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Outcrop Summary
Outcrop 2: Inanam Quarry
LocationFor regional setting, location, and Executive Summary, see introductory overview paper, chapter 13, this volume
Specifics10 km (6 mi) north of Kota Kinabalu and 2 km (1.2 mi) north of Inanam village
Overall Outcrop Dimensions in Panel
LengthLocalized outcrops allow correlation of genetic packages from 500 m (1640 ft) to 7.5 km (4.7 mi).
Thickness165 m (541 ft)
Average Net-to-gross85%
Grain-size rangeFine- to medium-grained sandstone at the top (S2, T2, S3); coarse- to very coarse-grained sandstone in C1; chert-rich granule lag/pebbly sandstones along the channel base.
General Outcrop Description and Stacking Pattern(See overview paper, chapter 13, this volume, for abbreviation definitions and legend for logs.) S1–T1 (0–35 m [0–115 ft] thick) comprises thin-bedded, classical turbidites with dewatering structures (Figure 2), sole marks (flutes indicate paleoflow to the northeast), and interbedded mudstones (10–70% sand).
Intervals refer to lithology column. C1-S2-T2 facies elements (35–131 m [115–430 ft] thick) form a large-scale FU/TnU channel-fill sequence (Figure 4). The base of the channel is erosional and marked by megaflutes (paleoflow to the notheast), which are infilled with granules and pebbly sandstone (Figure 3). The high-energy, active channel fill comprises coarse-grained, thick-bedded, structureless, S3 sandstones (81–95 m [266–312 ft] thick; 100% sand). This grades upwards into fine- to medium-grained, non-pebbly, massive sandstones (S2). The T2 facies element (95–131 m [312–430 ft]) comprises thin-bedded turbidites characterized by Tab beds in the lower part and Tc beds towards the top: also includes flutes (Figure 6), thin debrites, and minor slumps (Figure 5). Flute casts indicate paleoflow towards the northeast. The S3 facies element (131–146 m [430–479 ft] thick) sharply overlies, and in places erosively overlies, T2 (Figures 4, 7). The S3 consists of a sand-rich lobe to channel-margin sheet sandstones with localized erosion (Figure 9) and variable internal organization (85% sand). This fines upwards abruptly into the mud-dominated T3 interval (146–156 m [479–512 ft] thick; Figure 4), which is characterized by very thin-bedded, distal turbidites (Figure 8). Sand deposition returns at the top of the section (S4; 156–164 m [512–538 ft] thick). The large-scale FU/TnU sequence forms the most obvious vertical facies succession, but genetic packages are difficult to identify within the sheet sand (S2–4) and thin-bedded (T2–3) successions. S1 andT1 are not shown.
Depositional Setting InterpretationThis succession records the incision, migration, and progressive abandonment of an active channel complex. It may also preserve an overall basinwards facies shift from lower-fan (T1), through middle-fan (C1–S2–T2), and into an inner-fan to channel-margin setting (upper T2–T3–S4). The channel-axis deposits are among the coarsest grained sediments seen in the study area and support the interpretation of this being a major channel complex. The lack of internal facies organization within the S2–T2–S3 interval suggests frequent flow fluctuations and shifting of sediment supply in an active channel margin environment.
Outcrop Summary
Outcrop 2: Inanam Quarry
LocationFor regional setting, location, and Executive Summary, see introductory overview paper, chapter 13, this volume
Specifics10 km (6 mi) north of Kota Kinabalu and 2 km (1.2 mi) north of Inanam village
Overall Outcrop Dimensions in Panel
LengthLocalized outcrops allow correlation of genetic packages from 500 m (1640 ft) to 7.5 km (4.7 mi).
Thickness165 m (541 ft)
Average Net-to-gross85%
Grain-size rangeFine- to medium-grained sandstone at the top (S2, T2, S3); coarse- to very coarse-grained sandstone in C1; chert-rich granule lag/pebbly sandstones along the channel base.
General Outcrop Description and Stacking Pattern(See overview paper, chapter 13, this volume, for abbreviation definitions and legend for logs.) S1–T1 (0–35 m [0–115 ft] thick) comprises thin-bedded, classical turbidites with dewatering structures (Figure 2), sole marks (flutes indicate paleoflow to the northeast), and interbedded mudstones (10–70% sand).
Intervals refer to lithology column. C1-S2-T2 facies elements (35–131 m [115–430 ft] thick) form a large-scale FU/TnU channel-fill sequence (Figure 4). The base of the channel is erosional and marked by megaflutes (paleoflow to the notheast), which are infilled with granules and pebbly sandstone (Figure 3). The high-energy, active channel fill comprises coarse-grained, thick-bedded, structureless, S3 sandstones (81–95 m [266–312 ft] thick; 100% sand). This grades upwards into fine- to medium-grained, non-pebbly, massive sandstones (S2). The T2 facies element (95–131 m [312–430 ft]) comprises thin-bedded turbidites characterized by Tab beds in the lower part and Tc beds towards the top: also includes flutes (Figure 6), thin debrites, and minor slumps (Figure 5). Flute casts indicate paleoflow towards the northeast. The S3 facies element (131–146 m [430–479 ft] thick) sharply overlies, and in places erosively overlies, T2 (Figures 4, 7). The S3 consists of a sand-rich lobe to channel-margin sheet sandstones with localized erosion (Figure 9) and variable internal organization (85% sand). This fines upwards abruptly into the mud-dominated T3 interval (146–156 m [479–512 ft] thick; Figure 4), which is characterized by very thin-bedded, distal turbidites (Figure 8). Sand deposition returns at the top of the section (S4; 156–164 m [512–538 ft] thick). The large-scale FU/TnU sequence forms the most obvious vertical facies succession, but genetic packages are difficult to identify within the sheet sand (S2–4) and thin-bedded (T2–3) successions. S1 andT1 are not shown.
Depositional Setting InterpretationThis succession records the incision, migration, and progressive abandonment of an active channel complex. It may also preserve an overall basinwards facies shift from lower-fan (T1), through middle-fan (C1–S2–T2), and into an inner-fan to channel-margin setting (upper T2–T3–S4). The channel-axis deposits are among the coarsest grained sediments seen in the study area and support the interpretation of this being a major channel complex. The lack of internal facies organization within the S2–T2–S3 interval suggests frequent flow fluctuations and shifting of sediment supply in an active channel margin environment.
Figure 1.

A) Overview photomontage and B) log of the south side of the Inamam Quarry section.

Figure 1.

A) Overview photomontage and B) log of the south side of the Inamam Quarry section.

Figure 2.

Fluid-escape dish structures in medium- to fine-grained sandstone. Lens cap is 6 cm (2.5 in.) wide.

Figure 2.

Fluid-escape dish structures in medium- to fine-grained sandstone. Lens cap is 6 cm (2.5 in.) wide.

0–35 m (0–115 ft): Lower fan complex

Variable bedded sandstone and shale.

35–135 m (115–430 ft): Middle fan/channel complex channel base downcuts into shale. It is very coarse-grained to granular sandstone with an erosive, fluted base. Lateral accretion bedforms are common. Coarse channel-axis facies is rapidly replaced upward by massive amalgamated sandstone of channel-axis facies. The upper 20 m (66 ft) of the channel changes upward to 3–5-m (10–16-ft)-thick sands with thin shale interbeds of channel-margin facies.

131–160 m (430–525 ft): Upper fan complex

channel-margin and overbank-levee facies.

Figure 3.

Bidirectional turbulent flow is recorded by flute casts in very coarse-grained to granular sandstone; base of channel axis. Pen is 15 cm (6 in.) long.

Figure 3.

Bidirectional turbulent flow is recorded by flute casts in very coarse-grained to granular sandstone; base of channel axis. Pen is 15 cm (6 in.) long.

Figure 4.

Overview of middle fan complex displaying thinning and fining upwards from amalgamated sands in stacked channel-axis (C1) to channel-margin (e.g., S2, S3) and overbank/levee facies (e.g., T2, T3).

Figure 4.

Overview of middle fan complex displaying thinning and fining upwards from amalgamated sands in stacked channel-axis (C1) to channel-margin (e.g., S2, S3) and overbank/levee facies (e.g., T2, T3).

Figure 5.

Slump bed (~2 m [6.6 ft] thick bed is shown in the center of the photograph) within channel-margin facies. Stratigraphic up is to the east.

Figure 5.

Slump bed (~2 m [6.6 ft] thick bed is shown in the center of the photograph) within channel-margin facies. Stratigraphic up is to the east.

Figure 6.

Unidirectional flute casts on the base of 0.5-m (1.6-ft)-thick sandstone bed of medium-grained, channel-margin facies.

Figure 6.

Unidirectional flute casts on the base of 0.5-m (1.6-ft)-thick sandstone bed of medium-grained, channel-margin facies.

Figure 7.

T2, S3. Person for scale; stratigraphic up is to the east/left.

Figure 7.

T2, S3. Person for scale; stratigraphic up is to the east/left.

Figure 8.

Thin-bedded shale with bed set (T3), upper part of quarry. Red backpack for scale; stratigraphic up is to the east/left

Figure 8.

Thin-bedded shale with bed set (T3), upper part of quarry. Red backpack for scale; stratigraphic up is to the east/left

Figure 9.

Opposite quarry wall showing channel margin with 1–2 m (3–6.6 ft) of relief/erosion. Stratigraphic up is to the east.

Figure 9.

Opposite quarry wall showing channel margin with 1–2 m (3–6.6 ft) of relief/erosion. Stratigraphic up is to the east.

Figure 10.

This correlation panel shows three laterally adjacent sections in the Inanam Quarry area: (1) Inanam Quarry–Bukit Padang Quarry, (2) Inanam Ridge, and (3) Julan Bundusan–Julan Bukit Padang. Inanam Quarry (Panel 1) is characterized by a major channel-fill complex, based on earlier interpretations. The correlation panel shows three sections along a southeast–northwest transect, which parallels the regional paleoflow direction. It shows good continuity of all the main units along a 8-km (4.9-mi)-long, depositional-dip section. At Inanam Ridge, the thick, coarse-grained unit forming the high-energy, active channel fill at Inanam Quarry (C1) is absent. The fine- to medium-grained sandstones at Inanam Ridge have more sheetlike geometries and, texturally, resemble the sheetlike channel-margin facies (S2 unit) seen at Inanam Quarry. Panel 3 is aligned approximately along depositional strike and shows thick mudstone-dominated units (T1–3) with two sheet-sand intercalations (S1–2). The mudstone units are interpreted as distal-fan to basin-floor deposits. More detailed structural mapping is required before reasonable correlation between the three panels can be attempted.

Figure 10.

This correlation panel shows three laterally adjacent sections in the Inanam Quarry area: (1) Inanam Quarry–Bukit Padang Quarry, (2) Inanam Ridge, and (3) Julan Bundusan–Julan Bukit Padang. Inanam Quarry (Panel 1) is characterized by a major channel-fill complex, based on earlier interpretations. The correlation panel shows three sections along a southeast–northwest transect, which parallels the regional paleoflow direction. It shows good continuity of all the main units along a 8-km (4.9-mi)-long, depositional-dip section. At Inanam Ridge, the thick, coarse-grained unit forming the high-energy, active channel fill at Inanam Quarry (C1) is absent. The fine- to medium-grained sandstones at Inanam Ridge have more sheetlike geometries and, texturally, resemble the sheetlike channel-margin facies (S2 unit) seen at Inanam Quarry. Panel 3 is aligned approximately along depositional strike and shows thick mudstone-dominated units (T1–3) with two sheet-sand intercalations (S1–2). The mudstone units are interpreted as distal-fan to basin-floor deposits. More detailed structural mapping is required before reasonable correlation between the three panels can be attempted.

Architectural Element Number on Outcrop Photo orInterpretation Panel
Sheetform Architectural ElementsS1S2S3Thin-bed Architectural ElementsT1T2T3
Length (beds extend across outcrop)NANANALength (beds extend across outcrop)NANANA
Thickness12 m (39 ft)14 m (46 ft)10 m (33 ft)Thickness33 m (108 ft)36 m (118 ft)10 m (33 ft)
Net-to-gross95%90%90%Net/Gross70%50%10%
Outcrop orientation for this elementNANANATexture — grain size range; average;
sorting
Fine to medium; NA; NAVery fine to medium; NA; NAFine to very fine; NA; NA
Average paleocurrentNANANAOutcrop orientation for this element20°20°20°
Typical facies successionTa–S3Ta–S3Ta–S3Average paleocurrent50°335°NA
Sand/Conglomerate-bed ArchitectureTypical facies successionTb–S3–Db–Tc–TeTb–S3–Db–Tc–TeTc–Te
Bed-thickness range0.5–2 m (1.6–6.6 ft)0.5–2 m (1.6–6.6 ft)0.5–2 m (1.6–6.6 ft)Sand-bed Architecture
Bed-thickness average1.25 m (4.1 ft)1.25 m (4.1 ft)1.25 m (4.1 ft)Bed-thickness range0.1–1 m (0.3–3.3 ft)0.1–1 m (0.3–3.3 ft)1–5 cm (0.4–2 in.)
Texture — grain size range; average;
sorting
Coarse to medium; NA; NAFine to medium; NA; NAFine to medium; NA; NABed-thickness averageNANANA
Shale-bed ArchitectureShale-bed Architecture
Bed-thickness range20–50 cm (7.8–20 in.)1–20 cm (0.4–7.8 in.)1–20 cm (0.4–7.8 in.)Bed-thickness range0.2–3 m (0.6–9.8 ft)0.2–3 m (0.6–9.8 ft)0.2–3 m (0.6–9.8 ft)
Bed-thickness averageNANANABed-thickness averageNANANA
Architectural Element Number on Outcrop Photo orInterpretation Panel
Sheetform Architectural ElementsS1S2S3Thin-bed Architectural ElementsT1T2T3
Length (beds extend across outcrop)NANANALength (beds extend across outcrop)NANANA
Thickness12 m (39 ft)14 m (46 ft)10 m (33 ft)Thickness33 m (108 ft)36 m (118 ft)10 m (33 ft)
Net-to-gross95%90%90%Net/Gross70%50%10%
Outcrop orientation for this elementNANANATexture — grain size range; average;
sorting
Fine to medium; NA; NAVery fine to medium; NA; NAFine to very fine; NA; NA
Average paleocurrentNANANAOutcrop orientation for this element20°20°20°
Typical facies successionTa–S3Ta–S3Ta–S3Average paleocurrent50°335°NA
Sand/Conglomerate-bed ArchitectureTypical facies successionTb–S3–Db–Tc–TeTb–S3–Db–Tc–TeTc–Te
Bed-thickness range0.5–2 m (1.6–6.6 ft)0.5–2 m (1.6–6.6 ft)0.5–2 m (1.6–6.6 ft)Sand-bed Architecture
Bed-thickness average1.25 m (4.1 ft)1.25 m (4.1 ft)1.25 m (4.1 ft)Bed-thickness range0.1–1 m (0.3–3.3 ft)0.1–1 m (0.3–3.3 ft)1–5 cm (0.4–2 in.)
Texture — grain size range; average;
sorting
Coarse to medium; NA; NAFine to medium; NA; NAFine to medium; NA; NABed-thickness averageNANANA
Shale-bed ArchitectureShale-bed Architecture
Bed-thickness range20–50 cm (7.8–20 in.)1–20 cm (0.4–7.8 in.)1–20 cm (0.4–7.8 in.)Bed-thickness range0.2–3 m (0.6–9.8 ft)0.2–3 m (0.6–9.8 ft)0.2–3 m (0.6–9.8 ft)
Bed-thickness averageNANANABed-thickness averageNANANA
Mass-transport DepositMTD1
WidthNA
Thickness2.5 m (8.2 ft)
Aspect ratio: Width/thicknessNA
Net-to-grossNA
Outcrop orientation for this elementNA
Average paleocurrentNA
Typical facies successionNA
Internal bedding architectureNA
Mass-transport DepositMTD1
WidthNA
Thickness2.5 m (8.2 ft)
Aspect ratio: Width/thicknessNA
Net-to-grossNA
Outcrop orientation for this elementNA
Average paleocurrentNA
Typical facies successionNA
Internal bedding architectureNA
channelform Architectural ElementsC1
channel formNA
WidthNA
Thickness47 m (154 ft)
Aspect ratio: Width/thicknessNA
Net-to-gross100%
Outcrop orientation for this elementNA
Average paleocurrent45° and 90°
Typical facies successionS1–S2S3
channel-infill bedding architectureNA
Sand/Conglomerate-bed Architecture
Bed-thickness range1.0–5 m (3.3–16 ft)
Bed-thickness average3 m (9.8 ft)
Texture — grain size range; average;
sorting
Pebbly very coarse-medium; NA; NA
channel-base shale drape coverageNone
Shale-bed ArchitectureNA
channelform Architectural ElementsC1
channel formNA
WidthNA
Thickness47 m (154 ft)
Aspect ratio: Width/thicknessNA
Net-to-gross100%
Outcrop orientation for this elementNA
Average paleocurrent45° and 90°
Typical facies successionS1–S2S3
channel-infill bedding architectureNA
Sand/Conglomerate-bed Architecture
Bed-thickness range1.0–5 m (3.3–16 ft)
Bed-thickness average3 m (9.8 ft)
Texture — grain size range; average;
sorting
Pebbly very coarse-medium; NA; NA
channel-base shale drape coverageNone
Shale-bed ArchitectureNA

Figures & Tables

Figure 1.

A) Overview photomontage and B) log of the south side of the Inamam Quarry section.

Figure 1.

A) Overview photomontage and B) log of the south side of the Inamam Quarry section.

Figure 2.

Fluid-escape dish structures in medium- to fine-grained sandstone. Lens cap is 6 cm (2.5 in.) wide.

Figure 2.

Fluid-escape dish structures in medium- to fine-grained sandstone. Lens cap is 6 cm (2.5 in.) wide.

Figure 3.

Bidirectional turbulent flow is recorded by flute casts in very coarse-grained to granular sandstone; base of channel axis. Pen is 15 cm (6 in.) long.

Figure 3.

Bidirectional turbulent flow is recorded by flute casts in very coarse-grained to granular sandstone; base of channel axis. Pen is 15 cm (6 in.) long.

Figure 4.

Overview of middle fan complex displaying thinning and fining upwards from amalgamated sands in stacked channel-axis (C1) to channel-margin (e.g., S2, S3) and overbank/levee facies (e.g., T2, T3).

Figure 4.

Overview of middle fan complex displaying thinning and fining upwards from amalgamated sands in stacked channel-axis (C1) to channel-margin (e.g., S2, S3) and overbank/levee facies (e.g., T2, T3).

Figure 5.

Slump bed (~2 m [6.6 ft] thick bed is shown in the center of the photograph) within channel-margin facies. Stratigraphic up is to the east.

Figure 5.

Slump bed (~2 m [6.6 ft] thick bed is shown in the center of the photograph) within channel-margin facies. Stratigraphic up is to the east.

Figure 6.

Unidirectional flute casts on the base of 0.5-m (1.6-ft)-thick sandstone bed of medium-grained, channel-margin facies.

Figure 6.

Unidirectional flute casts on the base of 0.5-m (1.6-ft)-thick sandstone bed of medium-grained, channel-margin facies.

Figure 7.

T2, S3. Person for scale; stratigraphic up is to the east/left.

Figure 7.

T2, S3. Person for scale; stratigraphic up is to the east/left.

Figure 8.

Thin-bedded shale with bed set (T3), upper part of quarry. Red backpack for scale; stratigraphic up is to the east/left

Figure 8.

Thin-bedded shale with bed set (T3), upper part of quarry. Red backpack for scale; stratigraphic up is to the east/left

Figure 9.

Opposite quarry wall showing channel margin with 1–2 m (3–6.6 ft) of relief/erosion. Stratigraphic up is to the east.

Figure 9.

Opposite quarry wall showing channel margin with 1–2 m (3–6.6 ft) of relief/erosion. Stratigraphic up is to the east.

Figure 10.

This correlation panel shows three laterally adjacent sections in the Inanam Quarry area: (1) Inanam Quarry–Bukit Padang Quarry, (2) Inanam Ridge, and (3) Julan Bundusan–Julan Bukit Padang. Inanam Quarry (Panel 1) is characterized by a major channel-fill complex, based on earlier interpretations. The correlation panel shows three sections along a southeast–northwest transect, which parallels the regional paleoflow direction. It shows good continuity of all the main units along a 8-km (4.9-mi)-long, depositional-dip section. At Inanam Ridge, the thick, coarse-grained unit forming the high-energy, active channel fill at Inanam Quarry (C1) is absent. The fine- to medium-grained sandstones at Inanam Ridge have more sheetlike geometries and, texturally, resemble the sheetlike channel-margin facies (S2 unit) seen at Inanam Quarry. Panel 3 is aligned approximately along depositional strike and shows thick mudstone-dominated units (T1–3) with two sheet-sand intercalations (S1–2). The mudstone units are interpreted as distal-fan to basin-floor deposits. More detailed structural mapping is required before reasonable correlation between the three panels can be attempted.

Figure 10.

This correlation panel shows three laterally adjacent sections in the Inanam Quarry area: (1) Inanam Quarry–Bukit Padang Quarry, (2) Inanam Ridge, and (3) Julan Bundusan–Julan Bukit Padang. Inanam Quarry (Panel 1) is characterized by a major channel-fill complex, based on earlier interpretations. The correlation panel shows three sections along a southeast–northwest transect, which parallels the regional paleoflow direction. It shows good continuity of all the main units along a 8-km (4.9-mi)-long, depositional-dip section. At Inanam Ridge, the thick, coarse-grained unit forming the high-energy, active channel fill at Inanam Quarry (C1) is absent. The fine- to medium-grained sandstones at Inanam Ridge have more sheetlike geometries and, texturally, resemble the sheetlike channel-margin facies (S2 unit) seen at Inanam Quarry. Panel 3 is aligned approximately along depositional strike and shows thick mudstone-dominated units (T1–3) with two sheet-sand intercalations (S1–2). The mudstone units are interpreted as distal-fan to basin-floor deposits. More detailed structural mapping is required before reasonable correlation between the three panels can be attempted.

Outcrop Summary
Outcrop 2: Inanam Quarry
LocationFor regional setting, location, and Executive Summary, see introductory overview paper, chapter 13, this volume
Specifics10 km (6 mi) north of Kota Kinabalu and 2 km (1.2 mi) north of Inanam village
Overall Outcrop Dimensions in Panel
LengthLocalized outcrops allow correlation of genetic packages from 500 m (1640 ft) to 7.5 km (4.7 mi).
Thickness165 m (541 ft)
Average Net-to-gross85%
Grain-size rangeFine- to medium-grained sandstone at the top (S2, T2, S3); coarse- to very coarse-grained sandstone in C1; chert-rich granule lag/pebbly sandstones along the channel base.
General Outcrop Description and Stacking Pattern(See overview paper, chapter 13, this volume, for abbreviation definitions and legend for logs.) S1–T1 (0–35 m [0–115 ft] thick) comprises thin-bedded, classical turbidites with dewatering structures (Figure 2), sole marks (flutes indicate paleoflow to the northeast), and interbedded mudstones (10–70% sand).
Intervals refer to lithology column. C1-S2-T2 facies elements (35–131 m [115–430 ft] thick) form a large-scale FU/TnU channel-fill sequence (Figure 4). The base of the channel is erosional and marked by megaflutes (paleoflow to the notheast), which are infilled with granules and pebbly sandstone (Figure 3). The high-energy, active channel fill comprises coarse-grained, thick-bedded, structureless, S3 sandstones (81–95 m [266–312 ft] thick; 100% sand). This grades upwards into fine- to medium-grained, non-pebbly, massive sandstones (S2). The T2 facies element (95–131 m [312–430 ft]) comprises thin-bedded turbidites characterized by Tab beds in the lower part and Tc beds towards the top: also includes flutes (Figure 6), thin debrites, and minor slumps (Figure 5). Flute casts indicate paleoflow towards the northeast. The S3 facies element (131–146 m [430–479 ft] thick) sharply overlies, and in places erosively overlies, T2 (Figures 4, 7). The S3 consists of a sand-rich lobe to channel-margin sheet sandstones with localized erosion (Figure 9) and variable internal organization (85% sand). This fines upwards abruptly into the mud-dominated T3 interval (146–156 m [479–512 ft] thick; Figure 4), which is characterized by very thin-bedded, distal turbidites (Figure 8). Sand deposition returns at the top of the section (S4; 156–164 m [512–538 ft] thick). The large-scale FU/TnU sequence forms the most obvious vertical facies succession, but genetic packages are difficult to identify within the sheet sand (S2–4) and thin-bedded (T2–3) successions. S1 andT1 are not shown.
Depositional Setting InterpretationThis succession records the incision, migration, and progressive abandonment of an active channel complex. It may also preserve an overall basinwards facies shift from lower-fan (T1), through middle-fan (C1–S2–T2), and into an inner-fan to channel-margin setting (upper T2–T3–S4). The channel-axis deposits are among the coarsest grained sediments seen in the study area and support the interpretation of this being a major channel complex. The lack of internal facies organization within the S2–T2–S3 interval suggests frequent flow fluctuations and shifting of sediment supply in an active channel margin environment.
Outcrop Summary
Outcrop 2: Inanam Quarry
LocationFor regional setting, location, and Executive Summary, see introductory overview paper, chapter 13, this volume
Specifics10 km (6 mi) north of Kota Kinabalu and 2 km (1.2 mi) north of Inanam village
Overall Outcrop Dimensions in Panel
LengthLocalized outcrops allow correlation of genetic packages from 500 m (1640 ft) to 7.5 km (4.7 mi).
Thickness165 m (541 ft)
Average Net-to-gross85%
Grain-size rangeFine- to medium-grained sandstone at the top (S2, T2, S3); coarse- to very coarse-grained sandstone in C1; chert-rich granule lag/pebbly sandstones along the channel base.
General Outcrop Description and Stacking Pattern(See overview paper, chapter 13, this volume, for abbreviation definitions and legend for logs.) S1–T1 (0–35 m [0–115 ft] thick) comprises thin-bedded, classical turbidites with dewatering structures (Figure 2), sole marks (flutes indicate paleoflow to the northeast), and interbedded mudstones (10–70% sand).
Intervals refer to lithology column. C1-S2-T2 facies elements (35–131 m [115–430 ft] thick) form a large-scale FU/TnU channel-fill sequence (Figure 4). The base of the channel is erosional and marked by megaflutes (paleoflow to the notheast), which are infilled with granules and pebbly sandstone (Figure 3). The high-energy, active channel fill comprises coarse-grained, thick-bedded, structureless, S3 sandstones (81–95 m [266–312 ft] thick; 100% sand). This grades upwards into fine- to medium-grained, non-pebbly, massive sandstones (S2). The T2 facies element (95–131 m [312–430 ft]) comprises thin-bedded turbidites characterized by Tab beds in the lower part and Tc beds towards the top: also includes flutes (Figure 6), thin debrites, and minor slumps (Figure 5). Flute casts indicate paleoflow towards the northeast. The S3 facies element (131–146 m [430–479 ft] thick) sharply overlies, and in places erosively overlies, T2 (Figures 4, 7). The S3 consists of a sand-rich lobe to channel-margin sheet sandstones with localized erosion (Figure 9) and variable internal organization (85% sand). This fines upwards abruptly into the mud-dominated T3 interval (146–156 m [479–512 ft] thick; Figure 4), which is characterized by very thin-bedded, distal turbidites (Figure 8). Sand deposition returns at the top of the section (S4; 156–164 m [512–538 ft] thick). The large-scale FU/TnU sequence forms the most obvious vertical facies succession, but genetic packages are difficult to identify within the sheet sand (S2–4) and thin-bedded (T2–3) successions. S1 andT1 are not shown.
Depositional Setting InterpretationThis succession records the incision, migration, and progressive abandonment of an active channel complex. It may also preserve an overall basinwards facies shift from lower-fan (T1), through middle-fan (C1–S2–T2), and into an inner-fan to channel-margin setting (upper T2–T3–S4). The channel-axis deposits are among the coarsest grained sediments seen in the study area and support the interpretation of this being a major channel complex. The lack of internal facies organization within the S2–T2–S3 interval suggests frequent flow fluctuations and shifting of sediment supply in an active channel margin environment.
Architectural Element Number on Outcrop Photo orInterpretation Panel
Sheetform Architectural ElementsS1S2S3Thin-bed Architectural ElementsT1T2T3
Length (beds extend across outcrop)NANANALength (beds extend across outcrop)NANANA
Thickness12 m (39 ft)14 m (46 ft)10 m (33 ft)Thickness33 m (108 ft)36 m (118 ft)10 m (33 ft)
Net-to-gross95%90%90%Net/Gross70%50%10%
Outcrop orientation for this elementNANANATexture — grain size range; average;
sorting
Fine to medium; NA; NAVery fine to medium; NA; NAFine to very fine; NA; NA
Average paleocurrentNANANAOutcrop orientation for this element20°20°20°
Typical facies successionTa–S3Ta–S3Ta–S3Average paleocurrent50°335°NA
Sand/Conglomerate-bed ArchitectureTypical facies successionTb–S3–Db–Tc–TeTb–S3–Db–Tc–TeTc–Te
Bed-thickness range0.5–2 m (1.6–6.6 ft)0.5–2 m (1.6–6.6 ft)0.5–2 m (1.6–6.6 ft)Sand-bed Architecture
Bed-thickness average1.25 m (4.1 ft)1.25 m (4.1 ft)1.25 m (4.1 ft)Bed-thickness range0.1–1 m (0.3–3.3 ft)0.1–1 m (0.3–3.3 ft)1–5 cm (0.4–2 in.)
Texture — grain size range; average;
sorting
Coarse to medium; NA; NAFine to medium; NA; NAFine to medium; NA; NABed-thickness averageNANANA
Shale-bed ArchitectureShale-bed Architecture
Bed-thickness range20–50 cm (7.8–20 in.)1–20 cm (0.4–7.8 in.)1–20 cm (0.4–7.8 in.)Bed-thickness range0.2–3 m (0.6–9.8 ft)0.2–3 m (0.6–9.8 ft)0.2–3 m (0.6–9.8 ft)
Bed-thickness averageNANANABed-thickness averageNANANA
Architectural Element Number on Outcrop Photo orInterpretation Panel
Sheetform Architectural ElementsS1S2S3Thin-bed Architectural ElementsT1T2T3
Length (beds extend across outcrop)NANANALength (beds extend across outcrop)NANANA
Thickness12 m (39 ft)14 m (46 ft)10 m (33 ft)Thickness33 m (108 ft)36 m (118 ft)10 m (33 ft)
Net-to-gross95%90%90%Net/Gross70%50%10%
Outcrop orientation for this elementNANANATexture — grain size range; average;
sorting
Fine to medium; NA; NAVery fine to medium; NA; NAFine to very fine; NA; NA
Average paleocurrentNANANAOutcrop orientation for this element20°20°20°
Typical facies successionTa–S3Ta–S3Ta–S3Average paleocurrent50°335°NA
Sand/Conglomerate-bed ArchitectureTypical facies successionTb–S3–Db–Tc–TeTb–S3–Db–Tc–TeTc–Te
Bed-thickness range0.5–2 m (1.6–6.6 ft)0.5–2 m (1.6–6.6 ft)0.5–2 m (1.6–6.6 ft)Sand-bed Architecture
Bed-thickness average1.25 m (4.1 ft)1.25 m (4.1 ft)1.25 m (4.1 ft)Bed-thickness range0.1–1 m (0.3–3.3 ft)0.1–1 m (0.3–3.3 ft)1–5 cm (0.4–2 in.)
Texture — grain size range; average;
sorting
Coarse to medium; NA; NAFine to medium; NA; NAFine to medium; NA; NABed-thickness averageNANANA
Shale-bed ArchitectureShale-bed Architecture
Bed-thickness range20–50 cm (7.8–20 in.)1–20 cm (0.4–7.8 in.)1–20 cm (0.4–7.8 in.)Bed-thickness range0.2–3 m (0.6–9.8 ft)0.2–3 m (0.6–9.8 ft)0.2–3 m (0.6–9.8 ft)
Bed-thickness averageNANANABed-thickness averageNANANA
Mass-transport DepositMTD1
WidthNA
Thickness2.5 m (8.2 ft)
Aspect ratio: Width/thicknessNA
Net-to-grossNA
Outcrop orientation for this elementNA
Average paleocurrentNA
Typical facies successionNA
Internal bedding architectureNA
Mass-transport DepositMTD1
WidthNA
Thickness2.5 m (8.2 ft)
Aspect ratio: Width/thicknessNA
Net-to-grossNA
Outcrop orientation for this elementNA
Average paleocurrentNA
Typical facies successionNA
Internal bedding architectureNA
channelform Architectural ElementsC1
channel formNA
WidthNA
Thickness47 m (154 ft)
Aspect ratio: Width/thicknessNA
Net-to-gross100%
Outcrop orientation for this elementNA
Average paleocurrent45° and 90°
Typical facies successionS1–S2S3
channel-infill bedding architectureNA
Sand/Conglomerate-bed Architecture
Bed-thickness range1.0–5 m (3.3–16 ft)
Bed-thickness average3 m (9.8 ft)
Texture — grain size range; average;
sorting
Pebbly very coarse-medium; NA; NA
channel-base shale drape coverageNone
Shale-bed ArchitectureNA
channelform Architectural ElementsC1
channel formNA
WidthNA
Thickness47 m (154 ft)
Aspect ratio: Width/thicknessNA
Net-to-gross100%
Outcrop orientation for this elementNA
Average paleocurrent45° and 90°
Typical facies successionS1–S2S3
channel-infill bedding architectureNA
Sand/Conglomerate-bed Architecture
Bed-thickness range1.0–5 m (3.3–16 ft)
Bed-thickness average3 m (9.8 ft)
Texture — grain size range; average;
sorting
Pebbly very coarse-medium; NA; NA
channel-base shale drape coverageNone
Shale-bed ArchitectureNA

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