue compared with others. KH sample has the highest oil yield due to its high content of CH2.

Coking coals of Mongolia: Distribution and resources Bat-Orshikh Erdenetsogt and Luvsanchultem Jargal Department of Geology and Geophysics, School of Arts and Sciences, National University of Mongolia, Mongolia (tsogo8000@yahoo.com) The coal deposits of Mongolia tend to become younger from west to east and can be subdivided into two provinces, twelve basins, and three areas. Main controlling factor of coal rank is the age of coal bearing sequences. Western Mongolian coal-bearing province contains mostly high rank bituminous coal in strata from Late Carboniferous. The basins in southern Mongolia and the western part of central Mongolia have low rank bituminous coal in strata from the Permian. The northern and central Mongolian basins contain mainly Jurassic subbituminous coal, whereas the Eastern Mongolian province has Lower Cretaceous lignite. Mongolian known coking coal reserves are located in western, southern and northern Mongolia and related to Carboniferous, Permian and Jurassic sequences, respectively. Pennsylvanian Nuurstkhotgor coal deposit is located in northwestern Mongolia (in Western Mongolian coalbearing province). The coals have 1-7.5 crucible swelling number (CSN) and 0-86 G-index. Vitrinite reflectance value (Rmax in oil) varies from 0.7% to 1.2% and sulfur content is low, ranging from 0.3% to 0.6% with an average of 0.4%. Coal reserve is estimated to be 1.0 billion ton, of which half is coking coal. Upper Permian Khurengol deposit is situated in western Mongolia (in Western Mongolian coal-bearing province). CSN and G-index of coal are 8-9 and 54-99, respectively. The coals have Rmax of 1.1 to 1.7% (average 1.4%) and sulfur content of 0.2 to 0.6% (average 0.4%). Coking coal reserve of the deposit is estimated to be 340 million ton. Upper Permian Tavantolgoi, the largest coking coal deposit, lies in southern Mongolia (in South Gobi coal-bearing basin). The coals have CSN of 1 to 7.5 and Rmax of 0.7% to 1.2%. Sulfur content is low, ranging from 0.5% to 0.9%. Coal reserve is estimated to be 6.0 billion ton, of which 2.0 billion ton is accounted as coking coal. Lower-Middle Jurassic Ovoot coal is located in northern Mongolia (in Orkhon-Selenge coal-bearing area). This is one of two Jurassic coking coals in Mongolia (the rest of Jurassic coals is subbituminous). Average CSN and G-index are 9 and 88, respectively. Vitrinite reflectance value ranges from 1.1% to 1.3% (average 1.2%) and sulfur content varies from 0.8% to 1.4% (average 1.0%). Coking coal reserve is estimated to be 281 million ton. Pennsylvanian and Upper Permian coking coals have similar maceral contents (vitrinite 45-78 vol.%), whereas Jurassic coking coals have distinct petrographic composition, characterized by very high vitrinite content (>90vol.%). Thus, Jurassic coking coals have higher fluidity and plastic properties compared with Paleozoic coals.

Petrographic compositions of Paleozoic coals of Mongolia Luvsanchultem Jargal and Bat-Orshikh Erdenetsogt Department of Geology and Geophysics, School of Arts and Sciences, National University of Mongolia, Mongolia (l_jargal@yahoo.com) In Mongolia, the deposition of coal bearing strata commenced in Pennsylvanian, and continued in Upper Permian, in Lower-Middle Jurassic and finally in Lower Cretaceous time. Pennsylvanian coal seams were deposited in Western Mongolia, where peat formation was initially developed in the southernmost part and later gradually shifted to northward. By the Late Permian, the locus of coal formation had changed and main peat accumulation took place in southern Mongolia. Lower-Middle Jurassic coal was accumulated in western, northern and eastern Mongolia. During this time, peat forming condition was comparatively stable in entire Mongolia. In the Early Cretaceous, thick and extensive coal was formed in the Eastern Mongolia. Due to this general trend of peat accumulation, coal rank decreases from west (bituminous) to east (lignite). The significant portion of Pennsylvanian and Upper Permian coal reserves, existed in western and southern Mongolia, are coking coal. Thus, petrographical studies of the coals are notably important. However, previous studies of Paleozoic coals have been sparse, and only few deposits have been conducted. The maceral compositions of Western Mongolian Pennsylvanian coals such as Khushuut, Maanit, Khurengol Zeegt, Tsagaangol, Nuurstkhotgor, Khartarvagatai and Olonbulag were studied. The results show that the coals are dominated by vitrinite (45 vol.% to 71 vol.%) and inertinite (28 vol.% to 53vol.%) macerals. Liptinite contents are low, less than 4 vol.%. In addition, vitrinite reflectance values (Rmax in oil) of Khushuut (1.85%), Maanit (0.92%), Khurengol (1.4%), Zeegt (0.86%), Tsagaangol (3.6%), Nuurstkhotgor (0.9%), Khartarvagatai (1.1%) and Olonbulag (1.7%) were determined. Upper Permian coals in southern Mongolia (Tavantolgoi, Nariinsukhait, Jargalant, Tsagaantolgoi, Buduuniikhyar) are dominated by vitrinite (55 vol.% to 78 vol.%) and inertinite macerals (19 vol.% to 44 vol.%). Liptinite contents range from 1 vol.% to 7 vol.%. The vitrinite reflectance values of Tavantolgoi and Nariinsukhait coals vary from 0.7% to 1.2% and from 0.7% to 0.8%, respectively.

The mid-Cretaceous period is characterized by an extremely warm "greenhouse" climate, elevated atmospheric C02 levels, and repeated occurrences of Ocean Anoxic Events (OAEs); however, detailed processes and causal mechanisms of these marked events, particularly the response of terrestrial climate system, have been poorly understood. Possible causal mechanisms of OAEs in the mid-Cretaceous greenhouse climatic conditions include following mechanism ; (1) increased terrestrial humidity and terrigenous input into the oceans, (2) enhanced ocean surface productivity, and (3) the excess of organic burial in the oceans. Increased terrestrial humidity and chemical weathering may have increased terrigenous input into the oceans (so-called "Weathering Hypothesis"; e.g., Weissert and Erba, 2004; Emeis and Weissert, 2009). To evaluate the interaction between the land and the ocean during the mid­ Cretaceous OAE interval, we investigated terrestrial paleoenvironmental changes using the mid-Cretaceous lacustrine deposits at intra-continental sites in the eastern Gobi basin, southeast Mongolia (Ando et al., 2011).